Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(1934)

Unified Diff: media/base/text_renderer.h

Issue 23702007: Render inband text tracks in the media pipeline (Closed) Base URL: http://git.chromium.org/chromium/src.git@master
Patch Set: fix compile errors 11/21 #6 Created 7 years, 1 month ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« no previous file with comments | « media/base/text_cue.cc ('k') | media/base/text_renderer.cc » ('j') | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: media/base/text_renderer.h
diff --git a/media/base/text_renderer.h b/media/base/text_renderer.h
new file mode 100644
index 0000000000000000000000000000000000000000..fbd51c2c66a440627b0012d55285a373e18a89b2
--- /dev/null
+++ b/media/base/text_renderer.h
@@ -0,0 +1,145 @@
+// 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 <map>
+#include <set>
+
+#include "base/callback.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "media/base/demuxer_stream.h"
+#include "media/base/media_export.h"
+#include "media/base/pipeline_status.h"
+#include "media/base/text_track.h"
+
+namespace base {
+class MessageLoopProxy;
+}
+
+namespace media {
+
+class TextCue;
+class TextTrackConfig;
+
+// Receives decoder buffers from the upstream demuxer, decodes them to text
+// cues, and then passes them onto the TextTrack object associated with each
+// demuxer text stream.
+class MEDIA_EXPORT TextRenderer {
+ public:
+ // |message_loop| is the thread on which TextRenderer will execute.
+ //
+ // |add_text_track_cb] is called when the demuxer requests (via its host)
+ // that a new text track be created.
+ TextRenderer(const scoped_refptr<base::MessageLoopProxy>& message_loop,
+ const AddTextTrackCB& add_text_track_cb);
+ ~TextRenderer();
+
+ // |ended_cb| is executed when all of the text tracks have reached
+ // end of stream, following a play request.
+ void Initialize(const base::Closure& ended_cb);
+
+ // Start text track cue decoding and rendering, executing |callback| when
+ // playback is underway.
+ void Play(const base::Closure& callback);
+
+ // Temporarily suspend decoding and rendering, executing |callback| when
+ // playback has been suspended.
+ void Pause(const base::Closure& callback);
+
+ // Discard any text data, executing |callback| when completed.
+ void Flush(const base::Closure& callback);
+
+ // Stop all operations in preparation for being deleted, executing |callback|
+ // when complete.
+ void Stop(const base::Closure& callback);
+
+ // Add new |text_stream|, having the indicated |config|, to the text stream
+ // collection managed by this text renderer.
+ void AddTextStream(DemuxerStream* text_stream,
+ const TextTrackConfig& config);
+
+ // Remove |text_stream| from the text stream collection.
+ void RemoveTextStream(DemuxerStream* text_stream);
+
+ // Returns true if there are extant text tracks.
+ bool HasTracks() const;
+
+ private:
+ struct TextTrackState {
+ // To determine read progress.
+ enum ReadState {
+ kReadIdle,
+ kReadPending
+ };
+
+ explicit TextTrackState(scoped_ptr<TextTrack> text_track);
+ ~TextTrackState();
+
+ ReadState read_state;
+ scoped_ptr<TextTrack> text_track;
+ };
+
+ // 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);
+
+ // Dispatches the decoded cue delivered on the demuxer's |text_stream|.
+ void CueReady(DemuxerStream* text_stream,
+ const scoped_refptr<TextCue>& text_cue);
+
+ // Dispatched when the AddTextTrackCB completes, after having created
+ // the TextTrack object associated with |text_stream|.
+ void OnAddTextTrackDone(DemuxerStream* text_stream,
+ scoped_ptr<TextTrack> text_track);
+
+ // Utility function to post a read request on |text_stream|.
+ void Read(TextTrackState* state, DemuxerStream* text_stream);
+
+ scoped_refptr<base::MessageLoopProxy> message_loop_;
+ base::WeakPtrFactory<TextRenderer> weak_factory_;
+ base::WeakPtr<TextRenderer> weak_this_;
+ const AddTextTrackCB add_text_track_cb_;
+
+ // Callbacks provided during Initialize().
+ base::Closure ended_cb_;
+
+ // Callback provided to Pause().
+ base::Closure pause_cb_;
+
+ // Callback provided to Stop().
+ base::Closure stop_cb_;
+
+ // Simple state tracking variable.
+ enum State {
+ kUninitialized,
+ kPausePending,
+ kPaused,
+ kPlaying,
+ kEnded,
+ kStopPending,
+ kStopped
+ };
+ State state_;
+
+ typedef std::map<DemuxerStream*, TextTrackState*> TextTrackStateMap;
+ TextTrackStateMap text_track_state_map_;
+
+ // Indicates how many read requests are in flight.
+ int pending_read_count_;
+
+ // Indicates which text streams have not delivered end-of-stream yet.
+ typedef std::set<DemuxerStream*> PendingEosSet;
+ PendingEosSet pending_eos_set_;
+
+ DISALLOW_IMPLICIT_CONSTRUCTORS(TextRenderer);
+};
+
+} // namespace media
+
+#endif // MEDIA_BASE_TEXT_RENDERER_H_
« no previous file with comments | « media/base/text_cue.cc ('k') | media/base/text_renderer.cc » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698