| /* |
| * Copyright 2024 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. |
| */ |
| |
| #ifndef VIDEO_CORRUPTION_DETECTION_HALTON_FRAME_SAMPLER_H_ |
| #define VIDEO_CORRUPTION_DETECTION_HALTON_FRAME_SAMPLER_H_ |
| |
| #include <cstdint> |
| #include <optional> |
| #include <vector> |
| |
| #include "api/scoped_refptr.h" |
| #include "api/video/video_frame_buffer.h" |
| #include "video/corruption_detection/halton_sequence.h" |
| |
| namespace webrtc { |
| |
| enum class ImagePlane { kLuma, kChroma }; |
| |
| struct FilteredSample { |
| double value; |
| ImagePlane plane; |
| }; |
| |
| // Determines if a frame should be sampled and, based on the 2 dimensional |
| // Halton sequence, finds the coordinates for those samples. |
| class HaltonFrameSampler { |
| public: |
| struct Coordinates { |
| double row = 0; |
| double column = 0; |
| }; |
| |
| HaltonFrameSampler(); |
| HaltonFrameSampler(const HaltonFrameSampler&) = default; |
| HaltonFrameSampler(HaltonFrameSampler&&) = default; |
| HaltonFrameSampler& operator=(const HaltonFrameSampler&) = default; |
| HaltonFrameSampler& operator=(HaltonFrameSampler&&) = default; |
| |
| std::vector<Coordinates> GetSampleCoordinatesForFrameIfFrameShouldBeSampled( |
| bool is_key_frame, |
| uint32_t rtp_timestamp, |
| int num_samples); |
| std::vector<Coordinates> GetSampleCoordinatesForFrame(int num_samples); |
| void Restart(); |
| int GetCurrentIndex() const; |
| void SetCurrentIndex(int index); |
| |
| private: |
| Coordinates GetNextSampleCoordinates(); |
| |
| HaltonSequence coordinate_sampler_prng_; |
| std::optional<uint32_t> rtp_timestamp_last_frame_sampled_; |
| int frames_sampled_ = 0; |
| int frames_until_next_sample_ = 0; |
| }; |
| |
| // 1. Scale the frame buffer to the resolution given by `scaled_width` and |
| // `scaled_height`. |
| // 2. Scale the `sample_coordinates` to the frame's resolution. |
| // 3. Apply the Gaussian filtering given by `stddev_gaussian_blur`. |
| // 4. Fetch the values at the scaled coordinates in the filtered frame. |
| std::vector<FilteredSample> GetSampleValuesForFrame( |
| scoped_refptr<I420BufferInterface> i420_frame_buffer, |
| std::vector<HaltonFrameSampler::Coordinates> sample_coordinates, |
| int scaled_width, |
| int scaled_height, |
| double stddev_gaussian_blur); |
| |
| double GetFilteredElement(int width, |
| int height, |
| int stride, |
| const uint8_t* data, |
| int row, |
| int column, |
| double stddev); |
| |
| } // namespace webrtc |
| |
| #endif // VIDEO_CORRUPTION_DETECTION_HALTON_FRAME_SAMPLER_H_ |