chromium/third_party/webrtc/rtc_tools/frame_analyzer/linear_least_squares.h

/*
 *  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 <valarray>
#include <vector>

#include "absl/types/optional.h"

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 { … };

}  // namespace test
}  // namespace webrtc

#endif  // RTC_TOOLS_FRAME_ANALYZER_LINEAR_LEAST_SQUARES_H_