1 files changed, 132 insertions, 0 deletions
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..e1b0365274
--- /dev/null
+++ b/third_party/jpeg-xl/lib/extras/dec/decode.cc
@@ -0,0 +1,132 @@
+// 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>
+
+#if JPEGXL_ENABLE_APNG
+#include "lib/extras/dec/apng.h"
+#endif
+#if JPEGXL_ENABLE_EXR
+#include "lib/extras/dec/exr.h"
+#endif
+#if JPEGXL_ENABLE_GIF
+#include "lib/extras/dec/gif.h"
+#endif
+#if JPEGXL_ENABLE_JPEG
+#include "lib/extras/dec/jpg.h"
+#endif
+#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;
+
+}  // namespace
+
+std::vector<Codec> AvailableCodecs() {
+  std::vector<Codec> out;
+#if JPEGXL_ENABLE_APNG
+  out.push_back(Codec::kPNG);
+#endif
+#if JPEGXL_ENABLE_EXR
+  out.push_back(Codec::kEXR);
+#endif
+#if JPEGXL_ENABLE_GIF
+  out.push_back(Codec::kGIF);
+#endif
+#if JPEGXL_ENABLE_JPEG
+  out.push_back(Codec::kJPG);
+#endif
+  out.push_back(Codec::kPGX);
+  out.push_back(Codec::kPNM);
+  return out;
+}
+
+Codec CodecFromExtension(std::string extension,
+                         size_t* JXL_RESTRICT bits_per_sample) {
+  std::transform(
+      extension.begin(), extension.end(), extension.begin(),
+      [](char c) { return std::tolower(c, std::locale::classic()); });
+  if (extension == ".png") return Codec::kPNG;
+
+  if (extension == ".jpg") return Codec::kJPG;
+  if (extension == ".jpeg") return Codec::kJPG;
+
+  if (extension == ".pgx") return Codec::kPGX;
+
+  if (extension == ".pam") return Codec::kPNM;
+  if (extension == ".pnm") return Codec::kPNM;
+  if (extension == ".pgm") return Codec::kPNM;
+  if (extension == ".ppm") return Codec::kPNM;
+  if (extension == ".pfm") {
+    if (bits_per_sample != nullptr) *bits_per_sample = 32;
+    return Codec::kPNM;
+  }
+
+  if (extension == ".gif") return Codec::kGIF;
+
+  if (extension == ".exr") return Codec::kEXR;
+
+  return Codec::kUnknown;
+}
+
+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 JPEGXL_ENABLE_APNG
+    if (DecodeImageAPNG(bytes, color_hints, ppf, constraints)) {
+      return Codec::kPNG;
+    }
+#endif
+    if (DecodeImagePGX(bytes, color_hints, ppf, constraints)) {
+      return Codec::kPGX;
+    }
+    if (DecodeImagePNM(bytes, color_hints, ppf, constraints)) {
+      return Codec::kPNM;
+    }
+#if JPEGXL_ENABLE_GIF
+    if (DecodeImageGIF(bytes, color_hints, ppf, constraints)) {
+      return Codec::kGIF;
+    }
+#endif
+#if JPEGXL_ENABLE_JPEG
+    if (DecodeImageJPG(bytes, color_hints, ppf, constraints)) {
+      return Codec::kJPG;
+    }
+#endif
+#if JPEGXL_ENABLE_EXR
+    if (DecodeImageEXR(bytes, color_hints, ppf, constraints)) {
+      return Codec::kEXR;
+    }
+#endif
+    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