Checking in media::FFmpegDemuxer and tests.

media/filters/ffmpeg_demuxer.h

+// Copyright (c) 2009 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.
+
+// Implements the Demuxer interface using FFmpeg's libavformat.  At this time
+// will support demuxing any audio/video format thrown at it.  The streams
+// output mime types audio/x-ffmpeg and video/x-ffmpeg and include an integer
+// key FFmpegCodecID which contains the CodecID enumeration value.  The CodecIDs
+// can be used to create and initialize the corresponding FFmpeg decoder.
+//
+// FFmpegDemuxer sets the duration of pipeline during initialization by using
+// the duration of the longest audio/video stream.
+//
+// NOTE: since FFmpegDemuxer reads packets sequentially without seeking, media
+// files with very large drift between audio/video streams may result in
+// excessive memory consumption.
+
+#ifndef MEDIA_FILTERS_FFMPEG_DEMUXER_H_
+#define MEDIA_FILTERS_FFMPEG_DEMUXER_H_
+
+#include <deque>
+#include <vector>
+
+#include "base/lock.h"
+#include "media/base/buffers.h"
+#include "media/base/factory.h"
+#include "media/base/filters.h"
+#include "media/base/media_format.h"
+
+// FFmpeg forward declarations.
+struct AVCodecContext;
+struct AVBitStreamFilterContext;
+struct AVFormatContext;
+struct AVPacket;
+struct AVStream;
+enum CodecID;
+
+namespace media {
+
+class FFmpegDemuxer;
+
+class FFmpegDemuxerStream : public DemuxerStream {
+ public:
+  // Maintains a reference to |demuxer| and initializes itself using information
+  // inside |stream|.
+  FFmpegDemuxerStream(FFmpegDemuxer* demuxer, const AVStream& stream);
+
+  virtual ~FFmpegDemuxerStream();
+
+  // Returns true is this stream has pending reads, false otherwise.
+  bool HasPendingReads();
+
+  // Enqueues and takes ownership over the given AVPacket.
+  void EnqueuePacket(AVPacket* packet);
+
+  // Returns the duration of this stream.
+  base::TimeDelta duration() { return duration_; }
+
+  // DemuxerStream implementation.
+  virtual const MediaFormat* GetMediaFormat();
+  virtual void Read(Assignable<Buffer>* buffer);
+
+ private:
+  // Returns true if there are still pending reads.
+  bool FulfillPendingReads();
+
+  FFmpegDemuxer* demuxer_;
+  MediaFormat media_format_;
+  base::TimeDelta time_base_;
+  base::TimeDelta duration_;
+  Lock lock_;
+
+  typedef std::deque< scoped_refptr<Buffer> > InputQueue;
+  InputQueue input_queue_;
+
+  typedef std::deque< scoped_refptr< Assignable<Buffer> > > OutputQueue;
+  OutputQueue output_queue_;
+
+  DISALLOW_COPY_AND_ASSIGN(FFmpegDemuxerStream);
+};
+
+class FFmpegDemuxer : public Demuxer {
+ public:
+  // FilterFactory provider.
+  static FilterFactory* CreateFilterFactory() {
+    return new FilterFactoryImpl0<FFmpegDemuxer>();
+  }
+
+  // Called by FFmpegDemuxerStreams to schedule a Demux() task.
+  void ScheduleDemux();
+
+  // MediaFilter implementation.
+  virtual void Stop();
+
+  // Demuxer implementation.
+  virtual bool Initialize(DataSource* data_source);
+  virtual size_t GetNumberOfStreams();
+  virtual DemuxerStream* GetStream(int stream_id);
+
+ private:
+  // Only allow a factory to create this class.
+  friend class FilterFactoryImpl0<FFmpegDemuxer>;
+  FFmpegDemuxer();
+  virtual ~FFmpegDemuxer();
+
+  // Demuxing task scheduled by streams.
+  void Demux();
+
+  // Returns true if any of the streams have pending reads.
+  bool StreamsHavePendingReads();
+
+  // Flag to prevent multiple Demux() tasks from being scheduled.
+  bool demuxing_;
+
+  // FFmpeg context handle.
+  AVFormatContext* format_context_;
+
+  // Vector of streams.
+  typedef std::vector<FFmpegDemuxerStream*> StreamVector;
+  StreamVector streams_;
+
+  DISALLOW_COPY_AND_ASSIGN(FFmpegDemuxer);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_FILTERS_FFMPEG_DEMUXER_H_