| // 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_VIDEO_RENDERER_H_ |
| #define MEDIA_BASE_VIDEO_RENDERER_H_ |
| |
| #include "base/callback.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/time/time.h" |
| #include "media/base/media_export.h" |
| #include "media/base/pipeline_status.h" |
| |
| namespace media { |
| |
| class DemuxerStream; |
| class VideoDecoder; |
| |
| class MEDIA_EXPORT VideoRenderer { |
| public: |
| // Used to update the pipeline's clock time. The parameter is the time that |
| // the clock should not exceed. |
| typedef base::Callback<void(base::TimeDelta)> TimeCB; |
| |
| // Used to query the current time or duration of the media. |
| typedef base::Callback<base::TimeDelta()> TimeDeltaCB; |
| |
| VideoRenderer(); |
| virtual ~VideoRenderer(); |
| |
| // Initialize a VideoRenderer with |stream|, executing |init_cb| upon |
| // completion. |
| // |
| // |statistics_cb| is executed periodically with video rendering stats, such |
| // as dropped frames. |
| // |
| // |time_cb| is executed whenever time has advanced by way of video rendering. |
| // |
| // |ended_cb| is executed when video rendering has reached the end of stream. |
| // |
| // |error_cb| is executed if an error was encountered. |
| // |
| // |get_time_cb| is used to query the current media playback time. |
| // |
| // |get_duration_cb| is used to query the media duration. |
| virtual void Initialize(DemuxerStream* stream, |
| bool low_delay, |
| const PipelineStatusCB& init_cb, |
| const StatisticsCB& statistics_cb, |
| const TimeCB& time_cb, |
| const base::Closure& ended_cb, |
| const PipelineStatusCB& error_cb, |
| const TimeDeltaCB& get_time_cb, |
| const TimeDeltaCB& get_duration_cb) = 0; |
| |
| // Start audio decoding and rendering at the current playback rate, executing |
| // |callback| when playback is underway. |
| virtual void Play(const base::Closure& callback) = 0; |
| |
| // Discard any video data and stop reading from |stream|, executing |callback| |
| // when completed. |
| virtual void Flush(const base::Closure& callback) = 0; |
| |
| // Start prerolling video data. If |time| equals kNoTimestamp() then all |
| // samples delivered to the renderer are used to complete preroll. If |time| |
| // does not equal kNoTimestamp(), then any samples delivered to the renderer |
| // with timestamps less than |time| are silently dropped and not used to |
| // satisfy preroll. |callback| is executed when preroll has completed. |
| // |
| // Only valid to call after a successful Initialize(), Pause(), or Flush(). |
| virtual void Preroll(base::TimeDelta time, |
| const PipelineStatusCB& callback) = 0; |
| |
| // Stop all operations in preparation for being deleted, executing |callback| |
| // when complete. |
| virtual void Stop(const base::Closure& callback) = 0; |
| |
| // Updates the current playback rate. |
| virtual void SetPlaybackRate(float playback_rate) = 0; |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(VideoRenderer); |
| }; |
| |
| } // namespace media |
| |
| #endif // MEDIA_BASE_VIDEO_RENDERER_H_ |