chromium/media/base/audio_buffer.h

// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_BASE_AUDIO_BUFFER_H_
#define MEDIA_BASE_AUDIO_BUFFER_H_

#include <stddef.h>
#include <stdint.h>

#include <list>
#include <memory>
#include <utility>
#include <vector>

#include "base/containers/span.h"
#include "base/memory/aligned_memory.h"
#include "base/memory/raw_span.h"
#include "base/memory/ref_counted.h"
#include "base/synchronization/lock.h"
#include "base/thread_annotations.h"
#include "base/time/time.h"
#include "media/base/audio_bus.h"
#include "media/base/channel_layout.h"
#include "media/base/media_export.h"
#include "media/base/sample_format.h"

namespace mojo {
template <typename T, typename U>
struct TypeConverter;
template <typename T>
class StructPtr;
}  // namespace mojo

namespace media {
class AudioBufferMemoryPool;

namespace mojom {
class AudioBuffer;
}

// An audio buffer that takes a copy of the data passed to it, holds it, and
// copies it into an AudioBus when needed. Also supports an end of stream
// marker.
class MEDIA_EXPORT AudioBuffer
    : public base::RefCountedThreadSafe<AudioBuffer> { … };

// Basic memory pool for reusing AudioBuffer internal memory to avoid thrashing.
//
// The pool is managed in a last-in-first-out manner, returned buffers are put
// at the back of the queue. When a new buffer is requested by AudioBuffer, we
// will scan from the front to find a matching buffer. All non-matching buffers
// are dropped. The assumption is that when we reach steady-state all buffers
// will have the same sized allocation. At most the pool will be equal in size
// to the maximum number of concurrent AudioBuffer instances.
//
// Each AudioBuffer instance created with an AudioBufferMemoryPool will take a
// ref on the pool instance so that it may return buffers in the future.
class MEDIA_EXPORT AudioBufferMemoryPool
    : public base::RefCountedThreadSafe<AudioBufferMemoryPool> { … };

}  // namespace media

#endif  // MEDIA_BASE_AUDIO_BUFFER_H_