summaryrefslogtreecommitdiffstats
path: root/third_party/jpeg-xl/lib/jxl/enc_fields.cc
diff options
context:
space:
mode:
Diffstat (limited to 'third_party/jpeg-xl/lib/jxl/enc_fields.cc')
-rw-r--r--third_party/jpeg-xl/lib/jxl/enc_fields.cc239
1 files changed, 239 insertions, 0 deletions
diff --git a/third_party/jpeg-xl/lib/jxl/enc_fields.cc b/third_party/jpeg-xl/lib/jxl/enc_fields.cc
new file mode 100644
index 0000000000..22c763e13f
--- /dev/null
+++ b/third_party/jpeg-xl/lib/jxl/enc_fields.cc
@@ -0,0 +1,239 @@
+// 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/jxl/enc_fields.h"
+
+#include "lib/jxl/enc_aux_out.h"
+#include "lib/jxl/fields.h"
+
+namespace jxl {
+
+namespace {
+using ::jxl::fields_internal::VisitorBase;
+class WriteVisitor : public VisitorBase {
+ public:
+ WriteVisitor(const size_t extension_bits, BitWriter* JXL_RESTRICT writer)
+ : extension_bits_(extension_bits), writer_(writer) {}
+
+ Status Bits(const size_t bits, const uint32_t /*default_value*/,
+ uint32_t* JXL_RESTRICT value) override {
+ ok_ &= BitsCoder::Write(bits, *value, writer_);
+ return true;
+ }
+ Status U32(const U32Enc enc, const uint32_t /*default_value*/,
+ uint32_t* JXL_RESTRICT value) override {
+ ok_ &= U32Coder::Write(enc, *value, writer_);
+ return true;
+ }
+
+ Status U64(const uint64_t /*default_value*/,
+ uint64_t* JXL_RESTRICT value) override {
+ ok_ &= U64Coder::Write(*value, writer_);
+ return true;
+ }
+
+ Status F16(const float /*default_value*/,
+ float* JXL_RESTRICT value) override {
+ ok_ &= F16Coder::Write(*value, writer_);
+ return true;
+ }
+
+ Status BeginExtensions(uint64_t* JXL_RESTRICT extensions) override {
+ JXL_QUIET_RETURN_IF_ERROR(VisitorBase::BeginExtensions(extensions));
+ if (*extensions == 0) {
+ JXL_ASSERT(extension_bits_ == 0);
+ return true;
+ }
+ // TODO(janwas): extend API to pass in array of extension_bits, one per
+ // extension. We currently ascribe all bits to the first extension, but
+ // this is only an encoder limitation. NOTE: extension_bits_ can be zero
+ // if an extension does not require any additional fields.
+ ok_ &= U64Coder::Write(extension_bits_, writer_);
+ // For each nonzero bit except the lowest/first (already written):
+ for (uint64_t remaining_extensions = *extensions & (*extensions - 1);
+ remaining_extensions != 0;
+ remaining_extensions &= remaining_extensions - 1) {
+ ok_ &= U64Coder::Write(0, writer_);
+ }
+ return true;
+ }
+ // EndExtensions = default.
+
+ Status OK() const { return ok_; }
+
+ private:
+ const size_t extension_bits_;
+ BitWriter* JXL_RESTRICT writer_;
+ bool ok_ = true;
+};
+} // namespace
+
+Status Bundle::Write(const Fields& fields, BitWriter* writer, size_t layer,
+ AuxOut* aux_out) {
+ size_t extension_bits, total_bits;
+ JXL_RETURN_IF_ERROR(Bundle::CanEncode(fields, &extension_bits, &total_bits));
+
+ BitWriter::Allotment allotment(writer, total_bits);
+ WriteVisitor visitor(extension_bits, writer);
+ JXL_RETURN_IF_ERROR(visitor.VisitConst(fields));
+ JXL_RETURN_IF_ERROR(visitor.OK());
+ allotment.ReclaimAndCharge(writer, layer, aux_out);
+ return true;
+}
+
+// Returns false if the value is too large to encode.
+Status BitsCoder::Write(const size_t bits, const uint32_t value,
+ BitWriter* JXL_RESTRICT writer) {
+ if (value >= (1ULL << bits)) {
+ return JXL_FAILURE("Value %d too large to encode in %" PRIu64 " bits",
+ value, static_cast<uint64_t>(bits));
+ }
+ writer->Write(bits, value);
+ return true;
+}
+
+// Returns false if the value is too large to encode.
+Status U32Coder::Write(const U32Enc enc, const uint32_t value,
+ BitWriter* JXL_RESTRICT writer) {
+ uint32_t selector;
+ size_t total_bits;
+ JXL_RETURN_IF_ERROR(ChooseSelector(enc, value, &selector, &total_bits));
+
+ writer->Write(2, selector);
+
+ const U32Distr d = enc.GetDistr(selector);
+ if (!d.IsDirect()) { // Nothing more to write for direct encoding
+ const uint32_t offset = d.Offset();
+ JXL_ASSERT(value >= offset);
+ writer->Write(total_bits - 2, value - offset);
+ }
+
+ return true;
+}
+
+// Returns false if the value is too large to encode.
+Status U64Coder::Write(uint64_t value, BitWriter* JXL_RESTRICT writer) {
+ if (value == 0) {
+ // Selector: use 0 bits, value 0
+ writer->Write(2, 0);
+ } else if (value <= 16) {
+ // Selector: use 4 bits, value 1..16
+ writer->Write(2, 1);
+ writer->Write(4, value - 1);
+ } else if (value <= 272) {
+ // Selector: use 8 bits, value 17..272
+ writer->Write(2, 2);
+ writer->Write(8, value - 17);
+ } else {
+ // Selector: varint, first a 12-bit group, after that per 8-bit group.
+ writer->Write(2, 3);
+ writer->Write(12, value & 4095);
+ value >>= 12;
+ int shift = 12;
+ while (value > 0 && shift < 60) {
+ // Indicate varint not done
+ writer->Write(1, 1);
+ writer->Write(8, value & 255);
+ value >>= 8;
+ shift += 8;
+ }
+ if (value > 0) {
+ // This only could happen if shift == N - 4.
+ writer->Write(1, 1);
+ writer->Write(4, value & 15);
+ // Implicitly closed sequence, no extra stop bit is required.
+ } else {
+ // Indicate end of varint
+ writer->Write(1, 0);
+ }
+ }
+
+ return true;
+}
+
+Status F16Coder::Write(float value, BitWriter* JXL_RESTRICT writer) {
+ uint32_t bits32;
+ memcpy(&bits32, &value, sizeof(bits32));
+ const uint32_t sign = bits32 >> 31;
+ const uint32_t biased_exp32 = (bits32 >> 23) & 0xFF;
+ const uint32_t mantissa32 = bits32 & 0x7FFFFF;
+
+ const int32_t exp = static_cast<int32_t>(biased_exp32) - 127;
+ if (JXL_UNLIKELY(exp > 15)) {
+ return JXL_FAILURE("Too big to encode, CanEncode should return false");
+ }
+
+ // Tiny or zero => zero.
+ if (exp < -24) {
+ writer->Write(16, 0);
+ return true;
+ }
+
+ uint32_t biased_exp16, mantissa16;
+
+ // exp = [-24, -15] => subnormal
+ if (JXL_UNLIKELY(exp < -14)) {
+ biased_exp16 = 0;
+ const uint32_t sub_exp = static_cast<uint32_t>(-14 - exp);
+ JXL_ASSERT(1 <= sub_exp && sub_exp < 11);
+ mantissa16 = (1 << (10 - sub_exp)) + (mantissa32 >> (13 + sub_exp));
+ } else {
+ // exp = [-14, 15]
+ biased_exp16 = static_cast<uint32_t>(exp + 15);
+ JXL_ASSERT(1 <= biased_exp16 && biased_exp16 < 31);
+ mantissa16 = mantissa32 >> 13;
+ }
+
+ JXL_ASSERT(mantissa16 < 1024);
+ const uint32_t bits16 = (sign << 15) | (biased_exp16 << 10) | mantissa16;
+ JXL_ASSERT(bits16 < 0x10000);
+ writer->Write(16, bits16);
+ return true;
+}
+
+Status WriteCodestreamHeaders(CodecMetadata* metadata, BitWriter* writer,
+ AuxOut* aux_out) {
+ // Marker/signature
+ BitWriter::Allotment allotment(writer, 16);
+ writer->Write(8, 0xFF);
+ writer->Write(8, kCodestreamMarker);
+ allotment.ReclaimAndCharge(writer, kLayerHeader, aux_out);
+
+ JXL_RETURN_IF_ERROR(
+ WriteSizeHeader(metadata->size, writer, kLayerHeader, aux_out));
+
+ JXL_RETURN_IF_ERROR(
+ WriteImageMetadata(metadata->m, writer, kLayerHeader, aux_out));
+
+ metadata->transform_data.nonserialized_xyb_encoded = metadata->m.xyb_encoded;
+ JXL_RETURN_IF_ERROR(
+ Bundle::Write(metadata->transform_data, writer, kLayerHeader, aux_out));
+
+ return true;
+}
+
+Status WriteFrameHeader(const FrameHeader& frame,
+ BitWriter* JXL_RESTRICT writer, AuxOut* aux_out) {
+ return Bundle::Write(frame, writer, kLayerHeader, aux_out);
+}
+
+Status WriteImageMetadata(const ImageMetadata& metadata,
+ BitWriter* JXL_RESTRICT writer, size_t layer,
+ AuxOut* aux_out) {
+ return Bundle::Write(metadata, writer, layer, aux_out);
+}
+
+Status WriteQuantizerParams(const QuantizerParams& params,
+ BitWriter* JXL_RESTRICT writer, size_t layer,
+ AuxOut* aux_out) {
+ return Bundle::Write(params, writer, layer, aux_out);
+}
+
+Status WriteSizeHeader(const SizeHeader& size, BitWriter* JXL_RESTRICT writer,
+ size_t layer, AuxOut* aux_out) {
+ return Bundle::Write(size, writer, layer, aux_out);
+}
+
+} // namespace jxl
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-20 11:29:57 +0000