Render inband text tracks in the media pipeline

media/base/text_renderer.h

+// Copyright (c) 2013 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_TEXT_RENDERER_H_
+#define MEDIA_BASE_TEXT_RENDERER_H_
+
+#include "base/callback.h"
+#include "media/base/media_export.h"
+#include "media/base/pipeline_status.h"
+
+namespace media {
+
+class Demuxer;
+
+class MEDIA_EXPORT TextRenderer {

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

I don't anticipate us having more than 1 TextRenderer impl so just get rid of
this abstract interface and just make TextRendererImpl TextRenderer.

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

Done.

+ public:
+  TextRenderer();
+  virtual ~TextRenderer();
+
+  // Initialize a TextRenderer with text streams in |demuxer|, executing
+  // |init_cb| upon completion.
+  //
+  // |ended_cb| is executed when all of the text tracks have reached end
+  // of stream.
+  virtual void Initialize(Demuxer* demuxer,
+                          const PipelineStatusCB& init_cb,
+                          const base::Closure& ended_cb) = 0;
+
+  // Start text track cue decoding and rendering, executing |callback| when
+  // playback is underway.
+  virtual void Play(const base::Closure& callback) = 0;
+
+  // Temporarily suspend decoding and rendering the text track, executing
+  // |callback| when playback has been suspended.
+  virtual void Pause(const base::Closure& callback) = 0;
+
+  // Stop all operations in preparation for being deleted, executing |callback|
+  // when complete.
+  virtual void Stop(const base::Closure& callback) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TextRenderer);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_BASE_TEXT_RENDERER_H_