Render inband text tracks in the media pipeline

media/base/pipeline.h

Index: media/base/pipeline.h
diff --git a/media/base/pipeline.h b/media/base/pipeline.h
index 09ff90416390fc8a3cc5d1f5071ee515df939c58..843c15ee4eb01721bcc669d50f680caf2c1bee14 100644
--- a/media/base/pipeline.h
+++ b/media/base/pipeline.h
@@ -30,6 +30,7 @@ namespace media {
 class Clock;
 class FilterCollection;
 class MediaLog;
+class TextRenderer;
 class VideoRenderer;
 
 // Pipeline runs the media pipeline.  Filters are created and called on the
@@ -138,6 +139,9 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
   // Returns true if the media has video.
   bool HasVideo() const;
 
+  // Returns true if the media has text.
+  bool HasText() const;

[acolwell GONE FROM CHROMIUM, 2013/09/12 00:15:15]

nit: This only appears to be used by test code. Do we really need it?

[Matthew Heaney (Chromium), 2013/09/13 19:51:54]

I don't think so.  We can replace it with some alternative, if you like.

[Matthew Heaney (Chromium), 2013/09/20 23:53:54]

I finally removed it.

+
   // Gets the current playback rate of the pipeline.  When the pipeline is
   // started, the playback rate will be 0.0f.  A rate of 1.0f indicates
   // that the pipeline is rendering the media at the standard rate.  Valid
@@ -205,6 +209,7 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
     kInitDemuxer,
     kInitAudioRenderer,
     kInitVideoRenderer,
+    kInitTextRenderer,
     kInitPrerolling,
     kSeeking,
     kStarting,
@@ -244,6 +249,7 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
   // Callbacks executed when a renderer has ended.
   void OnAudioRendererEnded();
   void OnVideoRendererEnded();
+  void OnTextRendererEnded();
 
   // Callback executed by filters to update statistics.
   void OnUpdateStatistics(const PipelineStatistics& stats);
@@ -283,9 +289,10 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
   // Carries out notifying filters that we are seeking to a new timestamp.
   void SeekTask(base::TimeDelta time, const PipelineStatusCB& seek_cb);
 
-  // Handles audio/video ended logic and running |ended_cb_|.
+  // Handles audio/video/text ended logic and running |ended_cb_|.
   void DoAudioRendererEnded();
   void DoVideoRendererEnded();
+  void DoTextRendererEnded();
   void RunEndedCallbackIfNeeded();
 
   // Carries out disabling the audio renderer.
@@ -296,6 +303,7 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
   void InitializeDemuxer(const PipelineStatusCB& done_cb);
   void InitializeAudioRenderer(const PipelineStatusCB& done_cb);
   void InitializeVideoRenderer(const PipelineStatusCB& done_cb);
+  void InitializeTextRenderer(const PipelineStatusCB& done_cb);
 
   // Kicks off destroying filters. Called by StopTask() and ErrorChangedTask().
   // When we start to tear down the pipeline, we will consider two cases:
@@ -392,12 +400,13 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
   // reset the pipeline state, and restore this to PIPELINE_OK.
   PipelineStatus status_;
 
-  // Whether the media contains rendered audio and video streams.
+  // Whether the media contains rendered audio, video, and text streams.
   // TODO(fischman,scherkus): replace these with checks for
   // {audio,video}_decoder_ once extraction of {Audio,Video}Decoder from the
   // Filter heirarchy is done.
   bool has_audio_;
   bool has_video_;
+  bool has_text_;
 
   // The following data members are only accessed by tasks posted to
   // |message_loop_|.
@@ -405,9 +414,10 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
   // Member that tracks the current state.
   State state_;
 
-  // Whether we've received the audio/video ended events.
+  // Whether we've received the audio/video/text ended events.
   bool audio_ended_;
   bool video_ended_;
+  bool text_ended_;
 
   // Set to true in DisableAudioRendererTask().
   bool audio_disabled_;
@@ -434,6 +444,7 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
   // playback rate, and determining when playback has finished.
   scoped_ptr<AudioRenderer> audio_renderer_;
   scoped_ptr<VideoRenderer> video_renderer_;
+  scoped_ptr<TextRenderer> text_renderer_;
 
   PipelineStatistics statistics_;