media/filters/decoder_stream.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef MEDIA_FILTERS_DECODER_STREAM_H_
   6 #define MEDIA_FILTERS_DECODER_STREAM_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/callback.h"
  10 #include "base/compiler_specific.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/scoped_vector.h"
  13 #include "base/memory/weak_ptr.h"
  14 #include "media/base/audio_decoder.h"
  15 #include "media/base/decryptor.h"
  16 #include "media/base/demuxer_stream.h"
  17 #include "media/base/media_export.h"
  18 #include "media/base/media_log.h"
  19 #include "media/base/pipeline_status.h"
  20 #include "media/filters/decoder_selector.h"
  21 #include "media/filters/decoder_stream_traits.h"
  22
  23 namespace base {
  24 class SingleThreadTaskRunner;
  25 }
  26
  27 namespace media {
  28
  29 class DecryptingDemuxerStream;
  30
  31 // Wraps a DemuxerStream and a list of Decoders and provides decoded
  32 // output to its client (e.g. Audio/VideoRendererImpl).
  33 template<DemuxerStream::Type StreamType>
  34 class MEDIA_EXPORT DecoderStream {
  35  public:
  36   typedef DecoderStreamTraits<StreamType> StreamTraits;
  37   typedef typename StreamTraits::DecoderType Decoder;
  38   typedef typename StreamTraits::OutputType Output;
  39   typedef typename Decoder::Status DecoderStatus;
  40
  41   enum Status {
  42     OK,  // Everything went as planned.
  43     ABORTED,  // Read aborted due to Reset() during pending read.
  44     DEMUXER_READ_ABORTED,  // Demuxer returned aborted read.
  45     DECODE_ERROR,  // Decoder returned decode error.
  46   };
  47
  48   // Indicates completion of a DecoderStream initialization.
  49   typedef base::Callback<void(bool success)> InitCB;
  50
  51   // Indicates completion of a DecoderStream read.
  52   typedef base::Callback<void(Status, const scoped_refptr<Output>&)> ReadCB;
  53
  54   DecoderStream(
  55       const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
  56       ScopedVector<Decoder> decoders,
  57       const scoped_refptr<MediaLog>& media_log);
  58   virtual ~DecoderStream();
  59
  60   // Returns the string representation of the StreamType for logging purpose.
  61   std::string GetStreamTypeString();
  62
  63   // Initializes the DecoderStream and returns the initialization result
  64   // through |init_cb|. Note that |init_cb| is always called asynchronously.
  65   void Initialize(DemuxerStream* stream,
  66                   const InitCB& init_cb,
  67                   const SetDecryptorReadyCB& set_decryptor_ready_cb,
  68                   const StatisticsCB& statistics_cb,
  69                   const base::Closure& waiting_for_decryption_key_cb);
  70
  71   // Reads a decoded Output and returns it via the |read_cb|. Note that
  72   // |read_cb| is always called asynchronously. This method should only be
  73   // called after initialization has succeeded and must not be called during
  74   // pending Reset().
  75   void Read(const ReadCB& read_cb);
  76
  77   // Resets the decoder, flushes all decoded outputs and/or internal buffers,
  78   // fires any existing pending read callback and calls |closure| on completion.
  79   // Note that |closure| is always called asynchronously. This method should
  80   // only be called after initialization has succeeded and must not be called
  81   // during pending Reset().
  82   void Reset(const base::Closure& closure);
  83
  84   // Returns true if the decoder currently has the ability to decode and return
  85   // an Output.
  86   // TODO(rileya): Remove the need for this by refactoring Decoder queueing
  87   // behavior.
  88   bool CanReadWithoutStalling() const;
  89
  90   // Returns maximum concurrent decode requests for the current |decoder_|.
  91   int GetMaxDecodeRequests() const;
  92
  93   // Returns true if one more decode request can be submitted to the decoder.
  94   bool CanDecodeMore() const;
  95
  96   // Allows callers to register for notification of splice buffers from the
  97   // demuxer.  I.e., DecoderBuffer::splice_timestamp() is not kNoTimestamp().
  98   //
  99   // The observer will be notified of all buffers with a splice_timestamp() and
 100   // the first buffer after which has a splice_timestamp() of kNoTimestamp().
 101   typedef base::Callback<void(base::TimeDelta)> SpliceObserverCB;
 102   void set_splice_observer(const SpliceObserverCB& splice_observer) {
 103     splice_observer_cb_ = splice_observer;
 104   }
 105
 106   // Allows callers to register for notification of config changes; this is
 107   // called immediately after receiving the 'kConfigChanged' status from the
 108   // DemuxerStream, before any action is taken to handle the config change.
 109   typedef base::Closure ConfigChangeObserverCB;
 110   void set_config_change_observer(
 111       const ConfigChangeObserverCB& config_change_observer) {
 112     config_change_observer_cb_ = config_change_observer;
 113   }
 114
 115  private:
 116   enum State {
 117     STATE_UNINITIALIZED,
 118     STATE_INITIALIZING,
 119     STATE_NORMAL,  // Includes idle, pending decoder decode/reset.
 120     STATE_FLUSHING_DECODER,
 121     STATE_PENDING_DEMUXER_READ,
 122     STATE_REINITIALIZING_DECODER,
 123     STATE_END_OF_STREAM,  // End of stream reached; returns EOS on all reads.
 124     STATE_ERROR
 125   };
 126
 127   void SelectDecoder(const SetDecryptorReadyCB& set_decryptor_ready_cb);
 128
 129   // Called when |decoder_selector| selected the |selected_decoder|.
 130   // |decrypting_demuxer_stream| was also populated if a DecryptingDemuxerStream
 131   // is created to help decrypt the encrypted stream.
 132   void OnDecoderSelected(
 133       scoped_ptr<Decoder> selected_decoder,
 134       scoped_ptr<DecryptingDemuxerStream> decrypting_demuxer_stream);
 135
 136   // Satisfy pending |read_cb_| with |status| and |output|.
 137   void SatisfyRead(Status status,
 138                    const scoped_refptr<Output>& output);
 139
 140   // Decodes |buffer| and returns the result via OnDecodeOutputReady().
 141   void Decode(const scoped_refptr<DecoderBuffer>& buffer);
 142
 143   // Flushes the decoder with an EOS buffer to retrieve internally buffered
 144   // decoder output.
 145   void FlushDecoder();
 146
 147   // Callback for Decoder::Decode().
 148   void OnDecodeDone(int buffer_size, bool end_of_stream, DecoderStatus status);
 149
 150   // Output callback passed to Decoder::Initialize().
 151   void OnDecodeOutputReady(const scoped_refptr<Output>& output);
 152
 153   // Reads a buffer from |stream_| and returns the result via OnBufferReady().
 154   void ReadFromDemuxerStream();
 155
 156   // Callback for DemuxerStream::Read().
 157   void OnBufferReady(DemuxerStream::Status status,
 158                      const scoped_refptr<DecoderBuffer>& buffer);
 159
 160   void ReinitializeDecoder();
 161
 162   // Callback for Decoder reinitialization.
 163   void OnDecoderReinitialized(bool success);
 164
 165   void CompleteDecoderReinitialization(bool success);
 166
 167   void ResetDecoder();
 168   void OnDecoderReset();
 169
 170   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 171
 172   scoped_refptr<MediaLog> media_log_;
 173
 174   State state_;
 175
 176   StatisticsCB statistics_cb_;
 177   InitCB init_cb_;
 178   base::Closure waiting_for_decryption_key_cb_;
 179
 180   ReadCB read_cb_;
 181   base::Closure reset_cb_;
 182
 183   DemuxerStream* stream_;
 184
 185   scoped_ptr<DecoderSelector<StreamType> > decoder_selector_;
 186
 187   scoped_ptr<Decoder> decoder_;
 188   // TODO(watk): When falling back from H/W decoding to S/W decoding,
 189   // destructing the GpuVideoDecoder too early results in black frames being
 190   // displayed. |previous_decoder_| is used to keep it alive.
 191   scoped_ptr<Decoder> previous_decoder_;
 192   scoped_ptr<DecryptingDemuxerStream> decrypting_demuxer_stream_;
 193
 194   SpliceObserverCB splice_observer_cb_;
 195   ConfigChangeObserverCB config_change_observer_cb_;
 196
 197   // If a splice_timestamp() has been seen, this is true until a
 198   // splice_timestamp() of kNoTimestamp() is encountered.
 199   bool active_splice_;
 200
 201   // An end-of-stream buffer has been sent for decoding, no more buffers should
 202   // be sent for decoding until it completes.
 203   // TODO(sandersd): Turn this into a State. http://crbug.com/408316
 204   bool decoding_eos_;
 205
 206   // Decoded buffers that haven't been read yet. Used when the decoder supports
 207   // parallel decoding.
 208   std::list<scoped_refptr<Output> > ready_outputs_;
 209
 210   // Number of outstanding decode requests sent to the |decoder_|.
 211   int pending_decode_requests_;
 212
 213   // NOTE: Weak pointers must be invalidated before all other member variables.
 214   base::WeakPtrFactory<DecoderStream<StreamType> > weak_factory_;
 215 };
 216
 217 template <>
 218 bool DecoderStream<DemuxerStream::AUDIO>::CanReadWithoutStalling() const;
 219
 220 template <>
 221 int DecoderStream<DemuxerStream::AUDIO>::GetMaxDecodeRequests() const;
 222
 223 typedef DecoderStream<DemuxerStream::VIDEO> VideoFrameStream;
 224 typedef DecoderStream<DemuxerStream::AUDIO> AudioBufferStream;
 225
 226 }  // namespace media
 227
 228 #endif  // MEDIA_FILTERS_DECODER_STREAM_H_