Render inband text tracks in the media pipeline

media/filters/text_decoder_impl.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_FILTERS_TEXT_DECODER_IMPL_H_
+#define MEDIA_FILTERS_TEXT_DECODER_IMPL_H_
+
+#include <map>
+
+#include "base/memory/weak_ptr.h"
+#include "media/base/demuxer_stream.h"
+#include "media/base/text_decoder.h"
+
+namespace base {
+class MessageLoopProxy;
+}
+
+namespace media {
+
+class MEDIA_EXPORT TextDecoderImpl : public TextDecoder {
+ public:
+  explicit TextDecoderImpl(
+      const scoped_refptr<base::MessageLoopProxy>& message_loop);
+  virtual ~TextDecoderImpl();
+
+  // TextDecoder implementation.
+  virtual void Initialize() OVERRIDE;
+  virtual void Read(DemuxerStream* stream, const ReadCB& read_cb) OVERRIDE;
+
+ private:
+  // Callback delivered by the demuxer |text_stream| when
+  // a read from the stream completes.
+  void BufferReady(DemuxerStream* text_stream,
+                   DemuxerStream::Status status,
+                   const scoped_refptr<DecoderBuffer>& input);
+
+  scoped_refptr<base::MessageLoopProxy> message_loop_;
+  base::WeakPtrFactory<TextDecoderImpl> weak_factory_;
+  base::WeakPtr<TextDecoderImpl> weak_this_;
+
+  // Holds the callbacks for the read requests made by
+  // the downstream text renderer.
+  typedef std::map<DemuxerStream*, ReadCB> ReadCallbacks;
+  ReadCallbacks read_callbacks_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(TextDecoderImpl);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_FILTERS_TEXT_DECODER_IMPL_H_