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Diffstat (limited to '')
-rw-r--r-- | third_party/libwebrtc/rtc_tools/frame_analyzer/video_color_aligner.cc | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/third_party/libwebrtc/rtc_tools/frame_analyzer/video_color_aligner.cc b/third_party/libwebrtc/rtc_tools/frame_analyzer/video_color_aligner.cc new file mode 100644 index 0000000000..5983e47f69 --- /dev/null +++ b/third_party/libwebrtc/rtc_tools/frame_analyzer/video_color_aligner.cc @@ -0,0 +1,237 @@ +/* + * Copyright (c) 2018 The WebRTC 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 in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + +#include "rtc_tools/frame_analyzer/video_color_aligner.h" + +#include <stddef.h> + +#include <algorithm> +#include <cmath> +#include <cstdint> +#include <vector> + +#include "api/array_view.h" +#include "api/make_ref_counted.h" +#include "api/video/i420_buffer.h" +#include "rtc_base/checks.h" +#include "rtc_tools/frame_analyzer/linear_least_squares.h" +#include "third_party/libyuv/include/libyuv/planar_functions.h" +#include "third_party/libyuv/include/libyuv/scale.h" + +namespace webrtc { +namespace test { + +namespace { + +// Helper function for AdjustColors(). This functions calculates a single output +// row for y with the given color coefficients. The u/v channels are assumed to +// be subsampled by a factor of 2, which is the case of I420. +void CalculateYChannel(rtc::ArrayView<const uint8_t> y_data, + rtc::ArrayView<const uint8_t> u_data, + rtc::ArrayView<const uint8_t> v_data, + const std::array<float, 4>& coeff, + rtc::ArrayView<uint8_t> output) { + RTC_CHECK_EQ(y_data.size(), output.size()); + // Each u/v element represents two y elements. Make sure we have enough to + // cover the Y values. + RTC_CHECK_GE(u_data.size() * 2, y_data.size()); + RTC_CHECK_GE(v_data.size() * 2, y_data.size()); + + // Do two pixels at a time since u/v are subsampled. + for (size_t i = 0; i * 2 < y_data.size() - 1; ++i) { + const float uv_contribution = + coeff[1] * u_data[i] + coeff[2] * v_data[i] + coeff[3]; + + const float val0 = coeff[0] * y_data[i * 2 + 0] + uv_contribution; + const float val1 = coeff[0] * y_data[i * 2 + 1] + uv_contribution; + + // Clamp result to a byte. + output[i * 2 + 0] = static_cast<uint8_t>( + std::round(std::max(0.0f, std::min(val0, 255.0f)))); + output[i * 2 + 1] = static_cast<uint8_t>( + std::round(std::max(0.0f, std::min(val1, 255.0f)))); + } + + // Handle the last pixel for odd widths. + if (y_data.size() % 2 == 1) { + const float val = coeff[0] * y_data[y_data.size() - 1] + + coeff[1] * u_data[(y_data.size() - 1) / 2] + + coeff[2] * v_data[(y_data.size() - 1) / 2] + coeff[3]; + output[y_data.size() - 1] = + static_cast<uint8_t>(std::round(std::max(0.0f, std::min(val, 255.0f)))); + } +} + +// Helper function for AdjustColors(). This functions calculates a single output +// row for either u or v, with the given color coefficients. Y, U, and V are +// assumed to be the same size, i.e. no subsampling. +void CalculateUVChannel(rtc::ArrayView<const uint8_t> y_data, + rtc::ArrayView<const uint8_t> u_data, + rtc::ArrayView<const uint8_t> v_data, + const std::array<float, 4>& coeff, + rtc::ArrayView<uint8_t> output) { + RTC_CHECK_EQ(y_data.size(), u_data.size()); + RTC_CHECK_EQ(y_data.size(), v_data.size()); + RTC_CHECK_EQ(y_data.size(), output.size()); + + for (size_t x = 0; x < y_data.size(); ++x) { + const float val = coeff[0] * y_data[x] + coeff[1] * u_data[x] + + coeff[2] * v_data[x] + coeff[3]; + // Clamp result to a byte. + output[x] = + static_cast<uint8_t>(std::round(std::max(0.0f, std::min(val, 255.0f)))); + } +} + +// Convert a frame to four vectors consisting of [y, u, v, 1]. +std::vector<std::vector<uint8_t>> FlattenYuvData( + const rtc::scoped_refptr<I420BufferInterface>& frame) { + std::vector<std::vector<uint8_t>> result( + 4, std::vector<uint8_t>(frame->ChromaWidth() * frame->ChromaHeight())); + + // Downscale the Y plane so that all YUV planes are the same size. + libyuv::ScalePlane(frame->DataY(), frame->StrideY(), frame->width(), + frame->height(), result[0].data(), frame->ChromaWidth(), + frame->ChromaWidth(), frame->ChromaHeight(), + libyuv::kFilterBox); + + libyuv::CopyPlane(frame->DataU(), frame->StrideU(), result[1].data(), + frame->ChromaWidth(), frame->ChromaWidth(), + frame->ChromaHeight()); + + libyuv::CopyPlane(frame->DataV(), frame->StrideV(), result[2].data(), + frame->ChromaWidth(), frame->ChromaWidth(), + frame->ChromaHeight()); + + std::fill(result[3].begin(), result[3].end(), 1u); + + return result; +} + +ColorTransformationMatrix VectorToColorMatrix( + const std::vector<std::vector<double>>& v) { + ColorTransformationMatrix color_transformation; + for (int i = 0; i < 3; ++i) { + for (int j = 0; j < 4; ++j) + color_transformation[i][j] = v[i][j]; + } + return color_transformation; +} + +} // namespace + +ColorTransformationMatrix CalculateColorTransformationMatrix( + const rtc::scoped_refptr<I420BufferInterface>& reference_frame, + const rtc::scoped_refptr<I420BufferInterface>& test_frame) { + IncrementalLinearLeastSquares incremental_lls; + incremental_lls.AddObservations(FlattenYuvData(test_frame), + FlattenYuvData(reference_frame)); + return VectorToColorMatrix(incremental_lls.GetBestSolution()); +} + +ColorTransformationMatrix CalculateColorTransformationMatrix( + const rtc::scoped_refptr<Video>& reference_video, + const rtc::scoped_refptr<Video>& test_video) { + RTC_CHECK_GE(reference_video->number_of_frames(), + test_video->number_of_frames()); + + IncrementalLinearLeastSquares incremental_lls; + for (size_t i = 0; i < test_video->number_of_frames(); ++i) { + incremental_lls.AddObservations( + FlattenYuvData(test_video->GetFrame(i)), + FlattenYuvData(reference_video->GetFrame(i))); + } + + return VectorToColorMatrix(incremental_lls.GetBestSolution()); +} + +rtc::scoped_refptr<Video> AdjustColors( + const ColorTransformationMatrix& color_transformation, + const rtc::scoped_refptr<Video>& video) { + class ColorAdjustedVideo : public Video { + public: + ColorAdjustedVideo(const ColorTransformationMatrix& color_transformation, + const rtc::scoped_refptr<Video>& video) + : color_transformation_(color_transformation), video_(video) {} + + int width() const override { return video_->width(); } + int height() const override { return video_->height(); } + size_t number_of_frames() const override { + return video_->number_of_frames(); + } + + rtc::scoped_refptr<I420BufferInterface> GetFrame( + size_t index) const override { + return AdjustColors(color_transformation_, video_->GetFrame(index)); + } + + private: + const ColorTransformationMatrix color_transformation_; + const rtc::scoped_refptr<Video> video_; + }; + + return rtc::make_ref_counted<ColorAdjustedVideo>(color_transformation, video); +} + +rtc::scoped_refptr<I420BufferInterface> AdjustColors( + const ColorTransformationMatrix& color_matrix, + const rtc::scoped_refptr<I420BufferInterface>& frame) { + // Allocate I420 buffer that will hold the color adjusted frame. + rtc::scoped_refptr<I420Buffer> adjusted_frame = + I420Buffer::Create(frame->width(), frame->height()); + + // Create a downscaled Y plane with the same size as the U/V planes to + // simplify converting the U/V planes. + std::vector<uint8_t> downscaled_y_plane(frame->ChromaWidth() * + frame->ChromaHeight()); + libyuv::ScalePlane(frame->DataY(), frame->StrideY(), frame->width(), + frame->height(), downscaled_y_plane.data(), + frame->ChromaWidth(), frame->ChromaWidth(), + frame->ChromaHeight(), libyuv::kFilterBox); + + // Fill in the adjusted data row by row. + for (int y = 0; y < frame->height(); ++y) { + const int half_y = y / 2; + rtc::ArrayView<const uint8_t> y_row(frame->DataY() + frame->StrideY() * y, + frame->width()); + rtc::ArrayView<const uint8_t> u_row( + frame->DataU() + frame->StrideU() * half_y, frame->ChromaWidth()); + rtc::ArrayView<const uint8_t> v_row( + frame->DataV() + frame->StrideV() * half_y, frame->ChromaWidth()); + rtc::ArrayView<uint8_t> output_y_row( + adjusted_frame->MutableDataY() + adjusted_frame->StrideY() * y, + frame->width()); + + CalculateYChannel(y_row, u_row, v_row, color_matrix[0], output_y_row); + + // Chroma channels only exist every second row for I420. + if (y % 2 == 0) { + rtc::ArrayView<const uint8_t> downscaled_y_row( + downscaled_y_plane.data() + frame->ChromaWidth() * half_y, + frame->ChromaWidth()); + rtc::ArrayView<uint8_t> output_u_row( + adjusted_frame->MutableDataU() + adjusted_frame->StrideU() * half_y, + frame->ChromaWidth()); + rtc::ArrayView<uint8_t> output_v_row( + adjusted_frame->MutableDataV() + adjusted_frame->StrideV() * half_y, + frame->ChromaWidth()); + + CalculateUVChannel(downscaled_y_row, u_row, v_row, color_matrix[1], + output_u_row); + CalculateUVChannel(downscaled_y_row, u_row, v_row, color_matrix[2], + output_v_row); + } + } + + return adjusted_frame; +} + +} // namespace test +} // namespace webrtc |