chromium/media/mojo/common/mojo_decoder_buffer_converter.h

// Copyright 2016 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_MOJO_COMMON_MOJO_DECODER_BUFFER_CONVERTER_H_
#define MEDIA_MOJO_COMMON_MOJO_DECODER_BUFFER_CONVERTER_H_

#include <memory>

#include "base/containers/circular_deque.h"
#include "base/memory/scoped_refptr.h"
#include "media/base/demuxer_stream.h"
#include "media/mojo/mojom/media_types.mojom.h"
#include "mojo/public/cpp/system/data_pipe.h"
#include "mojo/public/cpp/system/simple_watcher.h"

namespace media {

class DecoderBuffer;

// Creates mojo::DataPipe and sets `producer_handle` and `consumer_handle`.
// Returns true on success. Otherwise returns false and reset the handles.
bool CreateDataPipe(uint32_t capacity,
                    mojo::ScopedDataPipeProducerHandle* producer_handle,
                    mojo::ScopedDataPipeConsumerHandle* consumer_handle);

// Returns the default capacity to be used with MojoDecoderBufferReader and
// MojoDecoderBufferWriter for |type|.
uint32_t GetDefaultDecoderBufferConverterCapacity(DemuxerStream::Type type);

// Combines mojom::DecoderBuffers with data read from a DataPipe to produce
// media::DecoderBuffers (counterpart of MojoDecoderBufferWriter).
class MojoDecoderBufferReader { … };

// Converts media::DecoderBuffers to mojom::DecoderBuffers, writing the data
// part to a DataPipe (counterpart of MojoDecoderBufferReader).
//
// If necessary, writes to the DataPipe will be chunked to fit.
// MojoDecoderBufferWriter maintains an internal queue of buffers to enable
// this asynchronous process.
//
// On DataPipe closure, future calls to WriteDecoderBuffer() will return
// nullptr. There is no mechanism to determine which past writes were
// successful prior to the closure.
class MojoDecoderBufferWriter { … };

}  // namespace media

#endif  // MEDIA_MOJO_COMMON_MOJO_DECODER_BUFFER_CONVERTER_H_