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                   const base::Closure& waiting_for_decryption_key_cb);
  66
  67   // Reads a decoded Output and returns it via the |read_cb|. Note that
  68   // |read_cb| is always called asynchronously. This method should only be
  69   // called after initialization has succeeded and must not be called during
  70   // pending Reset().
  71   void Read(const ReadCB& read_cb);
  72
  73   // Resets the decoder, flushes all decoded outputs and/or internal buffers,
  74   // fires any existing pending read callback and calls |closure| on completion.
  75   // Note that |closure| is always called asynchronously. This method should
  76   // only be called after initialization has succeeded and must not be called
  77   // during pending Reset().
  78   void Reset(const base::Closure& closure);
  79
  80   // Returns true if the decoder currently has the ability to decode and return
  81   // an Output.
  82   // TODO(rileya): Remove the need for this by refactoring Decoder queueing
  83   // behavior.
  84   bool CanReadWithoutStalling() const;
  85
  86   // Returns maximum concurrent decode requests for the current |decoder_|.
  87   int GetMaxDecodeRequests() const;
  88
  89   // Returns true if one more decode request can be submitted to the decoder.
  90   bool CanDecodeMore() const;
  91
  92   // Allows callers to register for notification of splice buffers from the
  93   // demuxer.  I.e., DecoderBuffer::splice_timestamp() is not kNoTimestamp().
  94   //
  95   // The observer will be notified of all buffers with a splice_timestamp() and
  96   // the first buffer after which has a splice_timestamp() of kNoTimestamp().
  97   typedef base::Callback<void(base::TimeDelta)> SpliceObserverCB;
  98   void set_splice_observer(const SpliceObserverCB& splice_observer) {
  99     splice_observer_cb_ = splice_observer;
 100   }
 101
 102   // Allows callers to register for notification of config changes; this is
 103   // called immediately after receiving the 'kConfigChanged' status from the
 104   // DemuxerStream, before any action is taken to handle the config change.
 105   typedef base::Closure ConfigChangeObserverCB;
 106   void set_config_change_observer(
 107       const ConfigChangeObserverCB& config_change_observer) {
 108     config_change_observer_cb_ = config_change_observer;
 109   }
 110
 111  private:
 112   enum State {
 113     STATE_UNINITIALIZED,
 114     STATE_INITIALIZING,
 115     STATE_NORMAL,  // Includes idle, pending decoder decode/reset.
 116     STATE_FLUSHING_DECODER,
 117     STATE_PENDING_DEMUXER_READ,
 118     STATE_REINITIALIZING_DECODER,
 119     STATE_END_OF_STREAM,  // End of stream reached; returns EOS on all reads.
 120     STATE_ERROR
 121   };
 122
 123   void SelectDecoder(const SetDecryptorReadyCB& set_decryptor_ready_cb);
 124
 125   // Called when |decoder_selector| selected the |selected_decoder|.
 126   // |decrypting_demuxer_stream| was also populated if a DecryptingDemuxerStream
 127   // is created to help decrypt the encrypted stream.
 128   void OnDecoderSelected(
 129       scoped_ptr<Decoder> selected_decoder,
 130       scoped_ptr<DecryptingDemuxerStream> decrypting_demuxer_stream);
 131
 132   // Satisfy pending |read_cb_| with |status| and |output|.
 133   void SatisfyRead(Status status,
 134                    const scoped_refptr<Output>& output);
 135
 136   // Decodes |buffer| and returns the result via OnDecodeOutputReady().
 137   void Decode(const scoped_refptr<DecoderBuffer>& buffer);
 138
 139   // Flushes the decoder with an EOS buffer to retrieve internally buffered
 140   // decoder output.
 141   void FlushDecoder();
 142
 143   // Callback for Decoder::Decode().
 144   void OnDecodeDone(int buffer_size, bool end_of_stream, DecoderStatus status);
 145
 146   // Output callback passed to Decoder::Initialize().
 147   void OnDecodeOutputReady(const scoped_refptr<Output>& output);
 148
 149   // Reads a buffer from |stream_| and returns the result via OnBufferReady().
 150   void ReadFromDemuxerStream();
 151
 152   // Callback for DemuxerStream::Read().
 153   void OnBufferReady(DemuxerStream::Status status,
 154                      const scoped_refptr<DecoderBuffer>& buffer);
 155
 156   void ReinitializeDecoder();
 157
 158   // Callback for Decoder reinitialization.
 159   void OnDecoderReinitialized(PipelineStatus status);
 160
 161   void CompleteDecoderReinitialization(bool success);
 162
 163   void ResetDecoder();
 164   void OnDecoderReset();
 165
 166   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 167
 168   scoped_refptr<MediaLog> media_log_;
 169
 170   State state_;
 171
 172   StatisticsCB statistics_cb_;
 173   InitCB init_cb_;
 174   base::Closure waiting_for_decryption_key_cb_;
 175
 176   ReadCB read_cb_;
 177   base::Closure reset_cb_;
 178
 179   DemuxerStream* stream_;
 180
 181   scoped_ptr<DecoderSelector<StreamType> > decoder_selector_;
 182
 183   scoped_ptr<Decoder> decoder_;
 184   // TODO(watk): When falling back from H/W decoding to S/W decoding,
 185   // destructing the GpuVideoDecoder too early results in black frames being
 186   // displayed. |previous_decoder_| is used to keep it alive.
 187   scoped_ptr<Decoder> previous_decoder_;
 188   scoped_ptr<DecryptingDemuxerStream> decrypting_demuxer_stream_;
 189
 190   SpliceObserverCB splice_observer_cb_;
 191   ConfigChangeObserverCB config_change_observer_cb_;
 192
 193   // If a splice_timestamp() has been seen, this is true until a
 194   // splice_timestamp() of kNoTimestamp() is encountered.
 195   bool active_splice_;
 196
 197   // An end-of-stream buffer has been sent for decoding, no more buffers should
 198   // be sent for decoding until it completes.
 199   // TODO(sandersd): Turn this into a State. http://crbug.com/408316
 200   bool decoding_eos_;
 201
 202   // Decoded buffers that haven't been read yet. Used when the decoder supports
 203   // parallel decoding.
 204   std::list<scoped_refptr<Output> > ready_outputs_;
 205
 206   // Number of outstanding decode requests sent to the |decoder_|.
 207   int pending_decode_requests_;
 208
 209   // NOTE: Weak pointers must be invalidated before all other member variables.
 210   base::WeakPtrFactory<DecoderStream<StreamType> > weak_factory_;
 211 };
 212
 213 template <>
 214 bool DecoderStream<DemuxerStream::AUDIO>::CanReadWithoutStalling() const;
 215
 216 template <>
 217 int DecoderStream<DemuxerStream::AUDIO>::GetMaxDecodeRequests() const;
 218
 219 typedef DecoderStream<DemuxerStream::VIDEO> VideoFrameStream;
 220 typedef DecoderStream<DemuxerStream::AUDIO> AudioBufferStream;
 221
 222 }  // namespace media
 223
 224 #endif  // MEDIA_FILTERS_DECODER_STREAM_H_