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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.
// Interface and some concrete classes for applying various transforms
// to AVPackets. FFmpegBitstreamConverter, in particular, can be used
// to apply FFmpeg bitstream filters to the incoming AVPacket to transcode
// the packet format.
#ifndef MEDIA_FILTERS_BITSTREAM_CONVERTER_H_
#define MEDIA_FILTERS_BITSTREAM_CONVERTER_H_
#include <string>
#include "base/basictypes.h"
#include "base/gtest_prod_util.h"
#include "media/base/media_export.h"
// FFmpeg types.
struct AVBitStreamFilterContext;
struct AVCodecContext;
struct AVPacket;
namespace media {
class MEDIA_EXPORT BitstreamConverter {
public:
BitstreamConverter() {}
virtual ~BitstreamConverter() {}
// Initialize does any preparations needed before doing the actual
// conversion.
virtual bool Initialize() = 0;
// Attemps to convert the AVPacket from one format to another, based on the
// specific type of BitstreamConverter that was instantiated. Output will be
// stored into the |packet|, but user should be aware that conversion can free
// and reallocate the input buffer, if it needs to do so to fit it in.
virtual bool ConvertPacket(AVPacket* packet) = 0;
private:
DISALLOW_COPY_AND_ASSIGN(BitstreamConverter);
};
class IdentityBitstreamConverter : public BitstreamConverter {
public:
IdentityBitstreamConverter() {}
virtual ~IdentityBitstreamConverter() {}
virtual bool Initialize();
virtual bool ConvertPacket(AVPacket* packet);
private:
DISALLOW_COPY_AND_ASSIGN(IdentityBitstreamConverter);
};
class MEDIA_EXPORT FFmpegBitstreamConverter : public BitstreamConverter {
public:
// Creates FFmpegBitstreamConverter based on the FFmpeg bistream filter
// corresponding to |filter_name|.
//
// 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.
FFmpegBitstreamConverter(const std::string& filter_name,
AVCodecContext* stream_context);
virtual ~FFmpegBitstreamConverter();
virtual bool Initialize();
virtual bool ConvertPacket(AVPacket* packet);
private:
std::string filter_name_;
AVBitStreamFilterContext* stream_filter_;
AVCodecContext* stream_context_;
DISALLOW_COPY_AND_ASSIGN(FFmpegBitstreamConverter);
};
} // namespace media
#endif // MEDIA_FILTERS_BITSTREAM_CONVERTER_H_