diff options
Diffstat (limited to 'third_party/jpeg-xl/lib/extras/dec/exr.cc')
| -rw-r--r-- | third_party/jpeg-xl/lib/extras/dec/exr.cc | 184 |
1 files changed, 184 insertions, 0 deletions
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..f174ccd0c9 --- /dev/null +++ b/third_party/jpeg-xl/lib/extras/dec/exr.cc @@ -0,0 +1,184 @@ +// 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" + +#include <ImfChromaticitiesAttribute.h> +#include <ImfIO.h> +#include <ImfRgbaFile.h> +#include <ImfStandardAttributes.h> + +#include <vector> + +namespace jxl { +namespace extras { + +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()); + +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 + +Status DecodeImageEXR(Span<const uint8_t> bytes, const ColorHints& color_hints, + PackedPixelFile* ppf, + const SizeConstraints* constraints) { + InMemoryIStream is(bytes); + +#ifdef __EXCEPTIONS + std::unique_ptr<OpenEXR::RgbaInputFile> input_ptr; + try { + input_ptr.reset(new OpenEXR::RgbaInputFile(is)); + } catch (...) { + return JXL_FAILURE("OpenEXR failed to parse input"); + } + 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; + 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; +} + +} // namespace extras +} // namespace jxl |