chromium/media/filters/audio_renderer_algorithm.h

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// AudioRendererAlgorithm buffers and transforms audio data. The owner of
// this object provides audio data to the object through EnqueueBuffer() and
// requests data from the buffer via FillBuffer().
//
// This class is *not* thread-safe. Calls to enqueue and retrieve data must be
// locked if called from multiple threads.
//
// AudioRendererAlgorithm uses the Waveform Similarity Overlap and Add (WSOLA)
// algorithm to stretch or compress audio data to meet playback speeds less than
// or greater than the natural playback of the audio stream. The algorithm
// preserves local properties of the audio, therefore, pitch and harmonics are
// are preserved. See audio_renderer_algorith.cc for a more elaborate
// description of the algorithm.
//
// Audio at very low or very high playback rates are muted to preserve quality.

#ifndef MEDIA_FILTERS_AUDIO_RENDERER_ALGORITHM_H_
#define MEDIA_FILTERS_AUDIO_RENDERER_ALGORITHM_H_

#include <stdint.h>

#include <memory>
#include <optional>
#include <vector>

#include "base/memory/raw_ptr.h"
#include "base/memory/scoped_refptr.h"
#include "base/time/time.h"
#include "media/base/audio_buffer.h"
#include "media/base/audio_buffer_queue.h"
#include "media/base/audio_parameters.h"
#include "media/base/media_log.h"
#include "media/base/multi_channel_resampler.h"

namespace media {

class AudioBus;

class MEDIA_EXPORT AudioRendererAlgorithm { … };

}  // namespace media

#endif  // MEDIA_FILTERS_AUDIO_RENDERER_ALGORITHM_H_