1// Copyright 2014 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_RENDERER_H_ 6#define MEDIA_BASE_RENDERER_H_ 7 8#include "base/callback.h" 9#include "base/time/time.h" 10#include "media/base/buffering_state.h" 11#include "media/base/media_export.h" 12#include "media/base/pipeline_status.h" 13 14namespace media { 15 16class MediaKeys; 17 18class MEDIA_EXPORT Renderer { 19 public: 20 typedef base::Callback<base::TimeDelta()> TimeDeltaCB; 21 22 Renderer(); 23 24 // Stops rendering and fires any pending callbacks. 25 virtual ~Renderer(); 26 27 // Initializes the Renderer, executing |init_cb| upon completion. 28 // If initialization failed, fires |error_cb| before |init_cb|. 29 // 30 // Permanent callbacks: 31 // - |statistics_cb|: Executed periodically with rendering statistics. 32 // - |time_cb|: Executed whenever time has advanced through rendering. 33 // - |ended_cb|: Executed when rendering has reached the end of stream. 34 // - |error_cb|: Executed if any error was encountered during rendering. 35 virtual void Initialize(const base::Closure& init_cb, 36 const StatisticsCB& statistics_cb, 37 const base::Closure& ended_cb, 38 const PipelineStatusCB& error_cb, 39 const BufferingStateCB& buffering_state_cb) = 0; 40 41 // The following functions must be called after Initialize(). 42 43 // Discards any buffered data, executing |flush_cb| when completed. 44 virtual void Flush(const base::Closure& flush_cb) = 0; 45 46 // Starts rendering from |time|. 47 virtual void StartPlayingFrom(base::TimeDelta time) = 0; 48 49 // Updates the current playback rate. The default playback rate should be 1. 50 virtual void SetPlaybackRate(float playback_rate) = 0; 51 52 // Sets the output volume. The default volume should be 1. 53 virtual void SetVolume(float volume) = 0; 54 55 // Returns the current media time. 56 virtual base::TimeDelta GetMediaTime() = 0; 57 58 // Returns whether |this| renders audio. 59 virtual bool HasAudio() = 0; 60 61 // Returns whether |this| renders video. 62 virtual bool HasVideo() = 0; 63 64 // Associates the |cdm| with this Renderer. 65 virtual void SetCdm(MediaKeys* cdm) = 0; 66 67 private: 68 DISALLOW_COPY_AND_ASSIGN(Renderer); 69}; 70 71} // namespace media 72 73#endif // MEDIA_BASE_RENDERER_H_ 74