blob: 0056269389290bcec15ae01cfe81af0cf3e59bb5 [file] [log] [blame]
// 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.
#include <deque>
#include <list>
#include <memory>
#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/audio_timestamp_helper.h"
#include "media/base/demuxer_stream.h"
#include "media/base/media_export.h"
#include "media/base/media_log.h"
#include "media/base/moving_average.h"
#include "media/base/pipeline_status.h"
#include "media/base/timestamp_constants.h"
#include "media/filters/decoder_selector.h"
#include "media/filters/decoder_stream_traits.h"
namespace base {
class SingleThreadTaskRunner;
namespace media {
class CdmContext;
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 {
typedef DecoderStreamTraits<StreamType> StreamTraits;
typedef typename StreamTraits::DecoderType Decoder;
typedef typename StreamTraits::OutputType Output;
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.
// Indicates completion of a DecoderStream initialization.
typedef base::Callback<void(bool success)> InitCB;
// Indicates completion of a DecoderStream read.
typedef base::Callback<void(Status, const scoped_refptr<Output>&)> ReadCB;
const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
ScopedVector<Decoder> decoders,
const scoped_refptr<MediaLog>& media_log);
virtual ~DecoderStream();
// Returns the string representation of the StreamType for logging purpose.
std::string GetStreamTypeString();
// Initializes the DecoderStream and returns the initialization result
// through |init_cb|. Note that |init_cb| is always called asynchronously.
// |cdm_context| can be used to handle encrypted stream. Can be null if the
// stream is not encrypted.
void Initialize(DemuxerStream* stream,
const InitCB& init_cb,
CdmContext* cdm_context,
const StatisticsCB& statistics_cb,
const base::Closure& waiting_for_decryption_key_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
// pending Reset().
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 pending Reset().
// N.B: If the decoder stream has run into an error, calling this method does
// not 'reset' it to a normal state.
void Reset(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;
// Returns maximum concurrent decode requests for the current |decoder_|.
int GetMaxDecodeRequests() const;
// Returns true if one more decode request can be submitted to the decoder.
bool CanDecodeMore() const;
base::TimeDelta AverageDuration() const;
// Allows callers to register for notification of config changes; this is
// called immediately after receiving 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;
const Decoder* get_previous_decoder_for_testing() const {
return previous_decoder_.get();
int get_pending_buffers_size_for_testing() const {
return pending_buffers_.size();
int get_fallback_buffers_size_for_testing() const {
return fallback_buffers_.size();
enum State {
STATE_NORMAL, // Includes idle, pending decoder decode/reset.
STATE_END_OF_STREAM, // End of stream reached; returns EOS on all reads.
void SelectDecoder();
// 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(
std::unique_ptr<Decoder> selected_decoder,
std::unique_ptr<DecryptingDemuxerStream> decrypting_demuxer_stream);
// Satisfy pending |read_cb_| with |status| and |output|.
void SatisfyRead(Status status,
const scoped_refptr<Output>& output);
// Decodes |buffer| and returns the result via OnDecodeOutputReady().
// Saves |buffer| into |pending_buffers_| if appropriate.
void Decode(const scoped_refptr<DecoderBuffer>& buffer);
// Performs the heavy lifting of the decode call.
void DecodeInternal(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 OnDecodeDone(int buffer_size, bool end_of_stream, DecodeStatus status);
// Output callback passed to Decoder::Initialize().
void OnDecodeOutputReady(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(bool success);
void CompleteDecoderReinitialization(bool success);
void ResetDecoder();
void OnDecoderReset();
DecoderStreamTraits<StreamType> traits_;
scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
scoped_refptr<MediaLog> media_log_;
State state_;
StatisticsCB statistics_cb_;
InitCB init_cb_;
base::Closure waiting_for_decryption_key_cb_;
ReadCB read_cb_;
base::Closure reset_cb_;
DemuxerStream* stream_;
CdmContext* cdm_context_;
std::unique_ptr<DecoderSelector<StreamType>> decoder_selector_;
std::unique_ptr<Decoder> decoder_;
// When falling back from H/W decoding to S/W decoding, destructing the
// GpuVideoDecoder too early results in black frames being displayed.
// |previous_decoder_| is used to keep it alive. It is destroyed once we've
// decoded at least media::limits::kMaxVideoFrames frames after fallback.
int decoded_frames_since_fallback_;
std::unique_ptr<Decoder> previous_decoder_;
std::unique_ptr<DecryptingDemuxerStream> decrypting_demuxer_stream_;
ConfigChangeObserverCB config_change_observer_cb_;
// An end-of-stream buffer has been sent for decoding, no more buffers should
// be sent for decoding until it completes.
// TODO(sandersd): Turn this into a State.
bool decoding_eos_;
// Decoded buffers that haven't been read yet. Used when the decoder supports
// parallel decoding.
std::list<scoped_refptr<Output> > ready_outputs_;
// Number of outstanding decode requests sent to the |decoder_|.
int pending_decode_requests_;
// Tracks the duration of incoming packets over time.
MovingAverage duration_tracker_;
// Stores buffers that might be reused if the decoder fails right after
// Initialize().
std::deque<scoped_refptr<DecoderBuffer>> pending_buffers_;
// Stores buffers that are guaranteed to be fed to the decoder before fetching
// more from the demuxer stream. All buffers in this queue first were in
// |pending_buffers_|.
std::deque<scoped_refptr<DecoderBuffer>> fallback_buffers_;
// TODO(tguilbert): support config changes during decoder fallback, see
bool received_config_change_during_reinit_;
// Used to track read requests; not rolled into |state_| since that is
// overwritten in many cases.
bool pending_demuxer_read_;
// NOTE: Weak pointers must be invalidated before all other member variables.
base::WeakPtrFactory<DecoderStream<StreamType>> weak_factory_;
// Used to invalidate pending decode requests and output callbacks when
// falling back to a new decoder (on first decode error).
base::WeakPtrFactory<DecoderStream<StreamType>> fallback_weak_factory_;
template <>
bool DecoderStream<DemuxerStream::AUDIO>::CanReadWithoutStalling() const;
template <>
int DecoderStream<DemuxerStream::AUDIO>::GetMaxDecodeRequests() const;
typedef DecoderStream<DemuxerStream::VIDEO> VideoFrameStream;
typedef DecoderStream<DemuxerStream::AUDIO> AudioBufferStream;
} // namespace media