| /* |
| * 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_ |