8037fc6ffa
Bug: webrtc:342905193 No-Try: True Change-Id: Icc968be43b8830038ea9a1f5f604307220457807 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/361021 Auto-Submit: Florent Castelli <orphis@webrtc.org> Reviewed-by: Harald Alvestrand <hta@webrtc.org> Commit-Queue: Florent Castelli <orphis@webrtc.org> Cr-Commit-Position: refs/heads/main@{#42911}
56 lines
2.0 KiB
C++
56 lines
2.0 KiB
C++
/*
|
|
* 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.
|
|
*/
|
|
|
|
#ifndef RTC_TOOLS_FRAME_ANALYZER_LINEAR_LEAST_SQUARES_H_
|
|
#define RTC_TOOLS_FRAME_ANALYZER_LINEAR_LEAST_SQUARES_H_
|
|
|
|
#include <stdint.h>
|
|
|
|
#include <optional>
|
|
#include <valarray>
|
|
#include <vector>
|
|
|
|
namespace webrtc {
|
|
namespace test {
|
|
|
|
// This class is used for finding a matrix b that roughly solves the equation:
|
|
// y = x * b. This is generally impossible to do exactly, so the problem is
|
|
// rephrased as finding the matrix b that minimizes the difference:
|
|
// |y - x * b|^2. Calling multiple AddObservations() is equivalent to
|
|
// concatenating the observation vectors and calling AddObservations() once. The
|
|
// reason for doing it incrementally is that we can't store the raw YUV values
|
|
// for a whole video file in memory at once. This class has a constant memory
|
|
// footprint, regardless how may times AddObservations() is called.
|
|
class IncrementalLinearLeastSquares {
|
|
public:
|
|
IncrementalLinearLeastSquares();
|
|
~IncrementalLinearLeastSquares();
|
|
|
|
// Add a number of observations. The subvectors of x and y must have the same
|
|
// length.
|
|
void AddObservations(const std::vector<std::vector<uint8_t>>& x,
|
|
const std::vector<std::vector<uint8_t>>& y);
|
|
|
|
// Calculate and return the best linear solution, given the observations so
|
|
// far.
|
|
std::vector<std::vector<double>> GetBestSolution() const;
|
|
|
|
private:
|
|
// Running sum of x^T * x.
|
|
std::optional<std::valarray<std::valarray<uint64_t>>> sum_xx;
|
|
// Running sum of x^T * y.
|
|
std::optional<std::valarray<std::valarray<uint64_t>>> sum_xy;
|
|
};
|
|
|
|
} // namespace test
|
|
} // namespace webrtc
|
|
|
|
#endif // RTC_TOOLS_FRAME_ANALYZER_LINEAR_LEAST_SQUARES_H_
|