media: Introduce DemuxerStreamProvider interface.

media/base/demuxer.h

 // Copyright (c) 2012 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.
 
 #ifndef MEDIA_BASE_DEMUXER_H_
 #define MEDIA_BASE_DEMUXER_H_
 
 #include <vector>
 
 #include "base/time/time.h"
 #include "media/base/data_source.h"
 #include "media/base/demuxer_stream.h"
+#include "media/base/demuxer_stream_provider.h"
 #include "media/base/media_export.h"
 #include "media/base/pipeline_status.h"
 
 namespace media {
 
 class TextTrackConfig;
 
 class MEDIA_EXPORT DemuxerHost {
  public:
   // Notify the host that time range [start,end] has been buffered.
@@ skipping 12 matching lines @@
   virtual void AddTextStream(DemuxerStream* text_stream,
                              const TextTrackConfig& config) = 0;
 
   // Remove |text_stream| from the presentation.
   virtual void RemoveTextStream(DemuxerStream* text_stream) = 0;
 
  protected:
   virtual ~DemuxerHost();
 };
 
-class MEDIA_EXPORT Demuxer {
+class MEDIA_EXPORT Demuxer : public DemuxerStreamProvider {

[scherkus (not reviewing), 2014/09/05 23:23:21]

alternatively we can go the composition route and have Demuxer() provide a
DemuxerStreamProvider* getter, similar to what I did with TimeSource* from
AudioRenderer

but I suppose we'd only really want to do that if it'd make sense for there to
be stand alone DSP implementations (similar to how I have WallClockTimeSource
vs. AudioRendererImpl).

[xhwang, 2014/09/09 21:25:01]

Yeah, currently both ChunkDemuxer and FFD provides the DS's directly. I don't
feel very necessary to add a DemuxerStreamProvider impl for them right now. So I
tend to land this right now and iterate on that later...

  public:
-  enum Liveness {
-    LIVENESS_UNKNOWN,
-    LIVENESS_RECORDED,
-    LIVENESS_LIVE,
-  };
-
   // A new potentially encrypted stream has been parsed.
   // First parameter - The type of initialization data.
   // Second parameter - The initialization data associated with the stream.
   typedef base::Callback<void(const std::string& type,
                               const std::vector<uint8>& init_data)> NeedKeyCB;
 
   Demuxer();
   virtual ~Demuxer();
 
   // Completes initialization of the demuxer.
   //
   // The demuxer does not own |host| as it is guaranteed to outlive the
   // lifetime of the demuxer. Don't delete it!
   virtual void Initialize(DemuxerHost* host,
                           const PipelineStatusCB& status_cb,
                           bool enable_text_tracks) = 0;
 
   // Carry out any actions required to seek to the given time, executing the
   // callback upon completion.
   virtual void Seek(base::TimeDelta time,
                     const PipelineStatusCB& status_cb) = 0;
 
   // Starts stopping this demuxer, executing the callback upon completion.
   //
   // After the callback completes the demuxer may be destroyed. It is illegal to
   // call any method (including Stop()) after a demuxer has stopped.
   virtual void Stop(const base::Closure& callback) = 0;
 
-  // Returns the first stream of the given stream type (which is not allowed
-  // to be DemuxerStream::TEXT), or NULL if that type of stream is not present.
-  virtual DemuxerStream* GetStream(DemuxerStream::Type type) = 0;
-
   // Returns Time represented by presentation timestamp 0.
   // If the timstamps are not associated with a Time, then
   // a null Time is returned.
   virtual base::Time GetTimelineOffset() const = 0;
 
-  // Returns liveness of the stream, i.e. whether it is recorded or live.
+  // DemuxerStreamProvider implementation.

[scherkus (not reviewing), 2014/09/05 23:23:22]

I forget this part of C++ -- but do we need to duplicate these definitions here?

[xhwang, 2014/09/09 21:25:01]

No, it's not needed. Removed.

+  virtual DemuxerStream* GetStream(DemuxerStream::Type type) = 0;
   virtual Liveness GetLiveness() const = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(Demuxer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_DEMUXER_H_