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