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