Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

69 files changed, 10919 insertions, 0 deletions

diff --git a/third_party/jpeg-xl/lib/extras/LICENSE.apngdis b/third_party/jpeg-xl/lib/extras/LICENSE.apngdis
new file mode 100644
index 0000000000..eb0ba7c07b
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/LICENSE.apngdis
@@ -0,0 +1,27 @@
+APNG Disassembler 2.8
+
+Deconstructs APNG files into individual frames.
+
+http://apngdis.sourceforge.net
+
+Copyright (c) 2010-2015 Max Stepin
+maxst at users.sourceforge.net
+
+zlib license
+------------
+
+This software is provided 'as-is', without any express or implied
+warranty.  In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not
+   claim that you wrote the original software. If you use this software
+   in a product, an acknowledgment in the product documentation would be
+   appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be
+   misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
diff --git a/third_party/jpeg-xl/lib/extras/README.md b/third_party/jpeg-xl/lib/extras/README.md
new file mode 100644
index 0000000000..06a9b5ea07
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/README.md
@@ -0,0 +1,5 @@
+## JPEG XL "extras"
+
+The files in this directory do not form part of the library or codec and are
+only used by tests or specific internal tools that have access to the internals
+of the library.
diff --git a/third_party/jpeg-xl/lib/extras/alpha_blend.cc b/third_party/jpeg-xl/lib/extras/alpha_blend.cc
new file mode 100644
index 0000000000..50c141c6fb
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/alpha_blend.cc
@@ -0,0 +1,63 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/alpha_blend.h"
+
+#include "lib/extras/packed_image.h"
+
+namespace jxl {
+namespace extras {
+
+namespace {
+
+void AlphaBlend(PackedFrame* frame, float background[3]) {
+  if (!frame) return;
+  const PackedImage& im = frame->color;
+  JxlPixelFormat format = im.format;
+  if (format.num_channels != 2 && format.num_channels != 4) {
+    return;
+  }
+  --format.num_channels;
+  PackedImage blended(im.xsize, im.ysize, format);
+  // TODO(szabadka) SIMDify this and make it work for float16.
+  for (size_t y = 0; y < im.ysize; ++y) {
+    for (size_t x = 0; x < im.xsize; ++x) {
+      if (format.num_channels == 2) {
+        float g = im.GetPixelValue(y, x, 0);
+        float a = im.GetPixelValue(y, x, 1);
+        float out = g * a + background[0] * (1 - a);
+        blended.SetPixelValue(y, x, 0, out);
+      } else {
+        float r = im.GetPixelValue(y, x, 0);
+        float g = im.GetPixelValue(y, x, 1);
+        float b = im.GetPixelValue(y, x, 2);
+        float a = im.GetPixelValue(y, x, 3);
+        float out_r = r * a + background[0] * (1 - a);
+        float out_g = g * a + background[1] * (1 - a);
+        float out_b = b * a + background[2] * (1 - a);
+        blended.SetPixelValue(y, x, 0, out_r);
+        blended.SetPixelValue(y, x, 1, out_g);
+        blended.SetPixelValue(y, x, 2, out_b);
+      }
+    }
+  }
+  frame->color = blended.Copy();
+}
+
+}  // namespace
+
+void AlphaBlend(PackedPixelFile* ppf, float background[3]) {
+  if (!ppf || ppf->info.alpha_bits == 0) {
+    return;
+  }
+  ppf->info.alpha_bits = 0;
+  AlphaBlend(ppf->preview_frame.get(), background);
+  for (auto& frame : ppf->frames) {
+    AlphaBlend(&frame, background);
+  }
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/alpha_blend.h b/third_party/jpeg-xl/lib/extras/alpha_blend.h
new file mode 100644
index 0000000000..4d78e8681b
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/alpha_blend.h
@@ -0,0 +1,19 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_ALPHA_BLEND_H_
+#define LIB_EXTRAS_ALPHA_BLEND_H_
+
+#include "lib/extras/packed_image.h"
+
+namespace jxl {
+namespace extras {
+
+void AlphaBlend(PackedPixelFile* ppf, float background[3]);
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_ALPHA_BLEND_H_
diff --git a/third_party/jpeg-xl/lib/extras/codec.cc b/third_party/jpeg-xl/lib/extras/codec.cc
new file mode 100644
index 0000000000..3a1172125b
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/codec.cc
@@ -0,0 +1,112 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/codec.h"
+
+#include <jxl/decode.h>
+#include <jxl/types.h>
+
+#include "lib/extras/dec/decode.h"
+#include "lib/extras/enc/apng.h"
+#include "lib/extras/enc/exr.h"
+#include "lib/extras/enc/jpg.h"
+#include "lib/extras/enc/pgx.h"
+#include "lib/extras/enc/pnm.h"
+#include "lib/extras/packed_image.h"
+#include "lib/extras/packed_image_convert.h"
+#include "lib/jxl/base/status.h"
+#include "lib/jxl/image_bundle.h"
+
+namespace jxl {
+namespace {
+
+// Any valid encoding is larger (ensures codecs can read the first few bytes)
+constexpr size_t kMinBytes = 9;
+
+}  // namespace
+
+Status SetFromBytes(const Span<const uint8_t> bytes,
+                    const extras::ColorHints& color_hints, CodecInOut* io,
+                    ThreadPool* pool, const SizeConstraints* constraints,
+                    extras::Codec* orig_codec) {
+  if (bytes.size() < kMinBytes) return JXL_FAILURE("Too few bytes");
+
+  extras::PackedPixelFile ppf;
+  if (extras::DecodeBytes(bytes, color_hints, &ppf, constraints, orig_codec)) {
+    return ConvertPackedPixelFileToCodecInOut(ppf, pool, io);
+  }
+  return JXL_FAILURE("Codecs failed to decode");
+}
+
+Status Encode(const extras::PackedPixelFile& ppf, const extras::Codec codec,
+              std::vector<uint8_t>* bytes, ThreadPool* pool) {
+  bytes->clear();
+  std::unique_ptr<extras::Encoder> encoder;
+  switch (codec) {
+    case extras::Codec::kPNG:
+      encoder = extras::GetAPNGEncoder();
+      if (encoder) {
+        break;
+      } else {
+        return JXL_FAILURE("JPEG XL was built without (A)PNG support");
+      }
+    case extras::Codec::kJPG:
+      encoder = extras::GetJPEGEncoder();
+      if (encoder) {
+        break;
+      } else {
+        return JXL_FAILURE("JPEG XL was built without JPEG support");
+      }
+    case extras::Codec::kPNM:
+      if (ppf.info.alpha_bits > 0) {
+        encoder = extras::GetPAMEncoder();
+      } else if (ppf.info.num_color_channels == 1) {
+        encoder = extras::GetPGMEncoder();
+      } else if (ppf.info.bits_per_sample <= 16) {
+        encoder = extras::GetPPMEncoder();
+      } else {
+        encoder = extras::GetPFMEncoder();
+      }
+      break;
+    case extras::Codec::kPGX:
+      encoder = extras::GetPGXEncoder();
+      break;
+    case extras::Codec::kGIF:
+      return JXL_FAILURE("Encoding to GIF is not implemented");
+    case extras::Codec::kEXR:
+      encoder = extras::GetEXREncoder();
+      if (encoder) {
+        break;
+      } else {
+        return JXL_FAILURE("JPEG XL was built without OpenEXR support");
+      }
+    case extras::Codec::kJXL:
+      // TODO(user): implement
+      return JXL_FAILURE("Codec::kJXL is not supported yet");
+
+    case extras::Codec::kUnknown:
+      return JXL_FAILURE("Cannot encode using Codec::kUnknown");
+  }
+
+  if (!encoder) {
+    return JXL_FAILURE("Invalid codec.");
+  }
+  extras::EncodedImage encoded_image;
+  JXL_RETURN_IF_ERROR(encoder->Encode(ppf, &encoded_image, pool));
+  JXL_ASSERT(encoded_image.bitstreams.size() == 1);
+  *bytes = encoded_image.bitstreams[0];
+
+  return true;
+}
+
+Status Encode(const extras::PackedPixelFile& ppf, const std::string& pathname,
+              std::vector<uint8_t>* bytes, ThreadPool* pool) {
+  std::string extension;
+  const extras::Codec codec =
+      extras::CodecFromPath(pathname, nullptr, &extension);
+  return Encode(ppf, codec, bytes, pool);
+}
+
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/codec.h b/third_party/jpeg-xl/lib/extras/codec.h
new file mode 100644
index 0000000000..b7bc2a397e
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/codec.h
@@ -0,0 +1,54 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_CODEC_H_
+#define LIB_EXTRAS_CODEC_H_
+
+// Facade for image encoders/decoders (PNG, PNM, ...).
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <string>
+
+#include "lib/extras/dec/color_hints.h"
+#include "lib/extras/dec/decode.h"
+#include "lib/jxl/base/compiler_specific.h"
+#include "lib/jxl/base/data_parallel.h"
+#include "lib/jxl/base/span.h"
+#include "lib/jxl/base/status.h"
+#include "lib/jxl/codec_in_out.h"
+#include "lib/jxl/color_encoding_internal.h"
+#include "lib/jxl/field_encodings.h"  // MakeBit
+
+namespace jxl {
+
+struct SizeConstraints;
+
+// Decodes "bytes" and sets io->metadata.m.
+// color_space_hint may specify the color space, otherwise, defaults to sRGB.
+Status SetFromBytes(Span<const uint8_t> bytes,
+                    const extras::ColorHints& color_hints, CodecInOut* io,
+                    ThreadPool* pool = nullptr,
+                    const SizeConstraints* constraints = nullptr,
+                    extras::Codec* orig_codec = nullptr);
+// Helper function to use no color_space_hint.
+JXL_INLINE Status SetFromBytes(const Span<const uint8_t> bytes, CodecInOut* io,
+                               ThreadPool* pool = nullptr,
+                               const SizeConstraints* constraints = nullptr,
+                               extras::Codec* orig_codec = nullptr) {
+  return SetFromBytes(bytes, extras::ColorHints(), io, pool, constraints,
+                      orig_codec);
+}
+
+Status Encode(const extras::PackedPixelFile& ppf, const extras::Codec codec,
+              std::vector<uint8_t>* bytes, ThreadPool* pool);
+
+Status Encode(const extras::PackedPixelFile& ppf, const std::string& pathname,
+              std::vector<uint8_t>* bytes, ThreadPool* pool = nullptr);
+
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_CODEC_H_
diff --git a/third_party/jpeg-xl/lib/extras/codec_test.cc b/third_party/jpeg-xl/lib/extras/codec_test.cc
new file mode 100644
index 0000000000..4d8a60cb33
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/codec_test.cc
@@ -0,0 +1,458 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include <jxl/codestream_header.h>
+#include <jxl/color_encoding.h>
+#include <jxl/encode.h>
+#include <jxl/types.h>
+#include <stddef.h>
+
+#include <algorithm>
+#include <cstdint>
+#include <cstdio>
+#include <cstring>
+#include <memory>
+#include <sstream>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "lib/extras/common.h"
+#include "lib/extras/dec/color_hints.h"
+#include "lib/extras/dec/decode.h"
+#include "lib/extras/dec/pnm.h"
+#include "lib/extras/enc/encode.h"
+#include "lib/extras/packed_image.h"
+#include "lib/jxl/base/byte_order.h"
+#include "lib/jxl/base/random.h"
+#include "lib/jxl/base/span.h"
+#include "lib/jxl/base/status.h"
+#include "lib/jxl/color_encoding_internal.h"
+#include "lib/jxl/test_utils.h"
+#include "lib/jxl/testing.h"
+
+namespace jxl {
+
+using test::ThreadPoolForTests;
+
+namespace extras {
+namespace {
+
+using ::testing::AllOf;
+using ::testing::Contains;
+using ::testing::Field;
+using ::testing::IsEmpty;
+using ::testing::SizeIs;
+
+std::string ExtensionFromCodec(Codec codec, const bool is_gray,
+                               const bool has_alpha,
+                               const size_t bits_per_sample) {
+  switch (codec) {
+    case Codec::kJPG:
+      return ".jpg";
+    case Codec::kPGX:
+      return ".pgx";
+    case Codec::kPNG:
+      return ".png";
+    case Codec::kPNM:
+      if (bits_per_sample == 32) return ".pfm";
+      if (has_alpha) return ".pam";
+      return is_gray ? ".pgm" : ".ppm";
+    case Codec::kEXR:
+      return ".exr";
+    default:
+      return std::string();
+  }
+}
+
+void VerifySameImage(const PackedImage& im0, size_t bits_per_sample0,
+                     const PackedImage& im1, size_t bits_per_sample1,
+                     bool lossless = true) {
+  ASSERT_EQ(im0.xsize, im1.xsize);
+  ASSERT_EQ(im0.ysize, im1.ysize);
+  ASSERT_EQ(im0.format.num_channels, im1.format.num_channels);
+  auto get_factor = [](JxlPixelFormat f, size_t bits) -> double {
+    return 1.0 / ((1u << std::min(test::GetPrecision(f.data_type), bits)) - 1);
+  };
+  double factor0 = get_factor(im0.format, bits_per_sample0);
+  double factor1 = get_factor(im1.format, bits_per_sample1);
+  auto pixels0 = static_cast<const uint8_t*>(im0.pixels());
+  auto pixels1 = static_cast<const uint8_t*>(im1.pixels());
+  auto rgba0 =
+      test::ConvertToRGBA32(pixels0, im0.xsize, im0.ysize, im0.format, factor0);
+  auto rgba1 =
+      test::ConvertToRGBA32(pixels1, im1.xsize, im1.ysize, im1.format, factor1);
+  double tolerance =
+      lossless ? 0.5 * std::min(factor0, factor1) : 3.0f / 255.0f;
+  if (bits_per_sample0 == 32 || bits_per_sample1 == 32) {
+    tolerance = 0.5 * std::max(factor0, factor1);
+  }
+  for (size_t y = 0; y < im0.ysize; ++y) {
+    for (size_t x = 0; x < im0.xsize; ++x) {
+      for (size_t c = 0; c < im0.format.num_channels; ++c) {
+        size_t ix = (y * im0.xsize + x) * 4 + c;
+        double val0 = rgba0[ix];
+        double val1 = rgba1[ix];
+        ASSERT_NEAR(val1, val0, tolerance)
+            << "y = " << y << " x = " << x << " c = " << c;
+      }
+    }
+  }
+}
+
+JxlColorEncoding CreateTestColorEncoding(bool is_gray) {
+  JxlColorEncoding c;
+  c.color_space = is_gray ? JXL_COLOR_SPACE_GRAY : JXL_COLOR_SPACE_RGB;
+  c.white_point = JXL_WHITE_POINT_D65;
+  c.primaries = JXL_PRIMARIES_P3;
+  c.rendering_intent = JXL_RENDERING_INTENT_RELATIVE;
+  c.transfer_function = JXL_TRANSFER_FUNCTION_LINEAR;
+  // Roundtrip through internal color encoding to fill in primaries and white
+  // point CIE xy coordinates.
+  ColorEncoding c_internal;
+  JXL_CHECK(c_internal.FromExternal(c));
+  c = c_internal.ToExternal();
+  return c;
+}
+
+std::vector<uint8_t> GenerateICC(JxlColorEncoding color_encoding) {
+  ColorEncoding c;
+  JXL_CHECK(c.FromExternal(color_encoding));
+  JXL_CHECK(!c.ICC().empty());
+  return c.ICC();
+}
+
+void StoreRandomValue(uint8_t* out, Rng* rng, JxlPixelFormat format,
+                      size_t bits_per_sample) {
+  uint64_t max_val = (1ull << bits_per_sample) - 1;
+  if (format.data_type == JXL_TYPE_UINT8) {
+    *out = rng->UniformU(0, max_val);
+  } else if (format.data_type == JXL_TYPE_UINT16) {
+    uint32_t val = rng->UniformU(0, max_val);
+    if (format.endianness == JXL_BIG_ENDIAN) {
+      StoreBE16(val, out);
+    } else {
+      StoreLE16(val, out);
+    }
+  } else {
+    ASSERT_EQ(format.data_type, JXL_TYPE_FLOAT);
+    float val = rng->UniformF(0.0, 1.0);
+    uint32_t uval;
+    memcpy(&uval, &val, 4);
+    if (format.endianness == JXL_BIG_ENDIAN) {
+      StoreBE32(uval, out);
+    } else {
+      StoreLE32(uval, out);
+    }
+  }
+}
+
+void FillPackedImage(size_t bits_per_sample, PackedImage* image) {
+  JxlPixelFormat format = image->format;
+  size_t bytes_per_channel = PackedImage::BitsPerChannel(format.data_type) / 8;
+  uint8_t* out = static_cast<uint8_t*>(image->pixels());
+  size_t stride = image->xsize * format.num_channels * bytes_per_channel;
+  ASSERT_EQ(image->pixels_size, image->ysize * stride);
+  Rng rng(129);
+  for (size_t y = 0; y < image->ysize; ++y) {
+    for (size_t x = 0; x < image->xsize; ++x) {
+      for (size_t c = 0; c < format.num_channels; ++c) {
+        StoreRandomValue(out, &rng, format, bits_per_sample);
+        out += bytes_per_channel;
+      }
+    }
+  }
+}
+
+struct TestImageParams {
+  Codec codec;
+  size_t xsize;
+  size_t ysize;
+  size_t bits_per_sample;
+  bool is_gray;
+  bool add_alpha;
+  bool big_endian;
+  bool add_extra_channels;
+
+  bool ShouldTestRoundtrip() const {
+    if (codec == Codec::kPNG) {
+      return bits_per_sample <= 16;
+    } else if (codec == Codec::kPNM) {
+      // TODO(szabadka) Make PNM encoder endianness-aware.
+      return ((bits_per_sample <= 16 && big_endian) ||
+              (bits_per_sample == 32 && !add_alpha && !big_endian));
+    } else if (codec == Codec::kPGX) {
+      return ((bits_per_sample == 8 || bits_per_sample == 16) && is_gray &&
+              !add_alpha);
+    } else if (codec == Codec::kEXR) {
+#if defined(ADDRESS_SANITIZER) || defined(MEMORY_SANITIZER) || \
+    defined(THREAD_SANITIZER)
+      // OpenEXR 2.3 has a memory leak in IlmThread_2_3::ThreadPool
+      return false;
+#else
+      return bits_per_sample == 32 && !is_gray;
+#endif
+    } else if (codec == Codec::kJPG) {
+      return bits_per_sample == 8 && !add_alpha;
+    } else {
+      return false;
+    }
+  }
+
+  JxlPixelFormat PixelFormat() const {
+    JxlPixelFormat format;
+    format.num_channels = (is_gray ? 1 : 3) + (add_alpha ? 1 : 0);
+    format.data_type = (bits_per_sample == 32 ? JXL_TYPE_FLOAT
+                        : bits_per_sample > 8 ? JXL_TYPE_UINT16
+                                              : JXL_TYPE_UINT8);
+    format.endianness = big_endian ? JXL_BIG_ENDIAN : JXL_LITTLE_ENDIAN;
+    format.align = 0;
+    return format;
+  }
+
+  std::string DebugString() const {
+    std::ostringstream os;
+    os << "bps:" << bits_per_sample << " gr:" << is_gray << " al:" << add_alpha
+       << " be: " << big_endian << " ec: " << add_extra_channels;
+    return os.str();
+  }
+};
+
+void CreateTestImage(const TestImageParams& params, PackedPixelFile* ppf) {
+  ppf->info.xsize = params.xsize;
+  ppf->info.ysize = params.ysize;
+  ppf->info.bits_per_sample = params.bits_per_sample;
+  ppf->info.exponent_bits_per_sample = params.bits_per_sample == 32 ? 8 : 0;
+  ppf->info.num_color_channels = params.is_gray ? 1 : 3;
+  ppf->info.alpha_bits = params.add_alpha ? params.bits_per_sample : 0;
+  ppf->info.alpha_premultiplied = (params.codec == Codec::kEXR);
+
+  JxlColorEncoding color_encoding = CreateTestColorEncoding(params.is_gray);
+  ppf->icc = GenerateICC(color_encoding);
+  ppf->color_encoding = color_encoding;
+
+  PackedFrame frame(params.xsize, params.ysize, params.PixelFormat());
+  FillPackedImage(params.bits_per_sample, &frame.color);
+  if (params.add_extra_channels) {
+    for (size_t i = 0; i < 7; ++i) {
+      JxlPixelFormat ec_format = params.PixelFormat();
+      ec_format.num_channels = 1;
+      PackedImage ec(params.xsize, params.ysize, ec_format);
+      FillPackedImage(params.bits_per_sample, &ec);
+      frame.extra_channels.emplace_back(std::move(ec));
+      PackedExtraChannel pec;
+      pec.ec_info.bits_per_sample = params.bits_per_sample;
+      pec.ec_info.type = static_cast<JxlExtraChannelType>(i);
+      ppf->extra_channels_info.emplace_back(std::move(pec));
+    }
+  }
+  ppf->frames.emplace_back(std::move(frame));
+}
+
+// Ensures reading a newly written file leads to the same image pixels.
+void TestRoundTrip(const TestImageParams& params, ThreadPool* pool) {
+  if (!params.ShouldTestRoundtrip()) return;
+
+  std::string extension = ExtensionFromCodec(
+      params.codec, params.is_gray, params.add_alpha, params.bits_per_sample);
+  printf("Codec %s %s\n", extension.c_str(), params.DebugString().c_str());
+
+  PackedPixelFile ppf_in;
+  CreateTestImage(params, &ppf_in);
+
+  EncodedImage encoded;
+  auto encoder = Encoder::FromExtension(extension);
+  if (!encoder) {
+    fprintf(stderr, "Skipping test because of missing codec support.\n");
+    return;
+  }
+  ASSERT_TRUE(encoder->Encode(ppf_in, &encoded, pool));
+  ASSERT_EQ(encoded.bitstreams.size(), 1);
+
+  PackedPixelFile ppf_out;
+  ColorHints color_hints;
+  if (params.codec == Codec::kPNM || params.codec == Codec::kPGX) {
+    color_hints.Add("color_space",
+                    params.is_gray ? "Gra_D65_Rel_SRG" : "RGB_D65_SRG_Rel_SRG");
+  }
+  ASSERT_TRUE(DecodeBytes(Bytes(encoded.bitstreams[0]), color_hints, &ppf_out));
+  if (params.codec == Codec::kPNG && ppf_out.icc.empty()) {
+    // Decoding a PNG may drop the ICC profile if there's a valid cICP chunk.
+    // Rendering intent is not preserved in this case.
+    EXPECT_EQ(ppf_in.color_encoding.color_space,
+              ppf_out.color_encoding.color_space);
+    EXPECT_EQ(ppf_in.color_encoding.white_point,
+              ppf_out.color_encoding.white_point);
+    if (ppf_in.color_encoding.color_space != JXL_COLOR_SPACE_GRAY) {
+      EXPECT_EQ(ppf_in.color_encoding.primaries,
+                ppf_out.color_encoding.primaries);
+    }
+    EXPECT_EQ(ppf_in.color_encoding.transfer_function,
+              ppf_out.color_encoding.transfer_function);
+    EXPECT_EQ(ppf_out.color_encoding.rendering_intent,
+              JXL_RENDERING_INTENT_RELATIVE);
+  } else if (params.codec != Codec::kPNM && params.codec != Codec::kPGX &&
+             params.codec != Codec::kEXR) {
+    EXPECT_EQ(ppf_in.icc, ppf_out.icc);
+  }
+
+  ASSERT_EQ(ppf_out.frames.size(), 1);
+  const auto& frame_in = ppf_in.frames[0];
+  const auto& frame_out = ppf_out.frames[0];
+  VerifySameImage(frame_in.color, ppf_in.info.bits_per_sample, frame_out.color,
+                  ppf_out.info.bits_per_sample,
+                  /*lossless=*/params.codec != Codec::kJPG);
+  ASSERT_EQ(frame_in.extra_channels.size(), frame_out.extra_channels.size());
+  ASSERT_EQ(ppf_out.extra_channels_info.size(),
+            frame_out.extra_channels.size());
+  for (size_t i = 0; i < frame_in.extra_channels.size(); ++i) {
+    VerifySameImage(frame_in.extra_channels[i], ppf_in.info.bits_per_sample,
+                    frame_out.extra_channels[i], ppf_out.info.bits_per_sample,
+                    /*lossless=*/true);
+    EXPECT_EQ(ppf_out.extra_channels_info[i].ec_info.type,
+              ppf_in.extra_channels_info[i].ec_info.type);
+  }
+}
+
+TEST(CodecTest, TestRoundTrip) {
+  ThreadPoolForTests pool(12);
+
+  TestImageParams params;
+  params.xsize = 7;
+  params.ysize = 4;
+
+  for (Codec codec :
+       {Codec::kPNG, Codec::kPNM, Codec::kPGX, Codec::kEXR, Codec::kJPG}) {
+    for (int bits_per_sample : {4, 8, 10, 12, 16, 32}) {
+      for (bool is_gray : {false, true}) {
+        for (bool add_alpha : {false, true}) {
+          for (bool big_endian : {false, true}) {
+            params.codec = codec;
+            params.bits_per_sample = static_cast<size_t>(bits_per_sample);
+            params.is_gray = is_gray;
+            params.add_alpha = add_alpha;
+            params.big_endian = big_endian;
+            params.add_extra_channels = false;
+            TestRoundTrip(params, &pool);
+            if (codec == Codec::kPNM && add_alpha) {
+              params.add_extra_channels = true;
+              TestRoundTrip(params, &pool);
+            }
+          }
+        }
+      }
+    }
+  }
+}
+
+TEST(CodecTest, LosslessPNMRoundtrip) {
+  ThreadPoolForTests pool(12);
+
+  static const char* kChannels[] = {"", "g", "ga", "rgb", "rgba"};
+  static const char* kExtension[] = {"", ".pgm", ".pam", ".ppm", ".pam"};
+  for (size_t bit_depth = 1; bit_depth <= 16; ++bit_depth) {
+    for (size_t channels = 1; channels <= 4; ++channels) {
+      if (bit_depth == 1 && (channels == 2 || channels == 4)) continue;
+      std::string extension(kExtension[channels]);
+      std::string filename = "jxl/flower/flower_small." +
+                             std::string(kChannels[channels]) + ".depth" +
+                             std::to_string(bit_depth) + extension;
+      const std::vector<uint8_t> orig = jxl::test::ReadTestData(filename);
+
+      PackedPixelFile ppf;
+      ColorHints color_hints;
+      color_hints.Add("color_space",
+                      channels < 3 ? "Gra_D65_Rel_SRG" : "RGB_D65_SRG_Rel_SRG");
+      ASSERT_TRUE(
+          DecodeBytes(Bytes(orig.data(), orig.size()), color_hints, &ppf));
+
+      EncodedImage encoded;
+      auto encoder = Encoder::FromExtension(extension);
+      ASSERT_TRUE(encoder.get());
+      ASSERT_TRUE(encoder->Encode(ppf, &encoded, &pool));
+      ASSERT_EQ(encoded.bitstreams.size(), 1);
+      ASSERT_EQ(orig.size(), encoded.bitstreams[0].size());
+      EXPECT_EQ(0,
+                memcmp(orig.data(), encoded.bitstreams[0].data(), orig.size()));
+    }
+  }
+}
+
+TEST(CodecTest, TestPNM) { TestCodecPNM(); }
+
+TEST(CodecTest, FormatNegotiation) {
+  const std::vector<JxlPixelFormat> accepted_formats = {
+      {/*num_channels=*/4,
+       /*data_type=*/JXL_TYPE_UINT16,
+       /*endianness=*/JXL_NATIVE_ENDIAN,
+       /*align=*/0},
+      {/*num_channels=*/3,
+       /*data_type=*/JXL_TYPE_UINT8,
+       /*endianness=*/JXL_NATIVE_ENDIAN,
+       /*align=*/0},
+      {/*num_channels=*/3,
+       /*data_type=*/JXL_TYPE_UINT16,
+       /*endianness=*/JXL_NATIVE_ENDIAN,
+       /*align=*/0},
+      {/*num_channels=*/1,
+       /*data_type=*/JXL_TYPE_UINT8,
+       /*endianness=*/JXL_NATIVE_ENDIAN,
+       /*align=*/0},
+  };
+
+  JxlBasicInfo info;
+  JxlEncoderInitBasicInfo(&info);
+  info.bits_per_sample = 12;
+  info.num_color_channels = 2;
+
+  JxlPixelFormat format;
+  EXPECT_FALSE(SelectFormat(accepted_formats, info, &format));
+
+  info.num_color_channels = 3;
+  ASSERT_TRUE(SelectFormat(accepted_formats, info, &format));
+  EXPECT_EQ(format.num_channels, info.num_color_channels);
+  // 16 is the smallest accepted format that can accommodate the 12-bit data.
+  EXPECT_EQ(format.data_type, JXL_TYPE_UINT16);
+}
+
+TEST(CodecTest, EncodeToPNG) {
+  ThreadPool* const pool = nullptr;
+
+  std::unique_ptr<Encoder> png_encoder = Encoder::FromExtension(".png");
+  if (!png_encoder) {
+    fprintf(stderr, "Skipping test because of missing codec support.\n");
+    return;
+  }
+
+  const std::vector<uint8_t> original_png = jxl::test::ReadTestData(
+      "external/wesaturate/500px/tmshre_riaphotographs_srgb8.png");
+  PackedPixelFile ppf;
+  ASSERT_TRUE(extras::DecodeBytes(Bytes(original_png), ColorHints(), &ppf));
+
+  const JxlPixelFormat& format = ppf.frames.front().color.format;
+  ASSERT_THAT(
+      png_encoder->AcceptedFormats(),
+      Contains(AllOf(Field(&JxlPixelFormat::num_channels, format.num_channels),
+                     Field(&JxlPixelFormat::data_type, format.data_type),
+                     Field(&JxlPixelFormat::endianness, format.endianness))));
+  EncodedImage encoded_png;
+  ASSERT_TRUE(png_encoder->Encode(ppf, &encoded_png, pool));
+  EXPECT_THAT(encoded_png.icc, IsEmpty());
+  ASSERT_THAT(encoded_png.bitstreams, SizeIs(1));
+
+  PackedPixelFile decoded_ppf;
+  ASSERT_TRUE(extras::DecodeBytes(Bytes(encoded_png.bitstreams.front()),
+                                  ColorHints(), &decoded_ppf));
+
+  ASSERT_EQ(decoded_ppf.info.bits_per_sample, ppf.info.bits_per_sample);
+  ASSERT_EQ(decoded_ppf.frames.size(), 1);
+  VerifySameImage(ppf.frames[0].color, ppf.info.bits_per_sample,
+                  decoded_ppf.frames[0].color,
+                  decoded_ppf.info.bits_per_sample);
+}
+
+}  // namespace
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/common.cc b/third_party/jpeg-xl/lib/extras/common.cc
new file mode 100644
index 0000000000..e85b43a498
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/common.cc
@@ -0,0 +1,61 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/common.h"
+
+#include <jxl/codestream_header.h>
+#include <jxl/types.h>
+
+#include <cstddef>
+#include <vector>
+
+#include "lib/extras/packed_image.h"
+#include "lib/jxl/base/printf_macros.h"
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+namespace extras {
+
+Status SelectFormat(const std::vector<JxlPixelFormat>& accepted_formats,
+                    const JxlBasicInfo& basic_info, JxlPixelFormat* format) {
+  const size_t original_bit_depth = basic_info.bits_per_sample;
+  size_t current_bit_depth = 0;
+  size_t num_alpha_channels = (basic_info.alpha_bits != 0 ? 1 : 0);
+  size_t num_channels = basic_info.num_color_channels + num_alpha_channels;
+  for (;;) {
+    for (const JxlPixelFormat& candidate : accepted_formats) {
+      if (candidate.num_channels != num_channels) continue;
+      const size_t candidate_bit_depth =
+          PackedImage::BitsPerChannel(candidate.data_type);
+      if (
+          // Candidate bit depth is less than what we have and still enough
+          (original_bit_depth <= candidate_bit_depth &&
+           candidate_bit_depth < current_bit_depth) ||
+          // Or larger than the too-small bit depth we currently have
+          (current_bit_depth < candidate_bit_depth &&
+           current_bit_depth < original_bit_depth)) {
+        *format = candidate;
+        current_bit_depth = candidate_bit_depth;
+      }
+    }
+    if (current_bit_depth == 0) {
+      if (num_channels > basic_info.num_color_channels) {
+        // Try dropping the alpha channel.
+        --num_channels;
+        continue;
+      }
+      return JXL_FAILURE("no appropriate format found");
+    }
+    break;
+  }
+  if (current_bit_depth < original_bit_depth) {
+    JXL_WARNING("encoding %" PRIuS "-bit original to %" PRIuS " bits",
+                original_bit_depth, current_bit_depth);
+  }
+  return true;
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/common.h b/third_party/jpeg-xl/lib/extras/common.h
new file mode 100644
index 0000000000..88ed581af3
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/common.h
@@ -0,0 +1,26 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_COMMON_H_
+#define LIB_EXTRAS_COMMON_H_
+
+#include <jxl/codestream_header.h>
+#include <jxl/types.h>
+
+#include <vector>
+
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+namespace extras {
+
+// TODO(sboukortt): consider exposing this as part of the C API.
+Status SelectFormat(const std::vector<JxlPixelFormat>& accepted_formats,
+                    const JxlBasicInfo& basic_info, JxlPixelFormat* format);
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_COMMON_H_
diff --git a/third_party/jpeg-xl/lib/extras/dec/apng.cc b/third_party/jpeg-xl/lib/extras/dec/apng.cc
new file mode 100644
index 0000000000..f77dab77d1
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/apng.cc
@@ -0,0 +1,996 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/dec/apng.h"
+
+// Parts of this code are taken from apngdis, which has the following license:
+/* APNG Disassembler 2.8
+ *
+ * Deconstructs APNG files into individual frames.
+ *
+ * http://apngdis.sourceforge.net
+ *
+ * Copyright (c) 2010-2015 Max Stepin
+ * maxst at users.sourceforge.net
+ *
+ * zlib license
+ * ------------
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty.  In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ *
+ */
+
+#include <jxl/codestream_header.h>
+#include <jxl/encode.h>
+#include <string.h>
+
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "lib/extras/size_constraints.h"
+#include "lib/jxl/base/byte_order.h"
+#include "lib/jxl/base/common.h"
+#include "lib/jxl/base/compiler_specific.h"
+#include "lib/jxl/base/printf_macros.h"
+#include "lib/jxl/base/scope_guard.h"
+#include "lib/jxl/sanitizers.h"
+#if JPEGXL_ENABLE_APNG
+#include "png.h" /* original (unpatched) libpng is ok */
+#endif
+
+namespace jxl {
+namespace extras {
+
+#if JPEGXL_ENABLE_APNG
+namespace {
+
+constexpr unsigned char kExifSignature[6] = {0x45, 0x78, 0x69,
+                                             0x66, 0x00, 0x00};
+
+/* hIST chunk tail is not proccesed properly; skip this chunk completely;
+   see https://github.com/glennrp/libpng/pull/413 */
+const png_byte kIgnoredPngChunks[] = {
+    104, 73, 83, 84, '\0' /* hIST */
+};
+
+// Returns floating-point value from the PNG encoding (times 10^5).
+static double F64FromU32(const uint32_t x) {
+  return static_cast<int32_t>(x) * 1E-5;
+}
+
+Status DecodeSRGB(const unsigned char* payload, const size_t payload_size,
+                  JxlColorEncoding* color_encoding) {
+  if (payload_size != 1) return JXL_FAILURE("Wrong sRGB size");
+  // (PNG uses the same values as ICC.)
+  if (payload[0] >= 4) return JXL_FAILURE("Invalid Rendering Intent");
+  color_encoding->white_point = JXL_WHITE_POINT_D65;
+  color_encoding->primaries = JXL_PRIMARIES_SRGB;
+  color_encoding->transfer_function = JXL_TRANSFER_FUNCTION_SRGB;
+  color_encoding->rendering_intent =
+      static_cast<JxlRenderingIntent>(payload[0]);
+  return true;
+}
+
+// If the cICP profile is not fully supported, return false and leave
+// color_encoding unmodified.
+Status DecodeCICP(const unsigned char* payload, const size_t payload_size,
+                  JxlColorEncoding* color_encoding) {
+  if (payload_size != 4) return JXL_FAILURE("Wrong cICP size");
+  JxlColorEncoding color_enc = *color_encoding;
+
+  // From https://www.itu.int/rec/T-REC-H.273-202107-I/en
+  if (payload[0] == 1) {
+    // IEC 61966-2-1 sRGB
+    color_enc.primaries = JXL_PRIMARIES_SRGB;
+    color_enc.white_point = JXL_WHITE_POINT_D65;
+  } else if (payload[0] == 4) {
+    // Rec. ITU-R BT.470-6 System M
+    color_enc.primaries = JXL_PRIMARIES_CUSTOM;
+    color_enc.primaries_red_xy[0] = 0.67;
+    color_enc.primaries_red_xy[1] = 0.33;
+    color_enc.primaries_green_xy[0] = 0.21;
+    color_enc.primaries_green_xy[1] = 0.71;
+    color_enc.primaries_blue_xy[0] = 0.14;
+    color_enc.primaries_blue_xy[1] = 0.08;
+    color_enc.white_point = JXL_WHITE_POINT_CUSTOM;
+    color_enc.white_point_xy[0] = 0.310;
+    color_enc.white_point_xy[1] = 0.316;
+  } else if (payload[0] == 5) {
+    // Rec. ITU-R BT.1700-0 625 PAL and 625 SECAM
+    color_enc.primaries = JXL_PRIMARIES_CUSTOM;
+    color_enc.primaries_red_xy[0] = 0.64;
+    color_enc.primaries_red_xy[1] = 0.33;
+    color_enc.primaries_green_xy[0] = 0.29;
+    color_enc.primaries_green_xy[1] = 0.60;
+    color_enc.primaries_blue_xy[0] = 0.15;
+    color_enc.primaries_blue_xy[1] = 0.06;
+    color_enc.white_point = JXL_WHITE_POINT_D65;
+  } else if (payload[0] == 6 || payload[0] == 7) {
+    // SMPTE ST 170 (2004) / SMPTE ST 240 (1999)
+    color_enc.primaries = JXL_PRIMARIES_CUSTOM;
+    color_enc.primaries_red_xy[0] = 0.630;
+    color_enc.primaries_red_xy[1] = 0.340;
+    color_enc.primaries_green_xy[0] = 0.310;
+    color_enc.primaries_green_xy[1] = 0.595;
+    color_enc.primaries_blue_xy[0] = 0.155;
+    color_enc.primaries_blue_xy[1] = 0.070;
+    color_enc.white_point = JXL_WHITE_POINT_D65;
+  } else if (payload[0] == 8) {
+    // Generic film (colour filters using Illuminant C)
+    color_enc.primaries = JXL_PRIMARIES_CUSTOM;
+    color_enc.primaries_red_xy[0] = 0.681;
+    color_enc.primaries_red_xy[1] = 0.319;
+    color_enc.primaries_green_xy[0] = 0.243;
+    color_enc.primaries_green_xy[1] = 0.692;
+    color_enc.primaries_blue_xy[0] = 0.145;
+    color_enc.primaries_blue_xy[1] = 0.049;
+    color_enc.white_point = JXL_WHITE_POINT_CUSTOM;
+    color_enc.white_point_xy[0] = 0.310;
+    color_enc.white_point_xy[1] = 0.316;
+  } else if (payload[0] == 9) {
+    // Rec. ITU-R BT.2100-2
+    color_enc.primaries = JXL_PRIMARIES_2100;
+    color_enc.white_point = JXL_WHITE_POINT_D65;
+  } else if (payload[0] == 10) {
+    // CIE 1931 XYZ
+    color_enc.primaries = JXL_PRIMARIES_CUSTOM;
+    color_enc.primaries_red_xy[0] = 1;
+    color_enc.primaries_red_xy[1] = 0;
+    color_enc.primaries_green_xy[0] = 0;
+    color_enc.primaries_green_xy[1] = 1;
+    color_enc.primaries_blue_xy[0] = 0;
+    color_enc.primaries_blue_xy[1] = 0;
+    color_enc.white_point = JXL_WHITE_POINT_E;
+  } else if (payload[0] == 11) {
+    // SMPTE RP 431-2 (2011)
+    color_enc.primaries = JXL_PRIMARIES_P3;
+    color_enc.white_point = JXL_WHITE_POINT_DCI;
+  } else if (payload[0] == 12) {
+    // SMPTE EG 432-1 (2010)
+    color_enc.primaries = JXL_PRIMARIES_P3;
+    color_enc.white_point = JXL_WHITE_POINT_D65;
+  } else if (payload[0] == 22) {
+    color_enc.primaries = JXL_PRIMARIES_CUSTOM;
+    color_enc.primaries_red_xy[0] = 0.630;
+    color_enc.primaries_red_xy[1] = 0.340;
+    color_enc.primaries_green_xy[0] = 0.295;
+    color_enc.primaries_green_xy[1] = 0.605;
+    color_enc.primaries_blue_xy[0] = 0.155;
+    color_enc.primaries_blue_xy[1] = 0.077;
+    color_enc.white_point = JXL_WHITE_POINT_D65;
+  } else {
+    JXL_WARNING("Unsupported primaries specified in cICP chunk: %d",
+                static_cast<int>(payload[0]));
+    return false;
+  }
+
+  if (payload[1] == 1 || payload[1] == 6 || payload[1] == 14 ||
+      payload[1] == 15) {
+    // Rec. ITU-R BT.709-6
+    color_enc.transfer_function = JXL_TRANSFER_FUNCTION_709;
+  } else if (payload[1] == 4) {
+    // Rec. ITU-R BT.1700-0 625 PAL and 625 SECAM
+    color_enc.transfer_function = JXL_TRANSFER_FUNCTION_GAMMA;
+    color_enc.gamma = 1 / 2.2;
+  } else if (payload[1] == 5) {
+    // Rec. ITU-R BT.470-6 System B, G
+    color_enc.transfer_function = JXL_TRANSFER_FUNCTION_GAMMA;
+    color_enc.gamma = 1 / 2.8;
+  } else if (payload[1] == 8 || payload[1] == 13 || payload[1] == 16 ||
+             payload[1] == 17 || payload[1] == 18) {
+    // These codes all match the corresponding JXL enum values
+    color_enc.transfer_function = static_cast<JxlTransferFunction>(payload[1]);
+  } else {
+    JXL_WARNING("Unsupported transfer function specified in cICP chunk: %d",
+                static_cast<int>(payload[1]));
+    return false;
+  }
+
+  if (payload[2] != 0) {
+    JXL_WARNING("Unsupported color space specified in cICP chunk: %d",
+                static_cast<int>(payload[2]));
+    return false;
+  }
+  if (payload[3] != 1) {
+    JXL_WARNING("Unsupported full-range flag specified in cICP chunk: %d",
+                static_cast<int>(payload[3]));
+    return false;
+  }
+  // cICP has no rendering intent, so use the default
+  color_enc.rendering_intent = JXL_RENDERING_INTENT_RELATIVE;
+  *color_encoding = color_enc;
+  return true;
+}
+
+Status DecodeGAMA(const unsigned char* payload, const size_t payload_size,
+                  JxlColorEncoding* color_encoding) {
+  if (payload_size != 4) return JXL_FAILURE("Wrong gAMA size");
+  color_encoding->transfer_function = JXL_TRANSFER_FUNCTION_GAMMA;
+  color_encoding->gamma = F64FromU32(LoadBE32(payload));
+  return true;
+}
+
+Status DecodeCHRM(const unsigned char* payload, const size_t payload_size,
+                  JxlColorEncoding* color_encoding) {
+  if (payload_size != 32) return JXL_FAILURE("Wrong cHRM size");
+
+  color_encoding->white_point = JXL_WHITE_POINT_CUSTOM;
+  color_encoding->white_point_xy[0] = F64FromU32(LoadBE32(payload + 0));
+  color_encoding->white_point_xy[1] = F64FromU32(LoadBE32(payload + 4));
+
+  color_encoding->primaries = JXL_PRIMARIES_CUSTOM;
+  color_encoding->primaries_red_xy[0] = F64FromU32(LoadBE32(payload + 8));
+  color_encoding->primaries_red_xy[1] = F64FromU32(LoadBE32(payload + 12));
+  color_encoding->primaries_green_xy[0] = F64FromU32(LoadBE32(payload + 16));
+  color_encoding->primaries_green_xy[1] = F64FromU32(LoadBE32(payload + 20));
+  color_encoding->primaries_blue_xy[0] = F64FromU32(LoadBE32(payload + 24));
+  color_encoding->primaries_blue_xy[1] = F64FromU32(LoadBE32(payload + 28));
+  return true;
+}
+
+// Retrieves XMP and EXIF/IPTC from itext and text.
+class BlobsReaderPNG {
+ public:
+  static Status Decode(const png_text_struct& info, PackedMetadata* metadata) {
+    // We trust these are properly null-terminated by libpng.
+    const char* key = info.key;
+    const char* value = info.text;
+    if (strstr(key, "XML:com.adobe.xmp")) {
+      metadata->xmp.resize(strlen(value));  // safe, see above
+      memcpy(metadata->xmp.data(), value, metadata->xmp.size());
+    }
+
+    std::string type;
+    std::vector<uint8_t> bytes;
+
+    // Handle text chunks annotated with key "Raw profile type ####", with
+    // #### a type, which may contain metadata.
+    const char* kKey = "Raw profile type ";
+    if (strncmp(key, kKey, strlen(kKey)) != 0) return false;
+
+    if (!MaybeDecodeBase16(key, value, &type, &bytes)) {
+      JXL_WARNING("Couldn't parse 'Raw format type' text chunk");
+      return false;
+    }
+    if (type == "exif") {
+      // Remove "Exif\0\0" prefix if present
+      if (bytes.size() >= sizeof kExifSignature &&
+          memcmp(bytes.data(), kExifSignature, sizeof kExifSignature) == 0) {
+        bytes.erase(bytes.begin(), bytes.begin() + sizeof kExifSignature);
+      }
+      if (!metadata->exif.empty()) {
+        JXL_WARNING("overwriting EXIF (%" PRIuS " bytes) with base16 (%" PRIuS
+                    " bytes)",
+                    metadata->exif.size(), bytes.size());
+      }
+      metadata->exif = std::move(bytes);
+    } else if (type == "iptc") {
+      // TODO(jon): Deal with IPTC in some way
+    } else if (type == "8bim") {
+      // TODO(jon): Deal with 8bim in some way
+    } else if (type == "xmp") {
+      if (!metadata->xmp.empty()) {
+        JXL_WARNING("overwriting XMP (%" PRIuS " bytes) with base16 (%" PRIuS
+                    " bytes)",
+                    metadata->xmp.size(), bytes.size());
+      }
+      metadata->xmp = std::move(bytes);
+    } else {
+      JXL_WARNING("Unknown type in 'Raw format type' text chunk: %s: %" PRIuS
+                  " bytes",
+                  type.c_str(), bytes.size());
+    }
+    return true;
+  }
+
+ private:
+  // Returns false if invalid.
+  static JXL_INLINE Status DecodeNibble(const char c,
+                                        uint32_t* JXL_RESTRICT nibble) {
+    if ('a' <= c && c <= 'f') {
+      *nibble = 10 + c - 'a';
+    } else if ('0' <= c && c <= '9') {
+      *nibble = c - '0';
+    } else {
+      *nibble = 0;
+      return JXL_FAILURE("Invalid metadata nibble");
+    }
+    JXL_ASSERT(*nibble < 16);
+    return true;
+  }
+
+  // Returns false if invalid.
+  static JXL_INLINE Status DecodeDecimal(const char** pos, const char* end,
+                                         uint32_t* JXL_RESTRICT value) {
+    size_t len = 0;
+    *value = 0;
+    while (*pos < end) {
+      char next = **pos;
+      if (next >= '0' && next <= '9') {
+        *value = (*value * 10) + static_cast<uint32_t>(next - '0');
+        len++;
+        if (len > 8) {
+          break;
+        }
+      } else {
+        // Do not consume terminator (non-decimal digit).
+        break;
+      }
+      (*pos)++;
+    }
+    if (len == 0 || len > 8) {
+      return JXL_FAILURE("Failed to parse decimal");
+    }
+    return true;
+  }
+
+  // Parses a PNG text chunk with key of the form "Raw profile type ####", with
+  // #### a type.
+  // Returns whether it could successfully parse the content.
+  // We trust key and encoded are null-terminated because they come from
+  // libpng.
+  static Status MaybeDecodeBase16(const char* key, const char* encoded,
+                                  std::string* type,
+                                  std::vector<uint8_t>* bytes) {
+    const char* encoded_end = encoded + strlen(encoded);
+
+    const char* kKey = "Raw profile type ";
+    if (strncmp(key, kKey, strlen(kKey)) != 0) return false;
+    *type = key + strlen(kKey);
+    const size_t kMaxTypeLen = 20;
+    if (type->length() > kMaxTypeLen) return false;  // Type too long
+
+    // Header: freeform string and number of bytes
+    // Expected format is:
+    // \n
+    // profile name/description\n
+    //       40\n               (the number of bytes after hex-decoding)
+    // 01234566789abcdef....\n  (72 bytes per line max).
+    // 012345667\n              (last line)
+    const char* pos = encoded;
+
+    if (*(pos++) != '\n') return false;
+    while (pos < encoded_end && *pos != '\n') {
+      pos++;
+    }
+    if (pos == encoded_end) return false;
+    // We parsed so far a \n, some number of non \n characters and are now
+    // pointing at a \n.
+    if (*(pos++) != '\n') return false;
+    // Skip leading spaces
+    while (pos < encoded_end && *pos == ' ') {
+      pos++;
+    }
+    uint32_t bytes_to_decode = 0;
+    JXL_RETURN_IF_ERROR(DecodeDecimal(&pos, encoded_end, &bytes_to_decode));
+
+    // We need 2*bytes for the hex values plus 1 byte every 36 values,
+    // plus terminal \n for length.
+    const unsigned long needed_bytes =
+        bytes_to_decode * 2 + 1 + DivCeil(bytes_to_decode, 36);
+    if (needed_bytes != static_cast<size_t>(encoded_end - pos)) {
+      return JXL_FAILURE("Not enough bytes to parse %d bytes in hex",
+                         bytes_to_decode);
+    }
+    JXL_ASSERT(bytes->empty());
+    bytes->reserve(bytes_to_decode);
+
+    // Encoding: base16 with newline after 72 chars.
+    // pos points to the \n before the first line of hex values.
+    for (size_t i = 0; i < bytes_to_decode; ++i) {
+      if (i % 36 == 0) {
+        if (pos + 1 >= encoded_end) return false;  // Truncated base16 1
+        if (*pos != '\n') return false;            // Expected newline
+        ++pos;
+      }
+
+      if (pos + 2 >= encoded_end) return false;  // Truncated base16 2;
+      uint32_t nibble0, nibble1;
+      JXL_RETURN_IF_ERROR(DecodeNibble(pos[0], &nibble0));
+      JXL_RETURN_IF_ERROR(DecodeNibble(pos[1], &nibble1));
+      bytes->push_back(static_cast<uint8_t>((nibble0 << 4) + nibble1));
+      pos += 2;
+    }
+    if (pos + 1 != encoded_end) return false;  // Too many encoded bytes
+    if (pos[0] != '\n') return false;          // Incorrect metadata terminator
+    return true;
+  }
+};
+
+constexpr bool isAbc(char c) {
+  return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
+}
+
+constexpr uint32_t kId_IHDR = 0x52444849;
+constexpr uint32_t kId_acTL = 0x4C546361;
+constexpr uint32_t kId_fcTL = 0x4C546366;
+constexpr uint32_t kId_IDAT = 0x54414449;
+constexpr uint32_t kId_fdAT = 0x54416466;
+constexpr uint32_t kId_IEND = 0x444E4549;
+constexpr uint32_t kId_cICP = 0x50434963;
+constexpr uint32_t kId_iCCP = 0x50434369;
+constexpr uint32_t kId_sRGB = 0x42475273;
+constexpr uint32_t kId_gAMA = 0x414D4167;
+constexpr uint32_t kId_cHRM = 0x4D524863;
+constexpr uint32_t kId_eXIf = 0x66495865;
+
+struct APNGFrame {
+  std::vector<uint8_t> pixels;
+  std::vector<uint8_t*> rows;
+  unsigned int w, h, delay_num, delay_den;
+};
+
+struct Reader {
+  const uint8_t* next;
+  const uint8_t* last;
+  bool Read(void* data, size_t len) {
+    size_t cap = last - next;
+    size_t to_copy = std::min(cap, len);
+    memcpy(data, next, to_copy);
+    next += to_copy;
+    return (len == to_copy);
+  }
+  bool Eof() { return next == last; }
+};
+
+const unsigned long cMaxPNGSize = 1000000UL;
+const size_t kMaxPNGChunkSize = 1lu << 30;  // 1 GB
+
+void info_fn(png_structp png_ptr, png_infop info_ptr) {
+  png_set_expand(png_ptr);
+  png_set_palette_to_rgb(png_ptr);
+  png_set_tRNS_to_alpha(png_ptr);
+  (void)png_set_interlace_handling(png_ptr);
+  png_read_update_info(png_ptr, info_ptr);
+}
+
+void row_fn(png_structp png_ptr, png_bytep new_row, png_uint_32 row_num,
+            int pass) {
+  APNGFrame* frame = (APNGFrame*)png_get_progressive_ptr(png_ptr);
+  JXL_CHECK(frame);
+  JXL_CHECK(row_num < frame->rows.size());
+  JXL_CHECK(frame->rows[row_num] < frame->pixels.data() + frame->pixels.size());
+  png_progressive_combine_row(png_ptr, frame->rows[row_num], new_row);
+}
+
+inline unsigned int read_chunk(Reader* r, std::vector<uint8_t>* pChunk) {
+  unsigned char len[4];
+  if (r->Read(&len, 4)) {
+    const auto size = png_get_uint_32(len);
+    // Check first, to avoid overflow.
+    if (size > kMaxPNGChunkSize) {
+      JXL_WARNING("APNG chunk size is too big");
+      return 0;
+    }
+    pChunk->resize(size + 12);
+    memcpy(pChunk->data(), len, 4);
+    if (r->Read(pChunk->data() + 4, pChunk->size() - 4)) {
+      return LoadLE32(pChunk->data() + 4);
+    }
+  }
+  return 0;
+}
+
+int processing_start(png_structp& png_ptr, png_infop& info_ptr, void* frame_ptr,
+                     bool hasInfo, std::vector<uint8_t>& chunkIHDR,
+                     std::vector<std::vector<uint8_t>>& chunksInfo) {
+  unsigned char header[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+
+  // Cleanup prior decoder, if any.
+  png_destroy_read_struct(&png_ptr, &info_ptr, 0);
+  // Just in case. Not all versions on libpng wipe-out the pointers.
+  png_ptr = nullptr;
+  info_ptr = nullptr;
+
+  png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+  info_ptr = png_create_info_struct(png_ptr);
+  if (!png_ptr || !info_ptr) return 1;
+
+  if (setjmp(png_jmpbuf(png_ptr))) {
+    return 1;
+  }
+
+  png_set_keep_unknown_chunks(png_ptr, 1, kIgnoredPngChunks,
+                              (int)sizeof(kIgnoredPngChunks) / 5);
+
+  png_set_crc_action(png_ptr, PNG_CRC_QUIET_USE, PNG_CRC_QUIET_USE);
+  png_set_progressive_read_fn(png_ptr, frame_ptr, info_fn, row_fn, NULL);
+
+  png_process_data(png_ptr, info_ptr, header, 8);
+  png_process_data(png_ptr, info_ptr, chunkIHDR.data(), chunkIHDR.size());
+
+  if (hasInfo) {
+    for (unsigned int i = 0; i < chunksInfo.size(); i++) {
+      png_process_data(png_ptr, info_ptr, chunksInfo[i].data(),
+                       chunksInfo[i].size());
+    }
+  }
+  return 0;
+}
+
+int processing_data(png_structp png_ptr, png_infop info_ptr, unsigned char* p,
+                    unsigned int size) {
+  if (!png_ptr || !info_ptr) return 1;
+
+  if (setjmp(png_jmpbuf(png_ptr))) {
+    return 1;
+  }
+
+  png_process_data(png_ptr, info_ptr, p, size);
+  return 0;
+}
+
+int processing_finish(png_structp png_ptr, png_infop info_ptr,
+                      PackedMetadata* metadata) {
+  unsigned char footer[12] = {0, 0, 0, 0, 73, 69, 78, 68, 174, 66, 96, 130};
+
+  if (!png_ptr || !info_ptr) return 1;
+
+  if (setjmp(png_jmpbuf(png_ptr))) {
+    return 1;
+  }
+
+  png_process_data(png_ptr, info_ptr, footer, 12);
+  // before destroying: check if we encountered any metadata chunks
+  png_textp text_ptr;
+  int num_text;
+  png_get_text(png_ptr, info_ptr, &text_ptr, &num_text);
+  for (int i = 0; i < num_text; i++) {
+    (void)BlobsReaderPNG::Decode(text_ptr[i], metadata);
+  }
+
+  return 0;
+}
+
+}  // namespace
+#endif
+
+bool CanDecodeAPNG() {
+#if JPEGXL_ENABLE_APNG
+  return true;
+#else
+  return false;
+#endif
+}
+
+Status DecodeImageAPNG(const Span<const uint8_t> bytes,
+                       const ColorHints& color_hints, PackedPixelFile* ppf,
+                       const SizeConstraints* constraints) {
+#if JPEGXL_ENABLE_APNG
+  Reader r;
+  unsigned int id, j, w, h, w0, h0, x0, y0;
+  unsigned int delay_num, delay_den, dop, bop, rowbytes, imagesize;
+  unsigned char sig[8];
+  png_structp png_ptr = nullptr;
+  png_infop info_ptr = nullptr;
+  std::vector<uint8_t> chunk;
+  std::vector<uint8_t> chunkIHDR;
+  std::vector<std::vector<uint8_t>> chunksInfo;
+  bool isAnimated = false;
+  bool hasInfo = false;
+  bool seenFctl = false;
+  APNGFrame frameRaw = {};
+  uint32_t num_channels;
+  JxlPixelFormat format;
+  unsigned int bytes_per_pixel = 0;
+
+  struct FrameInfo {
+    PackedImage data;
+    uint32_t duration;
+    size_t x0, xsize;
+    size_t y0, ysize;
+    uint32_t dispose_op;
+    uint32_t blend_op;
+  };
+
+  std::vector<FrameInfo> frames;
+
+  // Make sure png memory is released in any case.
+  auto scope_guard = MakeScopeGuard([&]() {
+    png_destroy_read_struct(&png_ptr, &info_ptr, 0);
+    // Just in case. Not all versions on libpng wipe-out the pointers.
+    png_ptr = nullptr;
+    info_ptr = nullptr;
+  });
+
+  r = {bytes.data(), bytes.data() + bytes.size()};
+  // Not a PNG => not an error
+  unsigned char png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+  if (!r.Read(sig, 8) || memcmp(sig, png_signature, 8) != 0) {
+    return false;
+  }
+  id = read_chunk(&r, &chunkIHDR);
+
+  ppf->info.exponent_bits_per_sample = 0;
+  ppf->info.alpha_exponent_bits = 0;
+  ppf->info.orientation = JXL_ORIENT_IDENTITY;
+
+  ppf->frames.clear();
+
+  bool have_color = false;
+  bool have_cicp = false, have_iccp = false, have_srgb = false;
+  bool errorstate = true;
+  if (id == kId_IHDR && chunkIHDR.size() == 25) {
+    x0 = 0;
+    y0 = 0;
+    delay_num = 1;
+    delay_den = 10;
+    dop = 0;
+    bop = 0;
+
+    w0 = w = png_get_uint_32(chunkIHDR.data() + 8);
+    h0 = h = png_get_uint_32(chunkIHDR.data() + 12);
+    if (w > cMaxPNGSize || h > cMaxPNGSize) {
+      return false;
+    }
+
+    // default settings in case e.g. only gAMA is given
+    ppf->color_encoding.color_space = JXL_COLOR_SPACE_RGB;
+    ppf->color_encoding.white_point = JXL_WHITE_POINT_D65;
+    ppf->color_encoding.primaries = JXL_PRIMARIES_SRGB;
+    ppf->color_encoding.transfer_function = JXL_TRANSFER_FUNCTION_SRGB;
+    ppf->color_encoding.rendering_intent = JXL_RENDERING_INTENT_RELATIVE;
+
+    if (!processing_start(png_ptr, info_ptr, (void*)&frameRaw, hasInfo,
+                          chunkIHDR, chunksInfo)) {
+      while (!r.Eof()) {
+        id = read_chunk(&r, &chunk);
+        if (!id) break;
+        seenFctl |= (id == kId_fcTL);
+
+        if (id == kId_acTL && !hasInfo && !isAnimated) {
+          isAnimated = true;
+          ppf->info.have_animation = true;
+          ppf->info.animation.tps_numerator = 1000;
+          ppf->info.animation.tps_denominator = 1;
+        } else if (id == kId_IEND ||
+                   (id == kId_fcTL && (!hasInfo || isAnimated))) {
+          if (hasInfo) {
+            if (!processing_finish(png_ptr, info_ptr, &ppf->metadata)) {
+              // Allocates the frame buffer.
+              uint32_t duration = delay_num * 1000 / delay_den;
+              frames.push_back(FrameInfo{PackedImage(w0, h0, format), duration,
+                                         x0, w0, y0, h0, dop, bop});
+              auto& frame = frames.back().data;
+              for (size_t y = 0; y < h0; ++y) {
+                memcpy(static_cast<uint8_t*>(frame.pixels()) + frame.stride * y,
+                       frameRaw.rows[y], bytes_per_pixel * w0);
+              }
+            } else {
+              break;
+            }
+          }
+
+          if (id == kId_IEND) {
+            errorstate = false;
+            break;
+          }
+          if (chunk.size() < 34) {
+            return JXL_FAILURE("Received a chunk that is too small (%" PRIuS
+                               "B)",
+                               chunk.size());
+          }
+          // At this point the old frame is done. Let's start a new one.
+          w0 = png_get_uint_32(chunk.data() + 12);
+          h0 = png_get_uint_32(chunk.data() + 16);
+          x0 = png_get_uint_32(chunk.data() + 20);
+          y0 = png_get_uint_32(chunk.data() + 24);
+          delay_num = png_get_uint_16(chunk.data() + 28);
+          delay_den = png_get_uint_16(chunk.data() + 30);
+          dop = chunk[32];
+          bop = chunk[33];
+
+          if (!delay_den) delay_den = 100;
+
+          if (w0 > cMaxPNGSize || h0 > cMaxPNGSize || x0 > cMaxPNGSize ||
+              y0 > cMaxPNGSize || x0 + w0 > w || y0 + h0 > h || dop > 2 ||
+              bop > 1) {
+            break;
+          }
+
+          if (hasInfo) {
+            memcpy(chunkIHDR.data() + 8, chunk.data() + 12, 8);
+            if (processing_start(png_ptr, info_ptr, (void*)&frameRaw, hasInfo,
+                                 chunkIHDR, chunksInfo)) {
+              break;
+            }
+          }
+        } else if (id == kId_IDAT) {
+          // First IDAT chunk means we now have all header info
+          if (seenFctl) {
+            // `fcTL` chunk must appear after all `IDAT` chunks
+            return JXL_FAILURE("IDAT chunk after fcTL chunk");
+          }
+          hasInfo = true;
+          JXL_CHECK(w == png_get_image_width(png_ptr, info_ptr));
+          JXL_CHECK(h == png_get_image_height(png_ptr, info_ptr));
+          int colortype = png_get_color_type(png_ptr, info_ptr);
+          int png_bit_depth = png_get_bit_depth(png_ptr, info_ptr);
+          ppf->info.bits_per_sample = png_bit_depth;
+          png_color_8p sigbits = NULL;
+          png_get_sBIT(png_ptr, info_ptr, &sigbits);
+          if (colortype & 1) {
+            // palette will actually be 8-bit regardless of the index bitdepth
+            ppf->info.bits_per_sample = 8;
+          }
+          if (colortype & 2) {
+            ppf->info.num_color_channels = 3;
+            ppf->color_encoding.color_space = JXL_COLOR_SPACE_RGB;
+            if (sigbits && sigbits->red == sigbits->green &&
+                sigbits->green == sigbits->blue) {
+              ppf->info.bits_per_sample = sigbits->red;
+            } else if (sigbits) {
+              int maxbps = std::max(sigbits->red,
+                                    std::max(sigbits->green, sigbits->blue));
+              JXL_WARNING(
+                  "sBIT chunk: bit depths for R, G, and B are not the same (%i "
+                  "%i %i), while in JPEG XL they have to be the same. Setting "
+                  "RGB bit depth to %i.",
+                  sigbits->red, sigbits->green, sigbits->blue, maxbps);
+              ppf->info.bits_per_sample = maxbps;
+            }
+          } else {
+            ppf->info.num_color_channels = 1;
+            ppf->color_encoding.color_space = JXL_COLOR_SPACE_GRAY;
+            if (sigbits) ppf->info.bits_per_sample = sigbits->gray;
+          }
+          if (colortype & 4 ||
+              png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
+            ppf->info.alpha_bits = ppf->info.bits_per_sample;
+            if (sigbits && sigbits->alpha != ppf->info.bits_per_sample) {
+              JXL_WARNING(
+                  "sBIT chunk: bit depths for RGBA are inconsistent "
+                  "(%i %i %i %i). Setting A bitdepth to %i.",
+                  sigbits->red, sigbits->green, sigbits->blue, sigbits->alpha,
+                  ppf->info.bits_per_sample);
+            }
+          } else {
+            ppf->info.alpha_bits = 0;
+          }
+          ppf->color_encoding.color_space =
+              (ppf->info.num_color_channels == 1 ? JXL_COLOR_SPACE_GRAY
+                                                 : JXL_COLOR_SPACE_RGB);
+          ppf->info.xsize = w;
+          ppf->info.ysize = h;
+          JXL_RETURN_IF_ERROR(VerifyDimensions(constraints, w, h));
+          num_channels =
+              ppf->info.num_color_channels + (ppf->info.alpha_bits ? 1 : 0);
+          format = {
+              /*num_channels=*/num_channels,
+              /*data_type=*/ppf->info.bits_per_sample > 8 ? JXL_TYPE_UINT16
+                                                          : JXL_TYPE_UINT8,
+              /*endianness=*/JXL_BIG_ENDIAN,
+              /*align=*/0,
+          };
+          if (png_bit_depth > 8 && format.data_type == JXL_TYPE_UINT8) {
+            png_set_strip_16(png_ptr);
+          }
+          bytes_per_pixel =
+              num_channels * (format.data_type == JXL_TYPE_UINT16 ? 2 : 1);
+          rowbytes = w * bytes_per_pixel;
+          imagesize = h * rowbytes;
+          frameRaw.pixels.resize(imagesize);
+          frameRaw.rows.resize(h);
+          for (j = 0; j < h; j++)
+            frameRaw.rows[j] = frameRaw.pixels.data() + j * rowbytes;
+
+          if (processing_data(png_ptr, info_ptr, chunk.data(), chunk.size())) {
+            break;
+          }
+        } else if (id == kId_fdAT && isAnimated) {
+          if (!hasInfo) {
+            return JXL_FAILURE("fDAT chunk before iDAT");
+          }
+          png_save_uint_32(chunk.data() + 4, chunk.size() - 16);
+          memcpy(chunk.data() + 8, "IDAT", 4);
+          if (processing_data(png_ptr, info_ptr, chunk.data() + 4,
+                              chunk.size() - 4)) {
+            break;
+          }
+        } else if (id == kId_cICP) {
+          // Color profile chunks: cICP has the highest priority, followed by
+          // iCCP and sRGB (which shouldn't co-exist, but if they do, we use
+          // iCCP), followed finally by gAMA and cHRM.
+          if (DecodeCICP(chunk.data() + 8, chunk.size() - 12,
+                         &ppf->color_encoding)) {
+            have_cicp = true;
+            have_color = true;
+            ppf->icc.clear();
+          }
+        } else if (!have_cicp && id == kId_iCCP) {
+          if (processing_data(png_ptr, info_ptr, chunk.data(), chunk.size())) {
+            JXL_WARNING("Corrupt iCCP chunk");
+            break;
+          }
+
+          // TODO(jon): catch special case of PQ and synthesize color encoding
+          // in that case
+          int compression_type;
+          png_bytep profile;
+          png_charp name;
+          png_uint_32 proflen = 0;
+          auto ok = png_get_iCCP(png_ptr, info_ptr, &name, &compression_type,
+                                 &profile, &proflen);
+          if (ok && proflen) {
+            ppf->icc.assign(profile, profile + proflen);
+            have_color = true;
+            have_iccp = true;
+          } else {
+            // TODO(eustas): JXL_WARNING?
+          }
+        } else if (!have_cicp && !have_iccp && id == kId_sRGB) {
+          JXL_RETURN_IF_ERROR(DecodeSRGB(chunk.data() + 8, chunk.size() - 12,
+                                         &ppf->color_encoding));
+          have_srgb = true;
+          have_color = true;
+        } else if (!have_cicp && !have_srgb && !have_iccp && id == kId_gAMA) {
+          JXL_RETURN_IF_ERROR(DecodeGAMA(chunk.data() + 8, chunk.size() - 12,
+                                         &ppf->color_encoding));
+          have_color = true;
+        } else if (!have_cicp && !have_srgb && !have_iccp && id == kId_cHRM) {
+          JXL_RETURN_IF_ERROR(DecodeCHRM(chunk.data() + 8, chunk.size() - 12,
+                                         &ppf->color_encoding));
+          have_color = true;
+        } else if (id == kId_eXIf) {
+          ppf->metadata.exif.resize(chunk.size() - 12);
+          memcpy(ppf->metadata.exif.data(), chunk.data() + 8,
+                 chunk.size() - 12);
+        } else if (!isAbc(chunk[4]) || !isAbc(chunk[5]) || !isAbc(chunk[6]) ||
+                   !isAbc(chunk[7])) {
+          break;
+        } else {
+          if (processing_data(png_ptr, info_ptr, chunk.data(), chunk.size())) {
+            break;
+          }
+          if (!hasInfo) {
+            chunksInfo.push_back(chunk);
+            continue;
+          }
+        }
+      }
+    }
+
+    JXL_RETURN_IF_ERROR(ApplyColorHints(
+        color_hints, have_color, ppf->info.num_color_channels == 1, ppf));
+  }
+
+  if (errorstate) return false;
+
+  bool has_nontrivial_background = false;
+  bool previous_frame_should_be_cleared = false;
+  enum {
+    DISPOSE_OP_NONE = 0,
+    DISPOSE_OP_BACKGROUND = 1,
+    DISPOSE_OP_PREVIOUS = 2,
+  };
+  enum {
+    BLEND_OP_SOURCE = 0,
+    BLEND_OP_OVER = 1,
+  };
+  for (size_t i = 0; i < frames.size(); i++) {
+    auto& frame = frames[i];
+    JXL_ASSERT(frame.data.xsize == frame.xsize);
+    JXL_ASSERT(frame.data.ysize == frame.ysize);
+
+    // Before encountering a DISPOSE_OP_NONE frame, the canvas is filled with 0,
+    // so DISPOSE_OP_BACKGROUND and DISPOSE_OP_PREVIOUS are equivalent.
+    if (frame.dispose_op == DISPOSE_OP_NONE) {
+      has_nontrivial_background = true;
+    }
+    bool should_blend = frame.blend_op == BLEND_OP_OVER;
+    bool use_for_next_frame =
+        has_nontrivial_background && frame.dispose_op != DISPOSE_OP_PREVIOUS;
+    size_t x0 = frame.x0;
+    size_t y0 = frame.y0;
+    size_t xsize = frame.data.xsize;
+    size_t ysize = frame.data.ysize;
+    if (previous_frame_should_be_cleared) {
+      size_t px0 = frames[i - 1].x0;
+      size_t py0 = frames[i - 1].y0;
+      size_t pxs = frames[i - 1].xsize;
+      size_t pys = frames[i - 1].ysize;
+      if (px0 >= x0 && py0 >= y0 && px0 + pxs <= x0 + xsize &&
+          py0 + pys <= y0 + ysize && frame.blend_op == BLEND_OP_SOURCE &&
+          use_for_next_frame) {
+        // If the previous frame is entirely contained in the current frame and
+        // we are using BLEND_OP_SOURCE, nothing special needs to be done.
+        ppf->frames.emplace_back(std::move(frame.data));
+      } else if (px0 == x0 && py0 == y0 && px0 + pxs == x0 + xsize &&
+                 py0 + pys == y0 + ysize && use_for_next_frame) {
+        // If the new frame has the same size as the old one, but we are
+        // blending, we can instead just not blend.
+        should_blend = false;
+        ppf->frames.emplace_back(std::move(frame.data));
+      } else if (px0 <= x0 && py0 <= y0 && px0 + pxs >= x0 + xsize &&
+                 py0 + pys >= y0 + ysize && use_for_next_frame) {
+        // If the new frame is contained within the old frame, we can pad the
+        // new frame with zeros and not blend.
+        PackedImage new_data(pxs, pys, frame.data.format);
+        memset(new_data.pixels(), 0, new_data.pixels_size);
+        for (size_t y = 0; y < ysize; y++) {
+          size_t bytes_per_pixel =
+              PackedImage::BitsPerChannel(new_data.format.data_type) *
+              new_data.format.num_channels / 8;
+          memcpy(static_cast<uint8_t*>(new_data.pixels()) +
+                     new_data.stride * (y + y0 - py0) +
+                     bytes_per_pixel * (x0 - px0),
+                 static_cast<const uint8_t*>(frame.data.pixels()) +
+                     frame.data.stride * y,
+                 xsize * bytes_per_pixel);
+        }
+
+        x0 = px0;
+        y0 = py0;
+        xsize = pxs;
+        ysize = pys;
+        should_blend = false;
+        ppf->frames.emplace_back(std::move(new_data));
+      } else {
+        // If all else fails, insert a placeholder blank frame with kReplace.
+        PackedImage blank(pxs, pys, frame.data.format);
+        memset(blank.pixels(), 0, blank.pixels_size);
+        ppf->frames.emplace_back(std::move(blank));
+        auto& pframe = ppf->frames.back();
+        pframe.frame_info.layer_info.crop_x0 = px0;
+        pframe.frame_info.layer_info.crop_y0 = py0;
+        pframe.frame_info.layer_info.xsize = pxs;
+        pframe.frame_info.layer_info.ysize = pys;
+        pframe.frame_info.duration = 0;
+        bool is_full_size = px0 == 0 && py0 == 0 && pxs == ppf->info.xsize &&
+                            pys == ppf->info.ysize;
+        pframe.frame_info.layer_info.have_crop = is_full_size ? 0 : 1;
+        pframe.frame_info.layer_info.blend_info.blendmode = JXL_BLEND_REPLACE;
+        pframe.frame_info.layer_info.blend_info.source = 1;
+        pframe.frame_info.layer_info.save_as_reference = 1;
+        ppf->frames.emplace_back(std::move(frame.data));
+      }
+    } else {
+      ppf->frames.emplace_back(std::move(frame.data));
+    }
+
+    auto& pframe = ppf->frames.back();
+    pframe.frame_info.layer_info.crop_x0 = x0;
+    pframe.frame_info.layer_info.crop_y0 = y0;
+    pframe.frame_info.layer_info.xsize = xsize;
+    pframe.frame_info.layer_info.ysize = ysize;
+    pframe.frame_info.duration = frame.duration;
+    pframe.frame_info.layer_info.blend_info.blendmode =
+        should_blend ? JXL_BLEND_BLEND : JXL_BLEND_REPLACE;
+    bool is_full_size = x0 == 0 && y0 == 0 && xsize == ppf->info.xsize &&
+                        ysize == ppf->info.ysize;
+    pframe.frame_info.layer_info.have_crop = is_full_size ? 0 : 1;
+    pframe.frame_info.layer_info.blend_info.source = 1;
+    pframe.frame_info.layer_info.blend_info.alpha = 0;
+    pframe.frame_info.layer_info.save_as_reference = use_for_next_frame ? 1 : 0;
+
+    previous_frame_should_be_cleared =
+        has_nontrivial_background && frame.dispose_op == DISPOSE_OP_BACKGROUND;
+  }
+  if (ppf->frames.empty()) return JXL_FAILURE("No frames decoded");
+  ppf->frames.back().frame_info.is_last = true;
+
+  return true;
+#else
+  return false;
+#endif
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/dec/apng.h b/third_party/jpeg-xl/lib/extras/dec/apng.h
new file mode 100644
index 0000000000..d91364b1e6
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/apng.h
@@ -0,0 +1,35 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_DEC_APNG_H_
+#define LIB_EXTRAS_DEC_APNG_H_
+
+// Decodes APNG images in memory.
+
+#include <stdint.h>
+
+#include "lib/extras/dec/color_hints.h"
+#include "lib/extras/packed_image.h"
+#include "lib/jxl/base/data_parallel.h"
+#include "lib/jxl/base/span.h"
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+
+struct SizeConstraints;
+
+namespace extras {
+
+bool CanDecodeAPNG();
+
+// Decodes `bytes` into `ppf`.
+Status DecodeImageAPNG(Span<const uint8_t> bytes, const ColorHints& color_hints,
+                       PackedPixelFile* ppf,
+                       const SizeConstraints* constraints = nullptr);
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_DEC_APNG_H_
diff --git a/third_party/jpeg-xl/lib/extras/dec/color_description.cc b/third_party/jpeg-xl/lib/extras/dec/color_description.cc
new file mode 100644
index 0000000000..54f6aa4206
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/color_description.cc
@@ -0,0 +1,218 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/dec/color_description.h"
+
+#include <errno.h>
+
+#include <cmath>
+
+namespace jxl {
+
+namespace {
+
+template <typename T>
+struct EnumName {
+  const char* name;
+  T value;
+};
+
+const EnumName<JxlColorSpace> kJxlColorSpaceNames[] = {
+    {"RGB", JXL_COLOR_SPACE_RGB},
+    {"Gra", JXL_COLOR_SPACE_GRAY},
+    {"XYB", JXL_COLOR_SPACE_XYB},
+    {"CS?", JXL_COLOR_SPACE_UNKNOWN},
+};
+
+const EnumName<JxlWhitePoint> kJxlWhitePointNames[] = {
+    {"D65", JXL_WHITE_POINT_D65},
+    {"Cst", JXL_WHITE_POINT_CUSTOM},
+    {"EER", JXL_WHITE_POINT_E},
+    {"DCI", JXL_WHITE_POINT_DCI},
+};
+
+const EnumName<JxlPrimaries> kJxlPrimariesNames[] = {
+    {"SRG", JXL_PRIMARIES_SRGB},
+    {"Cst", JXL_PRIMARIES_CUSTOM},
+    {"202", JXL_PRIMARIES_2100},
+    {"DCI", JXL_PRIMARIES_P3},
+};
+
+const EnumName<JxlTransferFunction> kJxlTransferFunctionNames[] = {
+    {"709", JXL_TRANSFER_FUNCTION_709},
+    {"TF?", JXL_TRANSFER_FUNCTION_UNKNOWN},
+    {"Lin", JXL_TRANSFER_FUNCTION_LINEAR},
+    {"SRG", JXL_TRANSFER_FUNCTION_SRGB},
+    {"PeQ", JXL_TRANSFER_FUNCTION_PQ},
+    {"DCI", JXL_TRANSFER_FUNCTION_DCI},
+    {"HLG", JXL_TRANSFER_FUNCTION_HLG},
+    {"", JXL_TRANSFER_FUNCTION_GAMMA},
+};
+
+const EnumName<JxlRenderingIntent> kJxlRenderingIntentNames[] = {
+    {"Per", JXL_RENDERING_INTENT_PERCEPTUAL},
+    {"Rel", JXL_RENDERING_INTENT_RELATIVE},
+    {"Sat", JXL_RENDERING_INTENT_SATURATION},
+    {"Abs", JXL_RENDERING_INTENT_ABSOLUTE},
+};
+
+template <typename T>
+Status ParseEnum(const std::string& token, const EnumName<T>* enum_values,
+                 size_t enum_len, T* value) {
+  for (size_t i = 0; i < enum_len; i++) {
+    if (enum_values[i].name == token) {
+      *value = enum_values[i].value;
+      return true;
+    }
+  }
+  return false;
+}
+#define ARRAY_SIZE(X) (sizeof(X) / sizeof((X)[0]))
+#define PARSE_ENUM(type, token, value) \
+  ParseEnum<type>(token, k##type##Names, ARRAY_SIZE(k##type##Names), value)
+
+class Tokenizer {
+ public:
+  Tokenizer(const std::string* input, char separator)
+      : input_(input), separator_(separator) {}
+
+  Status Next(std::string* next) {
+    const size_t end = input_->find(separator_, start_);
+    if (end == std::string::npos) {
+      *next = input_->substr(start_);  // rest of string
+    } else {
+      *next = input_->substr(start_, end - start_);
+    }
+    if (next->empty()) return JXL_FAILURE("Missing token");
+    start_ = end + 1;
+    return true;
+  }
+
+ private:
+  const std::string* const input_;  // not owned
+  const char separator_;
+  size_t start_ = 0;  // of next token
+};
+
+Status ParseDouble(const std::string& num, double* d) {
+  char* end;
+  errno = 0;
+  *d = strtod(num.c_str(), &end);
+  if (*d == 0.0 && end == num.c_str()) {
+    return JXL_FAILURE("Invalid double: %s", num.c_str());
+  }
+  if (std::isnan(*d)) {
+    return JXL_FAILURE("Invalid double: %s", num.c_str());
+  }
+  if (errno == ERANGE) {
+    return JXL_FAILURE("Double out of range: %s", num.c_str());
+  }
+  return true;
+}
+
+Status ParseDouble(Tokenizer* tokenizer, double* d) {
+  std::string num;
+  JXL_RETURN_IF_ERROR(tokenizer->Next(&num));
+  return ParseDouble(num, d);
+}
+
+Status ParseColorSpace(Tokenizer* tokenizer, JxlColorEncoding* c) {
+  std::string str;
+  JXL_RETURN_IF_ERROR(tokenizer->Next(&str));
+  JxlColorSpace cs;
+  if (PARSE_ENUM(JxlColorSpace, str, &cs)) {
+    c->color_space = cs;
+    return true;
+  }
+
+  return JXL_FAILURE("Unknown ColorSpace %s", str.c_str());
+}
+
+Status ParseWhitePoint(Tokenizer* tokenizer, JxlColorEncoding* c) {
+  if (c->color_space == JXL_COLOR_SPACE_XYB) {
+    // Implicit white point.
+    c->white_point = JXL_WHITE_POINT_D65;
+    return true;
+  }
+
+  std::string str;
+  JXL_RETURN_IF_ERROR(tokenizer->Next(&str));
+  if (PARSE_ENUM(JxlWhitePoint, str, &c->white_point)) return true;
+
+  Tokenizer xy_tokenizer(&str, ';');
+  c->white_point = JXL_WHITE_POINT_CUSTOM;
+  JXL_RETURN_IF_ERROR(ParseDouble(&xy_tokenizer, c->white_point_xy + 0));
+  JXL_RETURN_IF_ERROR(ParseDouble(&xy_tokenizer, c->white_point_xy + 1));
+  return true;
+}
+
+Status ParsePrimaries(Tokenizer* tokenizer, JxlColorEncoding* c) {
+  if (c->color_space == JXL_COLOR_SPACE_GRAY ||
+      c->color_space == JXL_COLOR_SPACE_XYB) {
+    // No primaries case.
+    return true;
+  }
+
+  std::string str;
+  JXL_RETURN_IF_ERROR(tokenizer->Next(&str));
+  if (PARSE_ENUM(JxlPrimaries, str, &c->primaries)) return true;
+
+  Tokenizer xy_tokenizer(&str, ';');
+  JXL_RETURN_IF_ERROR(ParseDouble(&xy_tokenizer, c->primaries_red_xy + 0));
+  JXL_RETURN_IF_ERROR(ParseDouble(&xy_tokenizer, c->primaries_red_xy + 1));
+  JXL_RETURN_IF_ERROR(ParseDouble(&xy_tokenizer, c->primaries_green_xy + 0));
+  JXL_RETURN_IF_ERROR(ParseDouble(&xy_tokenizer, c->primaries_green_xy + 1));
+  JXL_RETURN_IF_ERROR(ParseDouble(&xy_tokenizer, c->primaries_blue_xy + 0));
+  JXL_RETURN_IF_ERROR(ParseDouble(&xy_tokenizer, c->primaries_blue_xy + 1));
+  c->primaries = JXL_PRIMARIES_CUSTOM;
+
+  return JXL_FAILURE("Invalid primaries %s", str.c_str());
+}
+
+Status ParseRenderingIntent(Tokenizer* tokenizer, JxlColorEncoding* c) {
+  std::string str;
+  JXL_RETURN_IF_ERROR(tokenizer->Next(&str));
+  if (PARSE_ENUM(JxlRenderingIntent, str, &c->rendering_intent)) return true;
+
+  return JXL_FAILURE("Invalid RenderingIntent %s\n", str.c_str());
+}
+
+Status ParseTransferFunction(Tokenizer* tokenizer, JxlColorEncoding* c) {
+  if (c->color_space == JXL_COLOR_SPACE_XYB) {
+    // Implicit TF.
+    c->transfer_function = JXL_TRANSFER_FUNCTION_GAMMA;
+    c->gamma = 1 / 3.;
+    return true;
+  }
+
+  std::string str;
+  JXL_RETURN_IF_ERROR(tokenizer->Next(&str));
+  if (PARSE_ENUM(JxlTransferFunction, str, &c->transfer_function)) {
+    return true;
+  }
+
+  if (str[0] == 'g') {
+    JXL_RETURN_IF_ERROR(ParseDouble(str.substr(1), &c->gamma));
+    c->transfer_function = JXL_TRANSFER_FUNCTION_GAMMA;
+    return true;
+  }
+
+  return JXL_FAILURE("Invalid gamma %s", str.c_str());
+}
+
+}  // namespace
+
+Status ParseDescription(const std::string& description, JxlColorEncoding* c) {
+  *c = {};
+  Tokenizer tokenizer(&description, '_');
+  JXL_RETURN_IF_ERROR(ParseColorSpace(&tokenizer, c));
+  JXL_RETURN_IF_ERROR(ParseWhitePoint(&tokenizer, c));
+  JXL_RETURN_IF_ERROR(ParsePrimaries(&tokenizer, c));
+  JXL_RETURN_IF_ERROR(ParseRenderingIntent(&tokenizer, c));
+  JXL_RETURN_IF_ERROR(ParseTransferFunction(&tokenizer, c));
+  return true;
+}
+
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/dec/color_description.h b/third_party/jpeg-xl/lib/extras/dec/color_description.h
new file mode 100644
index 0000000000..23680ff7c6
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/color_description.h
@@ -0,0 +1,23 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_COLOR_DESCRIPTION_H_
+#define LIB_EXTRAS_COLOR_DESCRIPTION_H_
+
+#include <jxl/color_encoding.h>
+
+#include <string>
+
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+
+// Parse the color description into a JxlColorEncoding "RGB_D65_SRG_Rel_Lin".
+Status ParseDescription(const std::string& description,
+                        JxlColorEncoding* JXL_RESTRICT c);
+
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_COLOR_DESCRIPTION_H_
diff --git a/third_party/jpeg-xl/lib/extras/dec/color_description_test.cc b/third_party/jpeg-xl/lib/extras/dec/color_description_test.cc
new file mode 100644
index 0000000000..e6e34f0edf
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/color_description_test.cc
@@ -0,0 +1,37 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/dec/color_description.h"
+
+#include "lib/jxl/color_encoding_internal.h"
+#include "lib/jxl/test_utils.h"
+#include "lib/jxl/testing.h"
+
+namespace jxl {
+
+// Verify ParseDescription(Description) yields the same ColorEncoding
+TEST(ColorDescriptionTest, RoundTripAll) {
+  for (const auto& cdesc : test::AllEncodings()) {
+    const ColorEncoding c_original = test::ColorEncodingFromDescriptor(cdesc);
+    const std::string description = Description(c_original);
+    printf("%s\n", description.c_str());
+
+    JxlColorEncoding c_external = {};
+    EXPECT_TRUE(ParseDescription(description, &c_external));
+    ColorEncoding c_internal;
+    EXPECT_TRUE(c_internal.FromExternal(c_external));
+    EXPECT_TRUE(c_original.SameColorEncoding(c_internal))
+        << "Where c_original=" << c_original
+        << " and c_internal=" << c_internal;
+  }
+}
+
+TEST(ColorDescriptionTest, NanGamma) {
+  const std::string description = "Gra_2_Per_gnan";
+  JxlColorEncoding c;
+  EXPECT_FALSE(ParseDescription(description, &c));
+}
+
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/dec/color_hints.cc b/third_party/jpeg-xl/lib/extras/dec/color_hints.cc
new file mode 100644
index 0000000000..5c6d7b84a0
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/color_hints.cc
@@ -0,0 +1,78 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/dec/color_hints.h"
+
+#include <jxl/encode.h>
+
+#include <vector>
+
+#include "lib/extras/dec/color_description.h"
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+namespace extras {
+
+Status ApplyColorHints(const ColorHints& color_hints,
+                       const bool color_already_set, const bool is_gray,
+                       PackedPixelFile* ppf) {
+  bool got_color_space = color_already_set;
+
+  JXL_RETURN_IF_ERROR(color_hints.Foreach(
+      [color_already_set, is_gray, ppf, &got_color_space](
+          const std::string& key, const std::string& value) -> Status {
+        if (color_already_set && (key == "color_space" || key == "icc")) {
+          JXL_WARNING("Decoder ignoring %s hint", key.c_str());
+          return true;
+        }
+        if (key == "color_space") {
+          JxlColorEncoding c_original_external;
+          if (!ParseDescription(value, &c_original_external)) {
+            return JXL_FAILURE("Failed to apply color_space");
+          }
+          ppf->color_encoding = c_original_external;
+
+          if (is_gray !=
+              (ppf->color_encoding.color_space == JXL_COLOR_SPACE_GRAY)) {
+            return JXL_FAILURE("mismatch between file and color_space hint");
+          }
+
+          got_color_space = true;
+        } else if (key == "icc") {
+          const uint8_t* data = reinterpret_cast<const uint8_t*>(value.data());
+          std::vector<uint8_t> icc(data, data + value.size());
+          ppf->icc.swap(icc);
+          got_color_space = true;
+        } else if (key == "exif") {
+          const uint8_t* data = reinterpret_cast<const uint8_t*>(value.data());
+          std::vector<uint8_t> blob(data, data + value.size());
+          ppf->metadata.exif.swap(blob);
+        } else if (key == "xmp") {
+          const uint8_t* data = reinterpret_cast<const uint8_t*>(value.data());
+          std::vector<uint8_t> blob(data, data + value.size());
+          ppf->metadata.xmp.swap(blob);
+        } else if (key == "jumbf") {
+          const uint8_t* data = reinterpret_cast<const uint8_t*>(value.data());
+          std::vector<uint8_t> blob(data, data + value.size());
+          ppf->metadata.jumbf.swap(blob);
+        } else {
+          JXL_WARNING("Ignoring %s hint", key.c_str());
+        }
+        return true;
+      }));
+
+  if (!got_color_space) {
+    ppf->color_encoding.color_space =
+        is_gray ? JXL_COLOR_SPACE_GRAY : JXL_COLOR_SPACE_RGB;
+    ppf->color_encoding.white_point = JXL_WHITE_POINT_D65;
+    ppf->color_encoding.primaries = JXL_PRIMARIES_SRGB;
+    ppf->color_encoding.transfer_function = JXL_TRANSFER_FUNCTION_SRGB;
+  }
+
+  return true;
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/dec/color_hints.h b/third_party/jpeg-xl/lib/extras/dec/color_hints.h
new file mode 100644
index 0000000000..036f203e26
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/color_hints.h
@@ -0,0 +1,74 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_COLOR_HINTS_H_
+#define LIB_EXTRAS_COLOR_HINTS_H_
+
+// Not all the formats implemented in the extras lib support bundling color
+// information into the file, and those that support it may not have it.
+// To allow attaching color information to those file formats the caller can
+// define these color hints.
+// Besides color space information, 'ColorHints' may also include other
+// additional information such as Exif, XMP and JUMBF metadata.
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <string>
+#include <vector>
+
+#include "lib/extras/packed_image.h"
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+namespace extras {
+
+class ColorHints {
+ public:
+  // key=color_space, value=Description(c/pp): specify the ColorEncoding of
+  //   the pixels for decoding. Otherwise, if the codec did not obtain an ICC
+  //   profile from the image, assume sRGB.
+  //
+  // Strings are taken from the command line, so avoid spaces for convenience.
+  void Add(const std::string& key, const std::string& value) {
+    kv_.emplace_back(key, value);
+  }
+
+  // Calls `func(key, value)` for each key/value in the order they were added,
+  // returning false immediately if `func` returns false.
+  template <class Func>
+  Status Foreach(const Func& func) const {
+    for (const KeyValue& kv : kv_) {
+      Status ok = func(kv.key, kv.value);
+      if (!ok) {
+        return JXL_FAILURE("ColorHints::Foreach returned false");
+      }
+    }
+    return true;
+  }
+
+ private:
+  // Splitting into key/value avoids parsing in each codec.
+  struct KeyValue {
+    KeyValue(std::string key, std::string value)
+        : key(std::move(key)), value(std::move(value)) {}
+
+    std::string key;
+    std::string value;
+  };
+
+  std::vector<KeyValue> kv_;
+};
+
+// Apply the color hints to the decoded image in PackedPixelFile if any.
+// color_already_set tells whether the color encoding was already set, in which
+// case the hints are ignored if any hint is passed.
+Status ApplyColorHints(const ColorHints& color_hints, bool color_already_set,
+                       bool is_gray, PackedPixelFile* ppf);
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_COLOR_HINTS_H_
diff --git a/third_party/jpeg-xl/lib/extras/dec/decode.cc b/third_party/jpeg-xl/lib/extras/dec/decode.cc
new file mode 100644
index 0000000000..b3ca711bb2
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/decode.cc
@@ -0,0 +1,148 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/dec/decode.h"
+
+#include <locale>
+
+#include "lib/extras/dec/apng.h"
+#include "lib/extras/dec/exr.h"
+#include "lib/extras/dec/gif.h"
+#include "lib/extras/dec/jpg.h"
+#include "lib/extras/dec/jxl.h"
+#include "lib/extras/dec/pgx.h"
+#include "lib/extras/dec/pnm.h"
+
+namespace jxl {
+namespace extras {
+namespace {
+
+// Any valid encoding is larger (ensures codecs can read the first few bytes)
+constexpr size_t kMinBytes = 9;
+
+std::string GetExtension(const std::string& path) {
+  // Pattern: "name.png"
+  size_t pos = path.find_last_of('.');
+  if (pos != std::string::npos) {
+    return path.substr(pos);
+  }
+
+  // Extension not found
+  return "";
+}
+
+}  // namespace
+
+Codec CodecFromPath(std::string path, size_t* JXL_RESTRICT bits_per_sample,
+                    std::string* extension) {
+  std::string ext = GetExtension(path);
+  if (extension) {
+    if (extension->empty()) {
+      *extension = ext;
+    } else {
+      ext = *extension;
+    }
+  }
+  std::transform(ext.begin(), ext.end(), ext.begin(), [](char c) {
+    return std::tolower(c, std::locale::classic());
+  });
+  if (ext == ".png") return Codec::kPNG;
+
+  if (ext == ".jpg") return Codec::kJPG;
+  if (ext == ".jpeg") return Codec::kJPG;
+
+  if (ext == ".pgx") return Codec::kPGX;
+
+  if (ext == ".pam") return Codec::kPNM;
+  if (ext == ".pnm") return Codec::kPNM;
+  if (ext == ".pgm") return Codec::kPNM;
+  if (ext == ".ppm") return Codec::kPNM;
+  if (ext == ".pfm") {
+    if (bits_per_sample != nullptr) *bits_per_sample = 32;
+    return Codec::kPNM;
+  }
+
+  if (ext == ".gif") return Codec::kGIF;
+
+  if (ext == ".exr") return Codec::kEXR;
+
+  return Codec::kUnknown;
+}
+
+bool CanDecode(Codec codec) {
+  switch (codec) {
+    case Codec::kEXR:
+      return CanDecodeEXR();
+    case Codec::kGIF:
+      return CanDecodeGIF();
+    case Codec::kJPG:
+      return CanDecodeJPG();
+    case Codec::kPNG:
+      return CanDecodeAPNG();
+    case Codec::kPNM:
+    case Codec::kPGX:
+    case Codec::kJXL:
+      return true;
+    default:
+      return false;
+  }
+}
+
+Status DecodeBytes(const Span<const uint8_t> bytes,
+                   const ColorHints& color_hints, extras::PackedPixelFile* ppf,
+                   const SizeConstraints* constraints, Codec* orig_codec) {
+  if (bytes.size() < kMinBytes) return JXL_FAILURE("Too few bytes");
+
+  *ppf = extras::PackedPixelFile();
+
+  // Default values when not set by decoders.
+  ppf->info.uses_original_profile = true;
+  ppf->info.orientation = JXL_ORIENT_IDENTITY;
+
+  const auto choose_codec = [&]() -> Codec {
+    if (DecodeImageAPNG(bytes, color_hints, ppf, constraints)) {
+      return Codec::kPNG;
+    }
+    if (DecodeImagePGX(bytes, color_hints, ppf, constraints)) {
+      return Codec::kPGX;
+    }
+    if (DecodeImagePNM(bytes, color_hints, ppf, constraints)) {
+      return Codec::kPNM;
+    }
+    JXLDecompressParams dparams = {};
+    for (const uint32_t num_channels : {1, 2, 3, 4}) {
+      dparams.accepted_formats.push_back(
+          {num_channels, JXL_TYPE_FLOAT, JXL_LITTLE_ENDIAN, /*align=*/0});
+    }
+    size_t decoded_bytes;
+    if (DecodeImageJXL(bytes.data(), bytes.size(), dparams, &decoded_bytes,
+                       ppf) &&
+        ApplyColorHints(color_hints, true, ppf->info.num_color_channels == 1,
+                        ppf)) {
+      return Codec::kJXL;
+    }
+    if (DecodeImageGIF(bytes, color_hints, ppf, constraints)) {
+      return Codec::kGIF;
+    }
+    if (DecodeImageJPG(bytes, color_hints, ppf, constraints)) {
+      return Codec::kJPG;
+    }
+    if (DecodeImageEXR(bytes, color_hints, ppf, constraints)) {
+      return Codec::kEXR;
+    }
+    return Codec::kUnknown;
+  };
+
+  Codec codec = choose_codec();
+  if (codec == Codec::kUnknown) {
+    return JXL_FAILURE("Codecs failed to decode");
+  }
+  if (orig_codec) *orig_codec = codec;
+
+  return true;
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/dec/decode.h b/third_party/jpeg-xl/lib/extras/dec/decode.h
new file mode 100644
index 0000000000..0d7dfcbef2
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/decode.h
@@ -0,0 +1,57 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_DEC_DECODE_H_
+#define LIB_EXTRAS_DEC_DECODE_H_
+
+// Facade for image decoders (PNG, PNM, ...).
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <string>
+#include <vector>
+
+#include "lib/extras/dec/color_hints.h"
+#include "lib/jxl/base/span.h"
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+
+struct SizeConstraints;
+
+namespace extras {
+
+// Codecs supported by DecodeBytes.
+enum class Codec : uint32_t {
+  kUnknown,  // for CodecFromPath
+  kPNG,
+  kPNM,
+  kPGX,
+  kJPG,
+  kGIF,
+  kEXR,
+  kJXL
+};
+
+bool CanDecode(Codec codec);
+
+// If and only if extension is ".pfm", *bits_per_sample is updated to 32 so
+// that Encode() would encode to PFM instead of PPM.
+Codec CodecFromPath(std::string path,
+                    size_t* JXL_RESTRICT bits_per_sample = nullptr,
+                    std::string* extension = nullptr);
+
+// Decodes "bytes" info *ppf.
+// color_space_hint may specify the color space, otherwise, defaults to sRGB.
+Status DecodeBytes(Span<const uint8_t> bytes, const ColorHints& color_hints,
+                   extras::PackedPixelFile* ppf,
+                   const SizeConstraints* constraints = nullptr,
+                   Codec* orig_codec = nullptr);
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_DEC_DECODE_H_
diff --git a/third_party/jpeg-xl/lib/extras/dec/exr.cc b/third_party/jpeg-xl/lib/extras/dec/exr.cc
new file mode 100644
index 0000000000..821e0f4b21
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/exr.cc
@@ -0,0 +1,201 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/dec/exr.h"
+
+#if JPEGXL_ENABLE_EXR
+#include <ImfChromaticitiesAttribute.h>
+#include <ImfIO.h>
+#include <ImfRgbaFile.h>
+#include <ImfStandardAttributes.h>
+#endif
+
+#include <vector>
+
+namespace jxl {
+namespace extras {
+
+#if JPEGXL_ENABLE_EXR
+namespace {
+
+namespace OpenEXR = OPENEXR_IMF_NAMESPACE;
+
+// OpenEXR::Int64 is deprecated in favor of using uint64_t directly, but using
+// uint64_t as recommended causes build failures with previous OpenEXR versions
+// on macOS, where the definition for OpenEXR::Int64 was actually not equivalent
+// to uint64_t. This alternative should work in all cases.
+using ExrInt64 = decltype(std::declval<OpenEXR::IStream>().tellg());
+
+constexpr int kExrBitsPerSample = 16;
+constexpr int kExrAlphaBits = 16;
+
+class InMemoryIStream : public OpenEXR::IStream {
+ public:
+  // The data pointed to by `bytes` must outlive the InMemoryIStream.
+  explicit InMemoryIStream(const Span<const uint8_t> bytes)
+      : IStream(/*fileName=*/""), bytes_(bytes) {}
+
+  bool isMemoryMapped() const override { return true; }
+  char* readMemoryMapped(const int n) override {
+    JXL_ASSERT(pos_ + n <= bytes_.size());
+    char* const result =
+        const_cast<char*>(reinterpret_cast<const char*>(bytes_.data() + pos_));
+    pos_ += n;
+    return result;
+  }
+  bool read(char c[], const int n) override {
+    std::copy_n(readMemoryMapped(n), n, c);
+    return pos_ < bytes_.size();
+  }
+
+  ExrInt64 tellg() override { return pos_; }
+  void seekg(const ExrInt64 pos) override {
+    JXL_ASSERT(pos + 1 <= bytes_.size());
+    pos_ = pos;
+  }
+
+ private:
+  const Span<const uint8_t> bytes_;
+  size_t pos_ = 0;
+};
+
+}  // namespace
+#endif
+
+bool CanDecodeEXR() {
+#if JPEGXL_ENABLE_EXR
+  return true;
+#else
+  return false;
+#endif
+}
+
+Status DecodeImageEXR(Span<const uint8_t> bytes, const ColorHints& color_hints,
+                      PackedPixelFile* ppf,
+                      const SizeConstraints* constraints) {
+#if JPEGXL_ENABLE_EXR
+  InMemoryIStream is(bytes);
+
+#ifdef __EXCEPTIONS
+  std::unique_ptr<OpenEXR::RgbaInputFile> input_ptr;
+  try {
+    input_ptr.reset(new OpenEXR::RgbaInputFile(is));
+  } catch (...) {
+    // silently return false if it is not an EXR file
+    return false;
+  }
+  OpenEXR::RgbaInputFile& input = *input_ptr;
+#else
+  OpenEXR::RgbaInputFile input(is);
+#endif
+
+  if ((input.channels() & OpenEXR::RgbaChannels::WRITE_RGB) !=
+      OpenEXR::RgbaChannels::WRITE_RGB) {
+    return JXL_FAILURE("only RGB OpenEXR files are supported");
+  }
+  const bool has_alpha = (input.channels() & OpenEXR::RgbaChannels::WRITE_A) ==
+                         OpenEXR::RgbaChannels::WRITE_A;
+
+  const float intensity_target = OpenEXR::hasWhiteLuminance(input.header())
+                                     ? OpenEXR::whiteLuminance(input.header())
+                                     : 0;
+
+  auto image_size = input.displayWindow().size();
+  // Size is computed as max - min, but both bounds are inclusive.
+  ++image_size.x;
+  ++image_size.y;
+
+  ppf->info.xsize = image_size.x;
+  ppf->info.ysize = image_size.y;
+  ppf->info.num_color_channels = 3;
+
+  const JxlDataType data_type =
+      kExrBitsPerSample == 16 ? JXL_TYPE_FLOAT16 : JXL_TYPE_FLOAT;
+  const JxlPixelFormat format{
+      /*num_channels=*/3u + (has_alpha ? 1u : 0u),
+      /*data_type=*/data_type,
+      /*endianness=*/JXL_NATIVE_ENDIAN,
+      /*align=*/0,
+  };
+  ppf->frames.clear();
+  // Allocates the frame buffer.
+  ppf->frames.emplace_back(image_size.x, image_size.y, format);
+  const auto& frame = ppf->frames.back();
+
+  const int row_size = input.dataWindow().size().x + 1;
+  // Number of rows to read at a time.
+  // https://www.openexr.com/documentation/ReadingAndWritingImageFiles.pdf
+  // recommends reading the whole file at once.
+  const int y_chunk_size = input.displayWindow().size().y + 1;
+  std::vector<OpenEXR::Rgba> input_rows(row_size * y_chunk_size);
+  for (int start_y =
+           std::max(input.dataWindow().min.y, input.displayWindow().min.y);
+       start_y <=
+       std::min(input.dataWindow().max.y, input.displayWindow().max.y);
+       start_y += y_chunk_size) {
+    // Inclusive.
+    const int end_y = std::min(
+        start_y + y_chunk_size - 1,
+        std::min(input.dataWindow().max.y, input.displayWindow().max.y));
+    input.setFrameBuffer(
+        input_rows.data() - input.dataWindow().min.x - start_y * row_size,
+        /*xStride=*/1, /*yStride=*/row_size);
+    input.readPixels(start_y, end_y);
+    for (int exr_y = start_y; exr_y <= end_y; ++exr_y) {
+      const int image_y = exr_y - input.displayWindow().min.y;
+      const OpenEXR::Rgba* const JXL_RESTRICT input_row =
+          &input_rows[(exr_y - start_y) * row_size];
+      uint8_t* row = static_cast<uint8_t*>(frame.color.pixels()) +
+                     frame.color.stride * image_y;
+      const uint32_t pixel_size =
+          (3 + (has_alpha ? 1 : 0)) * kExrBitsPerSample / 8;
+      for (int exr_x =
+               std::max(input.dataWindow().min.x, input.displayWindow().min.x);
+           exr_x <=
+           std::min(input.dataWindow().max.x, input.displayWindow().max.x);
+           ++exr_x) {
+        const int image_x = exr_x - input.displayWindow().min.x;
+        // TODO(eustas): UB: OpenEXR::Rgba is not TriviallyCopyable
+        memcpy(row + image_x * pixel_size,
+               input_row + (exr_x - input.dataWindow().min.x), pixel_size);
+      }
+    }
+  }
+
+  ppf->color_encoding.transfer_function = JXL_TRANSFER_FUNCTION_LINEAR;
+  ppf->color_encoding.color_space = JXL_COLOR_SPACE_RGB;
+  ppf->color_encoding.primaries = JXL_PRIMARIES_SRGB;
+  ppf->color_encoding.white_point = JXL_WHITE_POINT_D65;
+  if (OpenEXR::hasChromaticities(input.header())) {
+    ppf->color_encoding.primaries = JXL_PRIMARIES_CUSTOM;
+    ppf->color_encoding.white_point = JXL_WHITE_POINT_CUSTOM;
+    const auto& chromaticities = OpenEXR::chromaticities(input.header());
+    ppf->color_encoding.primaries_red_xy[0] = chromaticities.red.x;
+    ppf->color_encoding.primaries_red_xy[1] = chromaticities.red.y;
+    ppf->color_encoding.primaries_green_xy[0] = chromaticities.green.x;
+    ppf->color_encoding.primaries_green_xy[1] = chromaticities.green.y;
+    ppf->color_encoding.primaries_blue_xy[0] = chromaticities.blue.x;
+    ppf->color_encoding.primaries_blue_xy[1] = chromaticities.blue.y;
+    ppf->color_encoding.white_point_xy[0] = chromaticities.white.x;
+    ppf->color_encoding.white_point_xy[1] = chromaticities.white.y;
+  }
+
+  // EXR uses binary16 or binary32 floating point format.
+  ppf->info.bits_per_sample = kExrBitsPerSample;
+  ppf->info.exponent_bits_per_sample = kExrBitsPerSample == 16 ? 5 : 8;
+  if (has_alpha) {
+    ppf->info.alpha_bits = kExrAlphaBits;
+    ppf->info.alpha_exponent_bits = ppf->info.exponent_bits_per_sample;
+    ppf->info.alpha_premultiplied = true;
+  }
+  ppf->info.intensity_target = intensity_target;
+  return true;
+#else
+  return false;
+#endif
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/dec/exr.h b/third_party/jpeg-xl/lib/extras/dec/exr.h
new file mode 100644
index 0000000000..0605cbba06
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/exr.h
@@ -0,0 +1,33 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_DEC_EXR_H_
+#define LIB_EXTRAS_DEC_EXR_H_
+
+// Decodes OpenEXR images in memory.
+
+#include "lib/extras/dec/color_hints.h"
+#include "lib/extras/packed_image.h"
+#include "lib/jxl/base/data_parallel.h"
+#include "lib/jxl/base/span.h"
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+
+struct SizeConstraints;
+
+namespace extras {
+
+bool CanDecodeEXR();
+
+// Decodes `bytes` into `ppf`. color_hints are ignored.
+Status DecodeImageEXR(Span<const uint8_t> bytes, const ColorHints& color_hints,
+                      PackedPixelFile* ppf,
+                      const SizeConstraints* constraints = nullptr);
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_DEC_EXR_H_
diff --git a/third_party/jpeg-xl/lib/extras/dec/gif.cc b/third_party/jpeg-xl/lib/extras/dec/gif.cc
new file mode 100644
index 0000000000..3d963941c0
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/gif.cc
@@ -0,0 +1,415 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/dec/gif.h"
+
+#if JPEGXL_ENABLE_GIF
+#include <gif_lib.h>
+#endif
+#include <jxl/codestream_header.h>
+#include <string.h>
+
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "lib/extras/size_constraints.h"
+#include "lib/jxl/base/compiler_specific.h"
+#include "lib/jxl/sanitizers.h"
+
+namespace jxl {
+namespace extras {
+
+#if JPEGXL_ENABLE_GIF
+namespace {
+
+struct ReadState {
+  Span<const uint8_t> bytes;
+};
+
+struct DGifCloser {
+  void operator()(GifFileType* const ptr) const { DGifCloseFile(ptr, nullptr); }
+};
+using GifUniquePtr = std::unique_ptr<GifFileType, DGifCloser>;
+
+struct PackedRgba {
+  uint8_t r, g, b, a;
+};
+
+struct PackedRgb {
+  uint8_t r, g, b;
+};
+
+void ensure_have_alpha(PackedFrame* frame) {
+  if (!frame->extra_channels.empty()) return;
+  const JxlPixelFormat alpha_format{
+      /*num_channels=*/1u,
+      /*data_type=*/JXL_TYPE_UINT8,
+      /*endianness=*/JXL_NATIVE_ENDIAN,
+      /*align=*/0,
+  };
+  frame->extra_channels.emplace_back(frame->color.xsize, frame->color.ysize,
+                                     alpha_format);
+  // We need to set opaque-by-default.
+  std::fill_n(static_cast<uint8_t*>(frame->extra_channels[0].pixels()),
+              frame->color.xsize * frame->color.ysize, 255u);
+}
+}  // namespace
+#endif
+
+bool CanDecodeGIF() {
+#if JPEGXL_ENABLE_GIF
+  return true;
+#else
+  return false;
+#endif
+}
+
+Status DecodeImageGIF(Span<const uint8_t> bytes, const ColorHints& color_hints,
+                      PackedPixelFile* ppf,
+                      const SizeConstraints* constraints) {
+#if JPEGXL_ENABLE_GIF
+  int error = GIF_OK;
+  ReadState state = {bytes};
+  const auto ReadFromSpan = [](GifFileType* const gif, GifByteType* const bytes,
+                               int n) {
+    ReadState* const state = reinterpret_cast<ReadState*>(gif->UserData);
+    // giflib API requires the input size `n` to be signed int.
+    if (static_cast<size_t>(n) > state->bytes.size()) {
+      n = state->bytes.size();
+    }
+    memcpy(bytes, state->bytes.data(), n);
+    state->bytes.remove_prefix(n);
+    return n;
+  };
+  GifUniquePtr gif(DGifOpen(&state, ReadFromSpan, &error));
+  if (gif == nullptr) {
+    if (error == D_GIF_ERR_NOT_GIF_FILE) {
+      // Not an error.
+      return false;
+    } else {
+      return JXL_FAILURE("Failed to read GIF: %s", GifErrorString(error));
+    }
+  }
+  error = DGifSlurp(gif.get());
+  if (error != GIF_OK) {
+    return JXL_FAILURE("Failed to read GIF: %s", GifErrorString(gif->Error));
+  }
+
+  msan::UnpoisonMemory(gif.get(), sizeof(*gif));
+  if (gif->SColorMap) {
+    msan::UnpoisonMemory(gif->SColorMap, sizeof(*gif->SColorMap));
+    msan::UnpoisonMemory(
+        gif->SColorMap->Colors,
+        sizeof(*gif->SColorMap->Colors) * gif->SColorMap->ColorCount);
+  }
+  msan::UnpoisonMemory(gif->SavedImages,
+                       sizeof(*gif->SavedImages) * gif->ImageCount);
+
+  JXL_RETURN_IF_ERROR(
+      VerifyDimensions<uint32_t>(constraints, gif->SWidth, gif->SHeight));
+  uint64_t total_pixel_count =
+      static_cast<uint64_t>(gif->SWidth) * gif->SHeight;
+  for (int i = 0; i < gif->ImageCount; ++i) {
+    const SavedImage& image = gif->SavedImages[i];
+    uint32_t w = image.ImageDesc.Width;
+    uint32_t h = image.ImageDesc.Height;
+    JXL_RETURN_IF_ERROR(VerifyDimensions<uint32_t>(constraints, w, h));
+    uint64_t pixel_count = static_cast<uint64_t>(w) * h;
+    if (total_pixel_count + pixel_count < total_pixel_count) {
+      return JXL_FAILURE("Image too big");
+    }
+    total_pixel_count += pixel_count;
+    if (constraints && (total_pixel_count > constraints->dec_max_pixels)) {
+      return JXL_FAILURE("Image too big");
+    }
+  }
+
+  if (!gif->SColorMap) {
+    for (int i = 0; i < gif->ImageCount; ++i) {
+      if (!gif->SavedImages[i].ImageDesc.ColorMap) {
+        return JXL_FAILURE("Missing GIF color map");
+      }
+    }
+  }
+
+  if (gif->ImageCount > 1) {
+    ppf->info.have_animation = true;
+    // Delays in GIF are specified in 100ths of a second.
+    ppf->info.animation.tps_numerator = 100;
+    ppf->info.animation.tps_denominator = 1;
+  }
+
+  ppf->frames.clear();
+  ppf->frames.reserve(gif->ImageCount);
+
+  ppf->info.xsize = gif->SWidth;
+  ppf->info.ysize = gif->SHeight;
+  ppf->info.bits_per_sample = 8;
+  ppf->info.exponent_bits_per_sample = 0;
+  // alpha_bits is later set to 8 if we find a frame with transparent pixels.
+  ppf->info.alpha_bits = 0;
+  ppf->info.alpha_exponent_bits = 0;
+  JXL_RETURN_IF_ERROR(ApplyColorHints(color_hints, /*color_already_set=*/false,
+                                      /*is_gray=*/false, ppf));
+
+  ppf->info.num_color_channels = 3;
+
+  // Pixel format for the 'canvas' onto which we paint
+  // the (potentially individually cropped) GIF frames
+  // of an animation.
+  const JxlPixelFormat canvas_format{
+      /*num_channels=*/4u,
+      /*data_type=*/JXL_TYPE_UINT8,
+      /*endianness=*/JXL_NATIVE_ENDIAN,
+      /*align=*/0,
+  };
+
+  // Pixel format for the JXL PackedFrame that goes into the
+  // PackedPixelFile. Here, we use 3 color channels, and provide
+  // the alpha channel as an extra_channel wherever it is used.
+  const JxlPixelFormat packed_frame_format{
+      /*num_channels=*/3u,
+      /*data_type=*/JXL_TYPE_UINT8,
+      /*endianness=*/JXL_NATIVE_ENDIAN,
+      /*align=*/0,
+  };
+
+  GifColorType background_color;
+  if (gif->SColorMap == nullptr ||
+      gif->SBackGroundColor >= gif->SColorMap->ColorCount) {
+    background_color = {0, 0, 0};
+  } else {
+    background_color = gif->SColorMap->Colors[gif->SBackGroundColor];
+  }
+  const PackedRgba background_rgba{background_color.Red, background_color.Green,
+                                   background_color.Blue, 0};
+  PackedFrame canvas(gif->SWidth, gif->SHeight, canvas_format);
+  std::fill_n(static_cast<PackedRgba*>(canvas.color.pixels()),
+              canvas.color.xsize * canvas.color.ysize, background_rgba);
+  Rect canvas_rect{0, 0, canvas.color.xsize, canvas.color.ysize};
+
+  Rect previous_rect_if_restore_to_background;
+
+  bool replace = true;
+  bool last_base_was_none = true;
+  for (int i = 0; i < gif->ImageCount; ++i) {
+    const SavedImage& image = gif->SavedImages[i];
+    msan::UnpoisonMemory(image.RasterBits, sizeof(*image.RasterBits) *
+                                               image.ImageDesc.Width *
+                                               image.ImageDesc.Height);
+    const Rect image_rect(image.ImageDesc.Left, image.ImageDesc.Top,
+                          image.ImageDesc.Width, image.ImageDesc.Height);
+
+    Rect total_rect;
+    if (previous_rect_if_restore_to_background.xsize() != 0 ||
+        previous_rect_if_restore_to_background.ysize() != 0) {
+      const size_t xbegin = std::min(
+          image_rect.x0(), previous_rect_if_restore_to_background.x0());
+      const size_t ybegin = std::min(
+          image_rect.y0(), previous_rect_if_restore_to_background.y0());
+      const size_t xend =
+          std::max(image_rect.x0() + image_rect.xsize(),
+                   previous_rect_if_restore_to_background.x0() +
+                       previous_rect_if_restore_to_background.xsize());
+      const size_t yend =
+          std::max(image_rect.y0() + image_rect.ysize(),
+                   previous_rect_if_restore_to_background.y0() +
+                       previous_rect_if_restore_to_background.ysize());
+      total_rect = Rect(xbegin, ybegin, xend - xbegin, yend - ybegin);
+      previous_rect_if_restore_to_background = Rect();
+      replace = true;
+    } else {
+      total_rect = image_rect;
+      replace = false;
+    }
+    if (!image_rect.IsInside(canvas_rect)) {
+      return JXL_FAILURE("GIF frame extends outside of the canvas");
+    }
+
+    // Allocates the frame buffer.
+    ppf->frames.emplace_back(total_rect.xsize(), total_rect.ysize(),
+                             packed_frame_format);
+    PackedFrame* frame = &ppf->frames.back();
+
+    // We cannot tell right from the start whether there will be a
+    // need for an alpha channel. This is discovered only as soon as
+    // we see a transparent pixel. We hence initialize alpha lazily.
+    auto set_pixel_alpha = [&frame](size_t x, size_t y, uint8_t a) {
+      // If we do not have an alpha-channel and a==255 (fully opaque),
+      // we can skip setting this pixel-value and rely on
+      // "no alpha channel = no transparency".
+      if (a == 255 && !frame->extra_channels.empty()) return;
+      ensure_have_alpha(frame);
+      static_cast<uint8_t*>(
+          frame->extra_channels[0].pixels())[y * frame->color.xsize + x] = a;
+    };
+
+    const ColorMapObject* const color_map =
+        image.ImageDesc.ColorMap ? image.ImageDesc.ColorMap : gif->SColorMap;
+    JXL_CHECK(color_map);
+    msan::UnpoisonMemory(color_map, sizeof(*color_map));
+    msan::UnpoisonMemory(color_map->Colors,
+                         sizeof(*color_map->Colors) * color_map->ColorCount);
+    GraphicsControlBlock gcb;
+    DGifSavedExtensionToGCB(gif.get(), i, &gcb);
+    msan::UnpoisonMemory(&gcb, sizeof(gcb));
+    bool is_full_size = total_rect.x0() == 0 && total_rect.y0() == 0 &&
+                        total_rect.xsize() == canvas.color.xsize &&
+                        total_rect.ysize() == canvas.color.ysize;
+    if (ppf->info.have_animation) {
+      frame->frame_info.duration = gcb.DelayTime;
+      frame->frame_info.layer_info.have_crop = static_cast<int>(!is_full_size);
+      frame->frame_info.layer_info.crop_x0 = total_rect.x0();
+      frame->frame_info.layer_info.crop_y0 = total_rect.y0();
+      frame->frame_info.layer_info.xsize = frame->color.xsize;
+      frame->frame_info.layer_info.ysize = frame->color.ysize;
+      if (last_base_was_none) {
+        replace = true;
+      }
+      frame->frame_info.layer_info.blend_info.blendmode =
+          replace ? JXL_BLEND_REPLACE : JXL_BLEND_BLEND;
+      // We always only reference at most the last frame
+      frame->frame_info.layer_info.blend_info.source =
+          last_base_was_none ? 0u : 1u;
+      frame->frame_info.layer_info.blend_info.clamp = 1;
+      frame->frame_info.layer_info.blend_info.alpha = 0;
+      // TODO(veluca): this could in principle be implemented.
+      if (last_base_was_none &&
+          (total_rect.x0() != 0 || total_rect.y0() != 0 ||
+           total_rect.xsize() != canvas.color.xsize ||
+           total_rect.ysize() != canvas.color.ysize || !replace)) {
+        return JXL_FAILURE(
+            "GIF with dispose-to-0 is not supported for non-full or "
+            "blended frames");
+      }
+      switch (gcb.DisposalMode) {
+        case DISPOSE_DO_NOT:
+        case DISPOSE_BACKGROUND:
+          frame->frame_info.layer_info.save_as_reference = 1u;
+          last_base_was_none = false;
+          break;
+        case DISPOSE_PREVIOUS:
+          frame->frame_info.layer_info.save_as_reference = 0u;
+          break;
+        default:
+          frame->frame_info.layer_info.save_as_reference = 0u;
+          last_base_was_none = true;
+      }
+    }
+
+    // Update the canvas by creating a copy first.
+    PackedImage new_canvas_image(canvas.color.xsize, canvas.color.ysize,
+                                 canvas.color.format);
+    memcpy(new_canvas_image.pixels(), canvas.color.pixels(),
+           new_canvas_image.pixels_size);
+    for (size_t y = 0, byte_index = 0; y < image_rect.ysize(); ++y) {
+      // Assumes format.align == 0. row points to the beginning of the y row in
+      // the image_rect.
+      PackedRgba* row = static_cast<PackedRgba*>(new_canvas_image.pixels()) +
+                        (y + image_rect.y0()) * new_canvas_image.xsize +
+                        image_rect.x0();
+      for (size_t x = 0; x < image_rect.xsize(); ++x, ++byte_index) {
+        const GifByteType byte = image.RasterBits[byte_index];
+        if (byte >= color_map->ColorCount) {
+          return JXL_FAILURE("GIF color is out of bounds");
+        }
+
+        if (byte == gcb.TransparentColor) continue;
+        GifColorType color = color_map->Colors[byte];
+        row[x].r = color.Red;
+        row[x].g = color.Green;
+        row[x].b = color.Blue;
+        row[x].a = 255;
+      }
+    }
+    const PackedImage& sub_frame_image = frame->color;
+    if (replace) {
+      // Copy from the new canvas image to the subframe
+      for (size_t y = 0; y < total_rect.ysize(); ++y) {
+        const PackedRgba* row_in =
+            static_cast<const PackedRgba*>(new_canvas_image.pixels()) +
+            (y + total_rect.y0()) * new_canvas_image.xsize + total_rect.x0();
+        PackedRgb* row_out = static_cast<PackedRgb*>(sub_frame_image.pixels()) +
+                             y * sub_frame_image.xsize;
+        for (size_t x = 0; x < sub_frame_image.xsize; ++x) {
+          row_out[x].r = row_in[x].r;
+          row_out[x].g = row_in[x].g;
+          row_out[x].b = row_in[x].b;
+          set_pixel_alpha(x, y, row_in[x].a);
+        }
+      }
+    } else {
+      for (size_t y = 0, byte_index = 0; y < image_rect.ysize(); ++y) {
+        // Assumes format.align == 0
+        PackedRgb* row = static_cast<PackedRgb*>(sub_frame_image.pixels()) +
+                         y * sub_frame_image.xsize;
+        for (size_t x = 0; x < image_rect.xsize(); ++x, ++byte_index) {
+          const GifByteType byte = image.RasterBits[byte_index];
+          if (byte > color_map->ColorCount) {
+            return JXL_FAILURE("GIF color is out of bounds");
+          }
+          if (byte == gcb.TransparentColor) {
+            row[x].r = 0;
+            row[x].g = 0;
+            row[x].b = 0;
+            set_pixel_alpha(x, y, 0);
+            continue;
+          }
+          GifColorType color = color_map->Colors[byte];
+          row[x].r = color.Red;
+          row[x].g = color.Green;
+          row[x].b = color.Blue;
+          set_pixel_alpha(x, y, 255);
+        }
+      }
+    }
+
+    if (!frame->extra_channels.empty()) {
+      ppf->info.alpha_bits = 8;
+    }
+
+    switch (gcb.DisposalMode) {
+      case DISPOSE_DO_NOT:
+        canvas.color = std::move(new_canvas_image);
+        break;
+
+      case DISPOSE_BACKGROUND:
+        std::fill_n(static_cast<PackedRgba*>(canvas.color.pixels()),
+                    canvas.color.xsize * canvas.color.ysize, background_rgba);
+        previous_rect_if_restore_to_background = image_rect;
+        break;
+
+      case DISPOSE_PREVIOUS:
+        break;
+
+      case DISPOSAL_UNSPECIFIED:
+      default:
+        std::fill_n(static_cast<PackedRgba*>(canvas.color.pixels()),
+                    canvas.color.xsize * canvas.color.ysize, background_rgba);
+    }
+  }
+  // Finally, if any frame has an alpha-channel, every frame will need
+  // to have an alpha-channel.
+  bool seen_alpha = false;
+  for (const PackedFrame& frame : ppf->frames) {
+    if (!frame.extra_channels.empty()) {
+      seen_alpha = true;
+      break;
+    }
+  }
+  if (seen_alpha) {
+    for (PackedFrame& frame : ppf->frames) {
+      ensure_have_alpha(&frame);
+    }
+  }
+  return true;
+#else
+  return false;
+#endif
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/dec/gif.h b/third_party/jpeg-xl/lib/extras/dec/gif.h
new file mode 100644
index 0000000000..4d5be8664e
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/gif.h
@@ -0,0 +1,35 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_DEC_GIF_H_
+#define LIB_EXTRAS_DEC_GIF_H_
+
+// Decodes GIF images in memory.
+
+#include <stdint.h>
+
+#include "lib/extras/dec/color_hints.h"
+#include "lib/extras/packed_image.h"
+#include "lib/jxl/base/data_parallel.h"
+#include "lib/jxl/base/span.h"
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+
+struct SizeConstraints;
+
+namespace extras {
+
+bool CanDecodeGIF();
+
+// Decodes `bytes` into `ppf`. color_hints are ignored.
+Status DecodeImageGIF(Span<const uint8_t> bytes, const ColorHints& color_hints,
+                      PackedPixelFile* ppf,
+                      const SizeConstraints* constraints = nullptr);
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_DEC_GIF_H_
diff --git a/third_party/jpeg-xl/lib/extras/dec/jpegli.cc b/third_party/jpeg-xl/lib/extras/dec/jpegli.cc
new file mode 100644
index 0000000000..ffa1b79c25
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/jpegli.cc
@@ -0,0 +1,271 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/dec/jpegli.h"
+
+#include <setjmp.h>
+#include <stdint.h>
+
+#include <algorithm>
+#include <numeric>
+#include <utility>
+#include <vector>
+
+#include "lib/jpegli/decode.h"
+#include "lib/jxl/base/status.h"
+#include "lib/jxl/sanitizers.h"
+
+namespace jxl {
+namespace extras {
+
+namespace {
+
+constexpr unsigned char kExifSignature[6] = {0x45, 0x78, 0x69,
+                                             0x66, 0x00, 0x00};
+constexpr int kExifMarker = JPEG_APP0 + 1;
+constexpr int kICCMarker = JPEG_APP0 + 2;
+
+static inline bool IsJPG(const std::vector<uint8_t>& bytes) {
+  if (bytes.size() < 2) return false;
+  if (bytes[0] != 0xFF || bytes[1] != 0xD8) return false;
+  return true;
+}
+
+bool MarkerIsExif(const jpeg_saved_marker_ptr marker) {
+  return marker->marker == kExifMarker &&
+         marker->data_length >= sizeof kExifSignature + 2 &&
+         std::equal(std::begin(kExifSignature), std::end(kExifSignature),
+                    marker->data);
+}
+
+Status ReadICCProfile(jpeg_decompress_struct* const cinfo,
+                      std::vector<uint8_t>* const icc) {
+  uint8_t* icc_data_ptr;
+  unsigned int icc_data_len;
+  if (jpegli_read_icc_profile(cinfo, &icc_data_ptr, &icc_data_len)) {
+    icc->assign(icc_data_ptr, icc_data_ptr + icc_data_len);
+    free(icc_data_ptr);
+    return true;
+  }
+  return false;
+}
+
+void ReadExif(jpeg_decompress_struct* const cinfo,
+              std::vector<uint8_t>* const exif) {
+  constexpr size_t kExifSignatureSize = sizeof kExifSignature;
+  for (jpeg_saved_marker_ptr marker = cinfo->marker_list; marker != nullptr;
+       marker = marker->next) {
+    // marker is initialized by libjpeg, which we are not instrumenting with
+    // msan.
+    msan::UnpoisonMemory(marker, sizeof(*marker));
+    msan::UnpoisonMemory(marker->data, marker->data_length);
+    if (!MarkerIsExif(marker)) continue;
+    size_t marker_length = marker->data_length - kExifSignatureSize;
+    exif->resize(marker_length);
+    std::copy_n(marker->data + kExifSignatureSize, marker_length, exif->data());
+    return;
+  }
+}
+
+JpegliDataType ConvertDataType(JxlDataType type) {
+  switch (type) {
+    case JXL_TYPE_UINT8:
+      return JPEGLI_TYPE_UINT8;
+    case JXL_TYPE_UINT16:
+      return JPEGLI_TYPE_UINT16;
+    case JXL_TYPE_FLOAT:
+      return JPEGLI_TYPE_FLOAT;
+    default:
+      return JPEGLI_TYPE_UINT8;
+  }
+}
+
+JpegliEndianness ConvertEndianness(JxlEndianness type) {
+  switch (type) {
+    case JXL_NATIVE_ENDIAN:
+      return JPEGLI_NATIVE_ENDIAN;
+    case JXL_BIG_ENDIAN:
+      return JPEGLI_BIG_ENDIAN;
+    case JXL_LITTLE_ENDIAN:
+      return JPEGLI_LITTLE_ENDIAN;
+    default:
+      return JPEGLI_NATIVE_ENDIAN;
+  }
+}
+
+JxlColorSpace ConvertColorSpace(J_COLOR_SPACE colorspace) {
+  switch (colorspace) {
+    case JCS_GRAYSCALE:
+      return JXL_COLOR_SPACE_GRAY;
+    case JCS_RGB:
+      return JXL_COLOR_SPACE_RGB;
+    default:
+      return JXL_COLOR_SPACE_UNKNOWN;
+  }
+}
+
+void MyErrorExit(j_common_ptr cinfo) {
+  jmp_buf* env = static_cast<jmp_buf*>(cinfo->client_data);
+  (*cinfo->err->output_message)(cinfo);
+  jpegli_destroy_decompress(reinterpret_cast<j_decompress_ptr>(cinfo));
+  longjmp(*env, 1);
+}
+
+void MyOutputMessage(j_common_ptr cinfo) {
+#if JXL_DEBUG_WARNING == 1
+  char buf[JMSG_LENGTH_MAX + 1];
+  (*cinfo->err->format_message)(cinfo, buf);
+  buf[JMSG_LENGTH_MAX] = 0;
+  JXL_WARNING("%s", buf);
+#endif
+}
+
+void UnmapColors(uint8_t* row, size_t xsize, int components,
+                 JSAMPARRAY colormap, size_t num_colors) {
+  JXL_CHECK(colormap != nullptr);
+  std::vector<uint8_t> tmp(xsize * components);
+  for (size_t x = 0; x < xsize; ++x) {
+    JXL_CHECK(row[x] < num_colors);
+    for (int c = 0; c < components; ++c) {
+      tmp[x * components + c] = colormap[c][row[x]];
+    }
+  }
+  memcpy(row, tmp.data(), tmp.size());
+}
+
+}  // namespace
+
+Status DecodeJpeg(const std::vector<uint8_t>& compressed,
+                  const JpegDecompressParams& dparams, ThreadPool* pool,
+                  PackedPixelFile* ppf) {
+  // Don't do anything for non-JPEG files (no need to report an error)
+  if (!IsJPG(compressed)) return false;
+
+  // TODO(veluca): use JPEGData also for pixels?
+
+  // We need to declare all the non-trivial destructor local variables before
+  // the call to setjmp().
+  std::unique_ptr<JSAMPLE[]> row;
+
+  jpeg_decompress_struct cinfo;
+  const auto try_catch_block = [&]() -> bool {
+    // Setup error handling in jpeg library so we can deal with broken jpegs in
+    // the fuzzer.
+    jpeg_error_mgr jerr;
+    jmp_buf env;
+    cinfo.err = jpegli_std_error(&jerr);
+    jerr.error_exit = &MyErrorExit;
+    jerr.output_message = &MyOutputMessage;
+    if (setjmp(env)) {
+      return false;
+    }
+    cinfo.client_data = static_cast<void*>(&env);
+
+    jpegli_create_decompress(&cinfo);
+    jpegli_mem_src(&cinfo,
+                   reinterpret_cast<const unsigned char*>(compressed.data()),
+                   compressed.size());
+    jpegli_save_markers(&cinfo, kICCMarker, 0xFFFF);
+    jpegli_save_markers(&cinfo, kExifMarker, 0xFFFF);
+    const auto failure = [&cinfo](const char* str) -> Status {
+      jpegli_abort_decompress(&cinfo);
+      jpegli_destroy_decompress(&cinfo);
+      return JXL_FAILURE("%s", str);
+    };
+    jpegli_read_header(&cinfo, TRUE);
+    // Might cause CPU-zip bomb.
+    if (cinfo.arith_code) {
+      return failure("arithmetic code JPEGs are not supported");
+    }
+    int nbcomp = cinfo.num_components;
+    if (nbcomp != 1 && nbcomp != 3) {
+      return failure("unsupported number of components in JPEG");
+    }
+    if (dparams.force_rgb) {
+      cinfo.out_color_space = JCS_RGB;
+    } else if (dparams.force_grayscale) {
+      cinfo.out_color_space = JCS_GRAYSCALE;
+    }
+    if (!ReadICCProfile(&cinfo, &ppf->icc)) {
+      ppf->icc.clear();
+      // Default to SRGB
+      ppf->color_encoding.color_space =
+          ConvertColorSpace(cinfo.out_color_space);
+      ppf->color_encoding.white_point = JXL_WHITE_POINT_D65;
+      ppf->color_encoding.primaries = JXL_PRIMARIES_SRGB;
+      ppf->color_encoding.transfer_function = JXL_TRANSFER_FUNCTION_SRGB;
+      ppf->color_encoding.rendering_intent = JXL_RENDERING_INTENT_PERCEPTUAL;
+    }
+    ReadExif(&cinfo, &ppf->metadata.exif);
+
+    ppf->info.xsize = cinfo.image_width;
+    ppf->info.ysize = cinfo.image_height;
+    if (dparams.output_data_type == JXL_TYPE_UINT8) {
+      ppf->info.bits_per_sample = 8;
+      ppf->info.exponent_bits_per_sample = 0;
+    } else if (dparams.output_data_type == JXL_TYPE_UINT16) {
+      ppf->info.bits_per_sample = 16;
+      ppf->info.exponent_bits_per_sample = 0;
+    } else if (dparams.output_data_type == JXL_TYPE_FLOAT) {
+      ppf->info.bits_per_sample = 32;
+      ppf->info.exponent_bits_per_sample = 8;
+    } else {
+      return failure("unsupported data type");
+    }
+    ppf->info.uses_original_profile = true;
+
+    // No alpha in JPG
+    ppf->info.alpha_bits = 0;
+    ppf->info.alpha_exponent_bits = 0;
+    ppf->info.orientation = JXL_ORIENT_IDENTITY;
+
+    jpegli_set_output_format(&cinfo, ConvertDataType(dparams.output_data_type),
+                             ConvertEndianness(dparams.output_endianness));
+
+    if (dparams.num_colors > 0) {
+      cinfo.quantize_colors = TRUE;
+      cinfo.desired_number_of_colors = dparams.num_colors;
+      cinfo.two_pass_quantize = dparams.two_pass_quant;
+      cinfo.dither_mode = (J_DITHER_MODE)dparams.dither_mode;
+    }
+
+    jpegli_start_decompress(&cinfo);
+
+    ppf->info.num_color_channels = cinfo.out_color_components;
+    const JxlPixelFormat format{
+        /*num_channels=*/static_cast<uint32_t>(cinfo.out_color_components),
+        dparams.output_data_type,
+        dparams.output_endianness,
+        /*align=*/0,
+    };
+    ppf->frames.clear();
+    // Allocates the frame buffer.
+    ppf->frames.emplace_back(cinfo.image_width, cinfo.image_height, format);
+    const auto& frame = ppf->frames.back();
+    JXL_ASSERT(sizeof(JSAMPLE) * cinfo.out_color_components *
+                   cinfo.image_width <=
+               frame.color.stride);
+
+    for (size_t y = 0; y < cinfo.image_height; ++y) {
+      JSAMPROW rows[] = {reinterpret_cast<JSAMPLE*>(
+          static_cast<uint8_t*>(frame.color.pixels()) +
+          frame.color.stride * y)};
+      jpegli_read_scanlines(&cinfo, rows, 1);
+      if (dparams.num_colors > 0) {
+        UnmapColors(rows[0], cinfo.output_width, cinfo.out_color_components,
+                    cinfo.colormap, cinfo.actual_number_of_colors);
+      }
+    }
+
+    jpegli_finish_decompress(&cinfo);
+    return true;
+  };
+  bool success = try_catch_block();
+  jpegli_destroy_decompress(&cinfo);
+  return success;
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/dec/jpegli.h b/third_party/jpeg-xl/lib/extras/dec/jpegli.h
new file mode 100644
index 0000000000..574df54c8e
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/jpegli.h
@@ -0,0 +1,41 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_DEC_JPEGLI_H_
+#define LIB_EXTRAS_DEC_JPEGLI_H_
+
+// Decodes JPG pixels and metadata in memory using the libjpegli library.
+
+#include <jxl/types.h>
+#include <stdint.h>
+
+#include <vector>
+
+#include "lib/extras/packed_image.h"
+#include "lib/jxl/base/data_parallel.h"
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+namespace extras {
+
+struct JpegDecompressParams {
+  JxlDataType output_data_type = JXL_TYPE_UINT8;
+  JxlEndianness output_endianness = JXL_NATIVE_ENDIAN;
+  bool force_rgb = false;
+  bool force_grayscale = false;
+  int num_colors = 0;
+  bool two_pass_quant = true;
+  // 0 = none, 1 = ordered, 2 = Floyd-Steinberg
+  int dither_mode = 2;
+};
+
+Status DecodeJpeg(const std::vector<uint8_t>& compressed,
+                  const JpegDecompressParams& dparams, ThreadPool* pool,
+                  PackedPixelFile* ppf);
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_DEC_JPEGLI_H_
diff --git a/third_party/jpeg-xl/lib/extras/dec/jpg.cc b/third_party/jpeg-xl/lib/extras/dec/jpg.cc
new file mode 100644
index 0000000000..3c8a4bccfe
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/jpg.cc
@@ -0,0 +1,338 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/dec/jpg.h"
+
+#if JPEGXL_ENABLE_JPEG
+#include <jpeglib.h>
+#include <setjmp.h>
+#endif
+#include <stdint.h>
+
+#include <algorithm>
+#include <numeric>
+#include <utility>
+#include <vector>
+
+#include "lib/extras/size_constraints.h"
+#include "lib/jxl/base/status.h"
+#include "lib/jxl/sanitizers.h"
+
+namespace jxl {
+namespace extras {
+
+#if JPEGXL_ENABLE_JPEG
+namespace {
+
+constexpr unsigned char kICCSignature[12] = {
+    0x49, 0x43, 0x43, 0x5F, 0x50, 0x52, 0x4F, 0x46, 0x49, 0x4C, 0x45, 0x00};
+constexpr int kICCMarker = JPEG_APP0 + 2;
+
+constexpr unsigned char kExifSignature[6] = {0x45, 0x78, 0x69,
+                                             0x66, 0x00, 0x00};
+constexpr int kExifMarker = JPEG_APP0 + 1;
+
+static inline bool IsJPG(const Span<const uint8_t> bytes) {
+  if (bytes.size() < 2) return false;
+  if (bytes[0] != 0xFF || bytes[1] != 0xD8) return false;
+  return true;
+}
+
+bool MarkerIsICC(const jpeg_saved_marker_ptr marker) {
+  return marker->marker == kICCMarker &&
+         marker->data_length >= sizeof kICCSignature + 2 &&
+         std::equal(std::begin(kICCSignature), std::end(kICCSignature),
+                    marker->data);
+}
+bool MarkerIsExif(const jpeg_saved_marker_ptr marker) {
+  return marker->marker == kExifMarker &&
+         marker->data_length >= sizeof kExifSignature + 2 &&
+         std::equal(std::begin(kExifSignature), std::end(kExifSignature),
+                    marker->data);
+}
+
+Status ReadICCProfile(jpeg_decompress_struct* const cinfo,
+                      std::vector<uint8_t>* const icc) {
+  constexpr size_t kICCSignatureSize = sizeof kICCSignature;
+  // ICC signature + uint8_t index + uint8_t max_index.
+  constexpr size_t kICCHeadSize = kICCSignatureSize + 2;
+  // Markers are 1-indexed, and we keep them that way in this vector to get a
+  // convenient 0 at the front for when we compute the offsets later.
+  std::vector<size_t> marker_lengths;
+  int num_markers = 0;
+  int seen_markers_count = 0;
+  bool has_num_markers = false;
+  for (jpeg_saved_marker_ptr marker = cinfo->marker_list; marker != nullptr;
+       marker = marker->next) {
+    // marker is initialized by libjpeg, which we are not instrumenting with
+    // msan.
+    msan::UnpoisonMemory(marker, sizeof(*marker));
+    msan::UnpoisonMemory(marker->data, marker->data_length);
+    if (!MarkerIsICC(marker)) continue;
+
+    const int current_marker = marker->data[kICCSignatureSize];
+    if (current_marker == 0) {
+      return JXL_FAILURE("inconsistent JPEG ICC marker numbering");
+    }
+    const int current_num_markers = marker->data[kICCSignatureSize + 1];
+    if (current_marker > current_num_markers) {
+      return JXL_FAILURE("inconsistent JPEG ICC marker numbering");
+    }
+    if (has_num_markers) {
+      if (current_num_markers != num_markers) {
+        return JXL_FAILURE("inconsistent numbers of JPEG ICC markers");
+      }
+    } else {
+      num_markers = current_num_markers;
+      has_num_markers = true;
+      marker_lengths.resize(num_markers + 1);
+    }
+
+    size_t marker_length = marker->data_length - kICCHeadSize;
+
+    if (marker_length == 0) {
+      // NB: if we allow empty chunks, then the next check is incorrect.
+      return JXL_FAILURE("Empty ICC chunk");
+    }
+
+    if (marker_lengths[current_marker] != 0) {
+      return JXL_FAILURE("duplicate JPEG ICC marker number");
+    }
+    marker_lengths[current_marker] = marker_length;
+    seen_markers_count++;
+  }
+
+  if (marker_lengths.empty()) {
+    // Not an error.
+    return false;
+  }
+
+  if (seen_markers_count != num_markers) {
+    JXL_DASSERT(has_num_markers);
+    return JXL_FAILURE("Incomplete set of ICC chunks");
+  }
+
+  std::vector<size_t> offsets = std::move(marker_lengths);
+  std::partial_sum(offsets.begin(), offsets.end(), offsets.begin());
+  icc->resize(offsets.back());
+
+  for (jpeg_saved_marker_ptr marker = cinfo->marker_list; marker != nullptr;
+       marker = marker->next) {
+    if (!MarkerIsICC(marker)) continue;
+    const uint8_t* first = marker->data + kICCHeadSize;
+    uint8_t current_marker = marker->data[kICCSignatureSize];
+    size_t offset = offsets[current_marker - 1];
+    size_t marker_length = offsets[current_marker] - offset;
+    std::copy_n(first, marker_length, icc->data() + offset);
+  }
+
+  return true;
+}
+
+void ReadExif(jpeg_decompress_struct* const cinfo,
+              std::vector<uint8_t>* const exif) {
+  constexpr size_t kExifSignatureSize = sizeof kExifSignature;
+  for (jpeg_saved_marker_ptr marker = cinfo->marker_list; marker != nullptr;
+       marker = marker->next) {
+    // marker is initialized by libjpeg, which we are not instrumenting with
+    // msan.
+    msan::UnpoisonMemory(marker, sizeof(*marker));
+    msan::UnpoisonMemory(marker->data, marker->data_length);
+    if (!MarkerIsExif(marker)) continue;
+    size_t marker_length = marker->data_length - kExifSignatureSize;
+    exif->resize(marker_length);
+    std::copy_n(marker->data + kExifSignatureSize, marker_length, exif->data());
+    return;
+  }
+}
+
+void MyErrorExit(j_common_ptr cinfo) {
+  jmp_buf* env = static_cast<jmp_buf*>(cinfo->client_data);
+  (*cinfo->err->output_message)(cinfo);
+  jpeg_destroy_decompress(reinterpret_cast<j_decompress_ptr>(cinfo));
+  longjmp(*env, 1);
+}
+
+void MyOutputMessage(j_common_ptr cinfo) {
+#if JXL_DEBUG_WARNING == 1
+  char buf[JMSG_LENGTH_MAX + 1];
+  (*cinfo->err->format_message)(cinfo, buf);
+  buf[JMSG_LENGTH_MAX] = 0;
+  JXL_WARNING("%s", buf);
+#endif
+}
+
+void UnmapColors(uint8_t* row, size_t xsize, int components,
+                 JSAMPARRAY colormap, size_t num_colors) {
+  JXL_CHECK(colormap != nullptr);
+  std::vector<uint8_t> tmp(xsize * components);
+  for (size_t x = 0; x < xsize; ++x) {
+    JXL_CHECK(row[x] < num_colors);
+    for (int c = 0; c < components; ++c) {
+      tmp[x * components + c] = colormap[c][row[x]];
+    }
+  }
+  memcpy(row, tmp.data(), tmp.size());
+}
+
+}  // namespace
+#endif
+
+bool CanDecodeJPG() {
+#if JPEGXL_ENABLE_JPEG
+  return true;
+#else
+  return false;
+#endif
+}
+
+Status DecodeImageJPG(const Span<const uint8_t> bytes,
+                      const ColorHints& color_hints, PackedPixelFile* ppf,
+                      const SizeConstraints* constraints,
+                      const JPGDecompressParams* dparams) {
+#if JPEGXL_ENABLE_JPEG
+  // Don't do anything for non-JPEG files (no need to report an error)
+  if (!IsJPG(bytes)) return false;
+
+  // TODO(veluca): use JPEGData also for pixels?
+
+  // We need to declare all the non-trivial destructor local variables before
+  // the call to setjmp().
+  std::unique_ptr<JSAMPLE[]> row;
+
+  const auto try_catch_block = [&]() -> bool {
+    jpeg_decompress_struct cinfo = {};
+    // Setup error handling in jpeg library so we can deal with broken jpegs in
+    // the fuzzer.
+    jpeg_error_mgr jerr;
+    jmp_buf env;
+    cinfo.err = jpeg_std_error(&jerr);
+    jerr.error_exit = &MyErrorExit;
+    jerr.output_message = &MyOutputMessage;
+    if (setjmp(env)) {
+      return false;
+    }
+    cinfo.client_data = static_cast<void*>(&env);
+
+    jpeg_create_decompress(&cinfo);
+    jpeg_mem_src(&cinfo, reinterpret_cast<const unsigned char*>(bytes.data()),
+                 bytes.size());
+    jpeg_save_markers(&cinfo, kICCMarker, 0xFFFF);
+    jpeg_save_markers(&cinfo, kExifMarker, 0xFFFF);
+    const auto failure = [&cinfo](const char* str) -> Status {
+      jpeg_abort_decompress(&cinfo);
+      jpeg_destroy_decompress(&cinfo);
+      return JXL_FAILURE("%s", str);
+    };
+    int read_header_result = jpeg_read_header(&cinfo, TRUE);
+    // TODO(eustas): what about JPEG_HEADER_TABLES_ONLY?
+    if (read_header_result == JPEG_SUSPENDED) {
+      return failure("truncated JPEG input");
+    }
+    if (!VerifyDimensions(constraints, cinfo.image_width, cinfo.image_height)) {
+      return failure("image too big");
+    }
+    // Might cause CPU-zip bomb.
+    if (cinfo.arith_code) {
+      return failure("arithmetic code JPEGs are not supported");
+    }
+    int nbcomp = cinfo.num_components;
+    if (nbcomp != 1 && nbcomp != 3) {
+      return failure("unsupported number of components in JPEG");
+    }
+    if (!ReadICCProfile(&cinfo, &ppf->icc)) {
+      ppf->icc.clear();
+      // Default to SRGB
+      // Actually, (cinfo.output_components == nbcomp) will be checked after
+      // `jpeg_start_decompress`.
+      ppf->color_encoding.color_space =
+          (nbcomp == 1) ? JXL_COLOR_SPACE_GRAY : JXL_COLOR_SPACE_RGB;
+      ppf->color_encoding.white_point = JXL_WHITE_POINT_D65;
+      ppf->color_encoding.primaries = JXL_PRIMARIES_SRGB;
+      ppf->color_encoding.transfer_function = JXL_TRANSFER_FUNCTION_SRGB;
+      ppf->color_encoding.rendering_intent = JXL_RENDERING_INTENT_PERCEPTUAL;
+    }
+    ReadExif(&cinfo, &ppf->metadata.exif);
+    if (!ApplyColorHints(color_hints, /*color_already_set=*/true,
+                         /*is_gray=*/false, ppf)) {
+      return failure("ApplyColorHints failed");
+    }
+
+    ppf->info.xsize = cinfo.image_width;
+    ppf->info.ysize = cinfo.image_height;
+    // Original data is uint, so exponent_bits_per_sample = 0.
+    ppf->info.bits_per_sample = BITS_IN_JSAMPLE;
+    JXL_ASSERT(BITS_IN_JSAMPLE == 8 || BITS_IN_JSAMPLE == 16);
+    ppf->info.exponent_bits_per_sample = 0;
+    ppf->info.uses_original_profile = true;
+
+    // No alpha in JPG
+    ppf->info.alpha_bits = 0;
+    ppf->info.alpha_exponent_bits = 0;
+
+    ppf->info.num_color_channels = nbcomp;
+    ppf->info.orientation = JXL_ORIENT_IDENTITY;
+
+    if (dparams && dparams->num_colors > 0) {
+      cinfo.quantize_colors = TRUE;
+      cinfo.desired_number_of_colors = dparams->num_colors;
+      cinfo.two_pass_quantize = dparams->two_pass_quant;
+      cinfo.dither_mode = (J_DITHER_MODE)dparams->dither_mode;
+    }
+
+    jpeg_start_decompress(&cinfo);
+    JXL_ASSERT(cinfo.out_color_components == nbcomp);
+    JxlDataType data_type =
+        ppf->info.bits_per_sample <= 8 ? JXL_TYPE_UINT8 : JXL_TYPE_UINT16;
+
+    const JxlPixelFormat format{
+        /*num_channels=*/static_cast<uint32_t>(nbcomp),
+        data_type,
+        /*endianness=*/JXL_NATIVE_ENDIAN,
+        /*align=*/0,
+    };
+    ppf->frames.clear();
+    // Allocates the frame buffer.
+    ppf->frames.emplace_back(cinfo.image_width, cinfo.image_height, format);
+    const auto& frame = ppf->frames.back();
+    JXL_ASSERT(sizeof(JSAMPLE) * cinfo.out_color_components *
+                   cinfo.image_width <=
+               frame.color.stride);
+
+    if (cinfo.quantize_colors) {
+      jxl::msan::UnpoisonMemory(cinfo.colormap, cinfo.out_color_components *
+                                                    sizeof(cinfo.colormap[0]));
+      for (int c = 0; c < cinfo.out_color_components; ++c) {
+        jxl::msan::UnpoisonMemory(
+            cinfo.colormap[c],
+            cinfo.actual_number_of_colors * sizeof(cinfo.colormap[c][0]));
+      }
+    }
+    for (size_t y = 0; y < cinfo.image_height; ++y) {
+      JSAMPROW rows[] = {reinterpret_cast<JSAMPLE*>(
+          static_cast<uint8_t*>(frame.color.pixels()) +
+          frame.color.stride * y)};
+      jpeg_read_scanlines(&cinfo, rows, 1);
+      msan::UnpoisonMemory(rows[0], sizeof(JSAMPLE) * cinfo.output_components *
+                                        cinfo.image_width);
+      if (dparams && dparams->num_colors > 0) {
+        UnmapColors(rows[0], cinfo.output_width, cinfo.out_color_components,
+                    cinfo.colormap, cinfo.actual_number_of_colors);
+      }
+    }
+
+    jpeg_finish_decompress(&cinfo);
+    jpeg_destroy_decompress(&cinfo);
+    return true;
+  };
+
+  return try_catch_block();
+#else
+  return false;
+#endif
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/dec/jpg.h b/third_party/jpeg-xl/lib/extras/dec/jpg.h
new file mode 100644
index 0000000000..6e7b2f786b
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/jpg.h
@@ -0,0 +1,45 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_DEC_JPG_H_
+#define LIB_EXTRAS_DEC_JPG_H_
+
+// Decodes JPG pixels and metadata in memory.
+
+#include <stdint.h>
+
+#include "lib/extras/codec.h"
+#include "lib/extras/dec/color_hints.h"
+#include "lib/jxl/base/data_parallel.h"
+#include "lib/jxl/base/span.h"
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+
+struct SizeConstraints;
+
+namespace extras {
+
+bool CanDecodeJPG();
+
+struct JPGDecompressParams {
+  int num_colors = 0;
+  bool two_pass_quant = false;
+  // 0 = none, 1 = ordered, 2 = Floyd-Steinberg
+  int dither_mode = 0;
+};
+
+// Decodes `bytes` into `ppf`. color_hints are ignored.
+// `elapsed_deinterleave`, if non-null, will be set to the time (in seconds)
+// that it took to deinterleave the raw JSAMPLEs to planar floats.
+Status DecodeImageJPG(Span<const uint8_t> bytes, const ColorHints& color_hints,
+                      PackedPixelFile* ppf,
+                      const SizeConstraints* constraints = nullptr,
+                      const JPGDecompressParams* dparams = nullptr);
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_DEC_JPG_H_
diff --git a/third_party/jpeg-xl/lib/extras/dec/jxl.cc b/third_party/jpeg-xl/lib/extras/dec/jxl.cc
new file mode 100644
index 0000000000..f3e62c970a
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/jxl.cc
@@ -0,0 +1,572 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/dec/jxl.h"
+
+#include <jxl/cms.h>
+#include <jxl/decode.h>
+#include <jxl/decode_cxx.h>
+#include <jxl/types.h>
+
+#include <cinttypes>
+
+#include "lib/extras/common.h"
+#include "lib/extras/dec/color_description.h"
+#include "lib/jxl/base/exif.h"
+#include "lib/jxl/base/printf_macros.h"
+
+namespace jxl {
+namespace extras {
+namespace {
+
+struct BoxProcessor {
+  BoxProcessor(JxlDecoder* dec) : dec_(dec) { Reset(); }
+
+  void InitializeOutput(std::vector<uint8_t>* out) {
+    box_data_ = out;
+    AddMoreOutput();
+  }
+
+  bool AddMoreOutput() {
+    Flush();
+    static const size_t kBoxOutputChunkSize = 1 << 16;
+    box_data_->resize(box_data_->size() + kBoxOutputChunkSize);
+    next_out_ = box_data_->data() + total_size_;
+    avail_out_ = box_data_->size() - total_size_;
+    if (JXL_DEC_SUCCESS !=
+        JxlDecoderSetBoxBuffer(dec_, next_out_, avail_out_)) {
+      fprintf(stderr, "JxlDecoderSetBoxBuffer failed\n");
+      return false;
+    }
+    return true;
+  }
+
+  void FinalizeOutput() {
+    if (box_data_ == nullptr) return;
+    Flush();
+    box_data_->resize(total_size_);
+    Reset();
+  }
+
+ private:
+  JxlDecoder* dec_;
+  std::vector<uint8_t>* box_data_;
+  uint8_t* next_out_;
+  size_t avail_out_;
+  size_t total_size_;
+
+  void Reset() {
+    box_data_ = nullptr;
+    next_out_ = nullptr;
+    avail_out_ = 0;
+    total_size_ = 0;
+  }
+  void Flush() {
+    if (box_data_ == nullptr) return;
+    size_t remaining = JxlDecoderReleaseBoxBuffer(dec_);
+    size_t bytes_written = avail_out_ - remaining;
+    next_out_ += bytes_written;
+    avail_out_ -= bytes_written;
+    total_size_ += bytes_written;
+  }
+};
+
+void SetBitDepthFromDataType(JxlDataType data_type, uint32_t* bits_per_sample,
+                             uint32_t* exponent_bits_per_sample) {
+  switch (data_type) {
+    case JXL_TYPE_UINT8:
+      *bits_per_sample = 8;
+      *exponent_bits_per_sample = 0;
+      break;
+    case JXL_TYPE_UINT16:
+      *bits_per_sample = 16;
+      *exponent_bits_per_sample = 0;
+      break;
+    case JXL_TYPE_FLOAT16:
+      *bits_per_sample = 16;
+      *exponent_bits_per_sample = 5;
+      break;
+    case JXL_TYPE_FLOAT:
+      *bits_per_sample = 32;
+      *exponent_bits_per_sample = 8;
+      break;
+  }
+}
+
+template <typename T>
+void UpdateBitDepth(JxlBitDepth bit_depth, JxlDataType data_type, T* info) {
+  if (bit_depth.type == JXL_BIT_DEPTH_FROM_PIXEL_FORMAT) {
+    SetBitDepthFromDataType(data_type, &info->bits_per_sample,
+                            &info->exponent_bits_per_sample);
+  } else if (bit_depth.type == JXL_BIT_DEPTH_CUSTOM) {
+    info->bits_per_sample = bit_depth.bits_per_sample;
+    info->exponent_bits_per_sample = bit_depth.exponent_bits_per_sample;
+  }
+}
+
+}  // namespace
+
+bool DecodeImageJXL(const uint8_t* bytes, size_t bytes_size,
+                    const JXLDecompressParams& dparams, size_t* decoded_bytes,
+                    PackedPixelFile* ppf, std::vector<uint8_t>* jpeg_bytes) {
+  JxlSignature sig = JxlSignatureCheck(bytes, bytes_size);
+  // silently return false if this is not a JXL file
+  if (sig == JXL_SIG_INVALID) return false;
+
+  auto decoder = JxlDecoderMake(/*memory_manager=*/nullptr);
+  JxlDecoder* dec = decoder.get();
+  ppf->frames.clear();
+
+  if (dparams.runner_opaque != nullptr &&
+      JXL_DEC_SUCCESS != JxlDecoderSetParallelRunner(dec, dparams.runner,
+                                                     dparams.runner_opaque)) {
+    fprintf(stderr, "JxlEncoderSetParallelRunner failed\n");
+    return false;
+  }
+
+  JxlPixelFormat format;
+  std::vector<JxlPixelFormat> accepted_formats = dparams.accepted_formats;
+
+  JxlColorEncoding color_encoding;
+  size_t num_color_channels = 0;
+  if (!dparams.color_space.empty()) {
+    if (!jxl::ParseDescription(dparams.color_space, &color_encoding)) {
+      fprintf(stderr, "Failed to parse color space %s.\n",
+              dparams.color_space.c_str());
+      return false;
+    }
+    num_color_channels =
+        color_encoding.color_space == JXL_COLOR_SPACE_GRAY ? 1 : 3;
+  }
+
+  bool can_reconstruct_jpeg = false;
+  std::vector<uint8_t> jpeg_data_chunk;
+  if (jpeg_bytes != nullptr) {
+    // This bound is very likely to be enough to hold the entire
+    // reconstructed JPEG, to avoid having to do expensive retries.
+    jpeg_data_chunk.resize(bytes_size * 3 / 2 + 1024);
+    jpeg_bytes->resize(0);
+  }
+
+  int events = (JXL_DEC_BASIC_INFO | JXL_DEC_FULL_IMAGE);
+
+  bool max_passes_defined =
+      (dparams.max_passes < std::numeric_limits<uint32_t>::max());
+  if (max_passes_defined || dparams.max_downsampling > 1) {
+    events |= JXL_DEC_FRAME_PROGRESSION;
+    if (max_passes_defined) {
+      JxlDecoderSetProgressiveDetail(dec, JxlProgressiveDetail::kPasses);
+    } else {
+      JxlDecoderSetProgressiveDetail(dec, JxlProgressiveDetail::kLastPasses);
+    }
+  }
+  if (jpeg_bytes != nullptr) {
+    events |= JXL_DEC_JPEG_RECONSTRUCTION;
+  } else {
+    events |= (JXL_DEC_COLOR_ENCODING | JXL_DEC_FRAME | JXL_DEC_PREVIEW_IMAGE |
+               JXL_DEC_BOX);
+    if (accepted_formats.empty()) {
+      // decoding just the metadata, not the pixel data
+      events ^= (JXL_DEC_FULL_IMAGE | JXL_DEC_PREVIEW_IMAGE);
+    }
+  }
+  if (JXL_DEC_SUCCESS != JxlDecoderSubscribeEvents(dec, events)) {
+    fprintf(stderr, "JxlDecoderSubscribeEvents failed\n");
+    return false;
+  }
+  if (jpeg_bytes == nullptr) {
+    if (JXL_DEC_SUCCESS !=
+        JxlDecoderSetRenderSpotcolors(dec, dparams.render_spotcolors)) {
+      fprintf(stderr, "JxlDecoderSetRenderSpotColors failed\n");
+      return false;
+    }
+    if (JXL_DEC_SUCCESS !=
+        JxlDecoderSetKeepOrientation(dec, dparams.keep_orientation)) {
+      fprintf(stderr, "JxlDecoderSetKeepOrientation failed\n");
+      return false;
+    }
+    if (JXL_DEC_SUCCESS !=
+        JxlDecoderSetUnpremultiplyAlpha(dec, dparams.unpremultiply_alpha)) {
+      fprintf(stderr, "JxlDecoderSetUnpremultiplyAlpha failed\n");
+      return false;
+    }
+    if (dparams.display_nits > 0 &&
+        JXL_DEC_SUCCESS !=
+            JxlDecoderSetDesiredIntensityTarget(dec, dparams.display_nits)) {
+      fprintf(stderr, "Decoder failed to set desired intensity target\n");
+      return false;
+    }
+    if (JXL_DEC_SUCCESS != JxlDecoderSetDecompressBoxes(dec, JXL_TRUE)) {
+      fprintf(stderr, "JxlDecoderSetDecompressBoxes failed\n");
+      return false;
+    }
+  }
+  if (JXL_DEC_SUCCESS != JxlDecoderSetInput(dec, bytes, bytes_size)) {
+    fprintf(stderr, "Decoder failed to set input\n");
+    return false;
+  }
+  uint32_t progression_index = 0;
+  bool codestream_done = accepted_formats.empty();
+  BoxProcessor boxes(dec);
+  for (;;) {
+    JxlDecoderStatus status = JxlDecoderProcessInput(dec);
+    if (status == JXL_DEC_ERROR) {
+      fprintf(stderr, "Failed to decode image\n");
+      return false;
+    } else if (status == JXL_DEC_NEED_MORE_INPUT) {
+      if (codestream_done) {
+        break;
+      }
+      if (dparams.allow_partial_input) {
+        if (JXL_DEC_SUCCESS != JxlDecoderFlushImage(dec)) {
+          fprintf(stderr,
+                  "Input file is truncated and there is no preview "
+                  "available yet.\n");
+          return false;
+        }
+        break;
+      }
+      size_t released_size = JxlDecoderReleaseInput(dec);
+      fprintf(stderr,
+              "Input file is truncated (total bytes: %" PRIuS
+              ", processed bytes: %" PRIuS
+              ") and --allow_partial_files is not present.\n",
+              bytes_size, bytes_size - released_size);
+      return false;
+    } else if (status == JXL_DEC_BOX) {
+      boxes.FinalizeOutput();
+      JxlBoxType box_type;
+      if (JXL_DEC_SUCCESS != JxlDecoderGetBoxType(dec, box_type, JXL_TRUE)) {
+        fprintf(stderr, "JxlDecoderGetBoxType failed\n");
+        return false;
+      }
+      std::vector<uint8_t>* box_data = nullptr;
+      if (memcmp(box_type, "Exif", 4) == 0) {
+        box_data = &ppf->metadata.exif;
+      } else if (memcmp(box_type, "iptc", 4) == 0) {
+        box_data = &ppf->metadata.iptc;
+      } else if (memcmp(box_type, "jumb", 4) == 0) {
+        box_data = &ppf->metadata.jumbf;
+      } else if (memcmp(box_type, "xml ", 4) == 0) {
+        box_data = &ppf->metadata.xmp;
+      }
+      if (box_data) {
+        boxes.InitializeOutput(box_data);
+      }
+    } else if (status == JXL_DEC_BOX_NEED_MORE_OUTPUT) {
+      boxes.AddMoreOutput();
+    } else if (status == JXL_DEC_JPEG_RECONSTRUCTION) {
+      can_reconstruct_jpeg = true;
+      // Decoding to JPEG.
+      if (JXL_DEC_SUCCESS != JxlDecoderSetJPEGBuffer(dec,
+                                                     jpeg_data_chunk.data(),
+                                                     jpeg_data_chunk.size())) {
+        fprintf(stderr, "Decoder failed to set JPEG Buffer\n");
+        return false;
+      }
+    } else if (status == JXL_DEC_JPEG_NEED_MORE_OUTPUT) {
+      // Decoded a chunk to JPEG.
+      size_t used_jpeg_output =
+          jpeg_data_chunk.size() - JxlDecoderReleaseJPEGBuffer(dec);
+      jpeg_bytes->insert(jpeg_bytes->end(), jpeg_data_chunk.data(),
+                         jpeg_data_chunk.data() + used_jpeg_output);
+      if (used_jpeg_output == 0) {
+        // Chunk is too small.
+        jpeg_data_chunk.resize(jpeg_data_chunk.size() * 2);
+      }
+      if (JXL_DEC_SUCCESS != JxlDecoderSetJPEGBuffer(dec,
+                                                     jpeg_data_chunk.data(),
+                                                     jpeg_data_chunk.size())) {
+        fprintf(stderr, "Decoder failed to set JPEG Buffer\n");
+        return false;
+      }
+    } else if (status == JXL_DEC_BASIC_INFO) {
+      if (JXL_DEC_SUCCESS != JxlDecoderGetBasicInfo(dec, &ppf->info)) {
+        fprintf(stderr, "JxlDecoderGetBasicInfo failed\n");
+        return false;
+      }
+      if (accepted_formats.empty()) continue;
+      if (num_color_channels != 0) {
+        // Mark the change in number of color channels due to the requested
+        // color space.
+        ppf->info.num_color_channels = num_color_channels;
+      }
+      if (dparams.output_bitdepth.type == JXL_BIT_DEPTH_CUSTOM) {
+        // Select format based on custom bits per sample.
+        ppf->info.bits_per_sample = dparams.output_bitdepth.bits_per_sample;
+      }
+      // Select format according to accepted formats.
+      if (!jxl::extras::SelectFormat(accepted_formats, ppf->info, &format)) {
+        fprintf(stderr, "SelectFormat failed\n");
+        return false;
+      }
+      bool have_alpha = (format.num_channels == 2 || format.num_channels == 4);
+      if (!have_alpha) {
+        // Mark in the basic info that alpha channel was dropped.
+        ppf->info.alpha_bits = 0;
+      } else {
+        if (dparams.unpremultiply_alpha) {
+          // Mark in the basic info that alpha was unpremultiplied.
+          ppf->info.alpha_premultiplied = false;
+        }
+      }
+      bool alpha_found = false;
+      for (uint32_t i = 0; i < ppf->info.num_extra_channels; ++i) {
+        JxlExtraChannelInfo eci;
+        if (JXL_DEC_SUCCESS != JxlDecoderGetExtraChannelInfo(dec, i, &eci)) {
+          fprintf(stderr, "JxlDecoderGetExtraChannelInfo failed\n");
+          return false;
+        }
+        if (eci.type == JXL_CHANNEL_ALPHA && have_alpha && !alpha_found) {
+          // Skip the first alpha channels because it is already present in the
+          // interleaved image.
+          alpha_found = true;
+          continue;
+        }
+        std::string name(eci.name_length + 1, 0);
+        if (JXL_DEC_SUCCESS !=
+            JxlDecoderGetExtraChannelName(dec, i, &name[0], name.size())) {
+          fprintf(stderr, "JxlDecoderGetExtraChannelName failed\n");
+          return false;
+        }
+        name.resize(eci.name_length);
+        ppf->extra_channels_info.push_back({eci, i, name});
+      }
+    } else if (status == JXL_DEC_COLOR_ENCODING) {
+      if (!dparams.color_space.empty()) {
+        if (ppf->info.uses_original_profile) {
+          fprintf(stderr,
+                  "Warning: --color_space ignored because the image is "
+                  "not XYB encoded.\n");
+        } else {
+          JxlDecoderSetCms(dec, *JxlGetDefaultCms());
+          if (JXL_DEC_SUCCESS !=
+              JxlDecoderSetPreferredColorProfile(dec, &color_encoding)) {
+            fprintf(stderr, "Failed to set color space.\n");
+            return false;
+          }
+        }
+      }
+      size_t icc_size = 0;
+      JxlColorProfileTarget target = JXL_COLOR_PROFILE_TARGET_DATA;
+      ppf->color_encoding.color_space = JXL_COLOR_SPACE_UNKNOWN;
+      if (JXL_DEC_SUCCESS != JxlDecoderGetColorAsEncodedProfile(
+                                 dec, target, &ppf->color_encoding) ||
+          dparams.need_icc) {
+        // only get ICC if it is not an Enum color encoding
+        if (JXL_DEC_SUCCESS !=
+            JxlDecoderGetICCProfileSize(dec, target, &icc_size)) {
+          fprintf(stderr, "JxlDecoderGetICCProfileSize failed\n");
+        }
+        if (icc_size != 0) {
+          ppf->icc.resize(icc_size);
+          if (JXL_DEC_SUCCESS != JxlDecoderGetColorAsICCProfile(
+                                     dec, target, ppf->icc.data(), icc_size)) {
+            fprintf(stderr, "JxlDecoderGetColorAsICCProfile failed\n");
+            return false;
+          }
+        }
+      }
+      icc_size = 0;
+      target = JXL_COLOR_PROFILE_TARGET_ORIGINAL;
+      if (JXL_DEC_SUCCESS !=
+          JxlDecoderGetICCProfileSize(dec, target, &icc_size)) {
+        fprintf(stderr, "JxlDecoderGetICCProfileSize failed\n");
+      }
+      if (icc_size != 0) {
+        ppf->orig_icc.resize(icc_size);
+        if (JXL_DEC_SUCCESS !=
+            JxlDecoderGetColorAsICCProfile(dec, target, ppf->orig_icc.data(),
+                                           icc_size)) {
+          fprintf(stderr, "JxlDecoderGetColorAsICCProfile failed\n");
+          return false;
+        }
+      }
+    } else if (status == JXL_DEC_FRAME) {
+      jxl::extras::PackedFrame frame(ppf->info.xsize, ppf->info.ysize, format);
+      if (JXL_DEC_SUCCESS != JxlDecoderGetFrameHeader(dec, &frame.frame_info)) {
+        fprintf(stderr, "JxlDecoderGetFrameHeader failed\n");
+        return false;
+      }
+      frame.name.resize(frame.frame_info.name_length + 1, 0);
+      if (JXL_DEC_SUCCESS !=
+          JxlDecoderGetFrameName(dec, &frame.name[0], frame.name.size())) {
+        fprintf(stderr, "JxlDecoderGetFrameName failed\n");
+        return false;
+      }
+      frame.name.resize(frame.frame_info.name_length);
+      ppf->frames.emplace_back(std::move(frame));
+      progression_index = 0;
+    } else if (status == JXL_DEC_FRAME_PROGRESSION) {
+      size_t downsampling = JxlDecoderGetIntendedDownsamplingRatio(dec);
+      if ((max_passes_defined && progression_index >= dparams.max_passes) ||
+          (!max_passes_defined && downsampling <= dparams.max_downsampling)) {
+        if (JXL_DEC_SUCCESS != JxlDecoderFlushImage(dec)) {
+          fprintf(stderr, "JxlDecoderFlushImage failed\n");
+          return false;
+        }
+        if (ppf->frames.back().frame_info.is_last) {
+          break;
+        }
+        if (JXL_DEC_SUCCESS != JxlDecoderSkipCurrentFrame(dec)) {
+          fprintf(stderr, "JxlDecoderSkipCurrentFrame failed\n");
+          return false;
+        }
+      }
+      ++progression_index;
+    } else if (status == JXL_DEC_NEED_PREVIEW_OUT_BUFFER) {
+      size_t buffer_size;
+      if (JXL_DEC_SUCCESS !=
+          JxlDecoderPreviewOutBufferSize(dec, &format, &buffer_size)) {
+        fprintf(stderr, "JxlDecoderPreviewOutBufferSize failed\n");
+        return false;
+      }
+      ppf->preview_frame = std::unique_ptr<jxl::extras::PackedFrame>(
+          new jxl::extras::PackedFrame(ppf->info.preview.xsize,
+                                       ppf->info.preview.ysize, format));
+      if (buffer_size != ppf->preview_frame->color.pixels_size) {
+        fprintf(stderr, "Invalid out buffer size %" PRIuS " %" PRIuS "\n",
+                buffer_size, ppf->preview_frame->color.pixels_size);
+        return false;
+      }
+      if (JXL_DEC_SUCCESS !=
+          JxlDecoderSetPreviewOutBuffer(
+              dec, &format, ppf->preview_frame->color.pixels(), buffer_size)) {
+        fprintf(stderr, "JxlDecoderSetPreviewOutBuffer failed\n");
+        return false;
+      }
+    } else if (status == JXL_DEC_NEED_IMAGE_OUT_BUFFER) {
+      if (jpeg_bytes != nullptr) {
+        break;
+      }
+      size_t buffer_size;
+      if (JXL_DEC_SUCCESS !=
+          JxlDecoderImageOutBufferSize(dec, &format, &buffer_size)) {
+        fprintf(stderr, "JxlDecoderImageOutBufferSize failed\n");
+        return false;
+      }
+      jxl::extras::PackedFrame& frame = ppf->frames.back();
+      if (buffer_size != frame.color.pixels_size) {
+        fprintf(stderr, "Invalid out buffer size %" PRIuS " %" PRIuS "\n",
+                buffer_size, frame.color.pixels_size);
+        return false;
+      }
+
+      if (dparams.use_image_callback) {
+        auto callback = [](void* opaque, size_t x, size_t y, size_t num_pixels,
+                           const void* pixels) {
+          auto* ppf = reinterpret_cast<jxl::extras::PackedPixelFile*>(opaque);
+          jxl::extras::PackedImage& color = ppf->frames.back().color;
+          uint8_t* pixels_buffer = reinterpret_cast<uint8_t*>(color.pixels());
+          size_t sample_size = color.pixel_stride();
+          memcpy(pixels_buffer + (color.stride * y + sample_size * x), pixels,
+                 num_pixels * sample_size);
+        };
+        if (JXL_DEC_SUCCESS !=
+            JxlDecoderSetImageOutCallback(dec, &format, callback, ppf)) {
+          fprintf(stderr, "JxlDecoderSetImageOutCallback failed\n");
+          return false;
+        }
+      } else {
+        if (JXL_DEC_SUCCESS != JxlDecoderSetImageOutBuffer(dec, &format,
+                                                           frame.color.pixels(),
+                                                           buffer_size)) {
+          fprintf(stderr, "JxlDecoderSetImageOutBuffer failed\n");
+          return false;
+        }
+      }
+      if (JXL_DEC_SUCCESS !=
+          JxlDecoderSetImageOutBitDepth(dec, &dparams.output_bitdepth)) {
+        fprintf(stderr, "JxlDecoderSetImageOutBitDepth failed\n");
+        return false;
+      }
+      UpdateBitDepth(dparams.output_bitdepth, format.data_type, &ppf->info);
+      bool have_alpha = (format.num_channels == 2 || format.num_channels == 4);
+      if (have_alpha) {
+        // Interleaved alpha channels has the same bit depth as color channels.
+        ppf->info.alpha_bits = ppf->info.bits_per_sample;
+        ppf->info.alpha_exponent_bits = ppf->info.exponent_bits_per_sample;
+      }
+      JxlPixelFormat ec_format = format;
+      ec_format.num_channels = 1;
+      for (auto& eci : ppf->extra_channels_info) {
+        frame.extra_channels.emplace_back(jxl::extras::PackedImage(
+            ppf->info.xsize, ppf->info.ysize, ec_format));
+        auto& ec = frame.extra_channels.back();
+        size_t buffer_size;
+        if (JXL_DEC_SUCCESS != JxlDecoderExtraChannelBufferSize(
+                                   dec, &ec_format, &buffer_size, eci.index)) {
+          fprintf(stderr, "JxlDecoderExtraChannelBufferSize failed\n");
+          return false;
+        }
+        if (buffer_size != ec.pixels_size) {
+          fprintf(stderr,
+                  "Invalid extra channel buffer size"
+                  " %" PRIuS " %" PRIuS "\n",
+                  buffer_size, ec.pixels_size);
+          return false;
+        }
+        if (JXL_DEC_SUCCESS !=
+            JxlDecoderSetExtraChannelBuffer(dec, &ec_format, ec.pixels(),
+                                            buffer_size, eci.index)) {
+          fprintf(stderr, "JxlDecoderSetExtraChannelBuffer failed\n");
+          return false;
+        }
+        UpdateBitDepth(dparams.output_bitdepth, ec_format.data_type,
+                       &eci.ec_info);
+      }
+    } else if (status == JXL_DEC_SUCCESS) {
+      // Decoding finished successfully.
+      break;
+    } else if (status == JXL_DEC_PREVIEW_IMAGE) {
+      // Nothing to do.
+    } else if (status == JXL_DEC_FULL_IMAGE) {
+      if (jpeg_bytes != nullptr || ppf->frames.back().frame_info.is_last) {
+        codestream_done = true;
+      }
+    } else {
+      fprintf(stderr, "Error: unexpected status: %d\n",
+              static_cast<int>(status));
+      return false;
+    }
+  }
+  boxes.FinalizeOutput();
+  if (!ppf->metadata.exif.empty()) {
+    // Verify that Exif box has a valid TIFF header at the specified offset.
+    // Discard bytes preceding the header.
+    if (ppf->metadata.exif.size() >= 4) {
+      uint32_t offset = LoadBE32(ppf->metadata.exif.data());
+      if (offset <= ppf->metadata.exif.size() - 8) {
+        std::vector<uint8_t> exif(ppf->metadata.exif.begin() + 4 + offset,
+                                  ppf->metadata.exif.end());
+        bool bigendian;
+        if (IsExif(exif, &bigendian)) {
+          ppf->metadata.exif = std::move(exif);
+        } else {
+          fprintf(stderr, "Warning: invalid TIFF header in Exif\n");
+        }
+      } else {
+        fprintf(stderr, "Warning: invalid Exif offset: %" PRIu32 "\n", offset);
+      }
+    } else {
+      fprintf(stderr, "Warning: invalid Exif length: %" PRIuS "\n",
+              ppf->metadata.exif.size());
+    }
+  }
+  if (jpeg_bytes != nullptr) {
+    if (!can_reconstruct_jpeg) return false;
+    size_t used_jpeg_output =
+        jpeg_data_chunk.size() - JxlDecoderReleaseJPEGBuffer(dec);
+    jpeg_bytes->insert(jpeg_bytes->end(), jpeg_data_chunk.data(),
+                       jpeg_data_chunk.data() + used_jpeg_output);
+  }
+  if (decoded_bytes) {
+    *decoded_bytes = bytes_size - JxlDecoderReleaseInput(dec);
+  }
+  return true;
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/dec/jxl.h b/third_party/jpeg-xl/lib/extras/dec/jxl.h
new file mode 100644
index 0000000000..cbada1f6dd
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/jxl.h
@@ -0,0 +1,73 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_DEC_JXL_H_
+#define LIB_EXTRAS_DEC_JXL_H_
+
+// Decodes JPEG XL images in memory.
+
+#include <jxl/parallel_runner.h>
+#include <jxl/types.h>
+#include <stdint.h>
+
+#include <limits>
+#include <string>
+#include <vector>
+
+#include "lib/extras/packed_image.h"
+
+namespace jxl {
+namespace extras {
+
+struct JXLDecompressParams {
+  // If empty, little endian float formats will be accepted.
+  std::vector<JxlPixelFormat> accepted_formats;
+
+  // Requested output color space description.
+  std::string color_space;
+  // If set, performs tone mapping to this intensity target luminance.
+  float display_nits = 0.0;
+  // Whether spot colors are rendered on the image.
+  bool render_spotcolors = true;
+  // Whether to keep or undo the orientation given in the header.
+  bool keep_orientation = false;
+
+  // If runner_opaque is set, the decoder uses this parallel runner.
+  JxlParallelRunner runner;
+  void* runner_opaque = nullptr;
+
+  // Whether truncated input should be treated as an error.
+  bool allow_partial_input = false;
+
+  // Set to true if an ICC profile has to be synthesized for Enum color
+  // encodings
+  bool need_icc = false;
+
+  // How many passes to decode at most. By default, decode everything.
+  uint32_t max_passes = std::numeric_limits<uint32_t>::max();
+
+  // Alternatively, one can specify the maximum tolerable downscaling factor
+  // with respect to the full size of the image. By default, nothing less than
+  // the full size is requested.
+  size_t max_downsampling = 1;
+
+  // Whether to use the image callback or the image buffer to get the output.
+  bool use_image_callback = true;
+  // Whether to unpremultiply colors for associated alpha channels.
+  bool unpremultiply_alpha = false;
+
+  // Controls the effective bit depth of the output pixels.
+  JxlBitDepth output_bitdepth = {JXL_BIT_DEPTH_FROM_PIXEL_FORMAT, 0, 0};
+};
+
+bool DecodeImageJXL(const uint8_t* bytes, size_t bytes_size,
+                    const JXLDecompressParams& dparams, size_t* decoded_bytes,
+                    PackedPixelFile* ppf,
+                    std::vector<uint8_t>* jpeg_bytes = nullptr);
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_DEC_JXL_H_
diff --git a/third_party/jpeg-xl/lib/extras/dec/pgx.cc b/third_party/jpeg-xl/lib/extras/dec/pgx.cc
new file mode 100644
index 0000000000..a99eb0f4ee
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/pgx.cc
@@ -0,0 +1,202 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/dec/pgx.h"
+
+#include <string.h>
+
+#include "lib/extras/size_constraints.h"
+#include "lib/jxl/base/bits.h"
+#include "lib/jxl/base/compiler_specific.h"
+
+namespace jxl {
+namespace extras {
+namespace {
+
+struct HeaderPGX {
+  // NOTE: PGX is always grayscale
+  size_t xsize;
+  size_t ysize;
+  size_t bits_per_sample;
+  bool big_endian;
+  bool is_signed;
+};
+
+class Parser {
+ public:
+  explicit Parser(const Span<const uint8_t> bytes)
+      : pos_(bytes.data()), end_(pos_ + bytes.size()) {}
+
+  // Sets "pos" to the first non-header byte/pixel on success.
+  Status ParseHeader(HeaderPGX* header, const uint8_t** pos) {
+    // codec.cc ensures we have at least two bytes => no range check here.
+    if (pos_[0] != 'P' || pos_[1] != 'G') return false;
+    pos_ += 2;
+    return ParseHeaderPGX(header, pos);
+  }
+
+  // Exposed for testing
+  Status ParseUnsigned(size_t* number) {
+    if (pos_ == end_) return JXL_FAILURE("PGX: reached end before number");
+    if (!IsDigit(*pos_)) return JXL_FAILURE("PGX: expected unsigned number");
+
+    *number = 0;
+    while (pos_ < end_ && *pos_ >= '0' && *pos_ <= '9') {
+      *number *= 10;
+      *number += *pos_ - '0';
+      ++pos_;
+    }
+
+    return true;
+  }
+
+ private:
+  static bool IsDigit(const uint8_t c) { return '0' <= c && c <= '9'; }
+  static bool IsLineBreak(const uint8_t c) { return c == '\r' || c == '\n'; }
+  static bool IsWhitespace(const uint8_t c) {
+    return IsLineBreak(c) || c == '\t' || c == ' ';
+  }
+
+  Status SkipSpace() {
+    if (pos_ == end_) return JXL_FAILURE("PGX: reached end before space");
+    const uint8_t c = *pos_;
+    if (c != ' ') return JXL_FAILURE("PGX: expected space");
+    ++pos_;
+    return true;
+  }
+
+  Status SkipLineBreak() {
+    if (pos_ == end_) return JXL_FAILURE("PGX: reached end before line break");
+    // Line break can be either "\n" (0a) or "\r\n" (0d 0a).
+    if (*pos_ == '\n') {
+      pos_++;
+      return true;
+    } else if (*pos_ == '\r' && pos_ + 1 != end_ && *(pos_ + 1) == '\n') {
+      pos_ += 2;
+      return true;
+    }
+    return JXL_FAILURE("PGX: expected line break");
+  }
+
+  Status SkipSingleWhitespace() {
+    if (pos_ == end_) return JXL_FAILURE("PGX: reached end before whitespace");
+    if (!IsWhitespace(*pos_)) return JXL_FAILURE("PGX: expected whitespace");
+    ++pos_;
+    return true;
+  }
+
+  Status ParseHeaderPGX(HeaderPGX* header, const uint8_t** pos) {
+    JXL_RETURN_IF_ERROR(SkipSpace());
+    if (pos_ + 2 > end_) return JXL_FAILURE("PGX: header too small");
+    if (*pos_ == 'M' && *(pos_ + 1) == 'L') {
+      header->big_endian = true;
+    } else if (*pos_ == 'L' && *(pos_ + 1) == 'M') {
+      header->big_endian = false;
+    } else {
+      return JXL_FAILURE("PGX: invalid endianness");
+    }
+    pos_ += 2;
+    JXL_RETURN_IF_ERROR(SkipSpace());
+    if (pos_ == end_) return JXL_FAILURE("PGX: header too small");
+    if (*pos_ == '+') {
+      header->is_signed = false;
+    } else if (*pos_ == '-') {
+      header->is_signed = true;
+    } else {
+      return JXL_FAILURE("PGX: invalid signedness");
+    }
+    pos_++;
+    // Skip optional space
+    if (pos_ < end_ && *pos_ == ' ') pos_++;
+    JXL_RETURN_IF_ERROR(ParseUnsigned(&header->bits_per_sample));
+    JXL_RETURN_IF_ERROR(SkipSingleWhitespace());
+    JXL_RETURN_IF_ERROR(ParseUnsigned(&header->xsize));
+    JXL_RETURN_IF_ERROR(SkipSingleWhitespace());
+    JXL_RETURN_IF_ERROR(ParseUnsigned(&header->ysize));
+    // 0xa, or 0xd 0xa.
+    JXL_RETURN_IF_ERROR(SkipLineBreak());
+
+    // TODO(jon): could do up to 24-bit by converting the values to
+    // JXL_TYPE_FLOAT.
+    if (header->bits_per_sample > 16) {
+      return JXL_FAILURE("PGX: >16 bits not yet supported");
+    }
+    // TODO(lode): support signed integers. This may require changing the way
+    // external_image works.
+    if (header->is_signed) {
+      return JXL_FAILURE("PGX: signed not yet supported");
+    }
+
+    size_t numpixels = header->xsize * header->ysize;
+    size_t bytes_per_pixel = header->bits_per_sample <= 8 ? 1 : 2;
+    if (pos_ + numpixels * bytes_per_pixel > end_) {
+      return JXL_FAILURE("PGX: data too small");
+    }
+
+    *pos = pos_;
+    return true;
+  }
+
+  const uint8_t* pos_;
+  const uint8_t* const end_;
+};
+
+}  // namespace
+
+Status DecodeImagePGX(const Span<const uint8_t> bytes,
+                      const ColorHints& color_hints, PackedPixelFile* ppf,
+                      const SizeConstraints* constraints) {
+  Parser parser(bytes);
+  HeaderPGX header = {};
+  const uint8_t* pos;
+  if (!parser.ParseHeader(&header, &pos)) return false;
+  JXL_RETURN_IF_ERROR(
+      VerifyDimensions(constraints, header.xsize, header.ysize));
+  if (header.bits_per_sample == 0 || header.bits_per_sample > 32) {
+    return JXL_FAILURE("PGX: bits_per_sample invalid");
+  }
+
+  JXL_RETURN_IF_ERROR(ApplyColorHints(color_hints, /*color_already_set=*/false,
+                                      /*is_gray=*/true, ppf));
+  ppf->info.xsize = header.xsize;
+  ppf->info.ysize = header.ysize;
+  // Original data is uint, so exponent_bits_per_sample = 0.
+  ppf->info.bits_per_sample = header.bits_per_sample;
+  ppf->info.exponent_bits_per_sample = 0;
+  ppf->info.uses_original_profile = true;
+
+  // No alpha in PGX
+  ppf->info.alpha_bits = 0;
+  ppf->info.alpha_exponent_bits = 0;
+  ppf->info.num_color_channels = 1;  // Always grayscale
+  ppf->info.orientation = JXL_ORIENT_IDENTITY;
+
+  JxlDataType data_type;
+  if (header.bits_per_sample > 8) {
+    data_type = JXL_TYPE_UINT16;
+  } else {
+    data_type = JXL_TYPE_UINT8;
+  }
+
+  const JxlPixelFormat format{
+      /*num_channels=*/1,
+      /*data_type=*/data_type,
+      /*endianness=*/header.big_endian ? JXL_BIG_ENDIAN : JXL_LITTLE_ENDIAN,
+      /*align=*/0,
+  };
+  ppf->frames.clear();
+  // Allocates the frame buffer.
+  ppf->frames.emplace_back(header.xsize, header.ysize, format);
+  const auto& frame = ppf->frames.back();
+  size_t pgx_remaining_size = bytes.data() + bytes.size() - pos;
+  if (pgx_remaining_size < frame.color.pixels_size) {
+    return JXL_FAILURE("PGX file too small");
+  }
+  memcpy(frame.color.pixels(), pos, frame.color.pixels_size);
+  return true;
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/dec/pgx.h b/third_party/jpeg-xl/lib/extras/dec/pgx.h
new file mode 100644
index 0000000000..ce852e6965
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/pgx.h
@@ -0,0 +1,34 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_DEC_PGX_H_
+#define LIB_EXTRAS_DEC_PGX_H_
+
+// Decodes PGX pixels in memory.
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "lib/extras/dec/color_hints.h"
+#include "lib/extras/packed_image.h"
+#include "lib/jxl/base/data_parallel.h"
+#include "lib/jxl/base/span.h"
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+
+struct SizeConstraints;
+
+namespace extras {
+
+// Decodes `bytes` into `ppf`.
+Status DecodeImagePGX(Span<const uint8_t> bytes, const ColorHints& color_hints,
+                      PackedPixelFile* ppf,
+                      const SizeConstraints* constraints = nullptr);
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_DEC_PGX_H_
diff --git a/third_party/jpeg-xl/lib/extras/dec/pgx_test.cc b/third_party/jpeg-xl/lib/extras/dec/pgx_test.cc
new file mode 100644
index 0000000000..5dbc3149a2
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/pgx_test.cc
@@ -0,0 +1,80 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/dec/pgx.h"
+
+#include <cstring>
+
+#include "lib/extras/packed_image_convert.h"
+#include "lib/jxl/image_bundle.h"
+#include "lib/jxl/testing.h"
+
+namespace jxl {
+namespace extras {
+namespace {
+
+Span<const uint8_t> MakeSpan(const char* str) {
+  return Bytes(reinterpret_cast<const uint8_t*>(str), strlen(str));
+}
+
+TEST(CodecPGXTest, Test8bits) {
+  std::string pgx = "PG ML + 8 2 3\npixels";
+
+  PackedPixelFile ppf;
+  ThreadPool* pool = nullptr;
+
+  EXPECT_TRUE(DecodeImagePGX(MakeSpan(pgx.c_str()), ColorHints(), &ppf));
+  CodecInOut io;
+  EXPECT_TRUE(ConvertPackedPixelFileToCodecInOut(ppf, pool, &io));
+
+  ScaleImage(255.f, io.Main().color());
+
+  EXPECT_FALSE(io.metadata.m.bit_depth.floating_point_sample);
+  EXPECT_EQ(8u, io.metadata.m.bit_depth.bits_per_sample);
+  EXPECT_TRUE(io.metadata.m.color_encoding.IsGray());
+  EXPECT_EQ(2u, io.xsize());
+  EXPECT_EQ(3u, io.ysize());
+
+  float eps = 1e-5;
+  EXPECT_NEAR('p', io.Main().color()->Plane(0).Row(0)[0], eps);
+  EXPECT_NEAR('i', io.Main().color()->Plane(0).Row(0)[1], eps);
+  EXPECT_NEAR('x', io.Main().color()->Plane(0).Row(1)[0], eps);
+  EXPECT_NEAR('e', io.Main().color()->Plane(0).Row(1)[1], eps);
+  EXPECT_NEAR('l', io.Main().color()->Plane(0).Row(2)[0], eps);
+  EXPECT_NEAR('s', io.Main().color()->Plane(0).Row(2)[1], eps);
+}
+
+TEST(CodecPGXTest, Test16bits) {
+  std::string pgx = "PG ML + 16 2 3\np_i_x_e_l_s_";
+
+  PackedPixelFile ppf;
+  ThreadPool* pool = nullptr;
+
+  EXPECT_TRUE(DecodeImagePGX(MakeSpan(pgx.c_str()), ColorHints(), &ppf));
+  CodecInOut io;
+  EXPECT_TRUE(ConvertPackedPixelFileToCodecInOut(ppf, pool, &io));
+
+  ScaleImage(255.f, io.Main().color());
+
+  EXPECT_FALSE(io.metadata.m.bit_depth.floating_point_sample);
+  EXPECT_EQ(16u, io.metadata.m.bit_depth.bits_per_sample);
+  EXPECT_TRUE(io.metadata.m.color_encoding.IsGray());
+  EXPECT_EQ(2u, io.xsize());
+  EXPECT_EQ(3u, io.ysize());
+
+  // Comparing ~16-bit numbers in floats, only ~7 bits left.
+  float eps = 1e-3;
+  const auto& plane = io.Main().color()->Plane(0);
+  EXPECT_NEAR(256.0f * 'p' + '_', plane.Row(0)[0] * 257, eps);
+  EXPECT_NEAR(256.0f * 'i' + '_', plane.Row(0)[1] * 257, eps);
+  EXPECT_NEAR(256.0f * 'x' + '_', plane.Row(1)[0] * 257, eps);
+  EXPECT_NEAR(256.0f * 'e' + '_', plane.Row(1)[1] * 257, eps);
+  EXPECT_NEAR(256.0f * 'l' + '_', plane.Row(2)[0] * 257, eps);
+  EXPECT_NEAR(256.0f * 's' + '_', plane.Row(2)[1] * 257, eps);
+}
+
+}  // namespace
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/dec/pnm.cc b/third_party/jpeg-xl/lib/extras/dec/pnm.cc
new file mode 100644
index 0000000000..4c4618d41d
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/pnm.cc
@@ -0,0 +1,575 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/dec/pnm.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <cmath>
+#include <mutex>
+
+#include "jxl/encode.h"
+#include "lib/extras/size_constraints.h"
+#include "lib/jxl/base/bits.h"
+#include "lib/jxl/base/compiler_specific.h"
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+namespace extras {
+namespace {
+
+class Parser {
+ public:
+  explicit Parser(const Span<const uint8_t> bytes)
+      : pos_(bytes.data()), end_(pos_ + bytes.size()) {}
+
+  // Sets "pos" to the first non-header byte/pixel on success.
+  Status ParseHeader(HeaderPNM* header, const uint8_t** pos) {
+    // codec.cc ensures we have at least two bytes => no range check here.
+    if (pos_[0] != 'P') return false;
+    const uint8_t type = pos_[1];
+    pos_ += 2;
+
+    switch (type) {
+      case '4':
+        return JXL_FAILURE("pbm not supported");
+
+      case '5':
+        header->is_gray = true;
+        return ParseHeaderPNM(header, pos);
+
+      case '6':
+        header->is_gray = false;
+        return ParseHeaderPNM(header, pos);
+
+      case '7':
+        return ParseHeaderPAM(header, pos);
+
+      case 'F':
+        header->is_gray = false;
+        return ParseHeaderPFM(header, pos);
+
+      case 'f':
+        header->is_gray = true;
+        return ParseHeaderPFM(header, pos);
+    }
+    return false;
+  }
+
+  // Exposed for testing
+  Status ParseUnsigned(size_t* number) {
+    if (pos_ == end_) return JXL_FAILURE("PNM: reached end before number");
+    if (!IsDigit(*pos_)) return JXL_FAILURE("PNM: expected unsigned number");
+
+    *number = 0;
+    while (pos_ < end_ && *pos_ >= '0' && *pos_ <= '9') {
+      *number *= 10;
+      *number += *pos_ - '0';
+      ++pos_;
+    }
+
+    return true;
+  }
+
+  Status ParseSigned(double* number) {
+    if (pos_ == end_) return JXL_FAILURE("PNM: reached end before signed");
+
+    if (*pos_ != '-' && *pos_ != '+' && !IsDigit(*pos_)) {
+      return JXL_FAILURE("PNM: expected signed number");
+    }
+
+    // Skip sign
+    const bool is_neg = *pos_ == '-';
+    if (is_neg || *pos_ == '+') {
+      ++pos_;
+      if (pos_ == end_) return JXL_FAILURE("PNM: reached end before digits");
+    }
+
+    // Leading digits
+    *number = 0.0;
+    while (pos_ < end_ && *pos_ >= '0' && *pos_ <= '9') {
+      *number *= 10;
+      *number += *pos_ - '0';
+      ++pos_;
+    }
+
+    // Decimal places?
+    if (pos_ < end_ && *pos_ == '.') {
+      ++pos_;
+      double place = 0.1;
+      while (pos_ < end_ && *pos_ >= '0' && *pos_ <= '9') {
+        *number += (*pos_ - '0') * place;
+        place *= 0.1;
+        ++pos_;
+      }
+    }
+
+    if (is_neg) *number = -*number;
+    return true;
+  }
+
+ private:
+  static bool IsDigit(const uint8_t c) { return '0' <= c && c <= '9'; }
+  static bool IsLineBreak(const uint8_t c) { return c == '\r' || c == '\n'; }
+  static bool IsWhitespace(const uint8_t c) {
+    return IsLineBreak(c) || c == '\t' || c == ' ';
+  }
+
+  Status SkipBlank() {
+    if (pos_ == end_) return JXL_FAILURE("PNM: reached end before blank");
+    const uint8_t c = *pos_;
+    if (c != ' ' && c != '\n') return JXL_FAILURE("PNM: expected blank");
+    ++pos_;
+    return true;
+  }
+
+  Status SkipSingleWhitespace() {
+    if (pos_ == end_) return JXL_FAILURE("PNM: reached end before whitespace");
+    if (!IsWhitespace(*pos_)) return JXL_FAILURE("PNM: expected whitespace");
+    ++pos_;
+    return true;
+  }
+
+  Status SkipWhitespace() {
+    if (pos_ == end_) return JXL_FAILURE("PNM: reached end before whitespace");
+    if (!IsWhitespace(*pos_) && *pos_ != '#') {
+      return JXL_FAILURE("PNM: expected whitespace/comment");
+    }
+
+    while (pos_ < end_ && IsWhitespace(*pos_)) {
+      ++pos_;
+    }
+
+    // Comment(s)
+    while (pos_ != end_ && *pos_ == '#') {
+      while (pos_ != end_ && !IsLineBreak(*pos_)) {
+        ++pos_;
+      }
+      // Newline(s)
+      while (pos_ != end_ && IsLineBreak(*pos_)) pos_++;
+    }
+
+    while (pos_ < end_ && IsWhitespace(*pos_)) {
+      ++pos_;
+    }
+    return true;
+  }
+
+  Status MatchString(const char* keyword, bool skipws = true) {
+    const uint8_t* ppos = pos_;
+    while (*keyword) {
+      if (ppos >= end_) return JXL_FAILURE("PAM: unexpected end of input");
+      if (*keyword != *ppos) return false;
+      ppos++;
+      keyword++;
+    }
+    pos_ = ppos;
+    if (skipws) {
+      JXL_RETURN_IF_ERROR(SkipWhitespace());
+    } else {
+      JXL_RETURN_IF_ERROR(SkipSingleWhitespace());
+    }
+    return true;
+  }
+
+  Status ParseHeaderPAM(HeaderPNM* header, const uint8_t** pos) {
+    size_t depth = 3;
+    size_t max_val = 255;
+    JXL_RETURN_IF_ERROR(SkipWhitespace());
+    while (!MatchString("ENDHDR", /*skipws=*/false)) {
+      if (MatchString("WIDTH")) {
+        JXL_RETURN_IF_ERROR(ParseUnsigned(&header->xsize));
+        JXL_RETURN_IF_ERROR(SkipWhitespace());
+      } else if (MatchString("HEIGHT")) {
+        JXL_RETURN_IF_ERROR(ParseUnsigned(&header->ysize));
+        JXL_RETURN_IF_ERROR(SkipWhitespace());
+      } else if (MatchString("DEPTH")) {
+        JXL_RETURN_IF_ERROR(ParseUnsigned(&depth));
+        JXL_RETURN_IF_ERROR(SkipWhitespace());
+      } else if (MatchString("MAXVAL")) {
+        JXL_RETURN_IF_ERROR(ParseUnsigned(&max_val));
+        JXL_RETURN_IF_ERROR(SkipWhitespace());
+      } else if (MatchString("TUPLTYPE")) {
+        if (MatchString("RGB_ALPHA")) {
+          header->has_alpha = true;
+        } else if (MatchString("RGB")) {
+        } else if (MatchString("GRAYSCALE_ALPHA")) {
+          header->has_alpha = true;
+          header->is_gray = true;
+        } else if (MatchString("GRAYSCALE")) {
+          header->is_gray = true;
+        } else if (MatchString("BLACKANDWHITE_ALPHA")) {
+          header->has_alpha = true;
+          header->is_gray = true;
+          max_val = 1;
+        } else if (MatchString("BLACKANDWHITE")) {
+          header->is_gray = true;
+          max_val = 1;
+        } else if (MatchString("Alpha")) {
+          header->ec_types.push_back(JXL_CHANNEL_ALPHA);
+        } else if (MatchString("Depth")) {
+          header->ec_types.push_back(JXL_CHANNEL_DEPTH);
+        } else if (MatchString("SpotColor")) {
+          header->ec_types.push_back(JXL_CHANNEL_SPOT_COLOR);
+        } else if (MatchString("SelectionMask")) {
+          header->ec_types.push_back(JXL_CHANNEL_SELECTION_MASK);
+        } else if (MatchString("Black")) {
+          header->ec_types.push_back(JXL_CHANNEL_BLACK);
+        } else if (MatchString("CFA")) {
+          header->ec_types.push_back(JXL_CHANNEL_CFA);
+        } else if (MatchString("Thermal")) {
+          header->ec_types.push_back(JXL_CHANNEL_THERMAL);
+        } else {
+          return JXL_FAILURE("PAM: unknown TUPLTYPE");
+        }
+      } else {
+        constexpr size_t kMaxHeaderLength = 20;
+        char unknown_header[kMaxHeaderLength + 1];
+        size_t len = std::min<size_t>(kMaxHeaderLength, end_ - pos_);
+        strncpy(unknown_header, reinterpret_cast<const char*>(pos_), len);
+        unknown_header[len] = 0;
+        return JXL_FAILURE("PAM: unknown header keyword: %s", unknown_header);
+      }
+    }
+    size_t num_channels = header->is_gray ? 1 : 3;
+    if (header->has_alpha) num_channels++;
+    if (num_channels + header->ec_types.size() != depth) {
+      return JXL_FAILURE("PAM: bad DEPTH");
+    }
+    if (max_val == 0 || max_val >= 65536) {
+      return JXL_FAILURE("PAM: bad MAXVAL");
+    }
+    // e.g. When `max_val` is 1 , we want 1 bit:
+    header->bits_per_sample = FloorLog2Nonzero(max_val) + 1;
+    if ((1u << header->bits_per_sample) - 1 != max_val)
+      return JXL_FAILURE("PNM: unsupported MaxVal (expected 2^n - 1)");
+    // PAM does not pack bits as in PBM.
+
+    header->floating_point = false;
+    header->big_endian = true;
+    *pos = pos_;
+    return true;
+  }
+
+  Status ParseHeaderPNM(HeaderPNM* header, const uint8_t** pos) {
+    JXL_RETURN_IF_ERROR(SkipWhitespace());
+    JXL_RETURN_IF_ERROR(ParseUnsigned(&header->xsize));
+
+    JXL_RETURN_IF_ERROR(SkipWhitespace());
+    JXL_RETURN_IF_ERROR(ParseUnsigned(&header->ysize));
+
+    JXL_RETURN_IF_ERROR(SkipWhitespace());
+    size_t max_val;
+    JXL_RETURN_IF_ERROR(ParseUnsigned(&max_val));
+    if (max_val == 0 || max_val >= 65536) {
+      return JXL_FAILURE("PNM: bad MaxVal");
+    }
+    header->bits_per_sample = FloorLog2Nonzero(max_val) + 1;
+    if ((1u << header->bits_per_sample) - 1 != max_val)
+      return JXL_FAILURE("PNM: unsupported MaxVal (expected 2^n - 1)");
+    header->floating_point = false;
+    header->big_endian = true;
+
+    JXL_RETURN_IF_ERROR(SkipSingleWhitespace());
+
+    *pos = pos_;
+    return true;
+  }
+
+  Status ParseHeaderPFM(HeaderPNM* header, const uint8_t** pos) {
+    JXL_RETURN_IF_ERROR(SkipSingleWhitespace());
+    JXL_RETURN_IF_ERROR(ParseUnsigned(&header->xsize));
+
+    JXL_RETURN_IF_ERROR(SkipBlank());
+    JXL_RETURN_IF_ERROR(ParseUnsigned(&header->ysize));
+
+    JXL_RETURN_IF_ERROR(SkipSingleWhitespace());
+    // The scale has no meaning as multiplier, only its sign is used to
+    // indicate endianness. All software expects nominal range 0..1.
+    double scale;
+    JXL_RETURN_IF_ERROR(ParseSigned(&scale));
+    if (scale == 0.0) {
+      return JXL_FAILURE("PFM: bad scale factor value.");
+    } else if (std::abs(scale) != 1.0) {
+      JXL_WARNING("PFM: Discarding non-unit scale factor");
+    }
+    header->big_endian = scale > 0.0;
+    header->bits_per_sample = 32;
+    header->floating_point = true;
+
+    JXL_RETURN_IF_ERROR(SkipSingleWhitespace());
+
+    *pos = pos_;
+    return true;
+  }
+
+  const uint8_t* pos_;
+  const uint8_t* const end_;
+};
+
+Span<const uint8_t> MakeSpan(const char* str) {
+  return Bytes(reinterpret_cast<const uint8_t*>(str), strlen(str));
+}
+
+}  // namespace
+
+struct PNMChunkedInputFrame {
+  JxlChunkedFrameInputSource operator()() {
+    return JxlChunkedFrameInputSource{
+        this,
+        METHOD_TO_C_CALLBACK(
+            &PNMChunkedInputFrame::GetColorChannelsPixelFormat),
+        METHOD_TO_C_CALLBACK(&PNMChunkedInputFrame::GetColorChannelDataAt),
+        METHOD_TO_C_CALLBACK(&PNMChunkedInputFrame::GetExtraChannelPixelFormat),
+        METHOD_TO_C_CALLBACK(&PNMChunkedInputFrame::GetExtraChannelDataAt),
+        METHOD_TO_C_CALLBACK(&PNMChunkedInputFrame::ReleaseCurrentData)};
+  }
+
+  void GetColorChannelsPixelFormat(JxlPixelFormat* pixel_format) {
+    *pixel_format = format;
+  }
+
+  const void* GetColorChannelDataAt(size_t xpos, size_t ypos, size_t xsize,
+                                    size_t ysize, size_t* row_offset) {
+    const size_t bytes_per_channel =
+        DivCeil(dec->header_.bits_per_sample, jxl::kBitsPerByte);
+    const size_t num_channels = dec->header_.is_gray ? 1 : 3;
+    const size_t bytes_per_pixel = num_channels * bytes_per_channel;
+    *row_offset = dec->header_.xsize * bytes_per_pixel;
+    const size_t offset = ypos * *row_offset + xpos * bytes_per_pixel;
+    return dec->pnm_.data() + offset + dec->data_start_;
+  }
+
+  void GetExtraChannelPixelFormat(size_t ec_index,
+                                  JxlPixelFormat* pixel_format) {
+    JXL_ABORT("Not implemented");
+  }
+
+  const void* GetExtraChannelDataAt(size_t ec_index, size_t xpos, size_t ypos,
+                                    size_t xsize, size_t ysize,
+                                    size_t* row_offset) {
+    JXL_ABORT("Not implemented");
+  }
+
+  void ReleaseCurrentData(const void* buffer) {}
+
+  JxlPixelFormat format;
+  const ChunkedPNMDecoder* dec;
+};
+
+StatusOr<ChunkedPNMDecoder> ChunkedPNMDecoder::Init(const char* path) {
+  ChunkedPNMDecoder dec;
+  JXL_ASSIGN_OR_RETURN(dec.pnm_, MemoryMappedFile::Init(path));
+  size_t size = dec.pnm_.size();
+  if (size < 2) return JXL_FAILURE("Invalid ppm");
+  size_t hdr_buf = std::min<size_t>(size, 10 * 1024);
+  Span<const uint8_t> span(dec.pnm_.data(), hdr_buf);
+  Parser parser(span);
+  HeaderPNM& header = dec.header_;
+  const uint8_t* pos = nullptr;
+  if (!parser.ParseHeader(&header, &pos)) {
+    return StatusCode::kGenericError;
+  }
+  dec.data_start_ = pos - span.data();
+
+  if (header.bits_per_sample == 0 || header.bits_per_sample > 16) {
+    return JXL_FAILURE("Invalid bits_per_sample");
+  }
+  if (header.has_alpha || !header.ec_types.empty() || header.floating_point) {
+    return JXL_FAILURE("Only PGM and PPM inputs are supported");
+  }
+
+  const size_t bytes_per_channel =
+      DivCeil(dec.header_.bits_per_sample, jxl::kBitsPerByte);
+  const size_t num_channels = dec.header_.is_gray ? 1 : 3;
+  const size_t bytes_per_pixel = num_channels * bytes_per_channel;
+  size_t row_size = dec.header_.xsize * bytes_per_pixel;
+  if (header.ysize * row_size + dec.data_start_ < size) {
+    return JXL_FAILURE("Invalid ppm");
+  }
+  return dec;
+}
+
+jxl::Status ChunkedPNMDecoder::InitializePPF(const ColorHints& color_hints,
+                                             PackedPixelFile* ppf) {
+  // PPM specifies that in the raster, the sample values are "nonlinear"
+  // (BP.709, with gamma number of 2.2). Deviate from the specification and
+  // assume `sRGB` in our implementation.
+  JXL_RETURN_IF_ERROR(ApplyColorHints(color_hints, /*color_already_set=*/false,
+                                      header_.is_gray, ppf));
+
+  ppf->info.xsize = header_.xsize;
+  ppf->info.ysize = header_.ysize;
+  ppf->info.bits_per_sample = header_.bits_per_sample;
+  ppf->info.exponent_bits_per_sample = 0;
+  ppf->info.orientation = JXL_ORIENT_IDENTITY;
+  ppf->info.alpha_bits = 0;
+  ppf->info.alpha_exponent_bits = 0;
+  ppf->info.num_color_channels = (header_.is_gray ? 1 : 3);
+  ppf->info.num_extra_channels = 0;
+
+  const JxlDataType data_type =
+      header_.bits_per_sample > 8 ? JXL_TYPE_UINT16 : JXL_TYPE_UINT8;
+  const JxlPixelFormat format{
+      /*num_channels=*/ppf->info.num_color_channels,
+      /*data_type=*/data_type,
+      /*endianness=*/header_.big_endian ? JXL_BIG_ENDIAN : JXL_LITTLE_ENDIAN,
+      /*align=*/0,
+  };
+
+  PNMChunkedInputFrame frame;
+  frame.format = format;
+  frame.dec = this;
+  ppf->chunked_frames.emplace_back(header_.xsize, header_.ysize, frame);
+  return true;
+}
+
+Status DecodeImagePNM(const Span<const uint8_t> bytes,
+                      const ColorHints& color_hints, PackedPixelFile* ppf,
+                      const SizeConstraints* constraints) {
+  Parser parser(bytes);
+  HeaderPNM header = {};
+  const uint8_t* pos = nullptr;
+  if (!parser.ParseHeader(&header, &pos)) return false;
+  JXL_RETURN_IF_ERROR(
+      VerifyDimensions(constraints, header.xsize, header.ysize));
+
+  if (header.bits_per_sample == 0 || header.bits_per_sample > 32) {
+    return JXL_FAILURE("PNM: bits_per_sample invalid");
+  }
+
+  // PPM specifies that in the raster, the sample values are "nonlinear"
+  // (BP.709, with gamma number of 2.2). Deviate from the specification and
+  // assume `sRGB` in our implementation.
+  JXL_RETURN_IF_ERROR(ApplyColorHints(color_hints, /*color_already_set=*/false,
+                                      header.is_gray, ppf));
+
+  ppf->info.xsize = header.xsize;
+  ppf->info.ysize = header.ysize;
+  if (header.floating_point) {
+    ppf->info.bits_per_sample = 32;
+    ppf->info.exponent_bits_per_sample = 8;
+  } else {
+    ppf->info.bits_per_sample = header.bits_per_sample;
+    ppf->info.exponent_bits_per_sample = 0;
+  }
+
+  ppf->info.orientation = JXL_ORIENT_IDENTITY;
+
+  // No alpha in PNM and PFM
+  ppf->info.alpha_bits = (header.has_alpha ? ppf->info.bits_per_sample : 0);
+  ppf->info.alpha_exponent_bits = 0;
+  ppf->info.num_color_channels = (header.is_gray ? 1 : 3);
+  uint32_t num_alpha_channels = (header.has_alpha ? 1 : 0);
+  uint32_t num_interleaved_channels =
+      ppf->info.num_color_channels + num_alpha_channels;
+  ppf->info.num_extra_channels = num_alpha_channels + header.ec_types.size();
+
+  for (auto type : header.ec_types) {
+    PackedExtraChannel pec;
+    pec.ec_info.bits_per_sample = ppf->info.bits_per_sample;
+    pec.ec_info.type = type;
+    ppf->extra_channels_info.emplace_back(std::move(pec));
+  }
+
+  JxlDataType data_type;
+  if (header.floating_point) {
+    // There's no float16 pnm version.
+    data_type = JXL_TYPE_FLOAT;
+  } else {
+    if (header.bits_per_sample > 8) {
+      data_type = JXL_TYPE_UINT16;
+    } else {
+      data_type = JXL_TYPE_UINT8;
+    }
+  }
+
+  const JxlPixelFormat format{
+      /*num_channels=*/num_interleaved_channels,
+      /*data_type=*/data_type,
+      /*endianness=*/header.big_endian ? JXL_BIG_ENDIAN : JXL_LITTLE_ENDIAN,
+      /*align=*/0,
+  };
+  const JxlPixelFormat ec_format{1, format.data_type, format.endianness, 0};
+  ppf->frames.clear();
+  ppf->frames.emplace_back(header.xsize, header.ysize, format);
+  auto* frame = &ppf->frames.back();
+  for (size_t i = 0; i < header.ec_types.size(); ++i) {
+    frame->extra_channels.emplace_back(header.xsize, header.ysize, ec_format);
+  }
+  size_t pnm_remaining_size = bytes.data() + bytes.size() - pos;
+  if (pnm_remaining_size < frame->color.pixels_size) {
+    return JXL_FAILURE("PNM file too small");
+  }
+
+  uint8_t* out = reinterpret_cast<uint8_t*>(frame->color.pixels());
+  std::vector<uint8_t*> ec_out(header.ec_types.size());
+  for (size_t i = 0; i < ec_out.size(); ++i) {
+    ec_out[i] = reinterpret_cast<uint8_t*>(frame->extra_channels[i].pixels());
+  }
+  if (ec_out.empty()) {
+    const bool flipped_y = header.bits_per_sample == 32;  // PFMs are flipped
+    for (size_t y = 0; y < header.ysize; ++y) {
+      size_t y_in = flipped_y ? header.ysize - 1 - y : y;
+      const uint8_t* row_in = &pos[y_in * frame->color.stride];
+      uint8_t* row_out = &out[y * frame->color.stride];
+      memcpy(row_out, row_in, frame->color.stride);
+    }
+  } else {
+    size_t pwidth = PackedImage::BitsPerChannel(data_type) / 8;
+    for (size_t y = 0; y < header.ysize; ++y) {
+      for (size_t x = 0; x < header.xsize; ++x) {
+        memcpy(out, pos, frame->color.pixel_stride());
+        out += frame->color.pixel_stride();
+        pos += frame->color.pixel_stride();
+        for (auto& p : ec_out) {
+          memcpy(p, pos, pwidth);
+          pos += pwidth;
+          p += pwidth;
+        }
+      }
+    }
+  }
+  return true;
+}
+
+void TestCodecPNM() {
+  size_t u = 77777;  // Initialized to wrong value.
+  double d = 77.77;
+// Failing to parse invalid strings results in a crash if `JXL_CRASH_ON_ERROR`
+// is defined and hence the tests fail. Therefore we only run these tests if
+// `JXL_CRASH_ON_ERROR` is not defined.
+#ifndef JXL_CRASH_ON_ERROR
+  JXL_CHECK(false == Parser(MakeSpan("")).ParseUnsigned(&u));
+  JXL_CHECK(false == Parser(MakeSpan("+")).ParseUnsigned(&u));
+  JXL_CHECK(false == Parser(MakeSpan("-")).ParseUnsigned(&u));
+  JXL_CHECK(false == Parser(MakeSpan("A")).ParseUnsigned(&u));
+
+  JXL_CHECK(false == Parser(MakeSpan("")).ParseSigned(&d));
+  JXL_CHECK(false == Parser(MakeSpan("+")).ParseSigned(&d));
+  JXL_CHECK(false == Parser(MakeSpan("-")).ParseSigned(&d));
+  JXL_CHECK(false == Parser(MakeSpan("A")).ParseSigned(&d));
+#endif
+  JXL_CHECK(true == Parser(MakeSpan("1")).ParseUnsigned(&u));
+  JXL_CHECK(u == 1);
+
+  JXL_CHECK(true == Parser(MakeSpan("32")).ParseUnsigned(&u));
+  JXL_CHECK(u == 32);
+
+  JXL_CHECK(true == Parser(MakeSpan("1")).ParseSigned(&d));
+  JXL_CHECK(d == 1.0);
+  JXL_CHECK(true == Parser(MakeSpan("+2")).ParseSigned(&d));
+  JXL_CHECK(d == 2.0);
+  JXL_CHECK(true == Parser(MakeSpan("-3")).ParseSigned(&d));
+  JXL_CHECK(std::abs(d - -3.0) < 1E-15);
+  JXL_CHECK(true == Parser(MakeSpan("3.141592")).ParseSigned(&d));
+  JXL_CHECK(std::abs(d - 3.141592) < 1E-15);
+  JXL_CHECK(true == Parser(MakeSpan("-3.141592")).ParseSigned(&d));
+  JXL_CHECK(std::abs(d - -3.141592) < 1E-15);
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/dec/pnm.h b/third_party/jpeg-xl/lib/extras/dec/pnm.h
new file mode 100644
index 0000000000..b740a79af5
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/pnm.h
@@ -0,0 +1,68 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_DEC_PNM_H_
+#define LIB_EXTRAS_DEC_PNM_H_
+
+// Decodes PBM/PGM/PPM/PFM pixels in memory.
+
+#include <stddef.h>
+#include <stdint.h>
+
+// TODO(janwas): workaround for incorrect Win64 codegen (cause unknown)
+#include <hwy/highway.h>
+#include <mutex>
+
+#include "lib/extras/dec/color_hints.h"
+#include "lib/extras/mmap.h"
+#include "lib/extras/packed_image.h"
+#include "lib/jxl/base/data_parallel.h"
+#include "lib/jxl/base/span.h"
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+
+struct SizeConstraints;
+
+namespace extras {
+
+// Decodes `bytes` into `ppf`. color_hints may specify "color_space", which
+// defaults to sRGB.
+Status DecodeImagePNM(Span<const uint8_t> bytes, const ColorHints& color_hints,
+                      PackedPixelFile* ppf,
+                      const SizeConstraints* constraints = nullptr);
+
+void TestCodecPNM();
+
+struct HeaderPNM {
+  size_t xsize;
+  size_t ysize;
+  bool is_gray;    // PGM
+  bool has_alpha;  // PAM
+  size_t bits_per_sample;
+  bool floating_point;
+  bool big_endian;
+  std::vector<JxlExtraChannelType> ec_types;  // PAM
+};
+
+class ChunkedPNMDecoder {
+ public:
+  static StatusOr<ChunkedPNMDecoder> Init(const char* file_path);
+  // Initializes `ppf` with a pointer to this `ChunkedPNMDecoder`.
+  jxl::Status InitializePPF(const ColorHints& color_hints,
+                            PackedPixelFile* ppf);
+
+ private:
+  HeaderPNM header_ = {};
+  size_t data_start_ = 0;
+  MemoryMappedFile pnm_;
+
+  friend struct PNMChunkedInputFrame;
+};
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_DEC_PNM_H_
diff --git a/third_party/jpeg-xl/lib/extras/enc/apng.cc b/third_party/jpeg-xl/lib/extras/enc/apng.cc
new file mode 100644
index 0000000000..413a9c8081
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/apng.cc
@@ -0,0 +1,452 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/enc/apng.h"
+
+// Parts of this code are taken from apngdis, which has the following license:
+/* APNG Disassembler 2.8
+ *
+ * Deconstructs APNG files into individual frames.
+ *
+ * http://apngdis.sourceforge.net
+ *
+ * Copyright (c) 2010-2015 Max Stepin
+ * maxst at users.sourceforge.net
+ *
+ * zlib license
+ * ------------
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty.  In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ *
+ */
+
+#include <string.h>
+
+#include <string>
+#include <vector>
+
+#include "lib/extras/exif.h"
+#include "lib/jxl/base/byte_order.h"
+#include "lib/jxl/base/printf_macros.h"
+#if JPEGXL_ENABLE_APNG
+#include "png.h" /* original (unpatched) libpng is ok */
+#endif
+
+namespace jxl {
+namespace extras {
+
+#if JPEGXL_ENABLE_APNG
+namespace {
+
+constexpr unsigned char kExifSignature[6] = {0x45, 0x78, 0x69,
+                                             0x66, 0x00, 0x00};
+
+class APNGEncoder : public Encoder {
+ public:
+  std::vector<JxlPixelFormat> AcceptedFormats() const override {
+    std::vector<JxlPixelFormat> formats;
+    for (const uint32_t num_channels : {1, 2, 3, 4}) {
+      for (const JxlDataType data_type : {JXL_TYPE_UINT8, JXL_TYPE_UINT16}) {
+        for (JxlEndianness endianness : {JXL_BIG_ENDIAN, JXL_LITTLE_ENDIAN}) {
+          formats.push_back(
+              JxlPixelFormat{num_channels, data_type, endianness, /*align=*/0});
+        }
+      }
+    }
+    return formats;
+  }
+  Status Encode(const PackedPixelFile& ppf, EncodedImage* encoded_image,
+                ThreadPool* pool) const override {
+    JXL_RETURN_IF_ERROR(VerifyBasicInfo(ppf.info));
+    encoded_image->icc.clear();
+    encoded_image->bitstreams.resize(1);
+    return EncodePackedPixelFileToAPNG(ppf, pool,
+                                       &encoded_image->bitstreams.front());
+  }
+
+ private:
+  Status EncodePackedPixelFileToAPNG(const PackedPixelFile& ppf,
+                                     ThreadPool* pool,
+                                     std::vector<uint8_t>* bytes) const;
+};
+
+static void PngWrite(png_structp png_ptr, png_bytep data, png_size_t length) {
+  std::vector<uint8_t>* bytes =
+      static_cast<std::vector<uint8_t>*>(png_get_io_ptr(png_ptr));
+  bytes->insert(bytes->end(), data, data + length);
+}
+
+// Stores XMP and EXIF/IPTC into key/value strings for PNG
+class BlobsWriterPNG {
+ public:
+  static Status Encode(const PackedMetadata& blobs,
+                       std::vector<std::string>* strings) {
+    if (!blobs.exif.empty()) {
+      // PNG viewers typically ignore Exif orientation but not all of them do
+      // (and e.g. cjxl doesn't), so we overwrite the Exif orientation to the
+      // identity to avoid repeated orientation.
+      std::vector<uint8_t> exif = blobs.exif;
+      ResetExifOrientation(exif);
+      // By convention, the data is prefixed with "Exif\0\0" when stored in
+      // the legacy (and non-standard) "Raw profile type exif" text chunk
+      // currently used here.
+      // TODO(user): Store Exif data in an eXIf chunk instead, which always
+      //             begins with the TIFF header.
+      if (exif.size() >= sizeof kExifSignature &&
+          memcmp(exif.data(), kExifSignature, sizeof kExifSignature) != 0) {
+        exif.insert(exif.begin(), kExifSignature,
+                    kExifSignature + sizeof kExifSignature);
+      }
+      JXL_RETURN_IF_ERROR(EncodeBase16("exif", exif, strings));
+    }
+    if (!blobs.iptc.empty()) {
+      JXL_RETURN_IF_ERROR(EncodeBase16("iptc", blobs.iptc, strings));
+    }
+    if (!blobs.xmp.empty()) {
+      // TODO(user): Store XMP data in an "XML:com.adobe.xmp" text chunk
+      //             instead.
+      JXL_RETURN_IF_ERROR(EncodeBase16("xmp", blobs.xmp, strings));
+    }
+    return true;
+  }
+
+ private:
+  static JXL_INLINE char EncodeNibble(const uint8_t nibble) {
+    JXL_ASSERT(nibble < 16);
+    return (nibble < 10) ? '0' + nibble : 'a' + nibble - 10;
+  }
+
+  static Status EncodeBase16(const std::string& type,
+                             const std::vector<uint8_t>& bytes,
+                             std::vector<std::string>* strings) {
+    // Encoding: base16 with newline after 72 chars.
+    const size_t base16_size =
+        2 * bytes.size() + DivCeil(bytes.size(), size_t(36)) + 1;
+    std::string base16;
+    base16.reserve(base16_size);
+    for (size_t i = 0; i < bytes.size(); ++i) {
+      if (i % 36 == 0) base16.push_back('\n');
+      base16.push_back(EncodeNibble(bytes[i] >> 4));
+      base16.push_back(EncodeNibble(bytes[i] & 0x0F));
+    }
+    base16.push_back('\n');
+    JXL_ASSERT(base16.length() == base16_size);
+
+    char key[30];
+    snprintf(key, sizeof(key), "Raw profile type %s", type.c_str());
+
+    char header[30];
+    snprintf(header, sizeof(header), "\n%s\n%8" PRIuS, type.c_str(),
+             bytes.size());
+
+    strings->push_back(std::string(key));
+    strings->push_back(std::string(header) + base16);
+    return true;
+  }
+};
+
+void MaybeAddCICP(const JxlColorEncoding& c_enc, png_structp png_ptr,
+                  png_infop info_ptr) {
+  png_byte cicp_data[4] = {};
+  png_unknown_chunk cicp_chunk;
+  if (c_enc.color_space != JXL_COLOR_SPACE_RGB) {
+    return;
+  }
+  if (c_enc.primaries == JXL_PRIMARIES_P3) {
+    if (c_enc.white_point == JXL_WHITE_POINT_D65) {
+      cicp_data[0] = 12;
+    } else if (c_enc.white_point == JXL_WHITE_POINT_DCI) {
+      cicp_data[0] = 11;
+    } else {
+      return;
+    }
+  } else if (c_enc.primaries != JXL_PRIMARIES_CUSTOM &&
+             c_enc.white_point == JXL_WHITE_POINT_D65) {
+    cicp_data[0] = static_cast<png_byte>(c_enc.primaries);
+  } else {
+    return;
+  }
+  if (c_enc.transfer_function == JXL_TRANSFER_FUNCTION_UNKNOWN ||
+      c_enc.transfer_function == JXL_TRANSFER_FUNCTION_GAMMA) {
+    return;
+  }
+  cicp_data[1] = static_cast<png_byte>(c_enc.transfer_function);
+  cicp_data[2] = 0;
+  cicp_data[3] = 1;
+  cicp_chunk.data = cicp_data;
+  cicp_chunk.size = sizeof(cicp_data);
+  cicp_chunk.location = PNG_HAVE_IHDR;
+  memcpy(cicp_chunk.name, "cICP", 5);
+  png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_ALWAYS,
+                              reinterpret_cast<const png_byte*>("cICP"), 1);
+  png_set_unknown_chunks(png_ptr, info_ptr, &cicp_chunk, 1);
+}
+
+bool MaybeAddSRGB(const JxlColorEncoding& c_enc, png_structp png_ptr,
+                  png_infop info_ptr) {
+  if (c_enc.transfer_function == JXL_TRANSFER_FUNCTION_SRGB &&
+      (c_enc.color_space == JXL_COLOR_SPACE_GRAY ||
+       (c_enc.color_space == JXL_COLOR_SPACE_RGB &&
+        c_enc.primaries == JXL_PRIMARIES_SRGB &&
+        c_enc.white_point == JXL_WHITE_POINT_D65))) {
+    png_set_sRGB(png_ptr, info_ptr, c_enc.rendering_intent);
+    png_set_cHRM_fixed(png_ptr, info_ptr, 31270, 32900, 64000, 33000, 30000,
+                       60000, 15000, 6000);
+    png_set_gAMA_fixed(png_ptr, info_ptr, 45455);
+    return true;
+  }
+  return false;
+}
+
+void MaybeAddCHRM(const JxlColorEncoding& c_enc, png_structp png_ptr,
+                  png_infop info_ptr) {
+  if (c_enc.color_space != JXL_COLOR_SPACE_RGB) return;
+  if (c_enc.primaries == 0) return;
+  png_set_cHRM(png_ptr, info_ptr, c_enc.white_point_xy[0],
+               c_enc.white_point_xy[1], c_enc.primaries_red_xy[0],
+               c_enc.primaries_red_xy[1], c_enc.primaries_green_xy[0],
+               c_enc.primaries_green_xy[1], c_enc.primaries_blue_xy[0],
+               c_enc.primaries_blue_xy[1]);
+}
+
+void MaybeAddGAMA(const JxlColorEncoding& c_enc, png_structp png_ptr,
+                  png_infop info_ptr) {
+  switch (c_enc.transfer_function) {
+    case JXL_TRANSFER_FUNCTION_LINEAR:
+      png_set_gAMA_fixed(png_ptr, info_ptr, PNG_FP_1);
+      break;
+    case JXL_TRANSFER_FUNCTION_SRGB:
+      png_set_gAMA_fixed(png_ptr, info_ptr, 45455);
+      break;
+    case JXL_TRANSFER_FUNCTION_GAMMA:
+      png_set_gAMA(png_ptr, info_ptr, c_enc.gamma);
+      break;
+
+    default:;
+      // No gAMA chunk.
+  }
+}
+
+void MaybeAddCLLi(const JxlColorEncoding& c_enc, const float intensity_target,
+                  png_structp png_ptr, png_infop info_ptr) {
+  if (c_enc.transfer_function != JXL_TRANSFER_FUNCTION_PQ) return;
+
+  const uint32_t max_cll =
+      static_cast<uint32_t>(10000.f * Clamp1(intensity_target, 0.f, 10000.f));
+  png_byte chunk_data[8] = {};
+  chunk_data[0] = (max_cll >> 24) & 0xFF;
+  chunk_data[1] = (max_cll >> 16) & 0xFF;
+  chunk_data[2] = (max_cll >> 8) & 0xFF;
+  chunk_data[3] = max_cll & 0xFF;
+  // Leave MaxFALL set to 0.
+  png_unknown_chunk chunk;
+  memcpy(chunk.name, "cLLi", 5);
+  chunk.data = chunk_data;
+  chunk.size = sizeof chunk_data;
+  chunk.location = PNG_HAVE_IHDR;
+  png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_ALWAYS,
+                              reinterpret_cast<const png_byte*>("cLLi"), 1);
+  png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1);
+}
+
+Status APNGEncoder::EncodePackedPixelFileToAPNG(
+    const PackedPixelFile& ppf, ThreadPool* pool,
+    std::vector<uint8_t>* bytes) const {
+  size_t xsize = ppf.info.xsize;
+  size_t ysize = ppf.info.ysize;
+  bool has_alpha = ppf.info.alpha_bits != 0;
+  bool is_gray = ppf.info.num_color_channels == 1;
+  size_t color_channels = ppf.info.num_color_channels;
+  size_t num_channels = color_channels + (has_alpha ? 1 : 0);
+  size_t num_samples = num_channels * xsize * ysize;
+
+  if (!ppf.info.have_animation && ppf.frames.size() != 1) {
+    return JXL_FAILURE("Invalid number of frames");
+  }
+
+  size_t count = 0;
+  size_t anim_chunks = 0;
+
+  for (const auto& frame : ppf.frames) {
+    JXL_RETURN_IF_ERROR(VerifyPackedImage(frame.color, ppf.info));
+
+    const PackedImage& color = frame.color;
+    const JxlPixelFormat format = color.format;
+    const uint8_t* in = reinterpret_cast<const uint8_t*>(color.pixels());
+    size_t data_bits_per_sample = PackedImage::BitsPerChannel(format.data_type);
+    size_t bytes_per_sample = data_bits_per_sample / 8;
+    size_t out_bytes_per_sample = bytes_per_sample > 1 ? 2 : 1;
+    size_t out_stride = xsize * num_channels * out_bytes_per_sample;
+    size_t out_size = ysize * out_stride;
+    std::vector<uint8_t> out(out_size);
+
+    if (format.data_type == JXL_TYPE_UINT8) {
+      if (ppf.info.bits_per_sample < 8) {
+        float mul = 255.0 / ((1u << ppf.info.bits_per_sample) - 1);
+        for (size_t i = 0; i < num_samples; ++i) {
+          out[i] = static_cast<uint8_t>(in[i] * mul + 0.5);
+        }
+      } else {
+        memcpy(&out[0], in, out_size);
+      }
+    } else if (format.data_type == JXL_TYPE_UINT16) {
+      if (ppf.info.bits_per_sample < 16 ||
+          format.endianness != JXL_BIG_ENDIAN) {
+        float mul = 65535.0 / ((1u << ppf.info.bits_per_sample) - 1);
+        const uint8_t* p_in = in;
+        uint8_t* p_out = out.data();
+        for (size_t i = 0; i < num_samples; ++i, p_in += 2, p_out += 2) {
+          uint32_t val = (format.endianness == JXL_BIG_ENDIAN ? LoadBE16(p_in)
+                                                              : LoadLE16(p_in));
+          StoreBE16(static_cast<uint32_t>(val * mul + 0.5), p_out);
+        }
+      } else {
+        memcpy(&out[0], in, out_size);
+      }
+    }
+    png_structp png_ptr;
+    png_infop info_ptr;
+
+    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+
+    if (!png_ptr) return JXL_FAILURE("Could not init png encoder");
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) return JXL_FAILURE("Could not init png info struct");
+
+    png_set_write_fn(png_ptr, bytes, PngWrite, NULL);
+    png_set_flush(png_ptr, 0);
+
+    int width = xsize;
+    int height = ysize;
+
+    png_byte color_type = (is_gray ? PNG_COLOR_TYPE_GRAY : PNG_COLOR_TYPE_RGB);
+    if (has_alpha) color_type |= PNG_COLOR_MASK_ALPHA;
+    png_byte bit_depth = out_bytes_per_sample * 8;
+
+    png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, color_type,
+                 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
+                 PNG_FILTER_TYPE_BASE);
+    if (count == 0) {
+      if (!ppf.icc.empty()) {
+        png_set_benign_errors(png_ptr, 1);
+        png_set_iCCP(png_ptr, info_ptr, "1", 0, ppf.icc.data(), ppf.icc.size());
+      } else if (!MaybeAddSRGB(ppf.color_encoding, png_ptr, info_ptr)) {
+        MaybeAddCICP(ppf.color_encoding, png_ptr, info_ptr);
+        MaybeAddCHRM(ppf.color_encoding, png_ptr, info_ptr);
+        MaybeAddGAMA(ppf.color_encoding, png_ptr, info_ptr);
+      }
+      MaybeAddCLLi(ppf.color_encoding, ppf.info.intensity_target, png_ptr,
+                   info_ptr);
+
+      std::vector<std::string> textstrings;
+      JXL_RETURN_IF_ERROR(BlobsWriterPNG::Encode(ppf.metadata, &textstrings));
+      for (size_t kk = 0; kk + 1 < textstrings.size(); kk += 2) {
+        png_text text;
+        text.key = const_cast<png_charp>(textstrings[kk].c_str());
+        text.text = const_cast<png_charp>(textstrings[kk + 1].c_str());
+        text.compression = PNG_TEXT_COMPRESSION_zTXt;
+        png_set_text(png_ptr, info_ptr, &text, 1);
+      }
+
+      png_write_info(png_ptr, info_ptr);
+    } else {
+      // fake writing a header, otherwise libpng gets confused
+      size_t pos = bytes->size();
+      png_write_info(png_ptr, info_ptr);
+      bytes->resize(pos);
+    }
+
+    if (ppf.info.have_animation) {
+      if (count == 0) {
+        png_byte adata[8];
+        png_save_uint_32(adata, ppf.frames.size());
+        png_save_uint_32(adata + 4, ppf.info.animation.num_loops);
+        png_byte actl[5] = "acTL";
+        png_write_chunk(png_ptr, actl, adata, 8);
+      }
+      png_byte fdata[26];
+      // TODO(jon): also make this work for the non-coalesced case
+      png_save_uint_32(fdata, anim_chunks++);
+      png_save_uint_32(fdata + 4, width);
+      png_save_uint_32(fdata + 8, height);
+      png_save_uint_32(fdata + 12, 0);
+      png_save_uint_32(fdata + 16, 0);
+      png_save_uint_16(fdata + 20, frame.frame_info.duration *
+                                       ppf.info.animation.tps_denominator);
+      png_save_uint_16(fdata + 22, ppf.info.animation.tps_numerator);
+      fdata[24] = 1;
+      fdata[25] = 0;
+      png_byte fctl[5] = "fcTL";
+      png_write_chunk(png_ptr, fctl, fdata, 26);
+    }
+
+    std::vector<uint8_t*> rows(height);
+    for (int y = 0; y < height; ++y) {
+      rows[y] = out.data() + y * out_stride;
+    }
+
+    png_write_flush(png_ptr);
+    const size_t pos = bytes->size();
+    png_write_image(png_ptr, &rows[0]);
+    png_write_flush(png_ptr);
+    if (count > 0) {
+      std::vector<uint8_t> fdata(4);
+      png_save_uint_32(fdata.data(), anim_chunks++);
+      size_t p = pos;
+      while (p + 8 < bytes->size()) {
+        size_t len = png_get_uint_32(bytes->data() + p);
+        JXL_ASSERT(bytes->operator[](p + 4) == 'I');
+        JXL_ASSERT(bytes->operator[](p + 5) == 'D');
+        JXL_ASSERT(bytes->operator[](p + 6) == 'A');
+        JXL_ASSERT(bytes->operator[](p + 7) == 'T');
+        fdata.insert(fdata.end(), bytes->data() + p + 8,
+                     bytes->data() + p + 8 + len);
+        p += len + 12;
+      }
+      bytes->resize(pos);
+
+      png_byte fdat[5] = "fdAT";
+      png_write_chunk(png_ptr, fdat, fdata.data(), fdata.size());
+    }
+
+    count++;
+    if (count == ppf.frames.size() || !ppf.info.have_animation) {
+      png_write_end(png_ptr, NULL);
+    }
+
+    png_destroy_write_struct(&png_ptr, &info_ptr);
+  }
+
+  return true;
+}
+
+}  // namespace
+#endif
+
+std::unique_ptr<Encoder> GetAPNGEncoder() {
+#if JPEGXL_ENABLE_APNG
+  return jxl::make_unique<APNGEncoder>();
+#else
+  return nullptr;
+#endif
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/enc/apng.h b/third_party/jpeg-xl/lib/extras/enc/apng.h
new file mode 100644
index 0000000000..2a2139c8fa
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/apng.h
@@ -0,0 +1,23 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_ENC_APNG_H_
+#define LIB_EXTRAS_ENC_APNG_H_
+
+// Encodes APNG images in memory.
+
+#include <memory>
+
+#include "lib/extras/enc/encode.h"
+
+namespace jxl {
+namespace extras {
+
+std::unique_ptr<Encoder> GetAPNGEncoder();
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_ENC_APNG_H_
diff --git a/third_party/jpeg-xl/lib/extras/enc/encode.cc b/third_party/jpeg-xl/lib/extras/enc/encode.cc
new file mode 100644
index 0000000000..8c9a148b27
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/encode.cc
@@ -0,0 +1,138 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/enc/encode.h"
+
+#include <locale>
+
+#include "lib/extras/enc/apng.h"
+#include "lib/extras/enc/exr.h"
+#include "lib/extras/enc/jpg.h"
+#include "lib/extras/enc/npy.h"
+#include "lib/extras/enc/pgx.h"
+#include "lib/extras/enc/pnm.h"
+
+namespace jxl {
+namespace extras {
+
+Status Encoder::VerifyBasicInfo(const JxlBasicInfo& info) {
+  if (info.xsize == 0 || info.ysize == 0) {
+    return JXL_FAILURE("Empty image");
+  }
+  if (info.num_color_channels != 1 && info.num_color_channels != 3) {
+    return JXL_FAILURE("Invalid number of color channels");
+  }
+  if (info.alpha_bits > 0 && info.alpha_bits != info.bits_per_sample) {
+    return JXL_FAILURE("Alpha bit depth does not match image bit depth");
+  }
+  if (info.orientation != JXL_ORIENT_IDENTITY) {
+    return JXL_FAILURE("Orientation must be identity");
+  }
+  return true;
+}
+
+Status Encoder::VerifyFormat(const JxlPixelFormat& format) const {
+  for (auto f : AcceptedFormats()) {
+    if (f.num_channels != format.num_channels) continue;
+    if (f.data_type != format.data_type) continue;
+    if (f.data_type == JXL_TYPE_UINT8 || f.endianness == format.endianness) {
+      return true;
+    }
+  }
+  return JXL_FAILURE("Format is not in the list of accepted formats.");
+}
+
+Status Encoder::VerifyBitDepth(JxlDataType data_type, uint32_t bits_per_sample,
+                               uint32_t exponent_bits) {
+  if ((data_type == JXL_TYPE_UINT8 &&
+       (bits_per_sample == 0 || bits_per_sample > 8 || exponent_bits != 0)) ||
+      (data_type == JXL_TYPE_UINT16 &&
+       (bits_per_sample <= 8 || bits_per_sample > 16 || exponent_bits != 0)) ||
+      (data_type == JXL_TYPE_FLOAT16 &&
+       (bits_per_sample > 16 || exponent_bits > 5))) {
+    return JXL_FAILURE(
+        "Incompatible data_type %d and bit depth %u with exponent bits %u",
+        (int)data_type, bits_per_sample, exponent_bits);
+  }
+  return true;
+}
+
+Status Encoder::VerifyImageSize(const PackedImage& image,
+                                const JxlBasicInfo& info) {
+  if (image.pixels() == nullptr) {
+    return JXL_FAILURE("Invalid image.");
+  }
+  if (image.stride != image.xsize * image.pixel_stride()) {
+    return JXL_FAILURE("Invalid image stride.");
+  }
+  if (image.pixels_size != image.ysize * image.stride) {
+    return JXL_FAILURE("Invalid image size.");
+  }
+  size_t info_num_channels =
+      (info.num_color_channels + (info.alpha_bits > 0 ? 1 : 0));
+  if (image.xsize != info.xsize || image.ysize != info.ysize ||
+      image.format.num_channels != info_num_channels) {
+    return JXL_FAILURE("Frame size does not match image size");
+  }
+  return true;
+}
+
+Status Encoder::VerifyPackedImage(const PackedImage& image,
+                                  const JxlBasicInfo& info) const {
+  JXL_RETURN_IF_ERROR(VerifyImageSize(image, info));
+  JXL_RETURN_IF_ERROR(VerifyFormat(image.format));
+  JXL_RETURN_IF_ERROR(VerifyBitDepth(image.format.data_type,
+                                     info.bits_per_sample,
+                                     info.exponent_bits_per_sample));
+  return true;
+}
+
+template <int metadata>
+class MetadataEncoder : public Encoder {
+ public:
+  std::vector<JxlPixelFormat> AcceptedFormats() const override {
+    std::vector<JxlPixelFormat> formats;
+    // empty, i.e. no need for actual pixel data
+    return formats;
+  }
+
+  Status Encode(const PackedPixelFile& ppf, EncodedImage* encoded,
+                ThreadPool* pool) const override {
+    JXL_RETURN_IF_ERROR(VerifyBasicInfo(ppf.info));
+    encoded->icc.clear();
+    encoded->bitstreams.resize(1);
+    if (metadata == 0) encoded->bitstreams.front() = ppf.metadata.exif;
+    if (metadata == 1) encoded->bitstreams.front() = ppf.metadata.xmp;
+    if (metadata == 2) encoded->bitstreams.front() = ppf.metadata.jumbf;
+    return true;
+  }
+};
+
+std::unique_ptr<Encoder> Encoder::FromExtension(std::string extension) {
+  std::transform(
+      extension.begin(), extension.end(), extension.begin(),
+      [](char c) { return std::tolower(c, std::locale::classic()); });
+  if (extension == ".png" || extension == ".apng") return GetAPNGEncoder();
+  if (extension == ".jpg") return GetJPEGEncoder();
+  if (extension == ".jpeg") return GetJPEGEncoder();
+  if (extension == ".npy") return GetNumPyEncoder();
+  if (extension == ".pgx") return GetPGXEncoder();
+  if (extension == ".pam") return GetPAMEncoder();
+  if (extension == ".pgm") return GetPGMEncoder();
+  if (extension == ".ppm") return GetPPMEncoder();
+  if (extension == ".pnm") return GetPNMEncoder();
+  if (extension == ".pfm") return GetPFMEncoder();
+  if (extension == ".exr") return GetEXREncoder();
+  if (extension == ".exif") return jxl::make_unique<MetadataEncoder<0>>();
+  if (extension == ".xmp") return jxl::make_unique<MetadataEncoder<1>>();
+  if (extension == ".xml") return jxl::make_unique<MetadataEncoder<1>>();
+  if (extension == ".jumbf") return jxl::make_unique<MetadataEncoder<2>>();
+  if (extension == ".jumb") return jxl::make_unique<MetadataEncoder<2>>();
+
+  return nullptr;
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/enc/encode.h b/third_party/jpeg-xl/lib/extras/enc/encode.h
new file mode 100644
index 0000000000..da5f509838
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/encode.h
@@ -0,0 +1,88 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_ENC_ENCODE_H_
+#define LIB_EXTRAS_ENC_ENCODE_H_
+
+// Facade for image encoders.
+
+#include <jxl/codestream_header.h>
+#include <jxl/types.h>
+
+#include <cstdint>
+#include <memory>
+#include <string>
+#include <unordered_map>
+#include <utility>
+#include <vector>
+
+#include "lib/extras/packed_image.h"
+#include "lib/jxl/base/data_parallel.h"
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+namespace extras {
+
+struct EncodedImage {
+  // One (if the format supports animations or the image has only one frame) or
+  // more 1quential bitstreams.
+  std::vector<std::vector<uint8_t>> bitstreams;
+
+  // For each extra channel one or more sequential bitstreams.
+  std::vector<std::vector<std::vector<uint8_t>>> extra_channel_bitstreams;
+
+  std::vector<uint8_t> preview_bitstream;
+
+  // If the format does not support embedding color profiles into the bitstreams
+  // above, it will be present here, to be written as a separate file. If it
+  // does support them, this field will be empty.
+  std::vector<uint8_t> icc;
+
+  // Additional output for conformance testing, only filled in by NumPyEncoder.
+  std::vector<uint8_t> metadata;
+};
+
+class Encoder {
+ public:
+  static std::unique_ptr<Encoder> FromExtension(std::string extension);
+
+  virtual ~Encoder() = default;
+
+  // Set of pixel formats that this encoder takes as input.
+  // If empty, the 'encoder' does not need any pixels (it's metadata-only).
+  virtual std::vector<JxlPixelFormat> AcceptedFormats() const = 0;
+
+  // Any existing data in encoded_image is discarded.
+  virtual Status Encode(const PackedPixelFile& ppf, EncodedImage* encoded_image,
+                        ThreadPool* pool = nullptr) const = 0;
+
+  void SetOption(std::string name, std::string value) {
+    options_[std::move(name)] = std::move(value);
+  }
+
+  static Status VerifyBasicInfo(const JxlBasicInfo& info);
+  static Status VerifyImageSize(const PackedImage& image,
+                                const JxlBasicInfo& info);
+  static Status VerifyBitDepth(JxlDataType data_type, uint32_t bits_per_sample,
+                               uint32_t exponent_bits);
+
+ protected:
+  const std::unordered_map<std::string, std::string>& options() const {
+    return options_;
+  }
+
+  Status VerifyFormat(const JxlPixelFormat& format) const;
+
+  Status VerifyPackedImage(const PackedImage& image,
+                           const JxlBasicInfo& info) const;
+
+ private:
+  std::unordered_map<std::string, std::string> options_;
+};
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_ENC_ENCODE_H_
diff --git a/third_party/jpeg-xl/lib/extras/enc/exr.cc b/third_party/jpeg-xl/lib/extras/enc/exr.cc
new file mode 100644
index 0000000000..d4005c3097
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/exr.cc
@@ -0,0 +1,208 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/enc/exr.h"
+
+#if JPEGXL_ENABLE_EXR
+#include <ImfChromaticitiesAttribute.h>
+#include <ImfIO.h>
+#include <ImfRgbaFile.h>
+#include <ImfStandardAttributes.h>
+#endif
+#include <jxl/codestream_header.h>
+
+#include <vector>
+
+#include "lib/extras/packed_image.h"
+#include "lib/jxl/base/byte_order.h"
+
+namespace jxl {
+namespace extras {
+
+#if JPEGXL_ENABLE_EXR
+namespace {
+
+namespace OpenEXR = OPENEXR_IMF_NAMESPACE;
+namespace Imath = IMATH_NAMESPACE;
+
+// OpenEXR::Int64 is deprecated in favor of using uint64_t directly, but using
+// uint64_t as recommended causes build failures with previous OpenEXR versions
+// on macOS, where the definition for OpenEXR::Int64 was actually not equivalent
+// to uint64_t. This alternative should work in all cases.
+using ExrInt64 = decltype(std::declval<OpenEXR::IStream>().tellg());
+
+class InMemoryOStream : public OpenEXR::OStream {
+ public:
+  // `bytes` must outlive the InMemoryOStream.
+  explicit InMemoryOStream(std::vector<uint8_t>* const bytes)
+      : OStream(/*fileName=*/""), bytes_(*bytes) {}
+
+  void write(const char c[], const int n) override {
+    if (bytes_.size() < pos_ + n) {
+      bytes_.resize(pos_ + n);
+    }
+    std::copy_n(c, n, bytes_.begin() + pos_);
+    pos_ += n;
+  }
+
+  ExrInt64 tellp() override { return pos_; }
+  void seekp(const ExrInt64 pos) override {
+    if (bytes_.size() + 1 < pos) {
+      bytes_.resize(pos - 1);
+    }
+    pos_ = pos;
+  }
+
+ private:
+  std::vector<uint8_t>& bytes_;
+  size_t pos_ = 0;
+};
+
+// Loads a Big-Endian float
+float LoadBEFloat(const uint8_t* p) {
+  uint32_t u = LoadBE32(p);
+  float result;
+  memcpy(&result, &u, 4);
+  return result;
+}
+
+// Loads a Little-Endian float
+float LoadLEFloat(const uint8_t* p) {
+  uint32_t u = LoadLE32(p);
+  float result;
+  memcpy(&result, &u, 4);
+  return result;
+}
+
+Status EncodeImageEXR(const PackedImage& image, const JxlBasicInfo& info,
+                      const JxlColorEncoding& c_enc, ThreadPool* pool,
+                      std::vector<uint8_t>* bytes) {
+  OpenEXR::setGlobalThreadCount(0);
+
+  const size_t xsize = info.xsize;
+  const size_t ysize = info.ysize;
+  const bool has_alpha = info.alpha_bits > 0;
+  const bool alpha_is_premultiplied = info.alpha_premultiplied;
+
+  if (info.num_color_channels != 3 ||
+      c_enc.color_space != JXL_COLOR_SPACE_RGB ||
+      c_enc.transfer_function != JXL_TRANSFER_FUNCTION_LINEAR) {
+    return JXL_FAILURE("Unsupported color encoding for OpenEXR output.");
+  }
+
+  const size_t num_channels = 3 + (has_alpha ? 1 : 0);
+  const JxlPixelFormat format = image.format;
+
+  if (format.data_type != JXL_TYPE_FLOAT) {
+    return JXL_FAILURE("Unsupported pixel format for OpenEXR output");
+  }
+
+  const uint8_t* in = reinterpret_cast<const uint8_t*>(image.pixels());
+  size_t in_stride = num_channels * 4 * xsize;
+
+  OpenEXR::Header header(xsize, ysize);
+  OpenEXR::Chromaticities chromaticities;
+  chromaticities.red =
+      Imath::V2f(c_enc.primaries_red_xy[0], c_enc.primaries_red_xy[1]);
+  chromaticities.green =
+      Imath::V2f(c_enc.primaries_green_xy[0], c_enc.primaries_green_xy[1]);
+  chromaticities.blue =
+      Imath::V2f(c_enc.primaries_blue_xy[0], c_enc.primaries_blue_xy[1]);
+  chromaticities.white =
+      Imath::V2f(c_enc.white_point_xy[0], c_enc.white_point_xy[1]);
+  OpenEXR::addChromaticities(header, chromaticities);
+  OpenEXR::addWhiteLuminance(header, info.intensity_target);
+
+  auto loadFloat =
+      format.endianness == JXL_BIG_ENDIAN ? LoadBEFloat : LoadLEFloat;
+  auto loadAlpha =
+      has_alpha ? loadFloat : [](const uint8_t* p) -> float { return 1.0f; };
+
+  // Ensure that the destructor of RgbaOutputFile has run before we look at the
+  // size of `bytes`.
+  {
+    InMemoryOStream os(bytes);
+    OpenEXR::RgbaOutputFile output(
+        os, header, has_alpha ? OpenEXR::WRITE_RGBA : OpenEXR::WRITE_RGB);
+    // How many rows to write at once. Again, the OpenEXR documentation
+    // recommends writing the whole image in one call.
+    const int y_chunk_size = ysize;
+    std::vector<OpenEXR::Rgba> output_rows(xsize * y_chunk_size);
+
+    for (size_t start_y = 0; start_y < ysize; start_y += y_chunk_size) {
+      // Inclusive.
+      const size_t end_y = std::min(start_y + y_chunk_size - 1, ysize - 1);
+      output.setFrameBuffer(output_rows.data() - start_y * xsize,
+                            /*xStride=*/1, /*yStride=*/xsize);
+      for (size_t y = start_y; y <= end_y; ++y) {
+        const uint8_t* in_row = &in[(y - start_y) * in_stride];
+        OpenEXR::Rgba* const JXL_RESTRICT row_data =
+            &output_rows[(y - start_y) * xsize];
+        for (size_t x = 0; x < xsize; ++x) {
+          const uint8_t* in_pixel = &in_row[4 * num_channels * x];
+          float r = loadFloat(&in_pixel[0]);
+          float g = loadFloat(&in_pixel[4]);
+          float b = loadFloat(&in_pixel[8]);
+          const float alpha = loadAlpha(&in_pixel[12]);
+          if (!alpha_is_premultiplied) {
+            r *= alpha;
+            g *= alpha;
+            b *= alpha;
+          }
+          row_data[x] = OpenEXR::Rgba(r, g, b, alpha);
+        }
+      }
+      output.writePixels(/*numScanLines=*/end_y - start_y + 1);
+    }
+  }
+
+  return true;
+}
+
+class EXREncoder : public Encoder {
+  std::vector<JxlPixelFormat> AcceptedFormats() const override {
+    std::vector<JxlPixelFormat> formats;
+    for (const uint32_t num_channels : {1, 2, 3, 4}) {
+      for (const JxlDataType data_type : {JXL_TYPE_FLOAT}) {
+        for (JxlEndianness endianness : {JXL_BIG_ENDIAN, JXL_LITTLE_ENDIAN}) {
+          formats.push_back(JxlPixelFormat{/*num_channels=*/num_channels,
+                                           /*data_type=*/data_type,
+                                           /*endianness=*/endianness,
+                                           /*align=*/0});
+        }
+      }
+    }
+    return formats;
+  }
+  Status Encode(const PackedPixelFile& ppf, EncodedImage* encoded_image,
+                ThreadPool* pool = nullptr) const override {
+    JXL_RETURN_IF_ERROR(VerifyBasicInfo(ppf.info));
+    encoded_image->icc.clear();
+    encoded_image->bitstreams.clear();
+    encoded_image->bitstreams.reserve(ppf.frames.size());
+    for (const auto& frame : ppf.frames) {
+      JXL_RETURN_IF_ERROR(VerifyPackedImage(frame.color, ppf.info));
+      encoded_image->bitstreams.emplace_back();
+      JXL_RETURN_IF_ERROR(EncodeImageEXR(frame.color, ppf.info,
+                                         ppf.color_encoding, pool,
+                                         &encoded_image->bitstreams.back()));
+    }
+    return true;
+  }
+};
+
+}  // namespace
+#endif
+
+std::unique_ptr<Encoder> GetEXREncoder() {
+#if JPEGXL_ENABLE_EXR
+  return jxl::make_unique<EXREncoder>();
+#else
+  return nullptr;
+#endif
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/enc/exr.h b/third_party/jpeg-xl/lib/extras/enc/exr.h
new file mode 100644
index 0000000000..1baaa0272f
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/exr.h
@@ -0,0 +1,23 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_ENC_EXR_H_
+#define LIB_EXTRAS_ENC_EXR_H_
+
+// Encodes OpenEXR images in memory.
+
+#include <memory>
+
+#include "lib/extras/enc/encode.h"
+
+namespace jxl {
+namespace extras {
+
+std::unique_ptr<Encoder> GetEXREncoder();
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_ENC_EXR_H_
diff --git a/third_party/jpeg-xl/lib/extras/enc/jpegli.cc b/third_party/jpeg-xl/lib/extras/enc/jpegli.cc
new file mode 100644
index 0000000000..7e1aa426df
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/jpegli.cc
@@ -0,0 +1,544 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/enc/jpegli.h"
+
+#include <jxl/cms.h>
+#include <jxl/codestream_header.h>
+#include <jxl/types.h>
+#include <setjmp.h>
+#include <stdint.h>
+
+#include <algorithm>
+#include <cmath>
+#include <cstddef>
+#include <cstdlib>
+#include <cstring>
+#include <hwy/aligned_allocator.h>
+#include <limits>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "lib/extras/enc/encode.h"
+#include "lib/extras/packed_image.h"
+#include "lib/jpegli/common.h"
+#include "lib/jpegli/encode.h"
+#include "lib/jpegli/types.h"
+#include "lib/jxl/base/byte_order.h"
+#include "lib/jxl/base/common.h"
+#include "lib/jxl/base/data_parallel.h"
+#include "lib/jxl/base/status.h"
+#include "lib/jxl/color_encoding_internal.h"
+#include "lib/jxl/enc_xyb.h"
+#include "lib/jxl/image.h"
+
+namespace jxl {
+namespace extras {
+
+namespace {
+
+void MyErrorExit(j_common_ptr cinfo) {
+  jmp_buf* env = static_cast<jmp_buf*>(cinfo->client_data);
+  (*cinfo->err->output_message)(cinfo);
+  jpegli_destroy_compress(reinterpret_cast<j_compress_ptr>(cinfo));
+  longjmp(*env, 1);
+}
+
+Status VerifyInput(const PackedPixelFile& ppf) {
+  const JxlBasicInfo& info = ppf.info;
+  JXL_RETURN_IF_ERROR(Encoder::VerifyBasicInfo(info));
+  if (ppf.frames.size() != 1) {
+    return JXL_FAILURE("JPEG input must have exactly one frame.");
+  }
+  const PackedImage& image = ppf.frames[0].color;
+  JXL_RETURN_IF_ERROR(Encoder::VerifyImageSize(image, info));
+  if (image.format.data_type == JXL_TYPE_FLOAT16) {
+    return JXL_FAILURE("FLOAT16 input is not supported.");
+  }
+  JXL_RETURN_IF_ERROR(Encoder::VerifyBitDepth(image.format.data_type,
+                                              info.bits_per_sample,
+                                              info.exponent_bits_per_sample));
+  if ((image.format.data_type == JXL_TYPE_UINT8 && info.bits_per_sample != 8) ||
+      (image.format.data_type == JXL_TYPE_UINT16 &&
+       info.bits_per_sample != 16)) {
+    return JXL_FAILURE("Only full bit depth unsigned types are supported.");
+  }
+  return true;
+}
+
+Status GetColorEncoding(const PackedPixelFile& ppf,
+                        ColorEncoding* color_encoding) {
+  if (!ppf.icc.empty()) {
+    IccBytes icc = ppf.icc;
+    JXL_RETURN_IF_ERROR(
+        color_encoding->SetICC(std::move(icc), JxlGetDefaultCms()));
+  } else {
+    JXL_RETURN_IF_ERROR(color_encoding->FromExternal(ppf.color_encoding));
+  }
+  if (color_encoding->ICC().empty()) {
+    return JXL_FAILURE("Invalid color encoding.");
+  }
+  return true;
+}
+
+bool HasICCProfile(const std::vector<uint8_t>& app_data) {
+  size_t pos = 0;
+  while (pos < app_data.size()) {
+    if (pos + 16 > app_data.size()) return false;
+    uint8_t marker = app_data[pos + 1];
+    size_t marker_len = (app_data[pos + 2] << 8) + app_data[pos + 3] + 2;
+    if (marker == 0xe2 && memcmp(&app_data[pos + 4], "ICC_PROFILE", 12) == 0) {
+      return true;
+    }
+    pos += marker_len;
+  }
+  return false;
+}
+
+Status WriteAppData(j_compress_ptr cinfo,
+                    const std::vector<uint8_t>& app_data) {
+  size_t pos = 0;
+  while (pos < app_data.size()) {
+    if (pos + 4 > app_data.size()) {
+      return JXL_FAILURE("Incomplete APP header.");
+    }
+    uint8_t marker = app_data[pos + 1];
+    size_t marker_len = (app_data[pos + 2] << 8) + app_data[pos + 3] + 2;
+    if (app_data[pos] != 0xff || marker < 0xe0 || marker > 0xef) {
+      return JXL_FAILURE("Invalid APP marker %02x %02x", app_data[pos], marker);
+    }
+    if (marker_len <= 4) {
+      return JXL_FAILURE("Invalid APP marker length.");
+    }
+    if (pos + marker_len > app_data.size()) {
+      return JXL_FAILURE("Incomplete APP data");
+    }
+    jpegli_write_marker(cinfo, marker, &app_data[pos + 4], marker_len - 4);
+    pos += marker_len;
+  }
+  return true;
+}
+
+static constexpr int kICCMarker = 0xe2;
+constexpr unsigned char kICCSignature[12] = {
+    0x49, 0x43, 0x43, 0x5F, 0x50, 0x52, 0x4F, 0x46, 0x49, 0x4C, 0x45, 0x00};
+static constexpr uint8_t kUnknownTf = 2;
+static constexpr unsigned char kCICPTagSignature[4] = {0x63, 0x69, 0x63, 0x70};
+static constexpr size_t kCICPTagSize = 12;
+
+bool FindCICPTag(const uint8_t* icc_data, size_t len, bool is_first_chunk,
+                 size_t* cicp_offset, size_t* cicp_length, uint8_t* cicp_tag,
+                 size_t* cicp_pos) {
+  if (is_first_chunk) {
+    // Look up the offset of the CICP tag from the first chunk of ICC data.
+    if (len < 132) {
+      return false;
+    }
+    uint32_t tag_count = LoadBE32(&icc_data[128]);
+    if (len < 132 + 12 * tag_count) {
+      return false;
+    }
+    for (uint32_t i = 0; i < tag_count; ++i) {
+      if (memcmp(&icc_data[132 + 12 * i], kCICPTagSignature, 4) == 0) {
+        *cicp_offset = LoadBE32(&icc_data[136 + 12 * i]);
+        *cicp_length = LoadBE32(&icc_data[140 + 12 * i]);
+      }
+    }
+    if (*cicp_length < kCICPTagSize) {
+      return false;
+    }
+  }
+  if (*cicp_offset < len) {
+    size_t n_bytes = std::min(len - *cicp_offset, kCICPTagSize - *cicp_pos);
+    memcpy(&cicp_tag[*cicp_pos], &icc_data[*cicp_offset], n_bytes);
+    *cicp_pos += n_bytes;
+    *cicp_offset = 0;
+  } else {
+    *cicp_offset -= len;
+  }
+  return true;
+}
+
+uint8_t LookupCICPTransferFunctionFromAppData(const uint8_t* app_data,
+                                              size_t len) {
+  size_t last_index = 0;
+  size_t cicp_offset = 0;
+  size_t cicp_length = 0;
+  uint8_t cicp_tag[kCICPTagSize] = {};
+  size_t cicp_pos = 0;
+  size_t pos = 0;
+  while (pos < len) {
+    const uint8_t* marker = &app_data[pos];
+    if (pos + 4 > len) {
+      return kUnknownTf;
+    }
+    size_t marker_size = (marker[2] << 8) + marker[3] + 2;
+    if (pos + marker_size > len) {
+      return kUnknownTf;
+    }
+    if (marker_size < 18 || marker[0] != 0xff || marker[1] != kICCMarker ||
+        memcmp(&marker[4], kICCSignature, 12) != 0) {
+      pos += marker_size;
+      continue;
+    }
+    uint8_t index = marker[16];
+    uint8_t total = marker[17];
+    const uint8_t* payload = marker + 18;
+    const size_t payload_size = marker_size - 18;
+    if (index != last_index + 1 || index > total) {
+      return kUnknownTf;
+    }
+    if (!FindCICPTag(payload, payload_size, last_index == 0, &cicp_offset,
+                     &cicp_length, &cicp_tag[0], &cicp_pos)) {
+      return kUnknownTf;
+    }
+    if (cicp_pos == kCICPTagSize) {
+      break;
+    }
+    ++last_index;
+  }
+  if (cicp_pos >= kCICPTagSize && memcmp(cicp_tag, kCICPTagSignature, 4) == 0) {
+    return cicp_tag[9];
+  }
+  return kUnknownTf;
+}
+
+uint8_t LookupCICPTransferFunctionFromICCProfile(const uint8_t* icc_data,
+                                                 size_t len) {
+  size_t cicp_offset = 0;
+  size_t cicp_length = 0;
+  uint8_t cicp_tag[kCICPTagSize] = {};
+  size_t cicp_pos = 0;
+  if (!FindCICPTag(icc_data, len, true, &cicp_offset, &cicp_length,
+                   &cicp_tag[0], &cicp_pos)) {
+    return kUnknownTf;
+  }
+  if (cicp_pos >= kCICPTagSize && memcmp(cicp_tag, kCICPTagSignature, 4) == 0) {
+    return cicp_tag[9];
+  }
+  return kUnknownTf;
+}
+
+JpegliDataType ConvertDataType(JxlDataType type) {
+  switch (type) {
+    case JXL_TYPE_UINT8:
+      return JPEGLI_TYPE_UINT8;
+    case JXL_TYPE_UINT16:
+      return JPEGLI_TYPE_UINT16;
+    case JXL_TYPE_FLOAT:
+      return JPEGLI_TYPE_FLOAT;
+    default:
+      return JPEGLI_TYPE_UINT8;
+  }
+}
+
+JpegliEndianness ConvertEndianness(JxlEndianness endianness) {
+  switch (endianness) {
+    case JXL_NATIVE_ENDIAN:
+      return JPEGLI_NATIVE_ENDIAN;
+    case JXL_LITTLE_ENDIAN:
+      return JPEGLI_LITTLE_ENDIAN;
+    case JXL_BIG_ENDIAN:
+      return JPEGLI_BIG_ENDIAN;
+    default:
+      return JPEGLI_NATIVE_ENDIAN;
+  }
+}
+
+void ToFloatRow(const uint8_t* row_in, JxlPixelFormat format, size_t len,
+                float* row_out) {
+  bool is_little_endian =
+      (format.endianness == JXL_LITTLE_ENDIAN ||
+       (format.endianness == JXL_NATIVE_ENDIAN && IsLittleEndian()));
+  static constexpr double kMul8 = 1.0 / 255.0;
+  static constexpr double kMul16 = 1.0 / 65535.0;
+  if (format.data_type == JXL_TYPE_UINT8) {
+    for (size_t x = 0; x < len; ++x) {
+      row_out[x] = row_in[x] * kMul8;
+    }
+  } else if (format.data_type == JXL_TYPE_UINT16 && is_little_endian) {
+    for (size_t x = 0; x < len; ++x) {
+      row_out[x] = LoadLE16(&row_in[2 * x]) * kMul16;
+    }
+  } else if (format.data_type == JXL_TYPE_UINT16 && !is_little_endian) {
+    for (size_t x = 0; x < len; ++x) {
+      row_out[x] = LoadBE16(&row_in[2 * x]) * kMul16;
+    }
+  } else if (format.data_type == JXL_TYPE_FLOAT && is_little_endian) {
+    for (size_t x = 0; x < len; ++x) {
+      row_out[x] = LoadLEFloat(&row_in[4 * x]);
+    }
+  } else if (format.data_type == JXL_TYPE_FLOAT && !is_little_endian) {
+    for (size_t x = 0; x < len; ++x) {
+      row_out[x] = LoadBEFloat(&row_in[4 * x]);
+    }
+  }
+}
+
+Status EncodeJpegToTargetSize(const PackedPixelFile& ppf,
+                              const JpegSettings& jpeg_settings,
+                              size_t target_size, ThreadPool* pool,
+                              std::vector<uint8_t>* output) {
+  output->clear();
+  size_t best_error = std::numeric_limits<size_t>::max();
+  float distance0 = -1.0f;
+  float distance1 = -1.0f;
+  float distance = 1.0f;
+  for (int step = 0; step < 15; ++step) {
+    JpegSettings settings = jpeg_settings;
+    settings.libjpeg_quality = 0;
+    settings.distance = distance;
+    settings.target_size = 0;
+    std::vector<uint8_t> compressed;
+    JXL_RETURN_IF_ERROR(EncodeJpeg(ppf, settings, pool, &compressed));
+    size_t size = compressed.size();
+    // prefer being under the target size to being over it
+    size_t error = size < target_size
+                       ? target_size - size
+                       : static_cast<size_t>(1.2f * (size - target_size));
+    if (error < best_error) {
+      best_error = error;
+      std::swap(*output, compressed);
+    }
+    float rel_error = size * 1.0f / target_size;
+    if (std::abs(rel_error - 1.0f) < 0.002f) {
+      break;
+    }
+    if (size < target_size) {
+      distance1 = distance;
+    } else {
+      distance0 = distance;
+    }
+    if (distance1 == -1) {
+      distance *= std::pow(rel_error, 1.5) * 1.05;
+    } else if (distance0 == -1) {
+      distance *= std::pow(rel_error, 1.5) * 0.95;
+    } else {
+      distance = 0.5 * (distance0 + distance1);
+    }
+  }
+  return true;
+}
+
+}  // namespace
+
+Status EncodeJpeg(const PackedPixelFile& ppf, const JpegSettings& jpeg_settings,
+                  ThreadPool* pool, std::vector<uint8_t>* compressed) {
+  if (jpeg_settings.libjpeg_quality > 0) {
+    auto encoder = Encoder::FromExtension(".jpg");
+    encoder->SetOption("q", std::to_string(jpeg_settings.libjpeg_quality));
+    if (!jpeg_settings.libjpeg_chroma_subsampling.empty()) {
+      encoder->SetOption("chroma_subsampling",
+                         jpeg_settings.libjpeg_chroma_subsampling);
+    }
+    EncodedImage encoded;
+    JXL_RETURN_IF_ERROR(encoder->Encode(ppf, &encoded, pool));
+    size_t target_size = encoded.bitstreams[0].size();
+    return EncodeJpegToTargetSize(ppf, jpeg_settings, target_size, pool,
+                                  compressed);
+  }
+  if (jpeg_settings.target_size > 0) {
+    return EncodeJpegToTargetSize(ppf, jpeg_settings, jpeg_settings.target_size,
+                                  pool, compressed);
+  }
+  JXL_RETURN_IF_ERROR(VerifyInput(ppf));
+
+  ColorEncoding color_encoding;
+  JXL_RETURN_IF_ERROR(GetColorEncoding(ppf, &color_encoding));
+
+  ColorSpaceTransform c_transform(*JxlGetDefaultCms());
+  ColorEncoding xyb_encoding;
+  if (jpeg_settings.xyb) {
+    if (ppf.info.num_color_channels != 3) {
+      return JXL_FAILURE("Only RGB input is supported in XYB mode.");
+    }
+    if (HasICCProfile(jpeg_settings.app_data)) {
+      return JXL_FAILURE("APP data ICC profile is not supported in XYB mode.");
+    }
+    const ColorEncoding& c_desired = ColorEncoding::LinearSRGB(false);
+    JXL_RETURN_IF_ERROR(
+        c_transform.Init(color_encoding, c_desired, 255.0f, ppf.info.xsize, 1));
+    xyb_encoding.SetColorSpace(jxl::ColorSpace::kXYB);
+    xyb_encoding.SetRenderingIntent(jxl::RenderingIntent::kPerceptual);
+    JXL_RETURN_IF_ERROR(xyb_encoding.CreateICC());
+  }
+  const ColorEncoding& output_encoding =
+      jpeg_settings.xyb ? xyb_encoding : color_encoding;
+
+  // We need to declare all the non-trivial destructor local variables
+  // before the call to setjmp().
+  std::vector<uint8_t> pixels;
+  unsigned char* output_buffer = nullptr;
+  unsigned long output_size = 0;
+  std::vector<uint8_t> row_bytes;
+  size_t rowlen = RoundUpTo(ppf.info.xsize, VectorSize());
+  hwy::AlignedFreeUniquePtr<float[]> xyb_tmp =
+      hwy::AllocateAligned<float>(6 * rowlen);
+  hwy::AlignedFreeUniquePtr<float[]> premul_absorb =
+      hwy::AllocateAligned<float>(VectorSize() * 12);
+  ComputePremulAbsorb(255.0f, premul_absorb.get());
+
+  jpeg_compress_struct cinfo;
+  const auto try_catch_block = [&]() -> bool {
+    jpeg_error_mgr jerr;
+    jmp_buf env;
+    cinfo.err = jpegli_std_error(&jerr);
+    jerr.error_exit = &MyErrorExit;
+    if (setjmp(env)) {
+      return false;
+    }
+    cinfo.client_data = static_cast<void*>(&env);
+    jpegli_create_compress(&cinfo);
+    jpegli_mem_dest(&cinfo, &output_buffer, &output_size);
+    const JxlBasicInfo& info = ppf.info;
+    cinfo.image_width = info.xsize;
+    cinfo.image_height = info.ysize;
+    cinfo.input_components = info.num_color_channels;
+    cinfo.in_color_space =
+        cinfo.input_components == 1 ? JCS_GRAYSCALE : JCS_RGB;
+    if (jpeg_settings.xyb) {
+      jpegli_set_xyb_mode(&cinfo);
+    } else if (jpeg_settings.use_std_quant_tables) {
+      jpegli_use_standard_quant_tables(&cinfo);
+    }
+    uint8_t cicp_tf = kUnknownTf;
+    if (!jpeg_settings.app_data.empty()) {
+      cicp_tf = LookupCICPTransferFunctionFromAppData(
+          jpeg_settings.app_data.data(), jpeg_settings.app_data.size());
+    } else if (!output_encoding.IsSRGB()) {
+      cicp_tf = LookupCICPTransferFunctionFromICCProfile(
+          output_encoding.ICC().data(), output_encoding.ICC().size());
+    }
+    jpegli_set_cicp_transfer_function(&cinfo, cicp_tf);
+    jpegli_set_defaults(&cinfo);
+    if (!jpeg_settings.chroma_subsampling.empty()) {
+      if (jpeg_settings.chroma_subsampling == "444") {
+        cinfo.comp_info[0].h_samp_factor = 1;
+        cinfo.comp_info[0].v_samp_factor = 1;
+      } else if (jpeg_settings.chroma_subsampling == "440") {
+        cinfo.comp_info[0].h_samp_factor = 1;
+        cinfo.comp_info[0].v_samp_factor = 2;
+      } else if (jpeg_settings.chroma_subsampling == "422") {
+        cinfo.comp_info[0].h_samp_factor = 2;
+        cinfo.comp_info[0].v_samp_factor = 1;
+      } else if (jpeg_settings.chroma_subsampling == "420") {
+        cinfo.comp_info[0].h_samp_factor = 2;
+        cinfo.comp_info[0].v_samp_factor = 2;
+      } else {
+        return false;
+      }
+      for (int i = 1; i < cinfo.num_components; ++i) {
+        cinfo.comp_info[i].h_samp_factor = 1;
+        cinfo.comp_info[i].v_samp_factor = 1;
+      }
+    }
+    jpegli_enable_adaptive_quantization(
+        &cinfo, jpeg_settings.use_adaptive_quantization);
+    if (jpeg_settings.psnr_target > 0.0) {
+      jpegli_set_psnr(&cinfo, jpeg_settings.psnr_target,
+                      jpeg_settings.search_tolerance,
+                      jpeg_settings.min_distance, jpeg_settings.max_distance);
+    } else if (jpeg_settings.quality > 0.0) {
+      float distance = jpegli_quality_to_distance(jpeg_settings.quality);
+      jpegli_set_distance(&cinfo, distance, TRUE);
+    } else {
+      jpegli_set_distance(&cinfo, jpeg_settings.distance, TRUE);
+    }
+    jpegli_set_progressive_level(&cinfo, jpeg_settings.progressive_level);
+    cinfo.optimize_coding = jpeg_settings.optimize_coding;
+    if (!jpeg_settings.app_data.empty()) {
+      // Make sure jpegli_start_compress() does not write any APP markers.
+      cinfo.write_JFIF_header = false;
+      cinfo.write_Adobe_marker = false;
+    }
+    const PackedImage& image = ppf.frames[0].color;
+    if (jpeg_settings.xyb) {
+      jpegli_set_input_format(&cinfo, JPEGLI_TYPE_FLOAT, JPEGLI_NATIVE_ENDIAN);
+    } else {
+      jpegli_set_input_format(&cinfo, ConvertDataType(image.format.data_type),
+                              ConvertEndianness(image.format.endianness));
+    }
+    jpegli_start_compress(&cinfo, TRUE);
+    if (!jpeg_settings.app_data.empty()) {
+      JXL_RETURN_IF_ERROR(WriteAppData(&cinfo, jpeg_settings.app_data));
+    }
+    if ((jpeg_settings.app_data.empty() && !output_encoding.IsSRGB()) ||
+        jpeg_settings.xyb) {
+      jpegli_write_icc_profile(&cinfo, output_encoding.ICC().data(),
+                               output_encoding.ICC().size());
+    }
+    const uint8_t* pixels = reinterpret_cast<const uint8_t*>(image.pixels());
+    if (jpeg_settings.xyb) {
+      float* src_buf = c_transform.BufSrc(0);
+      float* dst_buf = c_transform.BufDst(0);
+      for (size_t y = 0; y < image.ysize; ++y) {
+        // convert to float
+        ToFloatRow(&pixels[y * image.stride], image.format, 3 * image.xsize,
+                   src_buf);
+        // convert to linear srgb
+        if (!c_transform.Run(0, src_buf, dst_buf)) {
+          return false;
+        }
+        // deinterleave channels
+        float* row0 = &xyb_tmp[0];
+        float* row1 = &xyb_tmp[rowlen];
+        float* row2 = &xyb_tmp[2 * rowlen];
+        for (size_t x = 0; x < image.xsize; ++x) {
+          row0[x] = dst_buf[3 * x + 0];
+          row1[x] = dst_buf[3 * x + 1];
+          row2[x] = dst_buf[3 * x + 2];
+        }
+        // convert to xyb
+        LinearRGBRowToXYB(row0, row1, row2, premul_absorb.get(), image.xsize);
+        // scale xyb
+        ScaleXYBRow(row0, row1, row2, image.xsize);
+        // interleave channels
+        float* row_out = &xyb_tmp[3 * rowlen];
+        for (size_t x = 0; x < image.xsize; ++x) {
+          row_out[3 * x + 0] = row0[x];
+          row_out[3 * x + 1] = row1[x];
+          row_out[3 * x + 2] = row2[x];
+        }
+        // feed to jpegli as native endian floats
+        JSAMPROW row[] = {reinterpret_cast<uint8_t*>(row_out)};
+        jpegli_write_scanlines(&cinfo, row, 1);
+      }
+    } else {
+      row_bytes.resize(image.stride);
+      if (cinfo.num_components == (int)image.format.num_channels) {
+        for (size_t y = 0; y < info.ysize; ++y) {
+          memcpy(&row_bytes[0], pixels + y * image.stride, image.stride);
+          JSAMPROW row[] = {row_bytes.data()};
+          jpegli_write_scanlines(&cinfo, row, 1);
+        }
+      } else {
+        for (size_t y = 0; y < info.ysize; ++y) {
+          int bytes_per_channel =
+              PackedImage::BitsPerChannel(image.format.data_type) / 8;
+          int bytes_per_pixel = cinfo.num_components * bytes_per_channel;
+          for (size_t x = 0; x < info.xsize; ++x) {
+            memcpy(&row_bytes[x * bytes_per_pixel],
+                   &pixels[y * image.stride + x * image.pixel_stride()],
+                   bytes_per_pixel);
+          }
+          JSAMPROW row[] = {row_bytes.data()};
+          jpegli_write_scanlines(&cinfo, row, 1);
+        }
+      }
+    }
+    jpegli_finish_compress(&cinfo);
+    compressed->resize(output_size);
+    std::copy_n(output_buffer, output_size, compressed->data());
+    return true;
+  };
+  bool success = try_catch_block();
+  jpegli_destroy_compress(&cinfo);
+  if (output_buffer) free(output_buffer);
+  return success;
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/enc/jpegli.h b/third_party/jpeg-xl/lib/extras/enc/jpegli.h
new file mode 100644
index 0000000000..9538b2e3fc
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/jpegli.h
@@ -0,0 +1,53 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_ENC_JPEGLI_H_
+#define LIB_EXTRAS_ENC_JPEGLI_H_
+
+// Encodes JPG pixels and metadata in memory using the libjpegli library.
+
+#include <stdint.h>
+
+#include <string>
+#include <vector>
+
+#include "lib/extras/packed_image.h"
+#include "lib/jxl/base/data_parallel.h"
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+namespace extras {
+
+struct JpegSettings {
+  bool xyb = false;
+  size_t target_size = 0;
+  float quality = 0.0f;
+  float distance = 1.f;
+  bool use_adaptive_quantization = true;
+  bool use_std_quant_tables = false;
+  int progressive_level = 2;
+  bool optimize_coding = true;
+  std::string chroma_subsampling;
+  int libjpeg_quality = 0;
+  std::string libjpeg_chroma_subsampling;
+  // Parameters for selecting distance based on PSNR target.
+  float psnr_target = 0.0f;
+  float search_tolerance = 0.01;
+  float min_distance = 0.1f;
+  float max_distance = 25.0f;
+  // If not empty, must contain concatenated APP marker segments. In this case,
+  // these and only these APP marker segments will be written to the JPEG
+  // output. In xyb mode app_data must not contain an ICC profile, in this
+  // case an additional APP2 ICC profile for the XYB colorspace will be emitted.
+  std::vector<uint8_t> app_data;
+};
+
+Status EncodeJpeg(const PackedPixelFile& ppf, const JpegSettings& jpeg_settings,
+                  ThreadPool* pool, std::vector<uint8_t>* compressed);
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_ENC_JPEGLI_H_
diff --git a/third_party/jpeg-xl/lib/extras/enc/jpg.cc b/third_party/jpeg-xl/lib/extras/enc/jpg.cc
new file mode 100644
index 0000000000..c34dc6c13f
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/jpg.cc
@@ -0,0 +1,618 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/enc/jpg.h"
+
+#if JPEGXL_ENABLE_JPEG
+#include <jpeglib.h>
+#include <setjmp.h>
+#endif
+#include <stdint.h>
+
+#include <algorithm>
+#include <array>
+#include <cmath>
+#include <fstream>
+#include <iterator>
+#include <memory>
+#include <numeric>
+#include <sstream>
+#include <utility>
+#include <vector>
+
+#include "lib/extras/exif.h"
+#include "lib/jxl/base/status.h"
+#include "lib/jxl/sanitizers.h"
+#if JPEGXL_ENABLE_SJPEG
+#include "sjpeg.h"
+#include "sjpegi.h"
+#endif
+
+namespace jxl {
+namespace extras {
+
+#if JPEGXL_ENABLE_JPEG
+namespace {
+
+constexpr unsigned char kICCSignature[12] = {
+    0x49, 0x43, 0x43, 0x5F, 0x50, 0x52, 0x4F, 0x46, 0x49, 0x4C, 0x45, 0x00};
+constexpr int kICCMarker = JPEG_APP0 + 2;
+constexpr size_t kMaxBytesInMarker = 65533;
+
+constexpr unsigned char kExifSignature[6] = {0x45, 0x78, 0x69,
+                                             0x66, 0x00, 0x00};
+constexpr int kExifMarker = JPEG_APP0 + 1;
+
+enum class JpegEncoder {
+  kLibJpeg,
+  kSJpeg,
+};
+
+#define ARRAY_SIZE(X) (sizeof(X) / sizeof((X)[0]))
+
+// Popular jpeg scan scripts
+// The fields of the individual scans are:
+// comps_in_scan, component_index[], Ss, Se, Ah, Al
+static constexpr jpeg_scan_info kScanScript1[] = {
+    {1, {0}, 0, 0, 0, 0},   //
+    {1, {1}, 0, 0, 0, 0},   //
+    {1, {2}, 0, 0, 0, 0},   //
+    {1, {0}, 1, 8, 0, 0},   //
+    {1, {0}, 9, 63, 0, 0},  //
+    {1, {1}, 1, 63, 0, 0},  //
+    {1, {2}, 1, 63, 0, 0},  //
+};
+static constexpr size_t kNumScans1 = ARRAY_SIZE(kScanScript1);
+
+static constexpr jpeg_scan_info kScanScript2[] = {
+    {1, {0}, 0, 0, 0, 0},   //
+    {1, {1}, 0, 0, 0, 0},   //
+    {1, {2}, 0, 0, 0, 0},   //
+    {1, {0}, 1, 2, 0, 1},   //
+    {1, {0}, 3, 63, 0, 1},  //
+    {1, {0}, 1, 63, 1, 0},  //
+    {1, {1}, 1, 63, 0, 0},  //
+    {1, {2}, 1, 63, 0, 0},  //
+};
+static constexpr size_t kNumScans2 = ARRAY_SIZE(kScanScript2);
+
+static constexpr jpeg_scan_info kScanScript3[] = {
+    {1, {0}, 0, 0, 0, 0},   //
+    {1, {1}, 0, 0, 0, 0},   //
+    {1, {2}, 0, 0, 0, 0},   //
+    {1, {0}, 1, 63, 0, 2},  //
+    {1, {0}, 1, 63, 2, 1},  //
+    {1, {0}, 1, 63, 1, 0},  //
+    {1, {1}, 1, 63, 0, 0},  //
+    {1, {2}, 1, 63, 0, 0},  //
+};
+static constexpr size_t kNumScans3 = ARRAY_SIZE(kScanScript3);
+
+static constexpr jpeg_scan_info kScanScript4[] = {
+    {3, {0, 1, 2}, 0, 0, 0, 1},  //
+    {1, {0}, 1, 5, 0, 2},        //
+    {1, {2}, 1, 63, 0, 1},       //
+    {1, {1}, 1, 63, 0, 1},       //
+    {1, {0}, 6, 63, 0, 2},       //
+    {1, {0}, 1, 63, 2, 1},       //
+    {3, {0, 1, 2}, 0, 0, 1, 0},  //
+    {1, {2}, 1, 63, 1, 0},       //
+    {1, {1}, 1, 63, 1, 0},       //
+    {1, {0}, 1, 63, 1, 0},       //
+};
+static constexpr size_t kNumScans4 = ARRAY_SIZE(kScanScript4);
+
+static constexpr jpeg_scan_info kScanScript5[] = {
+    {3, {0, 1, 2}, 0, 0, 0, 1},  //
+    {1, {0}, 1, 5, 0, 2},        //
+    {1, {1}, 1, 5, 0, 2},        //
+    {1, {2}, 1, 5, 0, 2},        //
+    {1, {1}, 6, 63, 0, 2},       //
+    {1, {2}, 6, 63, 0, 2},       //
+    {1, {0}, 6, 63, 0, 2},       //
+    {1, {0}, 1, 63, 2, 1},       //
+    {1, {1}, 1, 63, 2, 1},       //
+    {1, {2}, 1, 63, 2, 1},       //
+    {3, {0, 1, 2}, 0, 0, 1, 0},  //
+    {1, {0}, 1, 63, 1, 0},       //
+    {1, {1}, 1, 63, 1, 0},       //
+    {1, {2}, 1, 63, 1, 0},       //
+};
+static constexpr size_t kNumScans5 = ARRAY_SIZE(kScanScript5);
+
+// default progressive mode of jpegli
+static constexpr jpeg_scan_info kScanScript6[] = {
+    {3, {0, 1, 2}, 0, 0, 0, 0},  //
+    {1, {0}, 1, 2, 0, 0},        //
+    {1, {1}, 1, 2, 0, 0},        //
+    {1, {2}, 1, 2, 0, 0},        //
+    {1, {0}, 3, 63, 0, 2},       //
+    {1, {1}, 3, 63, 0, 2},       //
+    {1, {2}, 3, 63, 0, 2},       //
+    {1, {0}, 3, 63, 2, 1},       //
+    {1, {1}, 3, 63, 2, 1},       //
+    {1, {2}, 3, 63, 2, 1},       //
+    {1, {0}, 3, 63, 1, 0},       //
+    {1, {1}, 3, 63, 1, 0},       //
+    {1, {2}, 3, 63, 1, 0},       //
+};
+static constexpr size_t kNumScans6 = ARRAY_SIZE(kScanScript6);
+
+// Adapt RGB scan info to grayscale jpegs.
+void FilterScanComponents(const jpeg_compress_struct* cinfo,
+                          jpeg_scan_info* si) {
+  const int all_comps_in_scan = si->comps_in_scan;
+  si->comps_in_scan = 0;
+  for (int j = 0; j < all_comps_in_scan; ++j) {
+    const int component = si->component_index[j];
+    if (component < cinfo->input_components) {
+      si->component_index[si->comps_in_scan++] = component;
+    }
+  }
+}
+
+Status SetJpegProgression(int progressive_id,
+                          std::vector<jpeg_scan_info>* scan_infos,
+                          jpeg_compress_struct* cinfo) {
+  if (progressive_id < 0) {
+    return true;
+  }
+  if (progressive_id == 0) {
+    jpeg_simple_progression(cinfo);
+    return true;
+  }
+  constexpr const jpeg_scan_info* kScanScripts[] = {kScanScript1, kScanScript2,
+                                                    kScanScript3, kScanScript4,
+                                                    kScanScript5, kScanScript6};
+  constexpr size_t kNumScans[] = {kNumScans1, kNumScans2, kNumScans3,
+                                  kNumScans4, kNumScans5, kNumScans6};
+  if (progressive_id > static_cast<int>(ARRAY_SIZE(kNumScans))) {
+    return JXL_FAILURE("Unknown jpeg scan script id %d", progressive_id);
+  }
+  const jpeg_scan_info* scan_script = kScanScripts[progressive_id - 1];
+  const size_t num_scans = kNumScans[progressive_id - 1];
+  // filter scan script for number of components
+  for (size_t i = 0; i < num_scans; ++i) {
+    jpeg_scan_info scan_info = scan_script[i];
+    FilterScanComponents(cinfo, &scan_info);
+    if (scan_info.comps_in_scan > 0) {
+      scan_infos->emplace_back(std::move(scan_info));
+    }
+  }
+  cinfo->scan_info = scan_infos->data();
+  cinfo->num_scans = scan_infos->size();
+  return true;
+}
+
+void WriteICCProfile(jpeg_compress_struct* const cinfo,
+                     const std::vector<uint8_t>& icc) {
+  constexpr size_t kMaxIccBytesInMarker =
+      kMaxBytesInMarker - sizeof kICCSignature - 2;
+  const int num_markers =
+      static_cast<int>(DivCeil(icc.size(), kMaxIccBytesInMarker));
+  size_t begin = 0;
+  for (int current_marker = 0; current_marker < num_markers; ++current_marker) {
+    const size_t length = std::min(kMaxIccBytesInMarker, icc.size() - begin);
+    jpeg_write_m_header(
+        cinfo, kICCMarker,
+        static_cast<unsigned int>(length + sizeof kICCSignature + 2));
+    for (const unsigned char c : kICCSignature) {
+      jpeg_write_m_byte(cinfo, c);
+    }
+    jpeg_write_m_byte(cinfo, current_marker + 1);
+    jpeg_write_m_byte(cinfo, num_markers);
+    for (size_t i = 0; i < length; ++i) {
+      jpeg_write_m_byte(cinfo, icc[begin]);
+      ++begin;
+    }
+  }
+}
+void WriteExif(jpeg_compress_struct* const cinfo,
+               const std::vector<uint8_t>& exif) {
+  jpeg_write_m_header(
+      cinfo, kExifMarker,
+      static_cast<unsigned int>(exif.size() + sizeof kExifSignature));
+  for (const unsigned char c : kExifSignature) {
+    jpeg_write_m_byte(cinfo, c);
+  }
+  for (size_t i = 0; i < exif.size(); ++i) {
+    jpeg_write_m_byte(cinfo, exif[i]);
+  }
+}
+
+Status SetChromaSubsampling(const std::string& subsampling,
+                            jpeg_compress_struct* const cinfo) {
+  const std::pair<const char*,
+                  std::pair<std::array<uint8_t, 3>, std::array<uint8_t, 3>>>
+      options[] = {{"444", {{{1, 1, 1}}, {{1, 1, 1}}}},
+                   {"420", {{{2, 1, 1}}, {{2, 1, 1}}}},
+                   {"422", {{{2, 1, 1}}, {{1, 1, 1}}}},
+                   {"440", {{{1, 1, 1}}, {{2, 1, 1}}}}};
+  for (const auto& option : options) {
+    if (subsampling == option.first) {
+      for (size_t i = 0; i < 3; i++) {
+        cinfo->comp_info[i].h_samp_factor = option.second.first[i];
+        cinfo->comp_info[i].v_samp_factor = option.second.second[i];
+      }
+      return true;
+    }
+  }
+  return false;
+}
+
+struct JpegParams {
+  // Common between sjpeg and libjpeg
+  int quality = 100;
+  std::string chroma_subsampling = "444";
+  // Libjpeg parameters
+  int progressive_id = -1;
+  bool optimize_coding = true;
+  bool is_xyb = false;
+  // Sjpeg parameters
+  int libjpeg_quality = 0;
+  std::string libjpeg_chroma_subsampling = "444";
+  float psnr_target = 0;
+  std::string custom_base_quant_fn;
+  float search_q_start = 65.0f;
+  float search_q_min = 1.0f;
+  float search_q_max = 100.0f;
+  int search_max_iters = 20;
+  float search_tolerance = 0.1f;
+  float search_q_precision = 0.01f;
+  float search_first_iter_slope = 3.0f;
+  bool enable_adaptive_quant = true;
+};
+
+Status EncodeWithLibJpeg(const PackedImage& image, const JxlBasicInfo& info,
+                         const std::vector<uint8_t>& icc,
+                         std::vector<uint8_t> exif, const JpegParams& params,
+                         std::vector<uint8_t>* bytes) {
+  if (BITS_IN_JSAMPLE != 8 || sizeof(JSAMPLE) != 1) {
+    return JXL_FAILURE("Only 8 bit JSAMPLE is supported.");
+  }
+  jpeg_compress_struct cinfo = {};
+  jpeg_error_mgr jerr;
+  cinfo.err = jpeg_std_error(&jerr);
+  jpeg_create_compress(&cinfo);
+  unsigned char* buffer = nullptr;
+  unsigned long size = 0;
+  jpeg_mem_dest(&cinfo, &buffer, &size);
+  cinfo.image_width = image.xsize;
+  cinfo.image_height = image.ysize;
+  cinfo.input_components = info.num_color_channels;
+  cinfo.in_color_space = info.num_color_channels == 1 ? JCS_GRAYSCALE : JCS_RGB;
+  jpeg_set_defaults(&cinfo);
+  cinfo.optimize_coding = params.optimize_coding;
+  if (cinfo.input_components == 3) {
+    JXL_RETURN_IF_ERROR(
+        SetChromaSubsampling(params.chroma_subsampling, &cinfo));
+  }
+  if (params.is_xyb) {
+    // Tell libjpeg not to convert XYB data to YCbCr.
+    jpeg_set_colorspace(&cinfo, JCS_RGB);
+  }
+  jpeg_set_quality(&cinfo, params.quality, TRUE);
+  std::vector<jpeg_scan_info> scan_infos;
+  JXL_RETURN_IF_ERROR(
+      SetJpegProgression(params.progressive_id, &scan_infos, &cinfo));
+  jpeg_start_compress(&cinfo, TRUE);
+  if (!icc.empty()) {
+    WriteICCProfile(&cinfo, icc);
+  }
+  if (!exif.empty()) {
+    ResetExifOrientation(exif);
+    WriteExif(&cinfo, exif);
+  }
+  if (cinfo.input_components > 3 || cinfo.input_components < 0)
+    return JXL_FAILURE("invalid numbers of components");
+
+  std::vector<uint8_t> row_bytes(image.stride);
+  const uint8_t* pixels = reinterpret_cast<const uint8_t*>(image.pixels());
+  if (cinfo.num_components == (int)image.format.num_channels &&
+      image.format.data_type == JXL_TYPE_UINT8) {
+    for (size_t y = 0; y < info.ysize; ++y) {
+      memcpy(&row_bytes[0], pixels + y * image.stride, image.stride);
+      JSAMPROW row[] = {row_bytes.data()};
+      jpeg_write_scanlines(&cinfo, row, 1);
+    }
+  } else if (image.format.data_type == JXL_TYPE_UINT8) {
+    for (size_t y = 0; y < info.ysize; ++y) {
+      const uint8_t* image_row = pixels + y * image.stride;
+      for (size_t x = 0; x < info.xsize; ++x) {
+        const uint8_t* image_pixel = image_row + x * image.pixel_stride();
+        memcpy(&row_bytes[x * cinfo.num_components], image_pixel,
+               cinfo.num_components);
+      }
+      JSAMPROW row[] = {row_bytes.data()};
+      jpeg_write_scanlines(&cinfo, row, 1);
+    }
+  } else {
+    for (size_t y = 0; y < info.ysize; ++y) {
+      const uint8_t* image_row = pixels + y * image.stride;
+      for (size_t x = 0; x < info.xsize; ++x) {
+        const uint8_t* image_pixel = image_row + x * image.pixel_stride();
+        for (int c = 0; c < cinfo.num_components; ++c) {
+          uint32_t val16 = (image_pixel[2 * c] << 8) + image_pixel[2 * c + 1];
+          row_bytes[x * cinfo.num_components + c] = (val16 + 128) / 257;
+        }
+      }
+      JSAMPROW row[] = {row_bytes.data()};
+      jpeg_write_scanlines(&cinfo, row, 1);
+    }
+  }
+  jpeg_finish_compress(&cinfo);
+  jpeg_destroy_compress(&cinfo);
+  bytes->resize(size);
+  // Compressed image data is initialized by libjpeg, which we are not
+  // instrumenting with msan.
+  msan::UnpoisonMemory(buffer, size);
+  std::copy_n(buffer, size, bytes->data());
+  std::free(buffer);
+  return true;
+}
+
+#if JPEGXL_ENABLE_SJPEG
+struct MySearchHook : public sjpeg::SearchHook {
+  uint8_t base_tables[2][64];
+  float q_start;
+  float q_precision;
+  float first_iter_slope;
+  void ReadBaseTables(const std::string& fn) {
+    const uint8_t kJPEGAnnexKMatrices[2][64] = {
+        {16, 11, 10, 16, 24,  40,  51,  61,  12, 12, 14, 19, 26,  58,  60,  55,
+         14, 13, 16, 24, 40,  57,  69,  56,  14, 17, 22, 29, 51,  87,  80,  62,
+         18, 22, 37, 56, 68,  109, 103, 77,  24, 35, 55, 64, 81,  104, 113, 92,
+         49, 64, 78, 87, 103, 121, 120, 101, 72, 92, 95, 98, 112, 100, 103, 99},
+        {17, 18, 24, 47, 99, 99, 99, 99, 18, 21, 26, 66, 99, 99, 99, 99,
+         24, 26, 56, 99, 99, 99, 99, 99, 47, 66, 99, 99, 99, 99, 99, 99,
+         99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99,
+         99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99}};
+    memcpy(base_tables[0], kJPEGAnnexKMatrices[0], sizeof(base_tables[0]));
+    memcpy(base_tables[1], kJPEGAnnexKMatrices[1], sizeof(base_tables[1]));
+    if (!fn.empty()) {
+      std::ifstream f(fn);
+      std::string line;
+      int idx = 0;
+      while (idx < 128 && std::getline(f, line)) {
+        if (line.empty() || line[0] == '#') continue;
+        std::istringstream line_stream(line);
+        std::string token;
+        while (idx < 128 && std::getline(line_stream, token, ',')) {
+          uint8_t val = std::stoi(token);
+          base_tables[idx / 64][idx % 64] = val;
+          idx++;
+        }
+      }
+    }
+  }
+  bool Setup(const sjpeg::EncoderParam& param) override {
+    sjpeg::SearchHook::Setup(param);
+    q = q_start;
+    return true;
+  }
+  void NextMatrix(int idx, uint8_t dst[64]) override {
+    float factor = (q <= 0)       ? 5000.0f
+                   : (q < 50.0f)  ? 5000.0f / q
+                   : (q < 100.0f) ? 2 * (100.0f - q)
+                                  : 0.0f;
+    sjpeg::SetQuantMatrix(base_tables[idx], factor, dst);
+  }
+  bool Update(float result) override {
+    value = result;
+    if (fabs(value - target) < tolerance * target) {
+      return true;
+    }
+    if (value > target) {
+      qmax = q;
+    } else {
+      qmin = q;
+    }
+    if (qmin == qmax) {
+      return true;
+    }
+    const float last_q = q;
+    if (pass == 0) {
+      q += first_iter_slope *
+           (for_size ? 0.1 * std::log(target / value) : (target - value));
+      q = std::max(qmin, std::min(qmax, q));
+    } else {
+      q = (qmin + qmax) / 2.;
+    }
+    return (pass > 0 && fabs(q - last_q) < q_precision);
+  }
+  ~MySearchHook() override {}
+};
+#endif
+
+Status EncodeWithSJpeg(const PackedImage& image, const JxlBasicInfo& info,
+                       const std::vector<uint8_t>& icc,
+                       std::vector<uint8_t> exif, const JpegParams& params,
+                       std::vector<uint8_t>* bytes) {
+#if !JPEGXL_ENABLE_SJPEG
+  return JXL_FAILURE("JPEG XL was built without sjpeg support");
+#else
+  if (image.format.data_type != JXL_TYPE_UINT8) {
+    return JXL_FAILURE("Unsupported pixel data type");
+  }
+  if (info.alpha_bits > 0) {
+    return JXL_FAILURE("alpha is not supported");
+  }
+  sjpeg::EncoderParam param(params.quality);
+  if (!icc.empty()) {
+    param.iccp.assign(icc.begin(), icc.end());
+  }
+  if (!exif.empty()) {
+    ResetExifOrientation(exif);
+    param.exif.assign(exif.begin(), exif.end());
+  }
+  if (params.chroma_subsampling == "444") {
+    param.yuv_mode = SJPEG_YUV_444;
+  } else if (params.chroma_subsampling == "420") {
+    param.yuv_mode = SJPEG_YUV_420;
+  } else if (params.chroma_subsampling == "420sharp") {
+    param.yuv_mode = SJPEG_YUV_SHARP;
+  } else {
+    return JXL_FAILURE("sjpeg does not support this chroma subsampling mode");
+  }
+  param.adaptive_quantization = params.enable_adaptive_quant;
+  std::unique_ptr<MySearchHook> hook;
+  if (params.libjpeg_quality > 0) {
+    JpegParams libjpeg_params;
+    libjpeg_params.quality = params.libjpeg_quality;
+    libjpeg_params.chroma_subsampling = params.libjpeg_chroma_subsampling;
+    std::vector<uint8_t> libjpeg_bytes;
+    JXL_RETURN_IF_ERROR(EncodeWithLibJpeg(image, info, icc, exif,
+                                          libjpeg_params, &libjpeg_bytes));
+    param.target_mode = sjpeg::EncoderParam::TARGET_SIZE;
+    param.target_value = libjpeg_bytes.size();
+  }
+  if (params.psnr_target > 0) {
+    param.target_mode = sjpeg::EncoderParam::TARGET_PSNR;
+    param.target_value = params.psnr_target;
+  }
+  if (param.target_mode != sjpeg::EncoderParam::TARGET_NONE) {
+    param.passes = params.search_max_iters;
+    param.tolerance = params.search_tolerance;
+    param.qmin = params.search_q_min;
+    param.qmax = params.search_q_max;
+    hook.reset(new MySearchHook());
+    hook->ReadBaseTables(params.custom_base_quant_fn);
+    hook->q_start = params.search_q_start;
+    hook->q_precision = params.search_q_precision;
+    hook->first_iter_slope = params.search_first_iter_slope;
+    param.search_hook = hook.get();
+  }
+  size_t stride = info.xsize * 3;
+  const uint8_t* pixels = reinterpret_cast<const uint8_t*>(image.pixels());
+  std::string output;
+  JXL_RETURN_IF_ERROR(
+      sjpeg::Encode(pixels, image.xsize, image.ysize, stride, param, &output));
+  bytes->assign(
+      reinterpret_cast<const uint8_t*>(output.data()),
+      reinterpret_cast<const uint8_t*>(output.data() + output.size()));
+  return true;
+#endif
+}
+
+Status EncodeImageJPG(const PackedImage& image, const JxlBasicInfo& info,
+                      const std::vector<uint8_t>& icc,
+                      std::vector<uint8_t> exif, JpegEncoder encoder,
+                      const JpegParams& params, ThreadPool* pool,
+                      std::vector<uint8_t>* bytes) {
+  if (params.quality > 100) {
+    return JXL_FAILURE("please specify a 0-100 JPEG quality");
+  }
+
+  switch (encoder) {
+    case JpegEncoder::kLibJpeg:
+      JXL_RETURN_IF_ERROR(
+          EncodeWithLibJpeg(image, info, icc, std::move(exif), params, bytes));
+      break;
+    case JpegEncoder::kSJpeg:
+      JXL_RETURN_IF_ERROR(
+          EncodeWithSJpeg(image, info, icc, std::move(exif), params, bytes));
+      break;
+    default:
+      return JXL_FAILURE("tried to use an unknown JPEG encoder");
+  }
+
+  return true;
+}
+
+class JPEGEncoder : public Encoder {
+  std::vector<JxlPixelFormat> AcceptedFormats() const override {
+    std::vector<JxlPixelFormat> formats;
+    for (const uint32_t num_channels : {1, 2, 3, 4}) {
+      for (JxlEndianness endianness : {JXL_BIG_ENDIAN, JXL_LITTLE_ENDIAN}) {
+        formats.push_back(JxlPixelFormat{/*num_channels=*/num_channels,
+                                         /*data_type=*/JXL_TYPE_UINT8,
+                                         /*endianness=*/endianness,
+                                         /*align=*/0});
+      }
+      formats.push_back(JxlPixelFormat{/*num_channels=*/num_channels,
+                                       /*data_type=*/JXL_TYPE_UINT16,
+                                       /*endianness=*/JXL_BIG_ENDIAN,
+                                       /*align=*/0});
+    }
+    return formats;
+  }
+  Status Encode(const PackedPixelFile& ppf, EncodedImage* encoded_image,
+                ThreadPool* pool = nullptr) const override {
+    JXL_RETURN_IF_ERROR(VerifyBasicInfo(ppf.info));
+    JpegEncoder jpeg_encoder = JpegEncoder::kLibJpeg;
+    JpegParams params;
+    for (const auto& it : options()) {
+      if (it.first == "q") {
+        std::istringstream is(it.second);
+        JXL_RETURN_IF_ERROR(static_cast<bool>(is >> params.quality));
+      } else if (it.first == "libjpeg_quality") {
+        std::istringstream is(it.second);
+        JXL_RETURN_IF_ERROR(static_cast<bool>(is >> params.libjpeg_quality));
+      } else if (it.first == "chroma_subsampling") {
+        params.chroma_subsampling = it.second;
+      } else if (it.first == "libjpeg_chroma_subsampling") {
+        params.libjpeg_chroma_subsampling = it.second;
+      } else if (it.first == "jpeg_encoder") {
+        if (it.second == "libjpeg") {
+          jpeg_encoder = JpegEncoder::kLibJpeg;
+        } else if (it.second == "sjpeg") {
+          jpeg_encoder = JpegEncoder::kSJpeg;
+        } else {
+          return JXL_FAILURE("unknown jpeg encoder \"%s\"", it.second.c_str());
+        }
+      } else if (it.first == "progressive") {
+        std::istringstream is(it.second);
+        JXL_RETURN_IF_ERROR(static_cast<bool>(is >> params.progressive_id));
+      } else if (it.first == "optimize" && it.second == "OFF") {
+        params.optimize_coding = false;
+      } else if (it.first == "adaptive_q" && it.second == "OFF") {
+        params.enable_adaptive_quant = false;
+      } else if (it.first == "psnr") {
+        params.psnr_target = std::stof(it.second);
+      } else if (it.first == "base_quant_fn") {
+        params.custom_base_quant_fn = it.second;
+      } else if (it.first == "search_q_start") {
+        params.search_q_start = std::stof(it.second);
+      } else if (it.first == "search_q_min") {
+        params.search_q_min = std::stof(it.second);
+      } else if (it.first == "search_q_max") {
+        params.search_q_max = std::stof(it.second);
+      } else if (it.first == "search_max_iters") {
+        params.search_max_iters = std::stoi(it.second);
+      } else if (it.first == "search_tolerance") {
+        params.search_tolerance = std::stof(it.second);
+      } else if (it.first == "search_q_precision") {
+        params.search_q_precision = std::stof(it.second);
+      } else if (it.first == "search_first_iter_slope") {
+        params.search_first_iter_slope = std::stof(it.second);
+      }
+    }
+    params.is_xyb = (ppf.color_encoding.color_space == JXL_COLOR_SPACE_XYB);
+    encoded_image->bitstreams.clear();
+    encoded_image->bitstreams.reserve(ppf.frames.size());
+    for (const auto& frame : ppf.frames) {
+      JXL_RETURN_IF_ERROR(VerifyPackedImage(frame.color, ppf.info));
+      encoded_image->bitstreams.emplace_back();
+      JXL_RETURN_IF_ERROR(EncodeImageJPG(
+          frame.color, ppf.info, ppf.icc, ppf.metadata.exif, jpeg_encoder,
+          params, pool, &encoded_image->bitstreams.back()));
+    }
+    return true;
+  }
+};
+
+}  // namespace
+#endif
+
+std::unique_ptr<Encoder> GetJPEGEncoder() {
+#if JPEGXL_ENABLE_JPEG
+  return jxl::make_unique<JPEGEncoder>();
+#else
+  return nullptr;
+#endif
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/enc/jpg.h b/third_party/jpeg-xl/lib/extras/enc/jpg.h
new file mode 100644
index 0000000000..20b37cd168
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/jpg.h
@@ -0,0 +1,23 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_ENC_JPG_H_
+#define LIB_EXTRAS_ENC_JPG_H_
+
+// Encodes JPG pixels and metadata in memory.
+
+#include <memory>
+
+#include "lib/extras/enc/encode.h"
+
+namespace jxl {
+namespace extras {
+
+std::unique_ptr<Encoder> GetJPEGEncoder();
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_ENC_JPG_H_
diff --git a/third_party/jpeg-xl/lib/extras/enc/jxl.cc b/third_party/jpeg-xl/lib/extras/enc/jxl.cc
new file mode 100644
index 0000000000..00adbb7dda
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/jxl.cc
@@ -0,0 +1,359 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/enc/jxl.h"
+
+#include <jxl/encode.h>
+#include <jxl/encode_cxx.h>
+
+#include "lib/jxl/base/exif.h"
+
+namespace jxl {
+namespace extras {
+
+JxlEncoderStatus SetOption(const JXLOption& opt,
+                           JxlEncoderFrameSettings* settings) {
+  return opt.is_float
+             ? JxlEncoderFrameSettingsSetFloatOption(settings, opt.id, opt.fval)
+             : JxlEncoderFrameSettingsSetOption(settings, opt.id, opt.ival);
+}
+
+bool SetFrameOptions(const std::vector<JXLOption>& options, size_t frame_index,
+                     size_t* option_idx, JxlEncoderFrameSettings* settings) {
+  while (*option_idx < options.size()) {
+    const auto& opt = options[*option_idx];
+    if (opt.frame_index > frame_index) {
+      break;
+    }
+    if (JXL_ENC_SUCCESS != SetOption(opt, settings)) {
+      fprintf(stderr, "Setting option id %d failed.\n", opt.id);
+      return false;
+    }
+    (*option_idx)++;
+  }
+  return true;
+}
+
+bool SetupFrame(JxlEncoder* enc, JxlEncoderFrameSettings* settings,
+                const JxlFrameHeader& frame_header,
+                const JXLCompressParams& params, const PackedPixelFile& ppf,
+                size_t frame_index, size_t num_alpha_channels,
+                size_t num_interleaved_alpha, size_t& option_idx) {
+  if (JXL_ENC_SUCCESS != JxlEncoderSetFrameHeader(settings, &frame_header)) {
+    fprintf(stderr, "JxlEncoderSetFrameHeader() failed.\n");
+    return false;
+  }
+  if (!SetFrameOptions(params.options, frame_index, &option_idx, settings)) {
+    return false;
+  }
+  if (num_alpha_channels > 0) {
+    JxlExtraChannelInfo extra_channel_info;
+    JxlEncoderInitExtraChannelInfo(JXL_CHANNEL_ALPHA, &extra_channel_info);
+    extra_channel_info.bits_per_sample = ppf.info.alpha_bits;
+    extra_channel_info.exponent_bits_per_sample = ppf.info.alpha_exponent_bits;
+    if (params.premultiply != -1) {
+      if (params.premultiply != 0 && params.premultiply != 1) {
+        fprintf(stderr, "premultiply must be one of: -1, 0, 1.\n");
+        return false;
+      }
+      extra_channel_info.alpha_premultiplied = params.premultiply;
+    }
+    if (JXL_ENC_SUCCESS !=
+        JxlEncoderSetExtraChannelInfo(enc, 0, &extra_channel_info)) {
+      fprintf(stderr, "JxlEncoderSetExtraChannelInfo() failed.\n");
+      return false;
+    }
+    // We take the extra channel blend info frame_info, but don't do
+    // clamping.
+    JxlBlendInfo extra_channel_blend_info = frame_header.layer_info.blend_info;
+    extra_channel_blend_info.clamp = JXL_FALSE;
+    JxlEncoderSetExtraChannelBlendInfo(settings, 0, &extra_channel_blend_info);
+  }
+  // Add extra channel info for the rest of the extra channels.
+  for (size_t i = 0; i < ppf.info.num_extra_channels; ++i) {
+    if (i < ppf.extra_channels_info.size()) {
+      const auto& ec_info = ppf.extra_channels_info[i].ec_info;
+      if (JXL_ENC_SUCCESS != JxlEncoderSetExtraChannelInfo(
+                                 enc, num_interleaved_alpha + i, &ec_info)) {
+        fprintf(stderr, "JxlEncoderSetExtraChannelInfo() failed.\n");
+        return false;
+      }
+    }
+  }
+  return true;
+}
+
+bool ReadCompressedOutput(JxlEncoder* enc, std::vector<uint8_t>* compressed) {
+  compressed->clear();
+  compressed->resize(4096);
+  uint8_t* next_out = compressed->data();
+  size_t avail_out = compressed->size() - (next_out - compressed->data());
+  JxlEncoderStatus result = JXL_ENC_NEED_MORE_OUTPUT;
+  while (result == JXL_ENC_NEED_MORE_OUTPUT) {
+    result = JxlEncoderProcessOutput(enc, &next_out, &avail_out);
+    if (result == JXL_ENC_NEED_MORE_OUTPUT) {
+      size_t offset = next_out - compressed->data();
+      compressed->resize(compressed->size() * 2);
+      next_out = compressed->data() + offset;
+      avail_out = compressed->size() - offset;
+    }
+  }
+  compressed->resize(next_out - compressed->data());
+  if (result != JXL_ENC_SUCCESS) {
+    fprintf(stderr, "JxlEncoderProcessOutput failed.\n");
+    return false;
+  }
+  return true;
+}
+
+bool EncodeImageJXL(const JXLCompressParams& params, const PackedPixelFile& ppf,
+                    const std::vector<uint8_t>* jpeg_bytes,
+                    std::vector<uint8_t>* compressed) {
+  auto encoder = JxlEncoderMake(/*memory_manager=*/nullptr);
+  JxlEncoder* enc = encoder.get();
+
+  if (params.allow_expert_options) {
+    JxlEncoderAllowExpertOptions(enc);
+  }
+
+  if (params.runner_opaque != nullptr &&
+      JXL_ENC_SUCCESS != JxlEncoderSetParallelRunner(enc, params.runner,
+                                                     params.runner_opaque)) {
+    fprintf(stderr, "JxlEncoderSetParallelRunner failed\n");
+    return false;
+  }
+
+  if (params.HasOutputProcessor() &&
+      JXL_ENC_SUCCESS !=
+          JxlEncoderSetOutputProcessor(enc, params.output_processor)) {
+    fprintf(stderr, "JxlEncoderSetOutputProcessorfailed\n");
+    return false;
+  }
+
+  auto settings = JxlEncoderFrameSettingsCreate(enc, nullptr);
+  size_t option_idx = 0;
+  if (!SetFrameOptions(params.options, 0, &option_idx, settings)) {
+    return false;
+  }
+  if (JXL_ENC_SUCCESS !=
+      JxlEncoderSetFrameDistance(settings, params.distance)) {
+    fprintf(stderr, "Setting frame distance failed.\n");
+    return false;
+  }
+  if (params.debug_image) {
+    JxlEncoderSetDebugImageCallback(settings, params.debug_image,
+                                    params.debug_image_opaque);
+  }
+  if (params.stats) {
+    JxlEncoderCollectStats(settings, params.stats);
+  }
+
+  bool use_boxes = !ppf.metadata.exif.empty() || !ppf.metadata.xmp.empty() ||
+                   !ppf.metadata.jumbf.empty() || !ppf.metadata.iptc.empty();
+  bool use_container = params.use_container || use_boxes ||
+                       (jpeg_bytes && params.jpeg_store_metadata);
+
+  if (JXL_ENC_SUCCESS !=
+      JxlEncoderUseContainer(enc, static_cast<int>(use_container))) {
+    fprintf(stderr, "JxlEncoderUseContainer failed.\n");
+    return false;
+  }
+
+  if (jpeg_bytes) {
+    if (params.jpeg_store_metadata &&
+        JXL_ENC_SUCCESS != JxlEncoderStoreJPEGMetadata(enc, JXL_TRUE)) {
+      fprintf(stderr, "Storing JPEG metadata failed.\n");
+      return false;
+    }
+    if (!params.jpeg_store_metadata && params.jpeg_strip_exif) {
+      JxlEncoderFrameSettingsSetOption(settings,
+                                       JXL_ENC_FRAME_SETTING_JPEG_KEEP_EXIF, 0);
+    }
+    if (!params.jpeg_store_metadata && params.jpeg_strip_xmp) {
+      JxlEncoderFrameSettingsSetOption(settings,
+                                       JXL_ENC_FRAME_SETTING_JPEG_KEEP_XMP, 0);
+    }
+    if (params.jpeg_strip_jumbf) {
+      JxlEncoderFrameSettingsSetOption(
+          settings, JXL_ENC_FRAME_SETTING_JPEG_KEEP_JUMBF, 0);
+    }
+    if (JXL_ENC_SUCCESS != JxlEncoderAddJPEGFrame(settings, jpeg_bytes->data(),
+                                                  jpeg_bytes->size())) {
+      JxlEncoderError error = JxlEncoderGetError(enc);
+      if (error == JXL_ENC_ERR_BAD_INPUT) {
+        fprintf(stderr,
+                "Error while decoding the JPEG image. It may be corrupt (e.g. "
+                "truncated) or of an unsupported type (e.g. CMYK).\n");
+      } else if (error == JXL_ENC_ERR_JBRD) {
+        fprintf(stderr,
+                "JPEG bitstream reconstruction data could not be created. "
+                "Possibly there is too much tail data.\n"
+                "Try using --jpeg_store_metadata 0, to losslessly "
+                "recompress the JPEG image data without bitstream "
+                "reconstruction data.\n");
+      } else {
+        fprintf(stderr, "JxlEncoderAddJPEGFrame() failed.\n");
+      }
+      return false;
+    }
+  } else {
+    size_t num_alpha_channels = 0;  // Adjusted below.
+    JxlBasicInfo basic_info = ppf.info;
+    basic_info.xsize *= params.already_downsampled;
+    basic_info.ysize *= params.already_downsampled;
+    if (basic_info.alpha_bits > 0) num_alpha_channels = 1;
+    if (params.intensity_target > 0) {
+      basic_info.intensity_target = params.intensity_target;
+    }
+    basic_info.num_extra_channels =
+        std::max<uint32_t>(num_alpha_channels, ppf.info.num_extra_channels);
+    basic_info.num_color_channels = ppf.info.num_color_channels;
+    const bool lossless = params.distance == 0;
+    basic_info.uses_original_profile = lossless;
+    if (params.override_bitdepth != 0) {
+      basic_info.bits_per_sample = params.override_bitdepth;
+      basic_info.exponent_bits_per_sample =
+          params.override_bitdepth == 32 ? 8 : 0;
+    }
+    if (JXL_ENC_SUCCESS !=
+        JxlEncoderSetCodestreamLevel(enc, params.codestream_level)) {
+      fprintf(stderr, "Setting --codestream_level failed.\n");
+      return false;
+    }
+    if (JXL_ENC_SUCCESS != JxlEncoderSetBasicInfo(enc, &basic_info)) {
+      fprintf(stderr, "JxlEncoderSetBasicInfo() failed.\n");
+      return false;
+    }
+    if (JXL_ENC_SUCCESS !=
+        JxlEncoderSetUpsamplingMode(enc, params.already_downsampled,
+                                    params.upsampling_mode)) {
+      fprintf(stderr, "JxlEncoderSetUpsamplingMode() failed.\n");
+      return false;
+    }
+    if (JXL_ENC_SUCCESS !=
+        JxlEncoderSetFrameBitDepth(settings, &params.input_bitdepth)) {
+      fprintf(stderr, "JxlEncoderSetFrameBitDepth() failed.\n");
+      return false;
+    }
+    if (num_alpha_channels != 0 &&
+        JXL_ENC_SUCCESS != JxlEncoderSetExtraChannelDistance(
+                               settings, 0, params.alpha_distance)) {
+      fprintf(stderr, "Setting alpha distance failed.\n");
+      return false;
+    }
+    if (lossless &&
+        JXL_ENC_SUCCESS != JxlEncoderSetFrameLossless(settings, JXL_TRUE)) {
+      fprintf(stderr, "JxlEncoderSetFrameLossless() failed.\n");
+      return false;
+    }
+    if (!ppf.icc.empty()) {
+      if (JXL_ENC_SUCCESS !=
+          JxlEncoderSetICCProfile(enc, ppf.icc.data(), ppf.icc.size())) {
+        fprintf(stderr, "JxlEncoderSetICCProfile() failed.\n");
+        return false;
+      }
+    } else {
+      if (JXL_ENC_SUCCESS !=
+          JxlEncoderSetColorEncoding(enc, &ppf.color_encoding)) {
+        fprintf(stderr, "JxlEncoderSetColorEncoding() failed.\n");
+        return false;
+      }
+    }
+
+    if (use_boxes) {
+      if (JXL_ENC_SUCCESS != JxlEncoderUseBoxes(enc)) {
+        fprintf(stderr, "JxlEncoderUseBoxes() failed.\n");
+        return false;
+      }
+      // Prepend 4 zero bytes to exif for tiff header offset
+      std::vector<uint8_t> exif_with_offset;
+      bool bigendian;
+      if (IsExif(ppf.metadata.exif, &bigendian)) {
+        exif_with_offset.resize(ppf.metadata.exif.size() + 4);
+        memcpy(exif_with_offset.data() + 4, ppf.metadata.exif.data(),
+               ppf.metadata.exif.size());
+      }
+      const struct BoxInfo {
+        const char* type;
+        const std::vector<uint8_t>& bytes;
+      } boxes[] = {
+          {"Exif", exif_with_offset},
+          {"xml ", ppf.metadata.xmp},
+          {"jumb", ppf.metadata.jumbf},
+          {"xml ", ppf.metadata.iptc},
+      };
+      for (size_t i = 0; i < sizeof boxes / sizeof *boxes; ++i) {
+        const BoxInfo& box = boxes[i];
+        if (!box.bytes.empty() &&
+            JXL_ENC_SUCCESS != JxlEncoderAddBox(enc, box.type, box.bytes.data(),
+                                                box.bytes.size(),
+                                                params.compress_boxes)) {
+          fprintf(stderr, "JxlEncoderAddBox() failed (%s).\n", box.type);
+          return false;
+        }
+      }
+      JxlEncoderCloseBoxes(enc);
+    }
+
+    for (size_t num_frame = 0; num_frame < ppf.frames.size(); ++num_frame) {
+      const jxl::extras::PackedFrame& pframe = ppf.frames[num_frame];
+      const jxl::extras::PackedImage& pimage = pframe.color;
+      JxlPixelFormat ppixelformat = pimage.format;
+      size_t num_interleaved_alpha =
+          (ppixelformat.num_channels - ppf.info.num_color_channels);
+      if (!SetupFrame(enc, settings, pframe.frame_info, params, ppf, num_frame,
+                      num_alpha_channels, num_interleaved_alpha, option_idx)) {
+        return false;
+      }
+      if (JXL_ENC_SUCCESS != JxlEncoderAddImageFrame(settings, &ppixelformat,
+                                                     pimage.pixels(),
+                                                     pimage.pixels_size)) {
+        fprintf(stderr, "JxlEncoderAddImageFrame() failed.\n");
+        return false;
+      }
+      // Only set extra channel buffer if it is provided non-interleaved.
+      for (size_t i = 0; i < pframe.extra_channels.size(); ++i) {
+        if (JXL_ENC_SUCCESS !=
+            JxlEncoderSetExtraChannelBuffer(settings, &ppixelformat,
+                                            pframe.extra_channels[i].pixels(),
+                                            pframe.extra_channels[i].stride *
+                                                pframe.extra_channels[i].ysize,
+                                            num_interleaved_alpha + i)) {
+          fprintf(stderr, "JxlEncoderSetExtraChannelBuffer() failed.\n");
+          return false;
+        }
+      }
+    }
+    for (size_t fi = 0; fi < ppf.chunked_frames.size(); ++fi) {
+      ChunkedPackedFrame& chunked_frame = ppf.chunked_frames[fi];
+      size_t num_interleaved_alpha =
+          (chunked_frame.format.num_channels - ppf.info.num_color_channels);
+      if (!SetupFrame(enc, settings, chunked_frame.frame_info, params, ppf, fi,
+                      num_alpha_channels, num_interleaved_alpha, option_idx)) {
+        return false;
+      }
+      const bool last_frame = fi + 1 == ppf.chunked_frames.size();
+      if (JXL_ENC_SUCCESS !=
+          JxlEncoderAddChunkedFrame(settings, last_frame,
+                                    chunked_frame.GetInputSource())) {
+        fprintf(stderr, "JxlEncoderAddChunkedFrame() failed.\n");
+        return false;
+      }
+    }
+  }
+  JxlEncoderCloseInput(enc);
+  if (params.HasOutputProcessor()) {
+    if (JXL_ENC_SUCCESS != JxlEncoderFlushInput(enc)) {
+      fprintf(stderr, "JxlEncoderAddChunkedFrame() failed.\n");
+      return false;
+    }
+  } else if (!ReadCompressedOutput(enc, compressed)) {
+    return false;
+  }
+  return true;
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/enc/jxl.h b/third_party/jpeg-xl/lib/extras/enc/jxl.h
new file mode 100644
index 0000000000..b8ca5bda2f
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/jxl.h
@@ -0,0 +1,91 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_ENC_JXL_H_
+#define LIB_EXTRAS_ENC_JXL_H_
+
+#include <jxl/encode.h>
+#include <jxl/parallel_runner.h>
+#include <jxl/thread_parallel_runner.h>
+#include <jxl/types.h>
+#include <stdint.h>
+
+#include <vector>
+
+#include "lib/extras/packed_image.h"
+
+namespace jxl {
+namespace extras {
+
+struct JXLOption {
+  JXLOption(JxlEncoderFrameSettingId id, int64_t val, size_t frame_index)
+      : id(id), is_float(false), ival(val), frame_index(frame_index) {}
+  JXLOption(JxlEncoderFrameSettingId id, float val, size_t frame_index)
+      : id(id), is_float(true), fval(val), frame_index(frame_index) {}
+
+  JxlEncoderFrameSettingId id;
+  bool is_float;
+  union {
+    int64_t ival;
+    float fval;
+  };
+  size_t frame_index;
+};
+
+struct JXLCompressParams {
+  std::vector<JXLOption> options;
+  // Target butteraugli distance, 0.0 means lossless.
+  float distance = 1.0f;
+  float alpha_distance = 1.0f;
+  // If set to true, forces container mode.
+  bool use_container = false;
+  // Whether to enable/disable byte-exact jpeg reconstruction for jpeg inputs.
+  bool jpeg_store_metadata = true;
+  bool jpeg_strip_exif = false;
+  bool jpeg_strip_xmp = false;
+  bool jpeg_strip_jumbf = false;
+  // Whether to create brob boxes.
+  bool compress_boxes = true;
+  // Upper bound on the intensity level present in the image in nits (zero means
+  // that the library chooses a default).
+  float intensity_target = 0;
+  int already_downsampled = 1;
+  int upsampling_mode = -1;
+  // Overrides for bitdepth, codestream level and alpha premultiply.
+  size_t override_bitdepth = 0;
+  int32_t codestream_level = -1;
+  int32_t premultiply = -1;
+  // Override input buffer interpretation.
+  JxlBitDepth input_bitdepth = {JXL_BIT_DEPTH_FROM_PIXEL_FORMAT, 0, 0};
+  // If runner_opaque is set, the decoder uses this parallel runner.
+  JxlParallelRunner runner = JxlThreadParallelRunner;
+  void* runner_opaque = nullptr;
+  JxlEncoderOutputProcessor output_processor = {};
+  JxlDebugImageCallback debug_image = nullptr;
+  void* debug_image_opaque = nullptr;
+  JxlEncoderStats* stats = nullptr;
+  bool allow_expert_options = false;
+
+  void AddOption(JxlEncoderFrameSettingId id, int64_t val) {
+    options.emplace_back(JXLOption(id, val, 0));
+  }
+  void AddFloatOption(JxlEncoderFrameSettingId id, float val) {
+    options.emplace_back(JXLOption(id, val, 0));
+  }
+  bool HasOutputProcessor() const {
+    return (output_processor.get_buffer != nullptr &&
+            output_processor.release_buffer != nullptr &&
+            output_processor.set_finalized_position != nullptr);
+  }
+};
+
+bool EncodeImageJXL(const JXLCompressParams& params, const PackedPixelFile& ppf,
+                    const std::vector<uint8_t>* jpeg_bytes,
+                    std::vector<uint8_t>* compressed);
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_ENC_JXL_H_
diff --git a/third_party/jpeg-xl/lib/extras/enc/npy.cc b/third_party/jpeg-xl/lib/extras/enc/npy.cc
new file mode 100644
index 0000000000..ae8cf13cc4
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/npy.cc
@@ -0,0 +1,321 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/enc/npy.h"
+
+#include <jxl/types.h>
+
+#include <sstream>
+#include <string>
+#include <vector>
+
+#include "lib/extras/packed_image.h"
+
+namespace jxl {
+namespace extras {
+namespace {
+
+// JSON value writing
+
+class JSONField {
+ public:
+  virtual ~JSONField() = default;
+  virtual void Write(std::ostream& o, uint32_t indent) const = 0;
+
+ protected:
+  JSONField() = default;
+};
+
+class JSONValue : public JSONField {
+ public:
+  template <typename T>
+  explicit JSONValue(const T& value) : value_(std::to_string(value)) {}
+
+  explicit JSONValue(const std::string& value) : value_("\"" + value + "\"") {}
+
+  explicit JSONValue(bool value) : value_(value ? "true" : "false") {}
+
+  void Write(std::ostream& o, uint32_t indent) const override { o << value_; }
+
+ private:
+  std::string value_;
+};
+
+class JSONDict : public JSONField {
+ public:
+  JSONDict() = default;
+
+  template <typename T>
+  T* AddEmpty(const std::string& key) {
+    static_assert(std::is_convertible<T*, JSONField*>::value,
+                  "T must be a JSONField");
+    T* ret = new T();
+    values_.emplace_back(
+        key, std::unique_ptr<JSONField>(static_cast<JSONField*>(ret)));
+    return ret;
+  }
+
+  template <typename T>
+  void Add(const std::string& key, const T& value) {
+    values_.emplace_back(key, std::unique_ptr<JSONField>(new JSONValue(value)));
+  }
+
+  void Write(std::ostream& o, uint32_t indent) const override {
+    std::string indent_str(indent, ' ');
+    o << "{";
+    bool is_first = true;
+    for (const auto& key_value : values_) {
+      if (!is_first) {
+        o << ",";
+      }
+      is_first = false;
+      o << std::endl << indent_str << "  \"" << key_value.first << "\": ";
+      key_value.second->Write(o, indent + 2);
+    }
+    if (!values_.empty()) {
+      o << std::endl << indent_str;
+    }
+    o << "}";
+  }
+
+ private:
+  // Dictionary with order.
+  std::vector<std::pair<std::string, std::unique_ptr<JSONField>>> values_;
+};
+
+class JSONArray : public JSONField {
+ public:
+  JSONArray() = default;
+
+  template <typename T>
+  T* AddEmpty() {
+    static_assert(std::is_convertible<T*, JSONField*>::value,
+                  "T must be a JSONField");
+    T* ret = new T();
+    values_.emplace_back(ret);
+    return ret;
+  }
+
+  template <typename T>
+  void Add(const T& value) {
+    values_.emplace_back(new JSONValue(value));
+  }
+
+  void Write(std::ostream& o, uint32_t indent) const override {
+    std::string indent_str(indent, ' ');
+    o << "[";
+    bool is_first = true;
+    for (const auto& value : values_) {
+      if (!is_first) {
+        o << ",";
+      }
+      is_first = false;
+      o << std::endl << indent_str << "  ";
+      value->Write(o, indent + 2);
+    }
+    if (!values_.empty()) {
+      o << std::endl << indent_str;
+    }
+    o << "]";
+  }
+
+ private:
+  std::vector<std::unique_ptr<JSONField>> values_;
+};
+
+void GenerateMetadata(const PackedPixelFile& ppf, std::vector<uint8_t>* out) {
+  JSONDict meta;
+  // Same order as in 18181-3 CD.
+
+  // Frames.
+  auto* meta_frames = meta.AddEmpty<JSONArray>("frames");
+  for (size_t i = 0; i < ppf.frames.size(); i++) {
+    auto* frame_i = meta_frames->AddEmpty<JSONDict>();
+    if (ppf.info.have_animation) {
+      frame_i->Add("duration",
+                   JSONValue(ppf.frames[i].frame_info.duration * 1.0f *
+                             ppf.info.animation.tps_denominator /
+                             ppf.info.animation.tps_numerator));
+    }
+
+    frame_i->Add("name", JSONValue(ppf.frames[i].name));
+
+    if (ppf.info.animation.have_timecodes) {
+      frame_i->Add("timecode", JSONValue(ppf.frames[i].frame_info.timecode));
+    }
+  }
+
+#define METADATA(FIELD) meta.Add(#FIELD, ppf.info.FIELD)
+
+  METADATA(intensity_target);
+  METADATA(min_nits);
+  METADATA(relative_to_max_display);
+  METADATA(linear_below);
+
+  if (ppf.info.have_preview) {
+    meta.AddEmpty<JSONDict>("preview");
+    // TODO(veluca): can we have duration/name/timecode here?
+  }
+
+  {
+    auto ectype = meta.AddEmpty<JSONArray>("extra_channel_type");
+    auto bps = meta.AddEmpty<JSONArray>("bits_per_sample");
+    auto ebps = meta.AddEmpty<JSONArray>("exp_bits_per_sample");
+    bps->Add(ppf.info.bits_per_sample);
+    ebps->Add(ppf.info.exponent_bits_per_sample);
+    for (size_t i = 0; i < ppf.extra_channels_info.size(); i++) {
+      switch (ppf.extra_channels_info[i].ec_info.type) {
+        case JXL_CHANNEL_ALPHA: {
+          ectype->Add(std::string("Alpha"));
+          break;
+        }
+        case JXL_CHANNEL_DEPTH: {
+          ectype->Add(std::string("Depth"));
+          break;
+        }
+        case JXL_CHANNEL_SPOT_COLOR: {
+          ectype->Add(std::string("SpotColor"));
+          break;
+        }
+        case JXL_CHANNEL_SELECTION_MASK: {
+          ectype->Add(std::string("SelectionMask"));
+          break;
+        }
+        case JXL_CHANNEL_BLACK: {
+          ectype->Add(std::string("Black"));
+          break;
+        }
+        case JXL_CHANNEL_CFA: {
+          ectype->Add(std::string("CFA"));
+          break;
+        }
+        case JXL_CHANNEL_THERMAL: {
+          ectype->Add(std::string("Thermal"));
+          break;
+        }
+        default: {
+          ectype->Add(std::string("UNKNOWN"));
+          break;
+        }
+      }
+      bps->Add(ppf.extra_channels_info[i].ec_info.bits_per_sample);
+      ebps->Add(ppf.extra_channels_info[i].ec_info.exponent_bits_per_sample);
+    }
+  }
+
+  std::ostringstream os;
+  meta.Write(os, 0);
+  out->resize(os.str().size());
+  memcpy(out->data(), os.str().data(), os.str().size());
+}
+
+void Append(std::vector<uint8_t>* out, const void* data, size_t size) {
+  size_t pos = out->size();
+  out->resize(pos + size);
+  memcpy(out->data() + pos, data, size);
+}
+
+void WriteNPYHeader(size_t xsize, size_t ysize, uint32_t num_channels,
+                    size_t num_frames, std::vector<uint8_t>* out) {
+  const uint8_t header[] = "\x93NUMPY\x01\x00";
+  Append(out, header, 8);
+  std::stringstream ss;
+  ss << "{'descr': '<f4', 'fortran_order': False, 'shape': (" << num_frames
+     << ", " << ysize << ", " << xsize << ", " << num_channels << "), }\n";
+  // 16-bit little endian header length.
+  uint8_t header_len[2] = {static_cast<uint8_t>(ss.str().size() % 256),
+                           static_cast<uint8_t>(ss.str().size() / 256)};
+  Append(out, header_len, 2);
+  Append(out, ss.str().data(), ss.str().size());
+}
+
+bool WriteFrameToNPYArray(size_t xsize, size_t ysize, const PackedFrame& frame,
+                          std::vector<uint8_t>* out) {
+  const auto& color = frame.color;
+  if (color.xsize != xsize || color.ysize != ysize) {
+    return false;
+  }
+  for (const auto& ec : frame.extra_channels) {
+    if (ec.xsize != xsize || ec.ysize != ysize) {
+      return false;
+    }
+  }
+  // interleave the samples from color and extra channels
+  for (size_t y = 0; y < ysize; ++y) {
+    for (size_t x = 0; x < xsize; ++x) {
+      {
+        size_t sample_size = color.pixel_stride();
+        size_t offset = y * color.stride + x * sample_size;
+        uint8_t* pixels = reinterpret_cast<uint8_t*>(color.pixels());
+        JXL_ASSERT(offset + sample_size <= color.pixels_size);
+        Append(out, pixels + offset, sample_size);
+      }
+      for (const auto& ec : frame.extra_channels) {
+        size_t sample_size = ec.pixel_stride();
+        size_t offset = y * ec.stride + x * sample_size;
+        uint8_t* pixels = reinterpret_cast<uint8_t*>(ec.pixels());
+        JXL_ASSERT(offset + sample_size <= ec.pixels_size);
+        Append(out, pixels + offset, sample_size);
+      }
+    }
+  }
+  return true;
+}
+
+// Writes a PackedPixelFile as a numpy 4D ndarray in binary format.
+bool WriteNPYArray(const PackedPixelFile& ppf, std::vector<uint8_t>* out) {
+  size_t xsize = ppf.info.xsize;
+  size_t ysize = ppf.info.ysize;
+  WriteNPYHeader(xsize, ysize,
+                 ppf.info.num_color_channels + ppf.extra_channels_info.size(),
+                 ppf.frames.size(), out);
+  for (const auto& frame : ppf.frames) {
+    if (!WriteFrameToNPYArray(xsize, ysize, frame, out)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+class NumPyEncoder : public Encoder {
+ public:
+  Status Encode(const PackedPixelFile& ppf, EncodedImage* encoded_image,
+                ThreadPool* pool = nullptr) const override {
+    JXL_RETURN_IF_ERROR(VerifyBasicInfo(ppf.info));
+    GenerateMetadata(ppf, &encoded_image->metadata);
+    encoded_image->bitstreams.emplace_back();
+    if (!WriteNPYArray(ppf, &encoded_image->bitstreams.back())) {
+      return false;
+    }
+    if (ppf.preview_frame) {
+      size_t xsize = ppf.info.preview.xsize;
+      size_t ysize = ppf.info.preview.ysize;
+      WriteNPYHeader(xsize, ysize, ppf.info.num_color_channels, 1,
+                     &encoded_image->preview_bitstream);
+      if (!WriteFrameToNPYArray(xsize, ysize, *ppf.preview_frame,
+                                &encoded_image->preview_bitstream)) {
+        return false;
+      }
+    }
+    return true;
+  }
+  std::vector<JxlPixelFormat> AcceptedFormats() const override {
+    std::vector<JxlPixelFormat> formats;
+    for (const uint32_t num_channels : {1, 3}) {
+      formats.push_back(JxlPixelFormat{num_channels, JXL_TYPE_FLOAT,
+                                       JXL_LITTLE_ENDIAN, /*align=*/0});
+    }
+    return formats;
+  }
+};
+
+}  // namespace
+
+std::unique_ptr<Encoder> GetNumPyEncoder() {
+  return jxl::make_unique<NumPyEncoder>();
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/enc/npy.h b/third_party/jpeg-xl/lib/extras/enc/npy.h
new file mode 100644
index 0000000000..3ee6208ec2
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/npy.h
@@ -0,0 +1,23 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_ENC_NPY_H_
+#define LIB_EXTRAS_ENC_NPY_H_
+
+// Encodes pixels to numpy array, used for conformance testing.
+
+#include <memory>
+
+#include "lib/extras/enc/encode.h"
+
+namespace jxl {
+namespace extras {
+
+std::unique_ptr<Encoder> GetNumPyEncoder();
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_ENC_NPY_H_
diff --git a/third_party/jpeg-xl/lib/extras/enc/pgx.cc b/third_party/jpeg-xl/lib/extras/enc/pgx.cc
new file mode 100644
index 0000000000..d4809e38b6
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/pgx.cc
@@ -0,0 +1,122 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/enc/pgx.h"
+
+#include <jxl/codestream_header.h>
+#include <string.h>
+
+#include "lib/extras/packed_image.h"
+#include "lib/jxl/base/byte_order.h"
+
+namespace jxl {
+namespace extras {
+namespace {
+
+constexpr size_t kMaxHeaderSize = 200;
+
+Status EncodeHeader(const JxlBasicInfo& info, char* header,
+                    int* chars_written) {
+  if (info.alpha_bits > 0) {
+    return JXL_FAILURE("PGX: can't store alpha");
+  }
+  if (info.num_color_channels != 1) {
+    return JXL_FAILURE("PGX: must be grayscale");
+  }
+  // TODO(lode): verify other bit depths: for other bit depths such as 1 or 4
+  // bits, have a test case to verify it works correctly. For bits > 16, we may
+  // need to change the way external_image works.
+  if (info.bits_per_sample != 8 && info.bits_per_sample != 16) {
+    return JXL_FAILURE("PGX: bits other than 8 or 16 not yet supported");
+  }
+
+  // Use ML (Big Endian), LM may not be well supported by all decoders.
+  *chars_written = snprintf(header, kMaxHeaderSize, "PG ML + %u %u %u\n",
+                            info.bits_per_sample, info.xsize, info.ysize);
+  JXL_RETURN_IF_ERROR(static_cast<unsigned int>(*chars_written) <
+                      kMaxHeaderSize);
+  return true;
+}
+
+Status EncodeImagePGX(const PackedFrame& frame, const JxlBasicInfo& info,
+                      std::vector<uint8_t>* bytes) {
+  char header[kMaxHeaderSize];
+  int header_size = 0;
+  JXL_RETURN_IF_ERROR(EncodeHeader(info, header, &header_size));
+
+  const PackedImage& color = frame.color;
+  const JxlPixelFormat format = color.format;
+  const uint8_t* in = reinterpret_cast<const uint8_t*>(color.pixels());
+  size_t data_bits_per_sample = PackedImage::BitsPerChannel(format.data_type);
+  size_t bytes_per_sample = data_bits_per_sample / kBitsPerByte;
+  size_t num_samples = info.xsize * info.ysize;
+
+  if (info.bits_per_sample != data_bits_per_sample) {
+    return JXL_FAILURE("Bit depth does not match pixel data type");
+  }
+
+  std::vector<uint8_t> pixels(num_samples * bytes_per_sample);
+
+  if (format.data_type == JXL_TYPE_UINT8) {
+    memcpy(&pixels[0], in, num_samples * bytes_per_sample);
+  } else if (format.data_type == JXL_TYPE_UINT16) {
+    if (format.endianness != JXL_BIG_ENDIAN) {
+      const uint8_t* p_in = in;
+      uint8_t* p_out = pixels.data();
+      for (size_t i = 0; i < num_samples; ++i, p_in += 2, p_out += 2) {
+        StoreBE16(LoadLE16(p_in), p_out);
+      }
+    } else {
+      memcpy(&pixels[0], in, num_samples * bytes_per_sample);
+    }
+  } else {
+    return JXL_FAILURE("Unsupported pixel data type");
+  }
+
+  bytes->resize(static_cast<size_t>(header_size) + pixels.size());
+  memcpy(bytes->data(), header, static_cast<size_t>(header_size));
+  memcpy(bytes->data() + header_size, pixels.data(), pixels.size());
+
+  return true;
+}
+
+class PGXEncoder : public Encoder {
+ public:
+  std::vector<JxlPixelFormat> AcceptedFormats() const override {
+    std::vector<JxlPixelFormat> formats;
+    for (const JxlDataType data_type : {JXL_TYPE_UINT8, JXL_TYPE_UINT16}) {
+      for (JxlEndianness endianness : {JXL_BIG_ENDIAN, JXL_LITTLE_ENDIAN}) {
+        formats.push_back(JxlPixelFormat{/*num_channels=*/1,
+                                         /*data_type=*/data_type,
+                                         /*endianness=*/endianness,
+                                         /*align=*/0});
+      }
+    }
+    return formats;
+  }
+  Status Encode(const PackedPixelFile& ppf, EncodedImage* encoded_image,
+                ThreadPool* pool) const override {
+    JXL_RETURN_IF_ERROR(VerifyBasicInfo(ppf.info));
+    encoded_image->icc.assign(ppf.icc.begin(), ppf.icc.end());
+    encoded_image->bitstreams.clear();
+    encoded_image->bitstreams.reserve(ppf.frames.size());
+    for (const auto& frame : ppf.frames) {
+      JXL_RETURN_IF_ERROR(VerifyPackedImage(frame.color, ppf.info));
+      encoded_image->bitstreams.emplace_back();
+      JXL_RETURN_IF_ERROR(
+          EncodeImagePGX(frame, ppf.info, &encoded_image->bitstreams.back()));
+    }
+    return true;
+  }
+};
+
+}  // namespace
+
+std::unique_ptr<Encoder> GetPGXEncoder() {
+  return jxl::make_unique<PGXEncoder>();
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/enc/pgx.h b/third_party/jpeg-xl/lib/extras/enc/pgx.h
new file mode 100644
index 0000000000..f24e391b09
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/pgx.h
@@ -0,0 +1,24 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_ENC_PGX_H_
+#define LIB_EXTRAS_ENC_PGX_H_
+
+// Encodes PGX pixels in memory.
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "lib/extras/enc/encode.h"
+
+namespace jxl {
+namespace extras {
+
+std::unique_ptr<Encoder> GetPGXEncoder();
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_ENC_PGX_H_
diff --git a/third_party/jpeg-xl/lib/extras/enc/pnm.cc b/third_party/jpeg-xl/lib/extras/enc/pnm.cc
new file mode 100644
index 0000000000..4183900198
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/pnm.cc
@@ -0,0 +1,331 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/enc/pnm.h"
+
+#include <string.h>
+
+#include <string>
+#include <vector>
+
+#include "lib/extras/packed_image.h"
+#include "lib/jxl/base/byte_order.h"
+#include "lib/jxl/base/compiler_specific.h"
+#include "lib/jxl/base/printf_macros.h"
+#include "lib/jxl/base/status.h"
+#include "lib/jxl/dec_external_image.h"
+#include "lib/jxl/enc_external_image.h"
+#include "lib/jxl/enc_image_bundle.h"
+#include "lib/jxl/fields.h"  // AllDefault
+#include "lib/jxl/image.h"
+#include "lib/jxl/image_bundle.h"
+
+namespace jxl {
+namespace extras {
+namespace {
+
+constexpr size_t kMaxHeaderSize = 200;
+
+class BasePNMEncoder : public Encoder {
+ public:
+  Status Encode(const PackedPixelFile& ppf, EncodedImage* encoded_image,
+                ThreadPool* pool = nullptr) const override {
+    JXL_RETURN_IF_ERROR(VerifyBasicInfo(ppf.info));
+    if (!ppf.metadata.exif.empty() || !ppf.metadata.iptc.empty() ||
+        !ppf.metadata.jumbf.empty() || !ppf.metadata.xmp.empty()) {
+      JXL_WARNING("PNM encoder ignoring metadata - use a different codec");
+    }
+    encoded_image->icc = ppf.icc;
+    encoded_image->bitstreams.clear();
+    encoded_image->bitstreams.reserve(ppf.frames.size());
+    for (const auto& frame : ppf.frames) {
+      JXL_RETURN_IF_ERROR(VerifyPackedImage(frame.color, ppf.info));
+      encoded_image->bitstreams.emplace_back();
+      JXL_RETURN_IF_ERROR(
+          EncodeFrame(ppf, frame, &encoded_image->bitstreams.back()));
+    }
+    for (size_t i = 0; i < ppf.extra_channels_info.size(); ++i) {
+      const auto& ec_info = ppf.extra_channels_info[i].ec_info;
+      encoded_image->extra_channel_bitstreams.emplace_back();
+      auto& ec_bitstreams = encoded_image->extra_channel_bitstreams.back();
+      for (const auto& frame : ppf.frames) {
+        ec_bitstreams.emplace_back();
+        JXL_RETURN_IF_ERROR(EncodeExtraChannel(frame.extra_channels[i],
+                                               ec_info.bits_per_sample,
+                                               &ec_bitstreams.back()));
+      }
+    }
+    return true;
+  }
+
+ protected:
+  virtual Status EncodeFrame(const PackedPixelFile& ppf,
+                             const PackedFrame& frame,
+                             std::vector<uint8_t>* bytes) const = 0;
+  virtual Status EncodeExtraChannel(const PackedImage& image,
+                                    size_t bits_per_sample,
+                                    std::vector<uint8_t>* bytes) const = 0;
+};
+
+class PNMEncoder : public BasePNMEncoder {
+ public:
+  static const std::vector<JxlPixelFormat> kAcceptedFormats;
+
+  std::vector<JxlPixelFormat> AcceptedFormats() const override {
+    return kAcceptedFormats;
+  }
+
+  Status EncodeFrame(const PackedPixelFile& ppf, const PackedFrame& frame,
+                     std::vector<uint8_t>* bytes) const override {
+    return EncodeImage(frame.color, ppf.info.bits_per_sample, bytes);
+  }
+  Status EncodeExtraChannel(const PackedImage& image, size_t bits_per_sample,
+                            std::vector<uint8_t>* bytes) const override {
+    return EncodeImage(image, bits_per_sample, bytes);
+  }
+
+ private:
+  Status EncodeImage(const PackedImage& image, size_t bits_per_sample,
+                     std::vector<uint8_t>* bytes) const {
+    uint32_t maxval = (1u << bits_per_sample) - 1;
+    char type = image.format.num_channels == 1 ? '5' : '6';
+    char header[kMaxHeaderSize];
+    size_t header_size =
+        snprintf(header, kMaxHeaderSize, "P%c\n%" PRIuS " %" PRIuS "\n%u\n",
+                 type, image.xsize, image.ysize, maxval);
+    JXL_RETURN_IF_ERROR(header_size < kMaxHeaderSize);
+    bytes->resize(header_size + image.pixels_size);
+    memcpy(bytes->data(), header, header_size);
+    memcpy(bytes->data() + header_size,
+           reinterpret_cast<uint8_t*>(image.pixels()), image.pixels_size);
+    return true;
+  }
+};
+
+class PGMEncoder : public PNMEncoder {
+ public:
+  static const std::vector<JxlPixelFormat> kAcceptedFormats;
+
+  std::vector<JxlPixelFormat> AcceptedFormats() const override {
+    return kAcceptedFormats;
+  }
+};
+
+const std::vector<JxlPixelFormat> PGMEncoder::kAcceptedFormats = {
+    JxlPixelFormat{1, JXL_TYPE_UINT8, JXL_BIG_ENDIAN, 0},
+    JxlPixelFormat{1, JXL_TYPE_UINT16, JXL_BIG_ENDIAN, 0}};
+
+class PPMEncoder : public PNMEncoder {
+ public:
+  static const std::vector<JxlPixelFormat> kAcceptedFormats;
+
+  std::vector<JxlPixelFormat> AcceptedFormats() const override {
+    return kAcceptedFormats;
+  }
+};
+
+const std::vector<JxlPixelFormat> PPMEncoder::kAcceptedFormats = {
+    JxlPixelFormat{3, JXL_TYPE_UINT8, JXL_BIG_ENDIAN, 0},
+    JxlPixelFormat{3, JXL_TYPE_UINT16, JXL_BIG_ENDIAN, 0}};
+
+const std::vector<JxlPixelFormat> PNMEncoder::kAcceptedFormats = [] {
+  std::vector<JxlPixelFormat> combined = PPMEncoder::kAcceptedFormats;
+  combined.insert(combined.end(), PGMEncoder::kAcceptedFormats.begin(),
+                  PGMEncoder::kAcceptedFormats.end());
+  return combined;
+}();
+
+class PFMEncoder : public BasePNMEncoder {
+ public:
+  std::vector<JxlPixelFormat> AcceptedFormats() const override {
+    std::vector<JxlPixelFormat> formats;
+    for (const uint32_t num_channels : {1, 3}) {
+      for (JxlEndianness endianness : {JXL_BIG_ENDIAN, JXL_LITTLE_ENDIAN}) {
+        formats.push_back(JxlPixelFormat{/*num_channels=*/num_channels,
+                                         /*data_type=*/JXL_TYPE_FLOAT,
+                                         /*endianness=*/endianness,
+                                         /*align=*/0});
+      }
+    }
+    return formats;
+  }
+  Status EncodeFrame(const PackedPixelFile& ppf, const PackedFrame& frame,
+                     std::vector<uint8_t>* bytes) const override {
+    return EncodeImage(frame.color, bytes);
+  }
+  Status EncodeExtraChannel(const PackedImage& image, size_t bits_per_sample,
+                            std::vector<uint8_t>* bytes) const override {
+    return EncodeImage(image, bytes);
+  }
+
+ private:
+  Status EncodeImage(const PackedImage& image,
+                     std::vector<uint8_t>* bytes) const {
+    char type = image.format.num_channels == 1 ? 'f' : 'F';
+    double scale = image.format.endianness == JXL_LITTLE_ENDIAN ? -1.0 : 1.0;
+    char header[kMaxHeaderSize];
+    size_t header_size =
+        snprintf(header, kMaxHeaderSize, "P%c\n%" PRIuS " %" PRIuS "\n%.1f\n",
+                 type, image.xsize, image.ysize, scale);
+    JXL_RETURN_IF_ERROR(header_size < kMaxHeaderSize);
+    bytes->resize(header_size + image.pixels_size);
+    memcpy(bytes->data(), header, header_size);
+    const uint8_t* in = reinterpret_cast<const uint8_t*>(image.pixels());
+    uint8_t* out = bytes->data() + header_size;
+    for (size_t y = 0; y < image.ysize; ++y) {
+      size_t y_out = image.ysize - 1 - y;
+      const uint8_t* row_in = &in[y * image.stride];
+      uint8_t* row_out = &out[y_out * image.stride];
+      memcpy(row_out, row_in, image.stride);
+    }
+    return true;
+  }
+};
+
+class PAMEncoder : public BasePNMEncoder {
+ public:
+  std::vector<JxlPixelFormat> AcceptedFormats() const override {
+    std::vector<JxlPixelFormat> formats;
+    for (const uint32_t num_channels : {1, 2, 3, 4}) {
+      for (const JxlDataType data_type : {JXL_TYPE_UINT8, JXL_TYPE_UINT16}) {
+        formats.push_back(JxlPixelFormat{/*num_channels=*/num_channels,
+                                         /*data_type=*/data_type,
+                                         /*endianness=*/JXL_BIG_ENDIAN,
+                                         /*align=*/0});
+      }
+    }
+    return formats;
+  }
+  Status EncodeFrame(const PackedPixelFile& ppf, const PackedFrame& frame,
+                     std::vector<uint8_t>* bytes) const override {
+    const PackedImage& color = frame.color;
+    const auto& ec_info = ppf.extra_channels_info;
+    JXL_RETURN_IF_ERROR(frame.extra_channels.size() == ec_info.size());
+    for (const auto& ec : frame.extra_channels) {
+      if (ec.xsize != color.xsize || ec.ysize != color.ysize) {
+        return JXL_FAILURE("Extra channel and color size mismatch.");
+      }
+      if (ec.format.data_type != color.format.data_type ||
+          ec.format.endianness != color.format.endianness) {
+        return JXL_FAILURE("Extra channel and color format mismatch.");
+      }
+    }
+    if (ppf.info.alpha_bits &&
+        (ppf.info.bits_per_sample != ppf.info.alpha_bits)) {
+      return JXL_FAILURE("Alpha bit depth does not match image bit depth");
+    }
+    for (const auto& it : ec_info) {
+      if (it.ec_info.bits_per_sample != ppf.info.bits_per_sample) {
+        return JXL_FAILURE(
+            "Extra channel bit depth does not match image bit depth");
+      }
+    }
+    const char* kColorTypes[4] = {"GRAYSCALE", "GRAYSCALE_ALPHA", "RGB",
+                                  "RGB_ALPHA"};
+    uint32_t maxval = (1u << ppf.info.bits_per_sample) - 1;
+    uint32_t depth = color.format.num_channels + ec_info.size();
+    char header[kMaxHeaderSize];
+    size_t pos = 0;
+    pos += snprintf(header + pos, kMaxHeaderSize - pos,
+                    "P7\nWIDTH %" PRIuS "\nHEIGHT %" PRIuS
+                    "\nDEPTH %u\n"
+                    "MAXVAL %u\nTUPLTYPE %s\n",
+                    color.xsize, color.ysize, depth, maxval,
+                    kColorTypes[color.format.num_channels - 1]);
+    JXL_RETURN_IF_ERROR(pos < kMaxHeaderSize);
+    for (const auto& info : ec_info) {
+      pos += snprintf(header + pos, kMaxHeaderSize - pos, "TUPLTYPE %s\n",
+                      ExtraChannelTypeName(info.ec_info.type).c_str());
+      JXL_RETURN_IF_ERROR(pos < kMaxHeaderSize);
+    }
+    pos += snprintf(header + pos, kMaxHeaderSize - pos, "ENDHDR\n");
+    JXL_RETURN_IF_ERROR(pos < kMaxHeaderSize);
+    size_t total_size = color.pixels_size;
+    for (const auto& ec : frame.extra_channels) {
+      total_size += ec.pixels_size;
+    }
+    bytes->resize(pos + total_size);
+    memcpy(bytes->data(), header, pos);
+    // If we have no extra channels, just copy color pixel data over.
+    if (frame.extra_channels.empty()) {
+      memcpy(bytes->data() + pos, reinterpret_cast<uint8_t*>(color.pixels()),
+             color.pixels_size);
+      return true;
+    }
+    // Interleave color and extra channels.
+    const uint8_t* in = reinterpret_cast<const uint8_t*>(color.pixels());
+    std::vector<const uint8_t*> ec_in(frame.extra_channels.size());
+    for (size_t i = 0; i < frame.extra_channels.size(); ++i) {
+      ec_in[i] =
+          reinterpret_cast<const uint8_t*>(frame.extra_channels[i].pixels());
+    }
+    uint8_t* out = bytes->data() + pos;
+    size_t pwidth = PackedImage::BitsPerChannel(color.format.data_type) / 8;
+    for (size_t y = 0; y < color.ysize; ++y) {
+      for (size_t x = 0; x < color.xsize; ++x) {
+        memcpy(out, in, color.pixel_stride());
+        out += color.pixel_stride();
+        in += color.pixel_stride();
+        for (auto& p : ec_in) {
+          memcpy(out, p, pwidth);
+          out += pwidth;
+          p += pwidth;
+        }
+      }
+    }
+    return true;
+  }
+  Status EncodeExtraChannel(const PackedImage& image, size_t bits_per_sample,
+                            std::vector<uint8_t>* bytes) const override {
+    return true;
+  }
+
+ private:
+  static std::string ExtraChannelTypeName(JxlExtraChannelType type) {
+    switch (type) {
+      case JXL_CHANNEL_ALPHA:
+        return std::string("Alpha");
+      case JXL_CHANNEL_DEPTH:
+        return std::string("Depth");
+      case JXL_CHANNEL_SPOT_COLOR:
+        return std::string("SpotColor");
+      case JXL_CHANNEL_SELECTION_MASK:
+        return std::string("SelectionMask");
+      case JXL_CHANNEL_BLACK:
+        return std::string("Black");
+      case JXL_CHANNEL_CFA:
+        return std::string("CFA");
+      case JXL_CHANNEL_THERMAL:
+        return std::string("Thermal");
+      default:
+        return std::string("UNKNOWN");
+    }
+  }
+};
+
+}  // namespace
+
+std::unique_ptr<Encoder> GetPPMEncoder() {
+  return jxl::make_unique<PPMEncoder>();
+}
+
+std::unique_ptr<Encoder> GetPNMEncoder() {
+  return jxl::make_unique<PNMEncoder>();
+}
+
+std::unique_ptr<Encoder> GetPFMEncoder() {
+  return jxl::make_unique<PFMEncoder>();
+}
+
+std::unique_ptr<Encoder> GetPGMEncoder() {
+  return jxl::make_unique<PGMEncoder>();
+}
+
+std::unique_ptr<Encoder> GetPAMEncoder() {
+  return jxl::make_unique<PAMEncoder>();
+}
+
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/enc/pnm.h b/third_party/jpeg-xl/lib/extras/enc/pnm.h
new file mode 100644
index 0000000000..1e0020cdbd
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/enc/pnm.h
@@ -0,0 +1,29 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_ENC_PNM_H_
+#define LIB_EXTRAS_ENC_PNM_H_
+
+// Encodes/decodes PBM/PGM/PPM/PFM pixels in memory.
+
+// TODO(janwas): workaround for incorrect Win64 codegen (cause unknown)
+#include <hwy/highway.h>
+#include <memory>
+
+#include "lib/extras/enc/encode.h"
+
+namespace jxl {
+namespace extras {
+
+std::unique_ptr<Encoder> GetPAMEncoder();
+std::unique_ptr<Encoder> GetPGMEncoder();
+std::unique_ptr<Encoder> GetPNMEncoder();
+std::unique_ptr<Encoder> GetPPMEncoder();
+std::unique_ptr<Encoder> GetPFMEncoder();
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_ENC_PNM_H_
diff --git a/third_party/jpeg-xl/lib/extras/exif.cc b/third_party/jpeg-xl/lib/extras/exif.cc
new file mode 100644
index 0000000000..aea632732b
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/exif.cc
@@ -0,0 +1,55 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/exif.h"
+
+#include "lib/jxl/base/byte_order.h"
+
+namespace jxl {
+
+constexpr uint16_t kExifOrientationTag = 274;
+
+void ResetExifOrientation(std::vector<uint8_t>& exif) {
+  if (exif.size() < 12) return;  // not enough bytes for a valid exif blob
+  bool bigendian;
+  uint8_t* t = exif.data();
+  if (LoadLE32(t) == 0x2A004D4D) {
+    bigendian = true;
+  } else if (LoadLE32(t) == 0x002A4949) {
+    bigendian = false;
+  } else {
+    return;  // not a valid tiff header
+  }
+  t += 4;
+  uint64_t offset = (bigendian ? LoadBE32(t) : LoadLE32(t));
+  if (exif.size() < 12 + offset + 2 || offset < 8) return;
+  t += offset - 4;
+  uint16_t nb_tags = (bigendian ? LoadBE16(t) : LoadLE16(t));
+  t += 2;
+  while (nb_tags > 0) {
+    if (t + 12 >= exif.data() + exif.size()) return;
+    uint16_t tag = (bigendian ? LoadBE16(t) : LoadLE16(t));
+    t += 2;
+    if (tag == kExifOrientationTag) {
+      uint16_t type = (bigendian ? LoadBE16(t) : LoadLE16(t));
+      t += 2;
+      uint32_t count = (bigendian ? LoadBE32(t) : LoadLE32(t));
+      t += 4;
+      if (type == 3 && count == 1) {
+        if (bigendian) {
+          StoreBE16(1, t);
+        } else {
+          StoreLE16(1, t);
+        }
+      }
+      return;
+    } else {
+      t += 10;
+      nb_tags--;
+    }
+  }
+}
+
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/exif.h b/third_party/jpeg-xl/lib/extras/exif.h
new file mode 100644
index 0000000000..f22b2ccef5
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/exif.h
@@ -0,0 +1,20 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_EXIF_H_
+#define LIB_EXTRAS_EXIF_H_
+
+#include <stdint.h>
+
+#include <vector>
+
+namespace jxl {
+
+// Sets the Exif orientation to the identity, to avoid repeated orientation
+void ResetExifOrientation(std::vector<uint8_t>& exif);
+
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_EXIF_H_
diff --git a/third_party/jpeg-xl/lib/extras/hlg.cc b/third_party/jpeg-xl/lib/extras/hlg.cc
new file mode 100644
index 0000000000..125005542b
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/hlg.cc
@@ -0,0 +1,57 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/hlg.h"
+
+#include <jxl/cms.h>
+
+#include <cmath>
+
+namespace jxl {
+
+float GetHlgGamma(const float peak_luminance, const float surround_luminance) {
+  return 1.2f * std::pow(1.111f, std::log2(peak_luminance / 1000.f)) *
+         std::pow(0.98f, std::log2(surround_luminance / 5.f));
+}
+
+Status HlgOOTF(ImageBundle* ib, const float gamma, ThreadPool* pool) {
+  ColorEncoding linear_rec2020;
+  linear_rec2020.SetColorSpace(ColorSpace::kRGB);
+  JXL_RETURN_IF_ERROR(linear_rec2020.SetPrimariesType(Primaries::k2100));
+  JXL_RETURN_IF_ERROR(linear_rec2020.SetWhitePointType(WhitePoint::kD65));
+  linear_rec2020.Tf().SetTransferFunction(TransferFunction::kLinear);
+  JXL_RETURN_IF_ERROR(linear_rec2020.CreateICC());
+  JXL_RETURN_IF_ERROR(
+      ib->TransformTo(linear_rec2020, *JxlGetDefaultCms(), pool));
+
+  JXL_RETURN_IF_ERROR(RunOnPool(
+      pool, 0, ib->ysize(), ThreadPool::NoInit,
+      [&](const int y, const int thread) {
+        float* const JXL_RESTRICT rows[3] = {ib->color()->PlaneRow(0, y),
+                                             ib->color()->PlaneRow(1, y),
+                                             ib->color()->PlaneRow(2, y)};
+        for (size_t x = 0; x < ib->xsize(); ++x) {
+          float& red = rows[0][x];
+          float& green = rows[1][x];
+          float& blue = rows[2][x];
+          const float luminance =
+              0.2627f * red + 0.6780f * green + 0.0593f * blue;
+          const float ratio = std::pow(luminance, gamma - 1);
+          if (std::isfinite(ratio)) {
+            red *= ratio;
+            green *= ratio;
+            blue *= ratio;
+          }
+        }
+      },
+      "HlgOOTF"));
+  return true;
+}
+
+Status HlgInverseOOTF(ImageBundle* ib, const float gamma, ThreadPool* pool) {
+  return HlgOOTF(ib, 1.f / gamma, pool);
+}
+
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/hlg.h b/third_party/jpeg-xl/lib/extras/hlg.h
new file mode 100644
index 0000000000..4cfec444f4
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/hlg.h
@@ -0,0 +1,21 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_HLG_H_
+#define LIB_EXTRAS_HLG_H_
+
+#include "lib/jxl/image_bundle.h"
+
+namespace jxl {
+
+float GetHlgGamma(float peak_luminance, float surround_luminance = 5.f);
+
+Status HlgOOTF(ImageBundle* ib, float gamma, ThreadPool* pool = nullptr);
+
+Status HlgInverseOOTF(ImageBundle* ib, float gamma, ThreadPool* pool = nullptr);
+
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_HLG_H_
diff --git a/third_party/jpeg-xl/lib/extras/jpegli_test.cc b/third_party/jpeg-xl/lib/extras/jpegli_test.cc
new file mode 100644
index 0000000000..66c18617a6
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/jpegli_test.cc
@@ -0,0 +1,422 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#if JPEGXL_ENABLE_JPEGLI
+
+#include "lib/extras/dec/jpegli.h"
+
+#include <jxl/color_encoding.h>
+#include <jxl/types.h>
+#include <stdint.h>
+
+#include <cstddef>
+#include <cstdint>
+#include <cstdio>
+#include <cstring>
+#include <memory>
+#include <ostream>
+#include <sstream>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "lib/extras/dec/color_hints.h"
+#include "lib/extras/dec/decode.h"
+#include "lib/extras/dec/jpg.h"
+#include "lib/extras/enc/encode.h"
+#include "lib/extras/enc/jpegli.h"
+#include "lib/extras/enc/jpg.h"
+#include "lib/extras/packed_image.h"
+#include "lib/jxl/base/span.h"
+#include "lib/jxl/base/status.h"
+#include "lib/jxl/color_encoding_internal.h"
+#include "lib/jxl/test_image.h"
+#include "lib/jxl/test_utils.h"
+#include "lib/jxl/testing.h"
+
+namespace jxl {
+namespace extras {
+namespace {
+
+using test::Butteraugli3Norm;
+using test::ButteraugliDistance;
+using test::TestImage;
+
+Status ReadTestImage(const std::string& pathname, PackedPixelFile* ppf) {
+  const std::vector<uint8_t> encoded = jxl::test::ReadTestData(pathname);
+  ColorHints color_hints;
+  if (pathname.find(".ppm") != std::string::npos) {
+    color_hints.Add("color_space", "RGB_D65_SRG_Rel_SRG");
+  } else if (pathname.find(".pgm") != std::string::npos) {
+    color_hints.Add("color_space", "Gra_D65_Rel_SRG");
+  }
+  return DecodeBytes(Bytes(encoded), color_hints, ppf);
+}
+
+std::vector<uint8_t> GetAppData(const std::vector<uint8_t>& compressed) {
+  std::vector<uint8_t> result;
+  size_t pos = 2;  // After SOI
+  while (pos + 4 < compressed.size()) {
+    if (compressed[pos] != 0xff || compressed[pos + 1] < 0xe0 ||
+        compressed[pos + 1] > 0xf0) {
+      break;
+    }
+    size_t len = (compressed[pos + 2] << 8) + compressed[pos + 3] + 2;
+    if (pos + len > compressed.size()) {
+      break;
+    }
+    result.insert(result.end(), &compressed[pos], &compressed[pos] + len);
+    pos += len;
+  }
+  return result;
+}
+
+Status DecodeWithLibjpeg(const std::vector<uint8_t>& compressed,
+                         PackedPixelFile* ppf,
+                         const JPGDecompressParams* dparams = nullptr) {
+  return DecodeImageJPG(Bytes(compressed), ColorHints(), ppf,
+                        /*constraints=*/nullptr, dparams);
+}
+
+Status EncodeWithLibjpeg(const PackedPixelFile& ppf, int quality,
+                         std::vector<uint8_t>* compressed) {
+  std::unique_ptr<Encoder> encoder = GetJPEGEncoder();
+  encoder->SetOption("q", std::to_string(quality));
+  EncodedImage encoded;
+  JXL_RETURN_IF_ERROR(encoder->Encode(ppf, &encoded));
+  JXL_RETURN_IF_ERROR(!encoded.bitstreams.empty());
+  *compressed = std::move(encoded.bitstreams[0]);
+  return true;
+}
+
+std::string Description(const JxlColorEncoding& color_encoding) {
+  ColorEncoding c_enc;
+  JXL_CHECK(c_enc.FromExternal(color_encoding));
+  return Description(c_enc);
+}
+
+float BitsPerPixel(const PackedPixelFile& ppf,
+                   const std::vector<uint8_t>& compressed) {
+  const size_t num_pixels = ppf.info.xsize * ppf.info.ysize;
+  return compressed.size() * 8.0 / num_pixels;
+}
+
+TEST(JpegliTest, JpegliSRGBDecodeTest) {
+  TEST_LIBJPEG_SUPPORT();
+  std::string testimage = "jxl/flower/flower_small.rgb.depth8.ppm";
+  PackedPixelFile ppf0;
+  ASSERT_TRUE(ReadTestImage(testimage, &ppf0));
+  EXPECT_EQ("RGB_D65_SRG_Rel_SRG", Description(ppf0.color_encoding));
+  EXPECT_EQ(8, ppf0.info.bits_per_sample);
+
+  std::vector<uint8_t> compressed;
+  ASSERT_TRUE(EncodeWithLibjpeg(ppf0, 90, &compressed));
+
+  PackedPixelFile ppf1;
+  ASSERT_TRUE(DecodeWithLibjpeg(compressed, &ppf1));
+  PackedPixelFile ppf2;
+  JpegDecompressParams dparams;
+  ASSERT_TRUE(DecodeJpeg(compressed, dparams, nullptr, &ppf2));
+  EXPECT_LT(ButteraugliDistance(ppf0, ppf2), ButteraugliDistance(ppf0, ppf1));
+}
+
+TEST(JpegliTest, JpegliGrayscaleDecodeTest) {
+  TEST_LIBJPEG_SUPPORT();
+  std::string testimage = "jxl/flower/flower_small.g.depth8.pgm";
+  PackedPixelFile ppf0;
+  ASSERT_TRUE(ReadTestImage(testimage, &ppf0));
+  EXPECT_EQ("Gra_D65_Rel_SRG", Description(ppf0.color_encoding));
+  EXPECT_EQ(8, ppf0.info.bits_per_sample);
+
+  std::vector<uint8_t> compressed;
+  ASSERT_TRUE(EncodeWithLibjpeg(ppf0, 90, &compressed));
+
+  PackedPixelFile ppf1;
+  ASSERT_TRUE(DecodeWithLibjpeg(compressed, &ppf1));
+  PackedPixelFile ppf2;
+  JpegDecompressParams dparams;
+  ASSERT_TRUE(DecodeJpeg(compressed, dparams, nullptr, &ppf2));
+  EXPECT_LT(ButteraugliDistance(ppf0, ppf2), ButteraugliDistance(ppf0, ppf1));
+}
+
+TEST(JpegliTest, JpegliXYBEncodeTest) {
+  TEST_LIBJPEG_SUPPORT();
+  std::string testimage = "jxl/flower/flower_small.rgb.depth8.ppm";
+  PackedPixelFile ppf_in;
+  ASSERT_TRUE(ReadTestImage(testimage, &ppf_in));
+  EXPECT_EQ("RGB_D65_SRG_Rel_SRG", Description(ppf_in.color_encoding));
+  EXPECT_EQ(8, ppf_in.info.bits_per_sample);
+
+  std::vector<uint8_t> compressed;
+  JpegSettings settings;
+  settings.xyb = true;
+  ASSERT_TRUE(EncodeJpeg(ppf_in, settings, nullptr, &compressed));
+
+  PackedPixelFile ppf_out;
+  ASSERT_TRUE(DecodeWithLibjpeg(compressed, &ppf_out));
+  EXPECT_THAT(BitsPerPixel(ppf_in, compressed), IsSlightlyBelow(1.45f));
+  EXPECT_THAT(ButteraugliDistance(ppf_in, ppf_out), IsSlightlyBelow(1.32f));
+}
+
+TEST(JpegliTest, JpegliDecodeTestLargeSmoothArea) {
+  TEST_LIBJPEG_SUPPORT();
+  TestImage t;
+  const size_t xsize = 2070;
+  const size_t ysize = 1063;
+  t.SetDimensions(xsize, ysize).SetChannels(3);
+  t.SetAllBitDepths(8).SetEndianness(JXL_NATIVE_ENDIAN);
+  TestImage::Frame frame = t.AddFrame();
+  frame.RandomFill();
+  // Create a large smooth area in the top half of the image. This is to test
+  // that the bias statistics calculation can handle many blocks with all-zero
+  // AC coefficients.
+  for (size_t y = 0; y < ysize / 2; ++y) {
+    for (size_t x = 0; x < xsize; ++x) {
+      for (size_t c = 0; c < 3; ++c) {
+        frame.SetValue(y, x, c, 0.5f);
+      }
+    }
+  }
+  const PackedPixelFile& ppf0 = t.ppf();
+
+  std::vector<uint8_t> compressed;
+  ASSERT_TRUE(EncodeWithLibjpeg(ppf0, 90, &compressed));
+
+  PackedPixelFile ppf1;
+  JpegDecompressParams dparams;
+  ASSERT_TRUE(DecodeJpeg(compressed, dparams, nullptr, &ppf1));
+  EXPECT_LT(ButteraugliDistance(ppf0, ppf1), 3.0f);
+}
+
+TEST(JpegliTest, JpegliYUVEncodeTest) {
+  TEST_LIBJPEG_SUPPORT();
+  std::string testimage = "jxl/flower/flower_small.rgb.depth8.ppm";
+  PackedPixelFile ppf_in;
+  ASSERT_TRUE(ReadTestImage(testimage, &ppf_in));
+  EXPECT_EQ("RGB_D65_SRG_Rel_SRG", Description(ppf_in.color_encoding));
+  EXPECT_EQ(8, ppf_in.info.bits_per_sample);
+
+  std::vector<uint8_t> compressed;
+  JpegSettings settings;
+  settings.xyb = false;
+  ASSERT_TRUE(EncodeJpeg(ppf_in, settings, nullptr, &compressed));
+
+  PackedPixelFile ppf_out;
+  ASSERT_TRUE(DecodeWithLibjpeg(compressed, &ppf_out));
+  EXPECT_THAT(BitsPerPixel(ppf_in, compressed), IsSlightlyBelow(1.7f));
+  EXPECT_THAT(ButteraugliDistance(ppf_in, ppf_out), IsSlightlyBelow(1.32f));
+}
+
+TEST(JpegliTest, JpegliYUVChromaSubsamplingEncodeTest) {
+  TEST_LIBJPEG_SUPPORT();
+  std::string testimage = "jxl/flower/flower_small.rgb.depth8.ppm";
+  PackedPixelFile ppf_in;
+  ASSERT_TRUE(ReadTestImage(testimage, &ppf_in));
+  EXPECT_EQ("RGB_D65_SRG_Rel_SRG", Description(ppf_in.color_encoding));
+  EXPECT_EQ(8, ppf_in.info.bits_per_sample);
+
+  std::vector<uint8_t> compressed;
+  JpegSettings settings;
+  for (const char* sampling : {"440", "422", "420"}) {
+    settings.xyb = false;
+    settings.chroma_subsampling = std::string(sampling);
+    ASSERT_TRUE(EncodeJpeg(ppf_in, settings, nullptr, &compressed));
+
+    PackedPixelFile ppf_out;
+    ASSERT_TRUE(DecodeWithLibjpeg(compressed, &ppf_out));
+    EXPECT_LE(BitsPerPixel(ppf_in, compressed), 1.55f);
+    EXPECT_LE(ButteraugliDistance(ppf_in, ppf_out), 1.82f);
+  }
+}
+
+TEST(JpegliTest, JpegliYUVEncodeTestNoAq) {
+  TEST_LIBJPEG_SUPPORT();
+  std::string testimage = "jxl/flower/flower_small.rgb.depth8.ppm";
+  PackedPixelFile ppf_in;
+  ASSERT_TRUE(ReadTestImage(testimage, &ppf_in));
+  EXPECT_EQ("RGB_D65_SRG_Rel_SRG", Description(ppf_in.color_encoding));
+  EXPECT_EQ(8, ppf_in.info.bits_per_sample);
+
+  std::vector<uint8_t> compressed;
+  JpegSettings settings;
+  settings.xyb = false;
+  settings.use_adaptive_quantization = false;
+  ASSERT_TRUE(EncodeJpeg(ppf_in, settings, nullptr, &compressed));
+
+  PackedPixelFile ppf_out;
+  ASSERT_TRUE(DecodeWithLibjpeg(compressed, &ppf_out));
+  EXPECT_THAT(BitsPerPixel(ppf_in, compressed), IsSlightlyBelow(1.85f));
+  EXPECT_THAT(ButteraugliDistance(ppf_in, ppf_out), IsSlightlyBelow(1.25f));
+}
+
+TEST(JpegliTest, JpegliHDRRoundtripTest) {
+  std::string testimage = "jxl/hdr_room.png";
+  PackedPixelFile ppf_in;
+  ASSERT_TRUE(ReadTestImage(testimage, &ppf_in));
+  EXPECT_EQ("RGB_D65_202_Rel_HLG", Description(ppf_in.color_encoding));
+  EXPECT_EQ(16, ppf_in.info.bits_per_sample);
+
+  std::vector<uint8_t> compressed;
+  JpegSettings settings;
+  settings.xyb = false;
+  ASSERT_TRUE(EncodeJpeg(ppf_in, settings, nullptr, &compressed));
+
+  PackedPixelFile ppf_out;
+  JpegDecompressParams dparams;
+  dparams.output_data_type = JXL_TYPE_UINT16;
+  ASSERT_TRUE(DecodeJpeg(compressed, dparams, nullptr, &ppf_out));
+  EXPECT_THAT(BitsPerPixel(ppf_in, compressed), IsSlightlyBelow(2.95f));
+  EXPECT_THAT(ButteraugliDistance(ppf_in, ppf_out), IsSlightlyBelow(1.05f));
+}
+
+TEST(JpegliTest, JpegliSetAppData) {
+  std::string testimage = "jxl/flower/flower_small.rgb.depth8.ppm";
+  PackedPixelFile ppf_in;
+  ASSERT_TRUE(ReadTestImage(testimage, &ppf_in));
+  EXPECT_EQ("RGB_D65_SRG_Rel_SRG", Description(ppf_in.color_encoding));
+  EXPECT_EQ(8, ppf_in.info.bits_per_sample);
+
+  std::vector<uint8_t> compressed;
+  JpegSettings settings;
+  settings.app_data = {0xff, 0xe3, 0, 4, 0, 1};
+  EXPECT_TRUE(EncodeJpeg(ppf_in, settings, nullptr, &compressed));
+  EXPECT_EQ(settings.app_data, GetAppData(compressed));
+
+  settings.app_data = {0xff, 0xe3, 0, 6, 0, 1, 2, 3, 0xff, 0xef, 0, 4, 0, 1};
+  EXPECT_TRUE(EncodeJpeg(ppf_in, settings, nullptr, &compressed));
+  EXPECT_EQ(settings.app_data, GetAppData(compressed));
+
+  settings.xyb = true;
+  EXPECT_TRUE(EncodeJpeg(ppf_in, settings, nullptr, &compressed));
+  EXPECT_EQ(0, memcmp(settings.app_data.data(), GetAppData(compressed).data(),
+                      settings.app_data.size()));
+
+  settings.xyb = false;
+  settings.app_data = {0};
+  EXPECT_FALSE(EncodeJpeg(ppf_in, settings, nullptr, &compressed));
+
+  settings.app_data = {0xff, 0xe0};
+  EXPECT_FALSE(EncodeJpeg(ppf_in, settings, nullptr, &compressed));
+
+  settings.app_data = {0xff, 0xe0, 0, 2};
+  EXPECT_FALSE(EncodeJpeg(ppf_in, settings, nullptr, &compressed));
+
+  settings.app_data = {0xff, 0xeb, 0, 4, 0};
+  EXPECT_FALSE(EncodeJpeg(ppf_in, settings, nullptr, &compressed));
+
+  settings.app_data = {0xff, 0xeb, 0, 4, 0, 1, 2, 3};
+  EXPECT_FALSE(EncodeJpeg(ppf_in, settings, nullptr, &compressed));
+
+  settings.app_data = {0xff, 0xab, 0, 4, 0, 1};
+  EXPECT_FALSE(EncodeJpeg(ppf_in, settings, nullptr, &compressed));
+
+  settings.xyb = false;
+  settings.app_data = {
+      0xff, 0xeb, 0,    4,    0,    1,                       //
+      0xff, 0xe2, 0,    20,   0x49, 0x43, 0x43, 0x5F, 0x50,  //
+      0x52, 0x4F, 0x46, 0x49, 0x4C, 0x45, 0x00, 0,    1,     //
+      0,    0,    0,    0,                                   //
+  };
+  EXPECT_TRUE(EncodeJpeg(ppf_in, settings, nullptr, &compressed));
+  EXPECT_EQ(settings.app_data, GetAppData(compressed));
+
+  settings.xyb = true;
+  EXPECT_FALSE(EncodeJpeg(ppf_in, settings, nullptr, &compressed));
+}
+
+struct TestConfig {
+  int num_colors;
+  int passes;
+  int dither;
+};
+
+class JpegliColorQuantTestParam : public ::testing::TestWithParam<TestConfig> {
+};
+
+TEST_P(JpegliColorQuantTestParam, JpegliColorQuantizeTest) {
+  TEST_LIBJPEG_SUPPORT();
+  TestConfig config = GetParam();
+  std::string testimage = "jxl/flower/flower_small.rgb.depth8.ppm";
+  PackedPixelFile ppf0;
+  ASSERT_TRUE(ReadTestImage(testimage, &ppf0));
+  EXPECT_EQ("RGB_D65_SRG_Rel_SRG", Description(ppf0.color_encoding));
+  EXPECT_EQ(8, ppf0.info.bits_per_sample);
+
+  std::vector<uint8_t> compressed;
+  ASSERT_TRUE(EncodeWithLibjpeg(ppf0, 90, &compressed));
+
+  PackedPixelFile ppf1;
+  JPGDecompressParams dparams1;
+  dparams1.two_pass_quant = (config.passes == 2);
+  dparams1.num_colors = config.num_colors;
+  dparams1.dither_mode = config.dither;
+  ASSERT_TRUE(DecodeWithLibjpeg(compressed, &ppf1, &dparams1));
+
+  PackedPixelFile ppf2;
+  JpegDecompressParams dparams2;
+  dparams2.two_pass_quant = (config.passes == 2);
+  dparams2.num_colors = config.num_colors;
+  dparams2.dither_mode = config.dither;
+  ASSERT_TRUE(DecodeJpeg(compressed, dparams2, nullptr, &ppf2));
+
+  double dist1 = Butteraugli3Norm(ppf0, ppf1);
+  double dist2 = Butteraugli3Norm(ppf0, ppf2);
+  printf("distance: %f  vs %f\n", dist2, dist1);
+  if (config.passes == 1) {
+    if (config.num_colors == 16 && config.dither == 2) {
+      // TODO(szabadka) Fix this case.
+      EXPECT_LT(dist2, dist1 * 1.5);
+    } else {
+      EXPECT_LT(dist2, dist1 * 1.05);
+    }
+  } else if (config.num_colors > 64) {
+    // TODO(szabadka) Fix 2pass quantization for <= 64 colors.
+    EXPECT_LT(dist2, dist1 * 1.1);
+  } else if (config.num_colors > 32) {
+    EXPECT_LT(dist2, dist1 * 1.2);
+  } else {
+    EXPECT_LT(dist2, dist1 * 1.7);
+  }
+}
+
+std::vector<TestConfig> GenerateTests() {
+  std::vector<TestConfig> all_tests;
+  for (int num_colors = 8; num_colors <= 256; num_colors *= 2) {
+    for (int passes = 1; passes <= 2; ++passes) {
+      for (int dither = 0; dither < 3; dither += passes) {
+        TestConfig config;
+        config.num_colors = num_colors;
+        config.passes = passes;
+        config.dither = dither;
+        all_tests.push_back(config);
+      }
+    }
+  }
+  return all_tests;
+}
+
+std::ostream& operator<<(std::ostream& os, const TestConfig& c) {
+  static constexpr const char* kDitherModeStr[] = {"No", "Ordered", "FS"};
+  os << c.passes << "pass";
+  os << c.num_colors << "colors";
+  os << kDitherModeStr[c.dither] << "dither";
+  return os;
+}
+
+std::string TestDescription(const testing::TestParamInfo<TestConfig>& info) {
+  std::stringstream name;
+  name << info.param;
+  return name.str();
+}
+
+JXL_GTEST_INSTANTIATE_TEST_SUITE_P(JpegliColorQuantTest,
+                                   JpegliColorQuantTestParam,
+                                   testing::ValuesIn(GenerateTests()),
+                                   TestDescription);
+
+}  // namespace
+}  // namespace extras
+}  // namespace jxl
+#endif  // JPEGXL_ENABLE_JPEGLI
diff --git a/third_party/jpeg-xl/lib/extras/metrics.cc b/third_party/jpeg-xl/lib/extras/metrics.cc
new file mode 100644
index 0000000000..4259d3c375
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/metrics.cc
@@ -0,0 +1,224 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/metrics.h"
+
+#include <math.h>
+#include <stdlib.h>
+
+#include <atomic>
+
+#undef HWY_TARGET_INCLUDE
+#define HWY_TARGET_INCLUDE "lib/extras/metrics.cc"
+#include <hwy/foreach_target.h>
+#include <hwy/highway.h>
+
+#include "lib/jxl/base/compiler_specific.h"
+#include "lib/jxl/base/status.h"
+#include "lib/jxl/color_encoding_internal.h"
+HWY_BEFORE_NAMESPACE();
+namespace jxl {
+namespace HWY_NAMESPACE {
+
+// These templates are not found via ADL.
+using hwy::HWY_NAMESPACE::Add;
+using hwy::HWY_NAMESPACE::GetLane;
+using hwy::HWY_NAMESPACE::Mul;
+using hwy::HWY_NAMESPACE::Rebind;
+
+double ComputeDistanceP(const ImageF& distmap, const ButteraugliParams& params,
+                        double p) {
+  const double onePerPixels = 1.0 / (distmap.ysize() * distmap.xsize());
+  if (std::abs(p - 3.0) < 1E-6) {
+    double sum1[3] = {0.0};
+
+// Prefer double if possible, but otherwise use float rather than scalar.
+#if HWY_CAP_FLOAT64
+    using T = double;
+    const Rebind<float, HWY_FULL(double)> df;
+#else
+    using T = float;
+#endif
+    const HWY_FULL(T) d;
+    constexpr size_t N = MaxLanes(d);
+    // Manually aligned storage to avoid asan crash on clang-7 due to
+    // unaligned spill.
+    HWY_ALIGN T sum_totals0[N] = {0};
+    HWY_ALIGN T sum_totals1[N] = {0};
+    HWY_ALIGN T sum_totals2[N] = {0};
+
+    for (size_t y = 0; y < distmap.ysize(); ++y) {
+      const float* JXL_RESTRICT row = distmap.ConstRow(y);
+
+      auto sums0 = Zero(d);
+      auto sums1 = Zero(d);
+      auto sums2 = Zero(d);
+
+      size_t x = 0;
+      for (; x + Lanes(d) <= distmap.xsize(); x += Lanes(d)) {
+#if HWY_CAP_FLOAT64
+        const auto d1 = PromoteTo(d, Load(df, row + x));
+#else
+        const auto d1 = Load(d, row + x);
+#endif
+        const auto d2 = Mul(d1, Mul(d1, d1));
+        sums0 = Add(sums0, d2);
+        const auto d3 = Mul(d2, d2);
+        sums1 = Add(sums1, d3);
+        const auto d4 = Mul(d3, d3);
+        sums2 = Add(sums2, d4);
+      }
+
+      Store(Add(sums0, Load(d, sum_totals0)), d, sum_totals0);
+      Store(Add(sums1, Load(d, sum_totals1)), d, sum_totals1);
+      Store(Add(sums2, Load(d, sum_totals2)), d, sum_totals2);
+
+      for (; x < distmap.xsize(); ++x) {
+        const double d1 = row[x];
+        double d2 = d1 * d1 * d1;
+        sum1[0] += d2;
+        d2 *= d2;
+        sum1[1] += d2;
+        d2 *= d2;
+        sum1[2] += d2;
+      }
+    }
+    double v = 0;
+    v += pow(
+        onePerPixels * (sum1[0] + GetLane(SumOfLanes(d, Load(d, sum_totals0)))),
+        1.0 / (p * 1.0));
+    v += pow(
+        onePerPixels * (sum1[1] + GetLane(SumOfLanes(d, Load(d, sum_totals1)))),
+        1.0 / (p * 2.0));
+    v += pow(
+        onePerPixels * (sum1[2] + GetLane(SumOfLanes(d, Load(d, sum_totals2)))),
+        1.0 / (p * 4.0));
+    v /= 3.0;
+    return v;
+  } else {
+    static std::atomic<int> once{0};
+    if (once.fetch_add(1, std::memory_order_relaxed) == 0) {
+      JXL_WARNING("WARNING: using slow ComputeDistanceP");
+    }
+    double sum1[3] = {0.0};
+    for (size_t y = 0; y < distmap.ysize(); ++y) {
+      const float* JXL_RESTRICT row = distmap.ConstRow(y);
+      for (size_t x = 0; x < distmap.xsize(); ++x) {
+        double d2 = std::pow(row[x], p);
+        sum1[0] += d2;
+        d2 *= d2;
+        sum1[1] += d2;
+        d2 *= d2;
+        sum1[2] += d2;
+      }
+    }
+    double v = 0;
+    for (int i = 0; i < 3; ++i) {
+      v += pow(onePerPixels * (sum1[i]), 1.0 / (p * (1 << i)));
+    }
+    v /= 3.0;
+    return v;
+  }
+}
+
+void ComputeSumOfSquares(const ImageBundle& ib1, const ImageBundle& ib2,
+                         const JxlCmsInterface& cms, double sum_of_squares[3]) {
+  // Convert to sRGB - closer to perception than linear.
+  const Image3F* srgb1 = &ib1.color();
+  Image3F copy1;
+  if (!ib1.IsSRGB()) {
+    JXL_CHECK(
+        ib1.CopyTo(Rect(ib1), ColorEncoding::SRGB(ib1.IsGray()), cms, &copy1));
+    srgb1 = &copy1;
+  }
+  const Image3F* srgb2 = &ib2.color();
+  Image3F copy2;
+  if (!ib2.IsSRGB()) {
+    JXL_CHECK(
+        ib2.CopyTo(Rect(ib2), ColorEncoding::SRGB(ib2.IsGray()), cms, &copy2));
+    srgb2 = &copy2;
+  }
+
+  JXL_CHECK(SameSize(*srgb1, *srgb2));
+
+  // TODO(veluca): SIMD.
+  float yuvmatrix[3][3] = {{0.299, 0.587, 0.114},
+                           {-0.14713, -0.28886, 0.436},
+                           {0.615, -0.51499, -0.10001}};
+  for (size_t y = 0; y < srgb1->ysize(); ++y) {
+    const float* JXL_RESTRICT row1[3];
+    const float* JXL_RESTRICT row2[3];
+    for (size_t j = 0; j < 3; j++) {
+      row1[j] = srgb1->ConstPlaneRow(j, y);
+      row2[j] = srgb2->ConstPlaneRow(j, y);
+    }
+    for (size_t x = 0; x < srgb1->xsize(); ++x) {
+      float cdiff[3] = {};
+      // YUV conversion is linear, so we can run it on the difference.
+      for (size_t j = 0; j < 3; j++) {
+        cdiff[j] = row1[j][x] - row2[j][x];
+      }
+      float yuvdiff[3] = {};
+      for (size_t j = 0; j < 3; j++) {
+        for (size_t k = 0; k < 3; k++) {
+          yuvdiff[j] += yuvmatrix[j][k] * cdiff[k];
+        }
+      }
+      for (size_t j = 0; j < 3; j++) {
+        sum_of_squares[j] += yuvdiff[j] * yuvdiff[j];
+      }
+    }
+  }
+}
+
+// NOLINTNEXTLINE(google-readability-namespace-comments)
+}  // namespace HWY_NAMESPACE
+}  // namespace jxl
+HWY_AFTER_NAMESPACE();
+
+#if HWY_ONCE
+namespace jxl {
+HWY_EXPORT(ComputeDistanceP);
+double ComputeDistanceP(const ImageF& distmap, const ButteraugliParams& params,
+                        double p) {
+  return HWY_DYNAMIC_DISPATCH(ComputeDistanceP)(distmap, params, p);
+}
+
+HWY_EXPORT(ComputeSumOfSquares);
+
+double ComputeDistance2(const ImageBundle& ib1, const ImageBundle& ib2,
+                        const JxlCmsInterface& cms) {
+  double sum_of_squares[3] = {};
+  HWY_DYNAMIC_DISPATCH(ComputeSumOfSquares)(ib1, ib2, cms, sum_of_squares);
+  // Weighted PSNR as in JPEG-XL: chroma counts 1/8.
+  const float weights[3] = {6.0f / 8, 1.0f / 8, 1.0f / 8};
+  // Avoid squaring the weight - 1/64 is too extreme.
+  double norm = 0;
+  for (size_t i = 0; i < 3; i++) {
+    norm += std::sqrt(sum_of_squares[i]) * weights[i];
+  }
+  // This function returns distance *squared*.
+  return norm * norm;
+}
+
+double ComputePSNR(const ImageBundle& ib1, const ImageBundle& ib2,
+                   const JxlCmsInterface& cms) {
+  if (!SameSize(ib1, ib2)) return 0.0;
+  double sum_of_squares[3] = {};
+  HWY_DYNAMIC_DISPATCH(ComputeSumOfSquares)(ib1, ib2, cms, sum_of_squares);
+  constexpr double kChannelWeights[3] = {6.0 / 8, 1.0 / 8, 1.0 / 8};
+  double avg_psnr = 0;
+  const size_t input_pixels = ib1.xsize() * ib1.ysize();
+  for (int i = 0; i < 3; ++i) {
+    const double rmse = std::sqrt(sum_of_squares[i] / input_pixels);
+    const double psnr =
+        sum_of_squares[i] == 0 ? 99.99 : (20 * std::log10(1 / rmse));
+    avg_psnr += kChannelWeights[i] * psnr;
+  }
+  return avg_psnr;
+}
+
+}  // namespace jxl
+#endif
diff --git a/third_party/jpeg-xl/lib/extras/metrics.h b/third_party/jpeg-xl/lib/extras/metrics.h
new file mode 100644
index 0000000000..87a69a99ce
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/metrics.h
@@ -0,0 +1,28 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_METRICS_H_
+#define LIB_EXTRAS_METRICS_H_
+
+#include <stdint.h>
+
+#include "lib/jxl/butteraugli/butteraugli.h"
+#include "lib/jxl/image_bundle.h"
+
+namespace jxl {
+
+// Computes p-norm given the butteraugli distmap.
+double ComputeDistanceP(const ImageF& distmap, const ButteraugliParams& params,
+                        double p);
+
+double ComputeDistance2(const ImageBundle& ib1, const ImageBundle& ib2,
+                        const JxlCmsInterface& cms);
+
+double ComputePSNR(const ImageBundle& ib1, const ImageBundle& ib2,
+                   const JxlCmsInterface& cms);
+
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_METRICS_H_
diff --git a/third_party/jpeg-xl/lib/extras/mmap.cc b/third_party/jpeg-xl/lib/extras/mmap.cc
new file mode 100644
index 0000000000..7852831ebd
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/mmap.cc
@@ -0,0 +1,146 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "mmap.h"
+
+#include <cstdint>
+#include <memory>
+
+#include "lib/jxl/base/common.h"
+
+#if __unix__
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+namespace jxl {
+
+struct MemoryMappedFileImpl {
+  static StatusOr<std::unique_ptr<MemoryMappedFileImpl>> Init(
+      const char* path) {
+    auto f = make_unique<MemoryMappedFileImpl>();
+    f->fd = open(path, O_RDONLY);
+    if (f->fd == -1) {
+      return JXL_FAILURE("Cannot open file %s", path);
+    }
+    f->mmap_len = lseek(f->fd, 0, SEEK_END);
+    lseek(f->fd, 0, SEEK_SET);
+
+    f->ptr = mmap(nullptr, f->mmap_len, PROT_READ, MAP_SHARED, f->fd, 0);
+    if (f->ptr == MAP_FAILED) {
+      return JXL_FAILURE("mmap failure");
+    }
+    return f;
+  }
+
+  const uint8_t* data() const { return reinterpret_cast<const uint8_t*>(ptr); }
+  size_t size() const { return mmap_len; }
+
+  ~MemoryMappedFileImpl() {
+    if (fd != -1) {
+      close(fd);
+    }
+    if (ptr != nullptr) {
+      munmap(ptr, mmap_len);
+    }
+  }
+
+  int fd = -1;
+  size_t mmap_len = 0;
+  void* ptr = nullptr;
+};
+
+}  // namespace jxl
+
+#elif __WIN32__
+#include <string.h>
+#include <windows.h>
+
+namespace {
+
+struct HandleDeleter {
+  void operator()(const HANDLE handle) const {
+    if (handle != INVALID_HANDLE_VALUE) {
+      CloseHandle(handle);
+    }
+  }
+};
+using HandleUniquePtr =
+    std::unique_ptr<std::remove_pointer<HANDLE>::type, HandleDeleter>;
+
+}  // namespace
+
+namespace jxl {
+
+struct MemoryMappedFileImpl {
+  static StatusOr<std::unique_ptr<MemoryMappedFileImpl>> Init(
+      const char* path) {
+    auto f = make_unique<MemoryMappedFileImpl>();
+    std::wstring stemp = std::wstring(path, path + strlen(path));
+    f->handle.reset(CreateFileW(stemp.c_str(), GENERIC_READ, FILE_SHARE_READ,
+                                nullptr, OPEN_EXISTING,
+                                FILE_FLAG_SEQUENTIAL_SCAN, nullptr));
+    if (f->handle.get() == INVALID_HANDLE_VALUE) {
+      return JXL_FAILURE("Cannot open file %s", path);
+    }
+    if (!GetFileSizeEx(f->handle.get(), &f->fsize)) {
+      return JXL_FAILURE("Cannot get file size (%s)", path);
+    }
+    f->handle_mapping.reset(CreateFileMappingW(f->handle.get(), nullptr,
+                                               PAGE_READONLY, 0, 0, nullptr));
+    if (f->handle_mapping == nullptr) {
+      return JXL_FAILURE("Cannot create memory mapping (%s)", path);
+    }
+    f->ptr = MapViewOfFile(f->handle_mapping.get(), FILE_MAP_READ, 0, 0, 0);
+    return f;
+  }
+
+  const uint8_t* data() const { return reinterpret_cast<const uint8_t*>(ptr); }
+  size_t size() const { return fsize.QuadPart; }
+
+  HandleUniquePtr handle;
+  HandleUniquePtr handle_mapping;
+  LARGE_INTEGER fsize;
+  void* ptr = nullptr;
+};
+
+}  // namespace jxl
+
+#else
+
+namespace jxl {
+
+struct MemoryMappedFileImpl {
+  static StatusOr<std::unique_ptr<MemoryMappedFileImpl>> Init(
+      const char* path) {
+    return JXL_FAILURE("Memory mapping not supported on this system");
+  }
+
+  const uint8_t* data() const { return nullptr; }
+  size_t size() const { return 0; }
+};
+
+}  // namespace jxl
+
+#endif
+
+namespace jxl {
+
+StatusOr<MemoryMappedFile> MemoryMappedFile::Init(const char* path) {
+  JXL_ASSIGN_OR_RETURN(auto mmf, MemoryMappedFileImpl::Init(path));
+  MemoryMappedFile ret;
+  ret.impl_ = std::move(mmf);
+  return ret;
+}
+
+MemoryMappedFile::MemoryMappedFile() = default;
+MemoryMappedFile::~MemoryMappedFile() = default;
+MemoryMappedFile::MemoryMappedFile(MemoryMappedFile&&) noexcept = default;
+MemoryMappedFile& MemoryMappedFile::operator=(MemoryMappedFile&&) noexcept =
+    default;
+
+const uint8_t* MemoryMappedFile::data() const { return impl_->data(); }
+size_t MemoryMappedFile::size() const { return impl_->size(); }
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/mmap.h b/third_party/jpeg-xl/lib/extras/mmap.h
new file mode 100644
index 0000000000..8bc023dec0
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/mmap.h
@@ -0,0 +1,31 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_MMAP_H_
+#define LIB_EXTRAS_MMAP_H_
+
+#include <memory>
+
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+struct MemoryMappedFileImpl;
+
+class MemoryMappedFile {
+ public:
+  static StatusOr<MemoryMappedFile> Init(const char* path);
+  const uint8_t* data() const;
+  size_t size() const;
+  MemoryMappedFile();
+  ~MemoryMappedFile();
+  MemoryMappedFile(MemoryMappedFile&&) noexcept;
+  MemoryMappedFile& operator=(MemoryMappedFile&&) noexcept;
+
+ private:
+  std::unique_ptr<MemoryMappedFileImpl> impl_;
+};
+}  // namespace jxl
+
+#endif
diff --git a/third_party/jpeg-xl/lib/extras/packed_image.h b/third_party/jpeg-xl/lib/extras/packed_image.h
new file mode 100644
index 0000000000..edd5f1be75
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/packed_image.h
@@ -0,0 +1,270 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_PACKED_IMAGE_H_
+#define LIB_EXTRAS_PACKED_IMAGE_H_
+
+// Helper class for storing external (int or float, interleaved) images. This is
+// the common format used by other libraries and in the libjxl API.
+
+#include <jxl/codestream_header.h>
+#include <jxl/encode.h>
+#include <jxl/types.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <algorithm>
+#include <cmath>
+#include <functional>
+#include <memory>
+#include <mutex>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "lib/jxl/base/byte_order.h"
+#include "lib/jxl/base/c_callback_support.h"
+#include "lib/jxl/base/common.h"
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+namespace extras {
+
+// Class representing an interleaved image with a bunch of channels.
+class PackedImage {
+ public:
+  PackedImage(size_t xsize, size_t ysize, const JxlPixelFormat& format)
+      : PackedImage(xsize, ysize, format, CalcStride(format, xsize)) {}
+
+  PackedImage Copy() const {
+    PackedImage copy(xsize, ysize, format);
+    memcpy(reinterpret_cast<uint8_t*>(copy.pixels()),
+           reinterpret_cast<const uint8_t*>(pixels()), pixels_size);
+    return copy;
+  }
+
+  // The interleaved pixels as defined in the storage format.
+  void* pixels() const { return pixels_.get(); }
+
+  uint8_t* pixels(size_t y, size_t x, size_t c) const {
+    return (reinterpret_cast<uint8_t*>(pixels_.get()) + y * stride +
+            x * pixel_stride_ + c * bytes_per_channel_);
+  }
+
+  const uint8_t* const_pixels(size_t y, size_t x, size_t c) const {
+    return (reinterpret_cast<const uint8_t*>(pixels_.get()) + y * stride +
+            x * pixel_stride_ + c * bytes_per_channel_);
+  }
+
+  // The image size in pixels.
+  size_t xsize;
+  size_t ysize;
+
+  // The number of bytes per row.
+  size_t stride;
+
+  // Pixel storage format and buffer size of the pixels_ pointer.
+  JxlPixelFormat format;
+  size_t pixels_size;
+
+  size_t pixel_stride() const { return pixel_stride_; }
+
+  static size_t BitsPerChannel(JxlDataType data_type) {
+    switch (data_type) {
+      case JXL_TYPE_UINT8:
+        return 8;
+      case JXL_TYPE_UINT16:
+        return 16;
+      case JXL_TYPE_FLOAT:
+        return 32;
+      case JXL_TYPE_FLOAT16:
+        return 16;
+      default:
+        JXL_ABORT("Unhandled JxlDataType");
+    }
+  }
+
+  float GetPixelValue(size_t y, size_t x, size_t c) const {
+    const uint8_t* data = const_pixels(y, x, c);
+    switch (format.data_type) {
+      case JXL_TYPE_UINT8:
+        return data[0] * (1.0f / 255);
+      case JXL_TYPE_UINT16: {
+        uint16_t val;
+        memcpy(&val, data, 2);
+        return (swap_endianness_ ? JXL_BSWAP16(val) : val) * (1.0f / 65535);
+      }
+      case JXL_TYPE_FLOAT: {
+        float val;
+        memcpy(&val, data, 4);
+        return swap_endianness_ ? BSwapFloat(val) : val;
+      }
+      default:
+        JXL_ABORT("Unhandled JxlDataType");
+    }
+  }
+
+  void SetPixelValue(size_t y, size_t x, size_t c, float val) {
+    uint8_t* data = pixels(y, x, c);
+    switch (format.data_type) {
+      case JXL_TYPE_UINT8:
+        data[0] = Clamp1(std::round(val * 255), 0.0f, 255.0f);
+        break;
+      case JXL_TYPE_UINT16: {
+        uint16_t val16 = Clamp1(std::round(val * 65535), 0.0f, 65535.0f);
+        if (swap_endianness_) {
+          val16 = JXL_BSWAP16(val16);
+        }
+        memcpy(data, &val16, 2);
+        break;
+      }
+      case JXL_TYPE_FLOAT: {
+        if (swap_endianness_) {
+          val = BSwapFloat(val);
+        }
+        memcpy(data, &val, 4);
+        break;
+      }
+      default:
+        JXL_ABORT("Unhandled JxlDataType");
+    }
+  }
+
+ private:
+  PackedImage(size_t xsize, size_t ysize, const JxlPixelFormat& format,
+              size_t stride)
+      : xsize(xsize),
+        ysize(ysize),
+        stride(stride),
+        format(format),
+        pixels_size(ysize * stride),
+        pixels_(malloc(std::max<size_t>(1, pixels_size)), free) {
+    bytes_per_channel_ = BitsPerChannel(format.data_type) / jxl::kBitsPerByte;
+    pixel_stride_ = format.num_channels * bytes_per_channel_;
+    swap_endianness_ = SwapEndianness(format.endianness);
+  }
+
+  static size_t CalcStride(const JxlPixelFormat& format, size_t xsize) {
+    size_t stride = xsize * (BitsPerChannel(format.data_type) *
+                             format.num_channels / jxl::kBitsPerByte);
+    if (format.align > 1) {
+      stride = jxl::DivCeil(stride, format.align) * format.align;
+    }
+    return stride;
+  }
+
+  size_t bytes_per_channel_;
+  size_t pixel_stride_;
+  bool swap_endianness_;
+  std::unique_ptr<void, decltype(free)*> pixels_;
+};
+
+// Helper class representing a frame, as seen from the API. Animations will have
+// multiple frames, but a single frame can have a color/grayscale channel and
+// multiple extra channels. The order of the extra channels should be the same
+// as all other frames in the same image.
+class PackedFrame {
+ public:
+  template <typename... Args>
+  explicit PackedFrame(Args&&... args) : color(std::forward<Args>(args)...) {}
+
+  PackedFrame Copy() const {
+    PackedFrame copy(color.xsize, color.ysize, color.format);
+    copy.frame_info = frame_info;
+    copy.name = name;
+    copy.color = color.Copy();
+    for (size_t i = 0; i < extra_channels.size(); ++i) {
+      PackedImage ec = extra_channels[i].Copy();
+      copy.extra_channels.emplace_back(std::move(ec));
+    }
+    return copy;
+  }
+
+  // The Frame metadata.
+  JxlFrameHeader frame_info = {};
+  std::string name;
+
+  // The pixel data for the color (or grayscale) channels.
+  PackedImage color;
+  // Extra channel image data.
+  std::vector<PackedImage> extra_channels;
+};
+
+class ChunkedPackedFrame {
+ public:
+  ChunkedPackedFrame(
+      size_t xsize, size_t ysize,
+      std::function<JxlChunkedFrameInputSource()> get_input_source)
+      : xsize(xsize),
+        ysize(ysize),
+        get_input_source_(std::move(get_input_source)) {
+    const auto input_source = get_input_source_();
+    input_source.get_color_channels_pixel_format(input_source.opaque, &format);
+  }
+
+  JxlChunkedFrameInputSource GetInputSource() { return get_input_source_(); }
+
+  // The Frame metadata.
+  JxlFrameHeader frame_info = {};
+  std::string name;
+
+  size_t xsize;
+  size_t ysize;
+  JxlPixelFormat format;
+
+ private:
+  std::function<JxlChunkedFrameInputSource()> get_input_source_;
+};
+
+// Optional metadata associated with a file
+class PackedMetadata {
+ public:
+  std::vector<uint8_t> exif;
+  std::vector<uint8_t> iptc;
+  std::vector<uint8_t> jumbf;
+  std::vector<uint8_t> xmp;
+};
+
+// The extra channel metadata information.
+struct PackedExtraChannel {
+  JxlExtraChannelInfo ec_info;
+  size_t index;
+  std::string name;
+};
+
+// Helper class representing a JXL image file as decoded to pixels from the API.
+class PackedPixelFile {
+ public:
+  JxlBasicInfo info = {};
+
+  std::vector<PackedExtraChannel> extra_channels_info;
+
+  // Color information of the decoded pixels.
+  // If the icc is empty, the JxlColorEncoding should be used instead.
+  std::vector<uint8_t> icc;
+  JxlColorEncoding color_encoding = {};
+  // The icc profile of the original image.
+  std::vector<uint8_t> orig_icc;
+
+  std::unique_ptr<PackedFrame> preview_frame;
+  std::vector<PackedFrame> frames;
+  mutable std::vector<ChunkedPackedFrame> chunked_frames;
+
+  PackedMetadata metadata;
+  PackedPixelFile() { JxlEncoderInitBasicInfo(&info); };
+
+  size_t num_frames() const {
+    return chunked_frames.empty() ? frames.size() : chunked_frames.size();
+  }
+  size_t xsize() const { return info.xsize; }
+  size_t ysize() const { return info.ysize; }
+};
+
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_PACKED_IMAGE_H_
diff --git a/third_party/jpeg-xl/lib/extras/packed_image_convert.cc b/third_party/jpeg-xl/lib/extras/packed_image_convert.cc
new file mode 100644
index 0000000000..56f3b044a4
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/packed_image_convert.cc
@@ -0,0 +1,333 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/packed_image_convert.h"
+
+#include <jxl/cms.h>
+#include <jxl/color_encoding.h>
+#include <jxl/types.h>
+
+#include <cstdint>
+
+#include "lib/jxl/base/status.h"
+#include "lib/jxl/color_encoding_internal.h"
+#include "lib/jxl/dec_external_image.h"
+#include "lib/jxl/enc_external_image.h"
+#include "lib/jxl/enc_image_bundle.h"
+#include "lib/jxl/luminance.h"
+
+namespace jxl {
+namespace extras {
+
+Status ConvertPackedFrameToImageBundle(const JxlBasicInfo& info,
+                                       const PackedFrame& frame,
+                                       const CodecInOut& io, ThreadPool* pool,
+                                       ImageBundle* bundle) {
+  JXL_ASSERT(frame.color.pixels() != nullptr);
+  const bool float_in = frame.color.format.data_type == JXL_TYPE_FLOAT16 ||
+                        frame.color.format.data_type == JXL_TYPE_FLOAT;
+  size_t frame_bits_per_sample =
+      float_in ? PackedImage::BitsPerChannel(frame.color.format.data_type)
+               : info.bits_per_sample;
+  JXL_ASSERT(frame_bits_per_sample != 0);
+  // It is ok for the frame.color.format.num_channels to not match the
+  // number of channels on the image.
+  JXL_ASSERT(1 <= frame.color.format.num_channels &&
+             frame.color.format.num_channels <= 4);
+
+  const Span<const uint8_t> span(
+      static_cast<const uint8_t*>(frame.color.pixels()),
+      frame.color.pixels_size);
+  JXL_ASSERT(Rect(frame.frame_info.layer_info.crop_x0,
+                  frame.frame_info.layer_info.crop_y0,
+                  frame.frame_info.layer_info.xsize,
+                  frame.frame_info.layer_info.ysize)
+                 .IsInside(Rect(0, 0, info.xsize, info.ysize)));
+  if (info.have_animation) {
+    bundle->duration = frame.frame_info.duration;
+    bundle->blend = frame.frame_info.layer_info.blend_info.blendmode > 0;
+    bundle->use_for_next_frame =
+        frame.frame_info.layer_info.save_as_reference > 0;
+    bundle->origin.x0 = frame.frame_info.layer_info.crop_x0;
+    bundle->origin.y0 = frame.frame_info.layer_info.crop_y0;
+  }
+  bundle->name = frame.name;  // frame.frame_info.name_length is ignored here.
+  JXL_ASSERT(io.metadata.m.color_encoding.IsGray() ==
+             (frame.color.format.num_channels <= 2));
+
+  JXL_RETURN_IF_ERROR(ConvertFromExternal(
+      span, frame.color.xsize, frame.color.ysize, io.metadata.m.color_encoding,
+      frame_bits_per_sample, frame.color.format, pool, bundle));
+
+  bundle->extra_channels().resize(io.metadata.m.extra_channel_info.size());
+  for (size_t i = 0; i < frame.extra_channels.size(); i++) {
+    const auto& ppf_ec = frame.extra_channels[i];
+    bundle->extra_channels()[i] = ImageF(ppf_ec.xsize, ppf_ec.ysize);
+    JXL_CHECK(BufferToImageF(ppf_ec.format, ppf_ec.xsize, ppf_ec.ysize,
+                             ppf_ec.pixels(), ppf_ec.pixels_size, pool,
+                             &bundle->extra_channels()[i]));
+  }
+  return true;
+}
+
+Status ConvertPackedPixelFileToCodecInOut(const PackedPixelFile& ppf,
+                                          ThreadPool* pool, CodecInOut* io) {
+  const bool has_alpha = ppf.info.alpha_bits != 0;
+  JXL_ASSERT(!ppf.frames.empty());
+  if (has_alpha) {
+    JXL_ASSERT(ppf.info.alpha_bits == ppf.info.bits_per_sample);
+    JXL_ASSERT(ppf.info.alpha_exponent_bits ==
+               ppf.info.exponent_bits_per_sample);
+  }
+
+  const bool is_gray = (ppf.info.num_color_channels == 1);
+  JXL_ASSERT(ppf.info.num_color_channels == 1 ||
+             ppf.info.num_color_channels == 3);
+
+  // Convert the image metadata
+  io->SetSize(ppf.info.xsize, ppf.info.ysize);
+  io->metadata.m.bit_depth.bits_per_sample = ppf.info.bits_per_sample;
+  io->metadata.m.bit_depth.exponent_bits_per_sample =
+      ppf.info.exponent_bits_per_sample;
+  io->metadata.m.bit_depth.floating_point_sample =
+      ppf.info.exponent_bits_per_sample != 0;
+  io->metadata.m.modular_16_bit_buffer_sufficient =
+      ppf.info.exponent_bits_per_sample == 0 && ppf.info.bits_per_sample <= 12;
+
+  io->metadata.m.SetAlphaBits(ppf.info.alpha_bits,
+                              ppf.info.alpha_premultiplied);
+  ExtraChannelInfo* alpha = io->metadata.m.Find(ExtraChannel::kAlpha);
+  if (alpha) alpha->bit_depth = io->metadata.m.bit_depth;
+
+  io->metadata.m.xyb_encoded = !ppf.info.uses_original_profile;
+  JXL_ASSERT(ppf.info.orientation > 0 && ppf.info.orientation <= 8);
+  io->metadata.m.orientation = ppf.info.orientation;
+
+  // Convert animation metadata
+  JXL_ASSERT(ppf.frames.size() == 1 || ppf.info.have_animation);
+  io->metadata.m.have_animation = ppf.info.have_animation;
+  io->metadata.m.animation.tps_numerator = ppf.info.animation.tps_numerator;
+  io->metadata.m.animation.tps_denominator = ppf.info.animation.tps_denominator;
+  io->metadata.m.animation.num_loops = ppf.info.animation.num_loops;
+
+  // Convert the color encoding.
+  if (!ppf.icc.empty()) {
+    IccBytes icc = ppf.icc;
+    if (!io->metadata.m.color_encoding.SetICC(std::move(icc),
+                                              JxlGetDefaultCms())) {
+      fprintf(stderr, "Warning: error setting ICC profile, assuming SRGB\n");
+      io->metadata.m.color_encoding = ColorEncoding::SRGB(is_gray);
+    } else {
+      if (io->metadata.m.color_encoding.IsCMYK()) {
+        // We expect gray or tri-color.
+        return JXL_FAILURE("Embedded ICC is CMYK");
+      }
+      if (io->metadata.m.color_encoding.IsGray() != is_gray) {
+        // E.g. JPG image has 3 channels, but gray ICC.
+        return JXL_FAILURE("Embedded ICC does not match image color type");
+      }
+    }
+  } else {
+    JXL_RETURN_IF_ERROR(
+        io->metadata.m.color_encoding.FromExternal(ppf.color_encoding));
+    if (io->metadata.m.color_encoding.ICC().empty()) {
+      return JXL_FAILURE("Failed to serialize ICC");
+    }
+  }
+
+  // Convert the extra blobs
+  io->blobs.exif = ppf.metadata.exif;
+  io->blobs.iptc = ppf.metadata.iptc;
+  io->blobs.jumbf = ppf.metadata.jumbf;
+  io->blobs.xmp = ppf.metadata.xmp;
+
+  // Append all other extra channels.
+  for (const auto& info : ppf.extra_channels_info) {
+    ExtraChannelInfo out;
+    out.type = static_cast<jxl::ExtraChannel>(info.ec_info.type);
+    out.bit_depth.bits_per_sample = info.ec_info.bits_per_sample;
+    out.bit_depth.exponent_bits_per_sample =
+        info.ec_info.exponent_bits_per_sample;
+    out.bit_depth.floating_point_sample =
+        info.ec_info.exponent_bits_per_sample != 0;
+    out.dim_shift = info.ec_info.dim_shift;
+    out.name = info.name;
+    out.alpha_associated = (info.ec_info.alpha_premultiplied != 0);
+    out.spot_color[0] = info.ec_info.spot_color[0];
+    out.spot_color[1] = info.ec_info.spot_color[1];
+    out.spot_color[2] = info.ec_info.spot_color[2];
+    out.spot_color[3] = info.ec_info.spot_color[3];
+    io->metadata.m.extra_channel_info.push_back(std::move(out));
+  }
+
+  // Convert the preview
+  if (ppf.preview_frame) {
+    size_t preview_xsize = ppf.preview_frame->color.xsize;
+    size_t preview_ysize = ppf.preview_frame->color.ysize;
+    io->metadata.m.have_preview = true;
+    JXL_RETURN_IF_ERROR(
+        io->metadata.m.preview_size.Set(preview_xsize, preview_ysize));
+    JXL_RETURN_IF_ERROR(ConvertPackedFrameToImageBundle(
+        ppf.info, *ppf.preview_frame, *io, pool, &io->preview_frame));
+  }
+
+  // Convert the pixels
+  io->frames.clear();
+  for (const auto& frame : ppf.frames) {
+    ImageBundle bundle(&io->metadata.m);
+    JXL_RETURN_IF_ERROR(
+        ConvertPackedFrameToImageBundle(ppf.info, frame, *io, pool, &bundle));
+    io->frames.push_back(std::move(bundle));
+  }
+
+  if (ppf.info.exponent_bits_per_sample == 0) {
+    // uint case.
+    io->metadata.m.bit_depth.bits_per_sample = io->Main().DetectRealBitdepth();
+  }
+  if (ppf.info.intensity_target != 0) {
+    io->metadata.m.SetIntensityTarget(ppf.info.intensity_target);
+  } else {
+    SetIntensityTarget(&io->metadata.m);
+  }
+  io->CheckMetadata();
+  return true;
+}
+
+PackedPixelFile ConvertImage3FToPackedPixelFile(const Image3F& image,
+                                                const ColorEncoding& c_enc,
+                                                JxlPixelFormat format,
+                                                ThreadPool* pool) {
+  PackedPixelFile ppf;
+  ppf.info.xsize = image.xsize();
+  ppf.info.ysize = image.ysize();
+  ppf.info.num_color_channels = 3;
+  ppf.info.bits_per_sample = PackedImage::BitsPerChannel(format.data_type);
+  ppf.info.exponent_bits_per_sample = format.data_type == JXL_TYPE_FLOAT ? 8
+                                      : format.data_type == JXL_TYPE_FLOAT16
+                                          ? 5
+                                          : 0;
+  ppf.color_encoding = c_enc.ToExternal();
+  ppf.frames.clear();
+  PackedFrame frame(image.xsize(), image.ysize(), format);
+  const ImageF* channels[3];
+  for (int c = 0; c < 3; ++c) {
+    channels[c] = &image.Plane(c);
+  }
+  bool float_samples = ppf.info.exponent_bits_per_sample > 0;
+  JXL_CHECK(ConvertChannelsToExternal(
+      channels, 3, ppf.info.bits_per_sample, float_samples, format.endianness,
+      frame.color.stride, pool, frame.color.pixels(0, 0, 0),
+      frame.color.pixels_size, PixelCallback(), Orientation::kIdentity));
+  ppf.frames.emplace_back(std::move(frame));
+  return ppf;
+}
+
+// Allows converting from internal CodecInOut to external PackedPixelFile
+Status ConvertCodecInOutToPackedPixelFile(const CodecInOut& io,
+                                          const JxlPixelFormat& pixel_format,
+                                          const ColorEncoding& c_desired,
+                                          ThreadPool* pool,
+                                          PackedPixelFile* ppf) {
+  const bool has_alpha = io.metadata.m.HasAlpha();
+  JXL_ASSERT(!io.frames.empty());
+
+  if (has_alpha) {
+    JXL_ASSERT(io.metadata.m.GetAlphaBits() ==
+               io.metadata.m.bit_depth.bits_per_sample);
+    const auto* alpha_channel = io.metadata.m.Find(ExtraChannel::kAlpha);
+    JXL_ASSERT(alpha_channel->bit_depth.exponent_bits_per_sample ==
+               io.metadata.m.bit_depth.exponent_bits_per_sample);
+    ppf->info.alpha_bits = alpha_channel->bit_depth.bits_per_sample;
+    ppf->info.alpha_exponent_bits =
+        alpha_channel->bit_depth.exponent_bits_per_sample;
+    ppf->info.alpha_premultiplied = alpha_channel->alpha_associated;
+  }
+
+  // Convert the image metadata
+  ppf->info.xsize = io.metadata.size.xsize();
+  ppf->info.ysize = io.metadata.size.ysize();
+  ppf->info.num_color_channels = io.metadata.m.color_encoding.Channels();
+  ppf->info.bits_per_sample = io.metadata.m.bit_depth.bits_per_sample;
+  ppf->info.exponent_bits_per_sample =
+      io.metadata.m.bit_depth.exponent_bits_per_sample;
+
+  ppf->info.intensity_target = io.metadata.m.tone_mapping.intensity_target;
+  ppf->info.linear_below = io.metadata.m.tone_mapping.linear_below;
+  ppf->info.min_nits = io.metadata.m.tone_mapping.min_nits;
+  ppf->info.relative_to_max_display =
+      io.metadata.m.tone_mapping.relative_to_max_display;
+
+  ppf->info.uses_original_profile = !io.metadata.m.xyb_encoded;
+  JXL_ASSERT(0 < io.metadata.m.orientation && io.metadata.m.orientation <= 8);
+  ppf->info.orientation =
+      static_cast<JxlOrientation>(io.metadata.m.orientation);
+  ppf->info.num_color_channels = io.metadata.m.color_encoding.Channels();
+
+  // Convert animation metadata
+  JXL_ASSERT(io.frames.size() == 1 || io.metadata.m.have_animation);
+  ppf->info.have_animation = io.metadata.m.have_animation;
+  ppf->info.animation.tps_numerator = io.metadata.m.animation.tps_numerator;
+  ppf->info.animation.tps_denominator = io.metadata.m.animation.tps_denominator;
+  ppf->info.animation.num_loops = io.metadata.m.animation.num_loops;
+
+  // Convert the color encoding
+  ppf->icc.assign(c_desired.ICC().begin(), c_desired.ICC().end());
+  ppf->color_encoding = c_desired.ToExternal();
+
+  // Convert the extra blobs
+  ppf->metadata.exif = io.blobs.exif;
+  ppf->metadata.iptc = io.blobs.iptc;
+  ppf->metadata.jumbf = io.blobs.jumbf;
+  ppf->metadata.xmp = io.blobs.xmp;
+  const bool float_out = pixel_format.data_type == JXL_TYPE_FLOAT ||
+                         pixel_format.data_type == JXL_TYPE_FLOAT16;
+  // Convert the pixels
+  ppf->frames.clear();
+  for (const auto& frame : io.frames) {
+    JXL_ASSERT(frame.metadata()->bit_depth.bits_per_sample != 0);
+    // It is ok for the frame.color().kNumPlanes to not match the
+    // number of channels on the image.
+    const uint32_t num_channels =
+        frame.metadata()->color_encoding.Channels() + has_alpha;
+    JxlPixelFormat format{/*num_channels=*/num_channels,
+                          /*data_type=*/pixel_format.data_type,
+                          /*endianness=*/pixel_format.endianness,
+                          /*align=*/pixel_format.align};
+
+    PackedFrame packed_frame(frame.oriented_xsize(), frame.oriented_ysize(),
+                             format);
+    const size_t bits_per_sample =
+        float_out ? packed_frame.color.BitsPerChannel(pixel_format.data_type)
+                  : ppf->info.bits_per_sample;
+    packed_frame.name = frame.name;
+    packed_frame.frame_info.name_length = frame.name.size();
+    // Color transform
+    ImageBundle ib = frame.Copy();
+    const ImageBundle* to_color_transform = &ib;
+    ImageMetadata metadata = io.metadata.m;
+    ImageBundle store(&metadata);
+    const ImageBundle* transformed;
+    // TODO(firsching): handle the transform here.
+    JXL_RETURN_IF_ERROR(TransformIfNeeded(*to_color_transform, c_desired,
+                                          *JxlGetDefaultCms(), pool, &store,
+                                          &transformed));
+
+    JXL_RETURN_IF_ERROR(ConvertToExternal(
+        *transformed, bits_per_sample, float_out, format.num_channels,
+        format.endianness,
+        /* stride_out=*/packed_frame.color.stride, pool,
+        packed_frame.color.pixels(), packed_frame.color.pixels_size,
+        /*out_callback=*/{}, frame.metadata()->GetOrientation()));
+
+    // TODO(firsching): Convert the extra channels, beside one potential alpha
+    // channel. FIXME!
+    JXL_CHECK(frame.extra_channels().size() <= has_alpha);
+    ppf->frames.push_back(std::move(packed_frame));
+  }
+
+  return true;
+}
+}  // namespace extras
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/packed_image_convert.h b/third_party/jpeg-xl/lib/extras/packed_image_convert.h
new file mode 100644
index 0000000000..b14eed174e
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/packed_image_convert.h
@@ -0,0 +1,41 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_PACKED_IMAGE_CONVERT_H_
+#define LIB_EXTRAS_PACKED_IMAGE_CONVERT_H_
+
+// Helper functions to convert from the external image types to the internal
+// CodecInOut to help transitioning to the external types.
+
+#include <jxl/types.h>
+
+#include "lib/extras/packed_image.h"
+#include "lib/jxl/base/status.h"
+#include "lib/jxl/codec_in_out.h"
+
+namespace jxl {
+namespace extras {
+
+// Converts an external PackedPixelFile to the internal CodecInOut for use with
+// internal functions directly.
+Status ConvertPackedPixelFileToCodecInOut(const PackedPixelFile& ppf,
+                                          ThreadPool* pool, CodecInOut* io);
+
+// Converts an internal CodecInOut for use with internal function to an external
+// PackedPixelFile.
+Status ConvertCodecInOutToPackedPixelFile(const CodecInOut& io,
+                                          const JxlPixelFormat& pixel_format,
+                                          const ColorEncoding& c_desired,
+                                          ThreadPool* pool,
+                                          PackedPixelFile* ppf);
+
+PackedPixelFile ConvertImage3FToPackedPixelFile(const Image3F& image,
+                                                const ColorEncoding& c_enc,
+                                                JxlPixelFormat format,
+                                                ThreadPool* pool);
+}  // namespace extras
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_PACKED_IMAGE_CONVERT_H_
diff --git a/third_party/jpeg-xl/lib/extras/size_constraints.h b/third_party/jpeg-xl/lib/extras/size_constraints.h
new file mode 100644
index 0000000000..cf06f8cb22
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/size_constraints.h
@@ -0,0 +1,43 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_JXL_SIZE_CONSTRAINTS_H_
+#define LIB_JXL_SIZE_CONSTRAINTS_H_
+
+#include <cstdint>
+#include <type_traits>
+
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+
+struct SizeConstraints {
+  // Upper limit on pixel dimensions/area, enforced by VerifyDimensions
+  // (called from decoders). Fuzzers set smaller values to limit memory use.
+  uint32_t dec_max_xsize = 0xFFFFFFFFu;
+  uint32_t dec_max_ysize = 0xFFFFFFFFu;
+  uint64_t dec_max_pixels = 0xFFFFFFFFu;  // Might be up to ~0ull
+};
+
+template <typename T,
+          class = typename std::enable_if<std::is_unsigned<T>::value>::type>
+Status VerifyDimensions(const SizeConstraints* constraints, T xs, T ys) {
+  if (!constraints) return true;
+
+  if (xs == 0 || ys == 0) return JXL_FAILURE("Empty image.");
+  if (xs > constraints->dec_max_xsize) return JXL_FAILURE("Image too wide.");
+  if (ys > constraints->dec_max_ysize) return JXL_FAILURE("Image too tall.");
+
+  const uint64_t num_pixels = static_cast<uint64_t>(xs) * ys;
+  if (num_pixels > constraints->dec_max_pixels) {
+    return JXL_FAILURE("Image too big.");
+  }
+
+  return true;
+}
+
+}  // namespace jxl
+
+#endif  // LIB_JXL_SIZE_CONSTRAINTS_H_
diff --git a/third_party/jpeg-xl/lib/extras/time.cc b/third_party/jpeg-xl/lib/extras/time.cc
new file mode 100644
index 0000000000..d4f41754da
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/time.cc
@@ -0,0 +1,59 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/time.h"
+
+#include <stdint.h>
+#include <stdlib.h>
+
+#include <ctime>
+
+#include "lib/jxl/base/os_macros.h"  // for JXL_OS_*
+
+#if JXL_OS_WIN
+#ifndef NOMINMAX
+#define NOMINMAX
+#endif  // NOMINMAX
+#include <windows.h>
+#endif  // JXL_OS_WIN
+
+#if JXL_OS_MAC
+#include <mach/mach.h>
+#include <mach/mach_time.h>
+#endif  // JXL_OS_MAC
+
+#if JXL_OS_HAIKU
+#include <OS.h>
+#endif  // JXL_OS_HAIKU
+
+namespace jxl {
+
+double Now() {
+#if JXL_OS_WIN
+  LARGE_INTEGER counter;
+  (void)QueryPerformanceCounter(&counter);
+  LARGE_INTEGER freq;
+  (void)QueryPerformanceFrequency(&freq);
+  return double(counter.QuadPart) / freq.QuadPart;
+#elif JXL_OS_MAC
+  const auto t = mach_absolute_time();
+  // On OSX/iOS platform the elapsed time is cpu time unit
+  // We have to query the time base information to convert it back
+  // See https://developer.apple.com/library/mac/qa/qa1398/_index.html
+  static mach_timebase_info_data_t timebase;
+  if (timebase.denom == 0) {
+    (void)mach_timebase_info(&timebase);
+  }
+  return double(t) * timebase.numer / timebase.denom * 1E-9;
+#elif JXL_OS_HAIKU
+  return double(system_time_nsecs()) * 1E-9;
+#else
+  timespec t;
+  clock_gettime(CLOCK_MONOTONIC, &t);
+  return t.tv_sec + t.tv_nsec * 1E-9;
+#endif
+}
+
+}  // namespace jxl
diff --git a/third_party/jpeg-xl/lib/extras/time.h b/third_party/jpeg-xl/lib/extras/time.h
new file mode 100644
index 0000000000..c71414b877
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/time.h
@@ -0,0 +1,19 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_TIME_H_
+#define LIB_EXTRAS_TIME_H_
+
+// OS-specific function for timing.
+
+namespace jxl {
+
+// Returns current time [seconds] from a monotonic clock with unspecified
+// starting point - only suitable for computing elapsed time.
+double Now();
+
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_TIME_H_
diff --git a/third_party/jpeg-xl/lib/extras/tone_mapping.cc b/third_party/jpeg-xl/lib/extras/tone_mapping.cc
new file mode 100644
index 0000000000..3d0269524b
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/tone_mapping.cc
@@ -0,0 +1,135 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/extras/tone_mapping.h"
+
+#undef HWY_TARGET_INCLUDE
+#define HWY_TARGET_INCLUDE "lib/extras/tone_mapping.cc"
+#include <jxl/cms.h>
+
+#include <hwy/foreach_target.h>
+#include <hwy/highway.h>
+
+#include "lib/jxl/cms/tone_mapping-inl.h"
+#include "lib/jxl/image_bundle.h"
+
+HWY_BEFORE_NAMESPACE();
+namespace jxl {
+namespace HWY_NAMESPACE {
+
+static constexpr float rec2020_luminances[3] = {0.2627f, 0.6780f, 0.0593f};
+
+Status ToneMapFrame(const std::pair<float, float> display_nits,
+                    ImageBundle* const ib, ThreadPool* const pool) {
+  // Perform tone mapping as described in Report ITU-R BT.2390-8, section 5.4
+  // (pp. 23-25).
+  // https://www.itu.int/pub/R-REP-BT.2390-8-2020
+
+  HWY_FULL(float) df;
+  using V = decltype(Zero(df));
+
+  ColorEncoding linear_rec2020;
+  linear_rec2020.SetColorSpace(ColorSpace::kRGB);
+  JXL_RETURN_IF_ERROR(linear_rec2020.SetPrimariesType(Primaries::k2100));
+  JXL_RETURN_IF_ERROR(linear_rec2020.SetWhitePointType(WhitePoint::kD65));
+  linear_rec2020.Tf().SetTransferFunction(TransferFunction::kLinear);
+  JXL_RETURN_IF_ERROR(linear_rec2020.CreateICC());
+  JXL_RETURN_IF_ERROR(
+      ib->TransformTo(linear_rec2020, *JxlGetDefaultCms(), pool));
+
+  Rec2408ToneMapper<decltype(df)> tone_mapper(
+      {ib->metadata()->tone_mapping.min_nits,
+       ib->metadata()->IntensityTarget()},
+      display_nits, rec2020_luminances);
+
+  return RunOnPool(
+      pool, 0, ib->ysize(), ThreadPool::NoInit,
+      [&](const uint32_t y, size_t /* thread */) {
+        float* const JXL_RESTRICT row_r = ib->color()->PlaneRow(0, y);
+        float* const JXL_RESTRICT row_g = ib->color()->PlaneRow(1, y);
+        float* const JXL_RESTRICT row_b = ib->color()->PlaneRow(2, y);
+        for (size_t x = 0; x < ib->xsize(); x += Lanes(df)) {
+          V red = Load(df, row_r + x);
+          V green = Load(df, row_g + x);
+          V blue = Load(df, row_b + x);
+          tone_mapper.ToneMap(&red, &green, &blue);
+          Store(red, df, row_r + x);
+          Store(green, df, row_g + x);
+          Store(blue, df, row_b + x);
+        }
+      },
+      "ToneMap");
+}
+
+Status GamutMapFrame(ImageBundle* const ib, float preserve_saturation,
+                     ThreadPool* const pool) {
+  HWY_FULL(float) df;
+  using V = decltype(Zero(df));
+
+  ColorEncoding linear_rec2020;
+  linear_rec2020.SetColorSpace(ColorSpace::kRGB);
+  JXL_RETURN_IF_ERROR(linear_rec2020.SetPrimariesType(Primaries::k2100));
+  JXL_RETURN_IF_ERROR(linear_rec2020.SetWhitePointType(WhitePoint::kD65));
+  linear_rec2020.Tf().SetTransferFunction(TransferFunction::kLinear);
+  JXL_RETURN_IF_ERROR(linear_rec2020.CreateICC());
+  JXL_RETURN_IF_ERROR(
+      ib->TransformTo(linear_rec2020, *JxlGetDefaultCms(), pool));
+
+  JXL_RETURN_IF_ERROR(RunOnPool(
+      pool, 0, ib->ysize(), ThreadPool::NoInit,
+      [&](const uint32_t y, size_t /* thread*/) {
+        float* const JXL_RESTRICT row_r = ib->color()->PlaneRow(0, y);
+        float* const JXL_RESTRICT row_g = ib->color()->PlaneRow(1, y);
+        float* const JXL_RESTRICT row_b = ib->color()->PlaneRow(2, y);
+        for (size_t x = 0; x < ib->xsize(); x += Lanes(df)) {
+          V red = Load(df, row_r + x);
+          V green = Load(df, row_g + x);
+          V blue = Load(df, row_b + x);
+          GamutMap(&red, &green, &blue, rec2020_luminances,
+                   preserve_saturation);
+          Store(red, df, row_r + x);
+          Store(green, df, row_g + x);
+          Store(blue, df, row_b + x);
+        }
+      },
+      "GamutMap"));
+
+  return true;
+}
+
+// NOLINTNEXTLINE(google-readability-namespace-comments)
+}  // namespace HWY_NAMESPACE
+}  // namespace jxl
+HWY_AFTER_NAMESPACE();
+
+#if HWY_ONCE
+namespace jxl {
+
+namespace {
+HWY_EXPORT(ToneMapFrame);
+HWY_EXPORT(GamutMapFrame);
+}  // namespace
+
+Status ToneMapTo(const std::pair<float, float> display_nits,
+                 CodecInOut* const io, ThreadPool* const pool) {
+  const auto tone_map_frame = HWY_DYNAMIC_DISPATCH(ToneMapFrame);
+  for (ImageBundle& ib : io->frames) {
+    JXL_RETURN_IF_ERROR(tone_map_frame(display_nits, &ib, pool));
+  }
+  io->metadata.m.SetIntensityTarget(display_nits.second);
+  return true;
+}
+
+Status GamutMap(CodecInOut* const io, float preserve_saturation,
+                ThreadPool* const pool) {
+  const auto gamut_map_frame = HWY_DYNAMIC_DISPATCH(GamutMapFrame);
+  for (ImageBundle& ib : io->frames) {
+    JXL_RETURN_IF_ERROR(gamut_map_frame(&ib, preserve_saturation, pool));
+  }
+  return true;
+}
+
+}  // namespace jxl
+#endif
diff --git a/third_party/jpeg-xl/lib/extras/tone_mapping.h b/third_party/jpeg-xl/lib/extras/tone_mapping.h
new file mode 100644
index 0000000000..1f474101eb
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/tone_mapping.h
@@ -0,0 +1,30 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_EXTRAS_TONE_MAPPING_H_
+#define LIB_EXTRAS_TONE_MAPPING_H_
+
+#include "lib/jxl/codec_in_out.h"
+
+namespace jxl {
+
+// Important: after calling this, the result will contain many out-of-gamut
+// colors. It is very strongly recommended to call GamutMap afterwards to
+// rectify this.
+Status ToneMapTo(std::pair<float, float> display_nits, CodecInOut* io,
+                 ThreadPool* pool = nullptr);
+
+// `preserve_saturation` indicates to what extent to favor saturation over
+// luminance when mapping out-of-gamut colors to Rec. 2020. 0 preserves
+// luminance at the complete expense of saturation, while 1 gives the most
+// saturated color with the same hue that Rec. 2020 can represent even if it
+// means lowering the luminance. Values in between correspond to linear mixtures
+// of those two extremes.
+Status GamutMap(CodecInOut* io, float preserve_saturation,
+                ThreadPool* pool = nullptr);
+
+}  // namespace jxl
+
+#endif  // LIB_EXTRAS_TONE_MAPPING_H_
diff --git a/third_party/jpeg-xl/lib/extras/tone_mapping_gbench.cc b/third_party/jpeg-xl/lib/extras/tone_mapping_gbench.cc
new file mode 100644
index 0000000000..34cbdde781
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/tone_mapping_gbench.cc
@@ -0,0 +1,41 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "benchmark/benchmark.h"
+#include "lib/extras/codec.h"
+#include "lib/extras/tone_mapping.h"
+
+namespace jxl {
+
+static void BM_ToneMapping(benchmark::State& state) {
+  Image3F color(2268, 1512);
+  FillImage(0.5f, &color);
+
+  // Use linear Rec. 2020 so that `ToneMapTo` doesn't have to convert to it and
+  // we mainly measure the tone mapping itself.
+  ColorEncoding linear_rec2020;
+  linear_rec2020.SetColorSpace(ColorSpace::kRGB);
+  JXL_CHECK(linear_rec2020.SetPrimariesType(Primaries::k2100));
+  JXL_CHECK(linear_rec2020.SetWhitePointType(WhitePoint::kD65));
+  linear_rec2020.Tf().SetTransferFunction(TransferFunction::kLinear);
+  JXL_CHECK(linear_rec2020.CreateICC());
+
+  for (auto _ : state) {
+    state.PauseTiming();
+    CodecInOut tone_mapping_input;
+    Image3F color2(color.xsize(), color.ysize());
+    CopyImageTo(color, &color2);
+    tone_mapping_input.SetFromImage(std::move(color2), linear_rec2020);
+    tone_mapping_input.metadata.m.SetIntensityTarget(255);
+    state.ResumeTiming();
+
+    JXL_CHECK(ToneMapTo({0.1, 100}, &tone_mapping_input));
+  }
+
+  state.SetItemsProcessed(state.iterations() * color.xsize() * color.ysize());
+}
+BENCHMARK(BM_ToneMapping);
+
+}  // namespace jxl