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// Copyright (c) 2012 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.
#ifndef MEDIA_FILTERS_FFMPEG_AUDIO_DECODER_H_
#define MEDIA_FILTERS_FFMPEG_AUDIO_DECODER_H_
#include <list>
#include <memory>
#include "base/callback.h"
#include "base/macros.h"
#include "base/sequence_checker.h"
#include "base/time/time.h"
#include "media/base/audio_buffer.h"
#include "media/base/audio_decoder.h"
#include "media/base/demuxer_stream.h"
#include "media/base/media_log.h"
#include "media/base/sample_format.h"
#include "media/ffmpeg/ffmpeg_deleters.h"
struct AVCodecContext;
struct AVFrame;
namespace base {
class SequencedTaskRunner;
}
namespace media {
class AudioDiscardHelper;
class DecoderBuffer;
class FFmpegDecodingLoop;
class MEDIA_EXPORT FFmpegAudioDecoder : public AudioDecoder {
public:
FFmpegAudioDecoder(
const scoped_refptr<base::SequencedTaskRunner>& task_runner,
MediaLog* media_log);
~FFmpegAudioDecoder() override;
// AudioDecoder implementation.
std::string GetDisplayName() const override;
void Initialize(const AudioDecoderConfig& config,
CdmContext* cdm_context,
InitCB init_cb,
const OutputCB& output_cb,
const WaitingCB& waiting_cb) override;
void Decode(scoped_refptr<DecoderBuffer> buffer, DecodeCB decode_cb) override;
void Reset(base::OnceClosure closure) override;
// Callback called from within FFmpeg to allocate a buffer based on the
// properties of |codec_context| and |frame|. See AVCodecContext.get_buffer2
// documentation inside FFmpeg.
int GetAudioBuffer(struct AVCodecContext* s, AVFrame* frame, int flags);
private:
// There are four states the decoder can be in:
//
// - kUninitialized: The decoder is not initialized.
// - kNormal: This is the normal state. The decoder is idle and ready to
// decode input buffers, or is decoding an input buffer.
// - kDecodeFinished: EOS buffer received, codec flushed and decode finished.
// No further Decode() call should be made.
// - kError: Unexpected error happened.
//
// These are the possible state transitions.
//
// kUninitialized -> kNormal:
// The decoder is successfully initialized and is ready to decode buffers.
// kNormal -> kDecodeFinished:
// When buffer->end_of_stream() is true.
// kNormal -> kError:
// A decoding error occurs and decoding needs to stop.
// (any state) -> kNormal:
// Any time Reset() is called.
enum DecoderState {
kUninitialized,
kNormal,
kDecodeFinished,
kError
};
// Reset decoder and call |reset_cb_|.
void DoReset();
// Handles decoding an unencrypted encoded buffer.
void DecodeBuffer(const DecoderBuffer& buffer, DecodeCB decode_cb);
bool FFmpegDecode(const DecoderBuffer& buffer);
bool OnNewFrame(const DecoderBuffer& buffer,
bool* decoded_frame_this_loop,
AVFrame* frame);
// Handles (re-)initializing the decoder with a (new) config.
// Returns true if initialization was successful.
bool ConfigureDecoder(const AudioDecoderConfig& config);
// Releases resources associated with |codec_context_| .
void ReleaseFFmpegResources();
void ResetTimestampState(const AudioDecoderConfig& config);
scoped_refptr<base::SequencedTaskRunner> task_runner_;
SEQUENCE_CHECKER(sequence_checker_);
OutputCB output_cb_;
DecoderState state_;
// FFmpeg structures owned by this object.
std::unique_ptr<AVCodecContext, ScopedPtrAVFreeContext> codec_context_;
AudioDecoderConfig config_;
// AVSampleFormat initially requested; not Chrome's SampleFormat.
int av_sample_format_;
std::unique_ptr<AudioDiscardHelper> discard_helper_;
MediaLog* media_log_;
scoped_refptr<AudioBufferMemoryPool> pool_;
std::unique_ptr<FFmpegDecodingLoop> decoding_loop_;
DISALLOW_IMPLICIT_CONSTRUCTORS(FFmpegAudioDecoder);
};
} // namespace media
#endif // MEDIA_FILTERS_FFMPEG_AUDIO_DECODER_H_
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