media/filters/ffmpeg_demuxer.h

   1 // Copyright (c) 2012 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 // Implements the Demuxer interface using FFmpeg's libavformat.  At this time
   6 // will support demuxing any audio/video format thrown at it.  The streams
   7 // output mime types audio/x-ffmpeg and video/x-ffmpeg and include an integer
   8 // key FFmpegCodecID which contains the CodecID enumeration value.  The CodecIDs
   9 // can be used to create and initialize the corresponding FFmpeg decoder.
  10 //
  11 // FFmpegDemuxer sets the duration of pipeline during initialization by using
  12 // the duration of the longest audio/video stream.
  13 //
  14 // NOTE: since FFmpegDemuxer reads packets sequentially without seeking, media
  15 // files with very large drift between audio/video streams may result in
  16 // excessive memory consumption.
  17 //
  18 // When stopped, FFmpegDemuxer and FFmpegDemuxerStream release all callbacks
  19 // and buffered packets.  Reads from a stopped FFmpegDemuxerStream will not be
  20 // replied to.
  21
  22 #ifndef MEDIA_FILTERS_FFMPEG_DEMUXER_H_
  23 #define MEDIA_FILTERS_FFMPEG_DEMUXER_H_
  24
  25 #include <string>
  26 #include <vector>
  27
  28 #include "base/callback.h"
  29 #include "base/gtest_prod_util.h"
  30 #include "base/memory/scoped_vector.h"
  31 #include "base/threading/thread.h"
  32 #include "media/base/audio_decoder_config.h"
  33 #include "media/base/decoder_buffer.h"
  34 #include "media/base/decoder_buffer_queue.h"
  35 #include "media/base/demuxer.h"
  36 #include "media/base/pipeline.h"
  37 #include "media/base/text_track_config.h"
  38 #include "media/base/video_decoder_config.h"
  39 #include "media/ffmpeg/ffmpeg_deleters.h"
  40 #include "media/filters/blocking_url_protocol.h"
  41
  42 // FFmpeg forward declarations.
  43 struct AVPacket;
  44 struct AVRational;
  45 struct AVStream;
  46
  47 namespace media {
  48
  49 class MediaLog;
  50 class FFmpegDemuxer;
  51 class FFmpegGlue;
  52 class FFmpegH264ToAnnexBBitstreamConverter;
  53
  54 typedef scoped_ptr<AVPacket, ScopedPtrAVFreePacket> ScopedAVPacket;
  55
  56 class FFmpegDemuxerStream : public DemuxerStream {
  57  public:
  58   // Keeps a copy of |demuxer| and initializes itself using information
  59   // inside |stream|.  Both parameters must outlive |this|.
  60   FFmpegDemuxerStream(FFmpegDemuxer* demuxer, AVStream* stream);
  61   virtual ~FFmpegDemuxerStream();
  62
  63   // Enqueues the given AVPacket. It is invalid to queue a |packet| after
  64   // SetEndOfStream() has been called.
  65   void EnqueuePacket(ScopedAVPacket packet);
  66
  67   // Enters the end of stream state. After delivering remaining queued buffers
  68   // only end of stream buffers will be delivered.
  69   void SetEndOfStream();
  70
  71   // Drops queued buffers and clears end of stream state.
  72   void FlushBuffers();
  73
  74   // Empties the queues and ignores any additional calls to Read().
  75   void Stop();
  76
  77   // Returns the duration of this stream.
  78   base::TimeDelta duration();
  79
  80   // DemuxerStream implementation.
  81   virtual Type type() OVERRIDE;
  82   virtual void Read(const ReadCB& read_cb) OVERRIDE;
  83   virtual void EnableBitstreamConverter() OVERRIDE;
  84   virtual bool SupportsConfigChanges() OVERRIDE;
  85   virtual AudioDecoderConfig audio_decoder_config() OVERRIDE;
  86   virtual VideoDecoderConfig video_decoder_config() OVERRIDE;
  87
  88   // Returns the range of buffered data in this stream.
  89   Ranges<base::TimeDelta> GetBufferedRanges() const;
  90
  91   // Returns elapsed time based on the already queued packets.
  92   // Used to determine stream duration when it's not known ahead of time.
  93   base::TimeDelta GetElapsedTime() const;
  94
  95   // Returns true if this stream has capacity for additional data.
  96   bool HasAvailableCapacity();
  97
  98   // Returns the total buffer size FFMpegDemuxerStream is holding onto.
  99   size_t MemoryUsage() const;
 100
 101   TextKind GetTextKind() const;
 102
 103   // Returns the value associated with |key| in the metadata for the avstream.
 104   // Returns an empty string if the key is not present.
 105   std::string GetMetadata(const char* key) const;
 106
 107  private:
 108   friend class FFmpegDemuxerTest;
 109
 110   // Runs |read_cb_| if present with the front of |buffer_queue_|, calling
 111   // NotifyCapacityAvailable() if capacity is still available.
 112   void SatisfyPendingRead();
 113
 114   // Converts an FFmpeg stream timestamp into a base::TimeDelta.
 115   static base::TimeDelta ConvertStreamTimestamp(const AVRational& time_base,
 116                                                 int64 timestamp);
 117
 118   FFmpegDemuxer* demuxer_;
 119   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 120   AVStream* stream_;
 121   AudioDecoderConfig audio_config_;
 122   VideoDecoderConfig video_config_;
 123   Type type_;
 124   base::TimeDelta duration_;
 125   bool end_of_stream_;
 126   base::TimeDelta last_packet_timestamp_;
 127   Ranges<base::TimeDelta> buffered_ranges_;
 128
 129   DecoderBufferQueue buffer_queue_;
 130   ReadCB read_cb_;
 131
 132 #if defined(USE_PROPRIETARY_CODECS)
 133   scoped_ptr<FFmpegH264ToAnnexBBitstreamConverter> bitstream_converter_;
 134 #endif
 135
 136   bool bitstream_converter_enabled_;
 137
 138   std::string encryption_key_id_;
 139
 140   DISALLOW_COPY_AND_ASSIGN(FFmpegDemuxerStream);
 141 };
 142
 143 class MEDIA_EXPORT FFmpegDemuxer : public Demuxer {
 144  public:
 145   FFmpegDemuxer(const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
 146                 DataSource* data_source,
 147                 const NeedKeyCB& need_key_cb,
 148                 const scoped_refptr<MediaLog>& media_log);
 149   virtual ~FFmpegDemuxer();
 150
 151   // Demuxer implementation.
 152   virtual void Initialize(DemuxerHost* host,
 153                           const PipelineStatusCB& status_cb,
 154                           bool enable_text_tracks) OVERRIDE;
 155   virtual void Stop(const base::Closure& callback) OVERRIDE;
 156   virtual void Seek(base::TimeDelta time, const PipelineStatusCB& cb) OVERRIDE;
 157   virtual void OnAudioRendererDisabled() OVERRIDE;
 158   virtual DemuxerStream* GetStream(DemuxerStream::Type type) OVERRIDE;
 159   virtual base::TimeDelta GetStartTime() const OVERRIDE;
 160   virtual base::Time GetTimelineOffset() const OVERRIDE;
 161   virtual Liveness GetLiveness() const OVERRIDE;
 162
 163   // Calls |need_key_cb_| with the initialization data encountered in the file.
 164   void FireNeedKey(const std::string& init_data_type,
 165                    const std::string& encryption_key_id);
 166
 167   // Allow FFmpegDemuxerStream to notify us when there is updated information
 168   // about capacity and what buffered data is available.
 169   void NotifyCapacityAvailable();
 170   void NotifyBufferingChanged();
 171
 172  private:
 173   // To allow tests access to privates.
 174   friend class FFmpegDemuxerTest;
 175
 176   // FFmpeg callbacks during initialization.
 177   void OnOpenContextDone(const PipelineStatusCB& status_cb, bool result);
 178   void OnFindStreamInfoDone(const PipelineStatusCB& status_cb, int result);
 179
 180   // FFmpeg callbacks during seeking.
 181   void OnSeekFrameDone(const PipelineStatusCB& cb, int result);
 182
 183   // FFmpeg callbacks during reading + helper method to initiate reads.
 184   void ReadFrameIfNeeded();
 185   void OnReadFrameDone(ScopedAVPacket packet, int result);
 186
 187   // DataSource callbacks during stopping.
 188   void OnDataSourceStopped(const base::Closure& callback);
 189
 190   // Returns true iff any stream has additional capacity. Note that streams can
 191   // go over capacity depending on how the file is muxed.
 192   bool StreamsHaveAvailableCapacity();
 193
 194   // Returns true if the maximum allowed memory usage has been reached.
 195   bool IsMaxMemoryUsageReached() const;
 196
 197   // Signal all FFmpegDemuxerStreams that the stream has ended.
 198   void StreamHasEnded();
 199
 200   // Called by |url_protocol_| whenever |data_source_| returns a read error.
 201   void OnDataSourceError();
 202
 203   // Returns the stream from |streams_| that matches |type| as an
 204   // FFmpegDemuxerStream.
 205   FFmpegDemuxerStream* GetFFmpegStream(DemuxerStream::Type type) const;
 206
 207   // Called after the streams have been collected from the media, to allow
 208   // the text renderer to bind each text stream to the cue rendering engine.
 209   void AddTextStreams();
 210
 211   DemuxerHost* host_;
 212
 213   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 214
 215   // Thread on which all blocking FFmpeg operations are executed.
 216   base::Thread blocking_thread_;
 217
 218   // Tracks if there's an outstanding av_read_frame() operation.
 219   //
 220   // TODO(scherkus): Allow more than one read in flight for higher read
 221   // throughput using demuxer_bench to verify improvements.
 222   bool pending_read_;
 223
 224   // Tracks if there's an outstanding av_seek_frame() operation. Used to discard
 225   // results of pre-seek av_read_frame() operations.
 226   bool pending_seek_;
 227
 228   // |streams_| mirrors the AVStream array in |format_context_|. It contains
 229   // FFmpegDemuxerStreams encapsluating AVStream objects at the same index.
 230   //
 231   // Since we only support a single audio and video stream, |streams_| will
 232   // contain NULL entries for additional audio/video streams as well as for
 233   // stream types that we do not currently support.
 234   //
 235   // Once initialized, operations on FFmpegDemuxerStreams should be carried out
 236   // on the demuxer thread.
 237   typedef ScopedVector<FFmpegDemuxerStream> StreamVector;
 238   StreamVector streams_;
 239
 240   // Provides asynchronous IO to this demuxer. Consumed by |url_protocol_| to
 241   // integrate with libavformat.
 242   DataSource* data_source_;
 243
 244   scoped_refptr<MediaLog> media_log_;
 245
 246   // Derived bitrate after initialization has completed.
 247   int bitrate_;
 248
 249   // The first timestamp of the opened media file. This is used to set the
 250   // starting clock value to match the timestamps in the media file. Default
 251   // is 0.
 252   base::TimeDelta start_time_;
 253
 254   // The Time associated with timestamp 0. Set to a null
 255   // time if the file doesn't have an association to Time.
 256   base::Time timeline_offset_;
 257
 258   // Liveness of the stream.
 259   Liveness liveness_;
 260
 261   // Whether audio has been disabled for this demuxer (in which case this class
 262   // drops packets destined for AUDIO demuxer streams on the floor).
 263   bool audio_disabled_;
 264
 265   // Whether text streams have been enabled for this demuxer.
 266   bool text_enabled_;
 267
 268   // Set if we know duration of the audio stream. Used when processing end of
 269   // stream -- at this moment we definitely know duration.
 270   bool duration_known_;
 271
 272   // FFmpegURLProtocol implementation and corresponding glue bits.
 273   scoped_ptr<BlockingUrlProtocol> url_protocol_;
 274   scoped_ptr<FFmpegGlue> glue_;
 275
 276   const NeedKeyCB need_key_cb_;
 277
 278   // NOTE: Weak pointers must be invalidated before all other member variables.
 279   base::WeakPtrFactory<FFmpegDemuxer> weak_factory_;
 280
 281   DISALLOW_COPY_AND_ASSIGN(FFmpegDemuxer);
 282 };
 283
 284 }  // namespace media
 285
 286 #endif  // MEDIA_FILTERS_FFMPEG_DEMUXER_H_