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// 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/buffering_state.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.
//
// |buffering_state_cb| is executed when video rendering has either run out of
// data or has enough data to continue playback.
//
// |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 BufferingStateCB& buffering_state_cb,
const base::Closure& ended_cb,
const PipelineStatusCB& error_cb,
const TimeDeltaCB& get_time_cb,
const TimeDeltaCB& get_duration_cb) = 0;
// Discard any video data and stop reading from |stream|, executing |callback|
// when completed.
//
// Clients should expect |buffering_state_cb| to be called with
// BUFFERING_HAVE_NOTHING while flushing is in progress.
virtual void Flush(const base::Closure& callback) = 0;
// Starts playback by reading from |stream| and decoding and rendering video.
// |timestamp| is the media timestamp playback should start rendering from.
//
// Only valid to call after a successful Initialize() or Flush().
virtual void StartPlayingFrom(base::TimeDelta timestamp) = 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_
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