channel_mapper.h

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/*
 * Copyright (c) 2022 Roc Streaming authors
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */
 
//! @file roc_audio/channel_mapper.h
//! @brief Channel mapper.
 
#ifndef ROC_AUDIO_CHANNEL_MAPPER_H_
#define ROC_AUDIO_CHANNEL_MAPPER_H_
 
#include "roc_audio/channel_mapper_matrix.h"
#include "roc_audio/channel_set.h"
#include "roc_core/noncopyable.h"
 
namespace roc {
namespace audio {
 
//! Channel mapper.
//!
//! Converts between input and output samples with specified channel sets.
//!
//! Supports converting between:
//!  - different channel layouts (e.g. surround, multitrack)
//!  - different channel orders (e.g. smpte, alsa)
//!  - different channel masks (e.g. stereo, mono)
class ChannelMapper : public core::NonCopyable<> {
public:
    //! Initialize.
    ChannelMapper(const ChannelSet& in_chans, const ChannelSet& out_chans);
 
    //! Map samples.
    void map(const sample_t* in_samples,
             size_t n_in_samples,
             sample_t* out_samples,
             size_t n_out_samples);
 
private:
    typedef void (ChannelMapper::*map_func_t)(const sample_t* in_samples,
                                              sample_t* out_samples,
                                              size_t n_samples);
 
    void map_surround_surround_(const sample_t* in_samples,
                                sample_t* out_samples,
                                size_t n_samples);
    void map_multitrack_surround_(const sample_t* in_samples,
                                  sample_t* out_samples,
                                  size_t n_samples);
    void map_multitrack_multitrack_(const sample_t* in_samples,
                                    sample_t* out_samples,
                                    size_t n_samples);
 
    void setup_map_func_();
 
    const ChannelSet in_chans_;
    const ChannelSet out_chans_;
    ChannelSet inout_chans_;
 
    map_func_t map_func_;
 
    // use for surround <=> surround mapping
    ChannelMapperMatrix map_matrix_;
};
 
} // namespace audio
} // namespace roc
 
#endif // ROC_AUDIO_CHANNEL_MAPPER_H_