Implement disabling and enabling media tracks

media/base/pipeline.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_PIPELINE_H_
 #define MEDIA_BASE_PIPELINE_H_
 
 #include <memory>
 
 #include "base/memory/ref_counted.h"
 #include "base/time/time.h"
 #include "media/base/buffering_state.h"
 #include "media/base/cdm_context.h"
 #include "media/base/media_export.h"
 #include "media/base/pipeline_metadata.h"
 #include "media/base/pipeline_status.h"
 #include "media/base/ranges.h"
 #include "media/base/text_track.h"
 #include "media/base/video_rotation.h"
 #include "ui/gfx/geometry/size.h"
 
 namespace media {
 
 class Demuxer;
+class DemuxerStream;
 class Renderer;
 class VideoFrame;
 
 class MEDIA_EXPORT Pipeline {
  public:
   class Client {
    public:
     // Executed whenever an error occurs except when the error occurs during
     // Start/Seek/Resume or Suspend. Those errors are reported via |seek_cb|
     // and |suspend_cb| respectively.
@@ skipping 33 matching lines @@
 
   // Build a pipeline to using the given |demuxer| and |renderer| to construct
   // a filter chain, executing |seek_cb| when the initial seek has completed.
   // Methods on PipelineClient may be called up until Stop() has completed.
   // It is an error to call this method after the pipeline has already started.
   virtual void Start(Demuxer* demuxer,
                      std::unique_ptr<Renderer> renderer,
                      Client* client,
                      const PipelineStatusCB& seek_cb) = 0;
 
+  // Restarts playback of the given demuxer |stream| from the |time| position.
+  virtual void RestartStreamPlayback(DemuxerStream* stream,
+                                     base::TimeDelta time) = 0;

[xhwang, 2016/06/04 00:09:43]

What if our current media time is at t1, and |time| != t1. What is the Pipeline
supposed to do?

[servolk, 2016/06/09 21:00:13]

Well, I suppose if we move the 'resume playback' logic deeper into
PipelineController or Pipeline as discussed in other comments, then we won't
need to pass |time| here explicitly and can pass just a set of track ids and
their status.

+
   // Stops the pipeline. This is a blocking function.
   // If the pipeline is started, it must be stopped before destroying it.
   // It it permissible to call Stop() at any point during the lifetime of the
   // pipeline.
   //
   // Once Stop is called any outstanding completion callbacks
   // for Start/Seek/Suspend/Resume or Client methods will *not* be called.
   virtual void Stop() = 0;
 
   // Attempt to seek to the position specified by time.  |seek_cb| will be
@@ skipping 69 matching lines @@
   // Gets the current pipeline statistics.
   virtual PipelineStatistics GetStatistics() const = 0;
 
   virtual void SetCdm(CdmContext* cdm_context,
                       const CdmAttachedCB& cdm_attached_cb) = 0;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_PIPELINE_H_