// Copyright 2014 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_DECODER_STREAM_H_
#define MEDIA_FILTERS_DECODER_STREAM_H_
#include "base/basictypes.h"
#include "base/callback.h"
#include "base/compiler_specific.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_vector.h"
#include "base/memory/weak_ptr.h"
#include "media/base/audio_decoder.h"
#include "media/base/decryptor.h"
#include "media/base/demuxer_stream.h"
#include "media/base/media_export.h"
#include "media/base/pipeline_status.h"
#include "media/filters/decoder_selector.h"
#include "media/filters/decoder_stream_traits.h"
namespace base {
class SingleThreadTaskRunner;
}
namespace media {
class DecryptingDemuxerStream;
// Wraps a DemuxerStream and a list of Decoders and provides decoded
// output to its client (e.g. Audio/VideoRendererImpl).
template<DemuxerStream::Type StreamType>
class MEDIA_EXPORT DecoderStream {
public:
typedef DecoderStreamTraits<StreamType> StreamTraits;
typedef typename StreamTraits::DecoderType Decoder;
typedef typename StreamTraits::OutputType Output;
typedef typename StreamTraits::StreamInitCB InitCB;
typedef typename Decoder::Status DecoderStatus;
enum Status {
OK, // Everything went as planned.
ABORTED, // Read aborted due to Reset() during pending read.
DEMUXER_READ_ABORTED, // Demuxer returned aborted read.
DECODE_ERROR, // Decoder returned decode error.
DECRYPT_ERROR // Decoder returned decrypt error.
};
// Indicates completion of a DecoderStream read.
typedef base::Callback<void(Status, const scoped_refptr<Output>&)> ReadCB;
DecoderStream(
const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
ScopedVector<Decoder> decoders,
const SetDecryptorReadyCB& set_decryptor_ready_cb);
virtual ~DecoderStream();
// Initializes the DecoderStream and returns the initialization result
// through |init_cb|. Note that |init_cb| is always called asynchronously.
void Initialize(DemuxerStream* stream,
const StatisticsCB& statistics_cb,
const InitCB& init_cb);
// Reads a decoded Output and returns it via the |read_cb|. Note that
// |read_cb| is always called asynchronously. This method should only be
// called after initialization has succeeded and must not be called during
// any pending Reset() and/or Stop().
void Read(const ReadCB& read_cb);
// Resets the decoder, flushes all decoded outputs and/or internal buffers,
// fires any existing pending read callback and calls |closure| on completion.
// Note that |closure| is always called asynchronously. This method should
// only be called after initialization has succeeded and must not be called
// during any pending Reset() and/or Stop().
void Reset(const base::Closure& closure);
// Stops the decoder, fires any existing pending read callback or reset
// callback and calls |closure| on completion. Note that |closure| is always
// called asynchronously. The DecoderStream cannot be used anymore after
// it is stopped. This method can be called at any time but not during another
// pending Stop().
void Stop(const base::Closure& closure);
// Returns true if the decoder currently has the ability to decode and return
// an Output.
// TODO(rileya): Remove the need for this by refactoring Decoder queueing
// behavior.
bool CanReadWithoutStalling() const;
// Allows callers to register for notification of splice buffers from the
// demuxer. I.e., DecoderBuffer::splice_timestamp() is not kNoTimestamp().
typedef base::Callback<void(base::TimeDelta)> SpliceObserverCB;
void set_splice_observer(const SpliceObserverCB& splice_observer) {
splice_observer_cb_ = splice_observer;
}
// Allows callers to register for notification of config changes; this is
// called immediately after recieving the 'kConfigChanged' status from the
// DemuxerStream, before any action is taken to handle the config change.
typedef base::Closure ConfigChangeObserverCB;
void set_config_change_observer(
const ConfigChangeObserverCB& config_change_observer) {
config_change_observer_cb_ = config_change_observer;
}
private:
enum State {
STATE_UNINITIALIZED,
STATE_INITIALIZING,
STATE_NORMAL, // Includes idle, pending decoder decode/reset/stop.
STATE_FLUSHING_DECODER,
STATE_PENDING_DEMUXER_READ,
STATE_REINITIALIZING_DECODER,
STATE_STOPPED,
STATE_ERROR
};
// Called when |decoder_selector| selected the |selected_decoder|.
// |decrypting_demuxer_stream| was also populated if a DecryptingDemuxerStream
// is created to help decrypt the encrypted stream.
void OnDecoderSelected(
scoped_ptr<Decoder> selected_decoder,
scoped_ptr<DecryptingDemuxerStream> decrypting_demuxer_stream);
// Satisfy pending |read_cb_| with |status| and |output|.
void SatisfyRead(Status status,
const scoped_refptr<Output>& output);
// Abort pending |read_cb_|.
void AbortRead();
// Decodes |buffer| and returns the result via OnDecodeOutputReady().
void Decode(const scoped_refptr<DecoderBuffer>& buffer);
// Flushes the decoder with an EOS buffer to retrieve internally buffered
// decoder output.
void FlushDecoder();
// Callback for Decoder::Decode().
void OnDecodeOutputReady(int buffer_size,
DecoderStatus status,
const scoped_refptr<Output>& output);
// Reads a buffer from |stream_| and returns the result via OnBufferReady().
void ReadFromDemuxerStream();
// Callback for DemuxerStream::Read().
void OnBufferReady(DemuxerStream::Status status,
const scoped_refptr<DecoderBuffer>& buffer);
void ReinitializeDecoder();
// Callback for Decoder reinitialization.
void OnDecoderReinitialized(PipelineStatus status);
void ResetDecoder();
void OnDecoderReset();
void StopDecoder();
scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
State state_;
StatisticsCB statistics_cb_;
InitCB init_cb_;
ReadCB read_cb_;
base::Closure reset_cb_;
base::Closure stop_cb_;
DemuxerStream* stream_;
scoped_ptr<DecoderSelector<StreamType> > decoder_selector_;
// These two will be set by DecoderSelector::SelectDecoder().
scoped_ptr<Decoder> decoder_;
scoped_ptr<DecryptingDemuxerStream> decrypting_demuxer_stream_;
SpliceObserverCB splice_observer_cb_;
ConfigChangeObserverCB config_change_observer_cb_;
// NOTE: Weak pointers must be invalidated before all other member variables.
base::WeakPtrFactory<DecoderStream<StreamType> > weak_factory_;
// This is required so the VideoFrameStream can access private members in
// FinishInitialization() and ReportStatistics().
DISALLOW_IMPLICIT_CONSTRUCTORS(DecoderStream);
};
template <>
bool DecoderStream<DemuxerStream::AUDIO>::CanReadWithoutStalling() const;
typedef DecoderStream<DemuxerStream::VIDEO> VideoFrameStream;
typedef DecoderStream<DemuxerStream::AUDIO> AudioBufferStream;
} // namespace media
#endif // MEDIA_FILTERS_DECODER_STREAM_H_