77 lines
2.8 KiB
C
77 lines
2.8 KiB
C
|
/*
|
||
|
|
* Copyright (c) 2019 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 AUDIO_UTILITY_CHANNEL_MIXING_MATRIX_H_
|
||
|
|
#define AUDIO_UTILITY_CHANNEL_MIXING_MATRIX_H_
|
||
|
|
|
||
|
|
#include <vector>
|
||
|
|
|
||
|
|
#include "api/audio/channel_layout.h"
|
||
|
|
|
||
|
|
namespace webrtc {
|
||
|
|
|
||
|
|
class ChannelMixingMatrix {
|
||
|
|
public:
|
||
|
|
ChannelMixingMatrix(ChannelLayout input_layout,
|
||
|
|
int input_channels,
|
||
|
|
ChannelLayout output_layout,
|
||
|
|
int output_channels);
|
||
|
|
|
||
|
|
~ChannelMixingMatrix();
|
||
|
|
|
||
|
|
// Create the transformation matrix of input channels to output channels.
|
||
|
|
// Updates the empty matrix with the transformation, and returns true
|
||
|
|
// if the transformation is just a remapping of channels (no mixing).
|
||
|
|
// The size of |matrix| is |output_channels| x |input_channels|, i.e., the
|
||
|
|
// number of rows equals the number of output channels and the number of
|
||
|
|
// columns corresponds to the number of input channels.
|
||
|
|
// This file is derived from Chromium's media/base/channel_mixing_matrix.h.
|
||
|
|
bool CreateTransformationMatrix(std::vector<std::vector<float>>* matrix);
|
||
|
|
|
||
|
|
private:
|
||
|
|
const bool use_voip_channel_mapping_adjustments_;
|
||
|
|
|
||
|
|
// Result transformation of input channels to output channels
|
||
|
|
std::vector<std::vector<float>>* matrix_;
|
||
|
|
|
||
|
|
// Input and output channel layout provided during construction.
|
||
|
|
ChannelLayout input_layout_;
|
||
|
|
int input_channels_;
|
||
|
|
ChannelLayout output_layout_;
|
||
|
|
int output_channels_;
|
||
|
|
|
||
|
|
// Helper variable for tracking which inputs are currently unaccounted,
|
||
|
|
// should be empty after construction completes.
|
||
|
|
std::vector<Channels> unaccounted_inputs_;
|
||
|
|
|
||
|
|
// Helper methods for managing unaccounted input channels.
|
||
|
|
void AccountFor(Channels ch);
|
||
|
|
bool IsUnaccounted(Channels ch) const;
|
||
|
|
|
||
|
|
// Helper methods for checking if |ch| exists in either |input_layout_| or
|
||
|
|
// |output_layout_| respectively.
|
||
|
|
bool HasInputChannel(Channels ch) const;
|
||
|
|
bool HasOutputChannel(Channels ch) const;
|
||
|
|
|
||
|
|
// Helper methods for updating |matrix_| with the proper value for
|
||
|
|
// mixing |input_ch| into |output_ch|. MixWithoutAccounting() does not
|
||
|
|
// remove the channel from |unaccounted_inputs_|.
|
||
|
|
void Mix(Channels input_ch, Channels output_ch, float scale);
|
||
|
|
void MixWithoutAccounting(Channels input_ch, Channels output_ch, float scale);
|
||
|
|
|
||
|
|
// Delete the copy constructor and assignment operator.
|
||
|
|
ChannelMixingMatrix(const ChannelMixingMatrix& other) = delete;
|
||
|
|
ChannelMixingMatrix& operator=(const ChannelMixingMatrix& other) = delete;
|
||
|
|
};
|
||
|
|
|
||
|
|
} // namespace webrtc
|
||
|
|
|
||
|
|
#endif // AUDIO_UTILITY_CHANNEL_MIXING_MATRIX_H_
|