1// Copyright (c) 2012 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5#ifndef MEDIA_BASE_VIDEO_RENDERER_H_ 6#define MEDIA_BASE_VIDEO_RENDERER_H_ 7 8#include "base/callback.h" 9#include "base/memory/ref_counted.h" 10#include "base/time/time.h" 11#include "media/base/media_export.h" 12#include "media/base/pipeline_status.h" 13 14namespace gfx { 15class Size; 16} 17 18namespace media { 19 20class DemuxerStream; 21class VideoDecoder; 22 23class MEDIA_EXPORT VideoRenderer { 24 public: 25 // Used to update the pipeline's clock time. The parameter is the time that 26 // the clock should not exceed. 27 typedef base::Callback<void(base::TimeDelta)> TimeCB; 28 29 // Executed when the natural size of the video has changed. 30 typedef base::Callback<void(const gfx::Size& size)> NaturalSizeChangedCB; 31 32 // Used to query the current time or duration of the media. 33 typedef base::Callback<base::TimeDelta()> TimeDeltaCB; 34 35 VideoRenderer(); 36 virtual ~VideoRenderer(); 37 38 // Initialize a VideoRenderer with |stream|, executing |init_cb| upon 39 // completion. 40 // 41 // |statistics_cb| is executed periodically with video rendering stats, such 42 // as dropped frames. 43 // 44 // |time_cb| is executed whenever time has advanced by way of video rendering. 45 // 46 // |size_changed_cb| is executed whenever the dimensions of the video has 47 // changed. 48 // 49 // |ended_cb| is executed when video rendering has reached the end of stream. 50 // 51 // |error_cb| is executed if an error was encountered. 52 // 53 // |get_time_cb| is used to query the current media playback time. 54 // 55 // |get_duration_cb| is used to query the media duration. 56 virtual void Initialize(DemuxerStream* stream, 57 const PipelineStatusCB& init_cb, 58 const StatisticsCB& statistics_cb, 59 const TimeCB& time_cb, 60 const NaturalSizeChangedCB& size_changed_cb, 61 const base::Closure& ended_cb, 62 const PipelineStatusCB& error_cb, 63 const TimeDeltaCB& get_time_cb, 64 const TimeDeltaCB& get_duration_cb) = 0; 65 66 // Start audio decoding and rendering at the current playback rate, executing 67 // |callback| when playback is underway. 68 virtual void Play(const base::Closure& callback) = 0; 69 70 // Temporarily suspend decoding and rendering video, executing |callback| when 71 // playback has been suspended. 72 virtual void Pause(const base::Closure& callback) = 0; 73 74 // Discard any video data, executing |callback| when completed. 75 virtual void Flush(const base::Closure& callback) = 0; 76 77 // Start prerolling video data for samples starting at |time|, executing 78 // |callback| when completed. 79 // 80 // Only valid to call after a successful Initialize() or Flush(). 81 virtual void Preroll(base::TimeDelta time, 82 const PipelineStatusCB& callback) = 0; 83 84 // Stop all operations in preparation for being deleted, executing |callback| 85 // when complete. 86 virtual void Stop(const base::Closure& callback) = 0; 87 88 // Updates the current playback rate. 89 virtual void SetPlaybackRate(float playback_rate) = 0; 90 91 private: 92 DISALLOW_COPY_AND_ASSIGN(VideoRenderer); 93}; 94 95} // namespace media 96 97#endif // MEDIA_BASE_VIDEO_RENDERER_H_ 98