opensles_output.h revision d0247b1b59f9c528cb6df88b4f2b9afaf80d181e 
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_AUDIO_ANDROID_OPENSLES_OUTPUT_H_
6#define MEDIA_AUDIO_ANDROID_OPENSLES_OUTPUT_H_
7
8#include <SLES/OpenSLES.h>
9#include <SLES/OpenSLES_Android.h>
10
11#include "base/compiler_specific.h"
12#include "base/synchronization/lock.h"
13#include "base/threading/thread_checker.h"
14#include "media/audio/android/opensles_util.h"
15#include "media/audio/audio_io.h"
16#include "media/audio/audio_parameters.h"
17
18namespace media {
19
20class AudioManagerAndroid;
21
22// Implements PCM audio output support for Android using the OpenSLES API.
23// This class is created and lives on the Audio Manager thread but recorded
24// audio buffers are given to us from an internal OpenSLES audio thread.
25// All public methods should be called on the Audio Manager thread.
26class OpenSLESOutputStream : public AudioOutputStream {
27 public:
28  static const int kMaxNumOfBuffersInQueue = 2;
29
30  OpenSLESOutputStream(AudioManagerAndroid* manager,
31                       const AudioParameters& params);
32
33  virtual ~OpenSLESOutputStream();
34
35  // Implementation of AudioOutputStream.
36  virtual bool Open() OVERRIDE;
37  virtual void Close() OVERRIDE;
38  virtual void Start(AudioSourceCallback* callback) OVERRIDE;
39  virtual void Stop() OVERRIDE;
40  virtual void SetVolume(double volume) OVERRIDE;
41  virtual void GetVolume(double* volume) OVERRIDE;
42
43 private:
44  bool CreatePlayer();
45
46  // Called from OpenSLES specific audio worker thread.
47  static void SimpleBufferQueueCallback(
48      SLAndroidSimpleBufferQueueItf buffer_queue,
49      void* instance);
50
51  // Fills up one buffer by asking the registered source for data.
52  // Called from OpenSLES specific audio worker thread.
53  void FillBufferQueue();
54
55  // Called from the audio manager thread.
56  void FillBufferQueueNoLock();
57
58  // Called in Open();
59  void SetupAudioBuffer();
60
61  // Called in Close();
62  void ReleaseAudioBuffer();
63
64  // If OpenSLES reports an error this function handles it and passes it to
65  // the attached AudioOutputCallback::OnError().
66  void HandleError(SLresult error);
67
68  base::ThreadChecker thread_checker_;
69
70  // Protects |callback_|, |active_buffer_index_|, |audio_data_|,
71  // |buffer_size_bytes_| and |simple_buffer_queue_|.
72  base::Lock lock_;
73
74  AudioManagerAndroid* audio_manager_;
75
76  AudioSourceCallback* callback_;
77
78  // Shared engine interfaces for the app.
79  media::ScopedSLObjectItf engine_object_;
80  media::ScopedSLObjectItf player_object_;
81  media::ScopedSLObjectItf output_mixer_;
82
83  SLPlayItf player_;
84
85  // Buffer queue recorder interface.
86  SLAndroidSimpleBufferQueueItf simple_buffer_queue_;
87
88  SLDataFormat_PCM format_;
89
90  // Audio buffers that are allocated in the constructor based on
91  // info from audio parameters.
92  uint8* audio_data_[kMaxNumOfBuffersInQueue];
93
94  int active_buffer_index_;
95  size_t buffer_size_bytes_;
96
97  bool started_;
98
99  // Volume level from 0 to 1.
100  float volume_;
101
102  // Container for retrieving data from AudioSourceCallback::OnMoreData().
103  scoped_ptr<AudioBus> audio_bus_;
104
105  DISALLOW_COPY_AND_ASSIGN(OpenSLESOutputStream);
106};
107
108}  // namespace media
109
110#endif  // MEDIA_AUDIO_ANDROID_OPENSLES_OUTPUT_H_
111