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                       SLint32 stream_type);
33
34  virtual ~OpenSLESOutputStream();
35
36  // Implementation of AudioOutputStream.
37  virtual bool Open() OVERRIDE;
38  virtual void Close() OVERRIDE;
39  virtual void Start(AudioSourceCallback* callback) OVERRIDE;
40  virtual void Stop() OVERRIDE;
41  virtual void SetVolume(double volume) OVERRIDE;
42  virtual void GetVolume(double* volume) OVERRIDE;
43
44  // Set the value of |muted_|. It does not affect |volume_| which can be
45  // got by calling GetVolume(). See comments for |muted_| below.
46  void SetMute(bool muted);
47
48 private:
49  bool CreatePlayer();
50
51  // Called from OpenSLES specific audio worker thread.
52  static void SimpleBufferQueueCallback(
53      SLAndroidSimpleBufferQueueItf buffer_queue,
54      void* instance);
55
56  // Fills up one buffer by asking the registered source for data.
57  // Called from OpenSLES specific audio worker thread.
58  void FillBufferQueue();
59
60  // Called from the audio manager thread.
61  void FillBufferQueueNoLock();
62
63  // Called in Open();
64  void SetupAudioBuffer();
65
66  // Called in Close();
67  void ReleaseAudioBuffer();
68
69  // If OpenSLES reports an error this function handles it and passes it to
70  // the attached AudioOutputCallback::OnError().
71  void HandleError(SLresult error);
72
73  base::ThreadChecker thread_checker_;
74
75  // Protects |callback_|, |active_buffer_index_|, |audio_data_|,
76  // |buffer_size_bytes_| and |simple_buffer_queue_|.
77  base::Lock lock_;
78
79  AudioManagerAndroid* audio_manager_;
80
81  // Audio playback stream type.
82  // See SLES/OpenSLES_Android.h for details.
83  SLint32 stream_type_;
84
85  AudioSourceCallback* callback_;
86
87  // Shared engine interfaces for the app.
88  media::ScopedSLObjectItf engine_object_;
89  media::ScopedSLObjectItf player_object_;
90  media::ScopedSLObjectItf output_mixer_;
91
92  SLPlayItf player_;
93
94  // Buffer queue recorder interface.
95  SLAndroidSimpleBufferQueueItf simple_buffer_queue_;
96
97  SLDataFormat_PCM format_;
98
99  // Audio buffers that are allocated in the constructor based on
100  // info from audio parameters.
101  uint8* audio_data_[kMaxNumOfBuffersInQueue];
102
103  int active_buffer_index_;
104  size_t buffer_size_bytes_;
105
106  bool started_;
107
108  // Volume control coming from hardware. It overrides |volume_| when it's
109  // true. Otherwise, use |volume_| for scaling.
110  // This is needed because platform voice volume never goes to zero in
111  // COMMUNICATION mode on Android.
112  bool muted_;
113
114  // Volume level from 0 to 1.
115  float volume_;
116
117  // Container for retrieving data from AudioSourceCallback::OnMoreData().
118  scoped_ptr<AudioBus> audio_bus_;
119
120  DISALLOW_COPY_AND_ASSIGN(OpenSLESOutputStream);
121};
122
123}  // namespace media
124
125#endif  // MEDIA_AUDIO_ANDROID_OPENSLES_OUTPUT_H_
126