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// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/basictypes.h"
#include "media/base/h264_bitstream_converter.h"
#include "media/filters/bitstream_converter.h"
// Forward declarations for FFmpeg datatypes used.
struct AVCodecContext;
struct AVPacket;
namespace media {
// FFmpegH264BitstreamConverter does the conversion on single NAL unit
// basis which is contained within the AVPacket given to ConvertPacket() member
// function with the exception of the first packet which is prepended with the
// AVC decoder configuration record information. For example:
// NAL unit #1 ==> bytestream buffer #1 (AVC configuraion + NAL unit #1)
// NAL unit #2 ==> bytestream buffer #2 (NAL unit #2)
// ...
// NAL unit #n ==> bytestream buffer #n (NAL unit #n)
// User of the object can append output into one bigger buffer by the client if
// efficiency reasons warrants the client to do so.
// FFmpegH264BitstreamConverter acts as an adapter for the H264 Bitstream
// converter class by implementing the BitstreamConverter interface expected
// by media pipeline streams demuxed by FFmpegDemuxer.
// FFmpegH264BitstreamConverter uses FFmpeg allocation methods for buffer
// allocation to ensure compatibility with FFmpeg's memory management.
class MEDIA_EXPORT FFmpegH264BitstreamConverter : public BitstreamConverter {
// The |stream_context| will be used during conversion and should be the
// AVCodecContext for the stream sourcing these packets. A reference to
// |stream_context| is retained, so it must outlive this class.
explicit FFmpegH264BitstreamConverter(AVCodecContext* stream_context);
virtual ~FFmpegH264BitstreamConverter();
// BitstreamConverter implementation
virtual bool Initialize();
virtual bool ConvertPacket(AVPacket* packet);
// Actual converter class.
H264BitstreamConverter converter_;
// Flag for indicating whether global parameter sets have been processed.
bool configuration_processed_;
// Variable to hold a pointer to memory where we can access the global
// data from the FFmpeg file format's global headers.
AVCodecContext* stream_context_;
} // namespace media