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_AUDIO_MANAGER_BASE_H_
6#define MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_
7
8#include <string>
9#include <utility>
10
11#include "base/compiler_specific.h"
12#include "base/memory/scoped_ptr.h"
13#include "base/memory/scoped_vector.h"
14#include "base/observer_list.h"
15#include "base/threading/thread.h"
16#include "media/audio/audio_manager.h"
17
18#include "media/audio/audio_output_dispatcher.h"
19
20#if defined(OS_WIN)
21#include "base/win/scoped_com_initializer.h"
22#endif
23
24namespace media {
25
26class AudioOutputDispatcher;
27
28// AudioManagerBase provides AudioManager functions common for all platforms.
29class MEDIA_EXPORT AudioManagerBase : public AudioManager {
30 public:
31  // TODO(sergeyu): The constants below belong to AudioManager interface, not
32  // to the base implementation.
33
34  // Name of the generic "default" device.
35  static const char kDefaultDeviceName[];
36  // Unique Id of the generic "default" device.
37  static const char kDefaultDeviceId[];
38
39  // Input device ID used to capture the default system playback stream. When
40  // this device ID is passed to MakeAudioInputStream() the returned
41  // AudioInputStream will be capturing audio currently being played on the
42  // default playback device. At the moment this feature is supported only on
43  // some platforms. AudioInputStream::Intialize() will return an error on
44  // platforms that don't support it. GetInputStreamParameters() must be used
45  // to get the parameters of the loopback device before creating a loopback
46  // stream, otherwise stream initialization may fail.
47  static const char kLoopbackInputDeviceId[];
48
49  virtual ~AudioManagerBase();
50
51  virtual scoped_refptr<base::MessageLoopProxy> GetMessageLoop() OVERRIDE;
52  virtual scoped_refptr<base::MessageLoopProxy> GetWorkerLoop() OVERRIDE;
53
54  virtual base::string16 GetAudioInputDeviceModel() OVERRIDE;
55
56  virtual void ShowAudioInputSettings() OVERRIDE;
57
58  virtual void GetAudioInputDeviceNames(
59      AudioDeviceNames* device_names) OVERRIDE;
60
61  virtual void GetAudioOutputDeviceNames(
62      AudioDeviceNames* device_names) OVERRIDE;
63
64  virtual AudioOutputStream* MakeAudioOutputStream(
65      const AudioParameters& params,
66      const std::string& device_id,
67      const std::string& input_device_id) OVERRIDE;
68
69  virtual AudioInputStream* MakeAudioInputStream(
70      const AudioParameters& params, const std::string& device_id) OVERRIDE;
71
72  virtual AudioOutputStream* MakeAudioOutputStreamProxy(
73      const AudioParameters& params,
74      const std::string& device_id,
75      const std::string& input_device_id) OVERRIDE;
76
77  // Called internally by the audio stream when it has been closed.
78  virtual void ReleaseOutputStream(AudioOutputStream* stream);
79  virtual void ReleaseInputStream(AudioInputStream* stream);
80
81  // Creates the output stream for the |AUDIO_PCM_LINEAR| format. The legacy
82  // name is also from |AUDIO_PCM_LINEAR|.
83  virtual AudioOutputStream* MakeLinearOutputStream(
84      const AudioParameters& params) = 0;
85
86  // Creates the output stream for the |AUDIO_PCM_LOW_LATENCY| format.
87  // |input_device_id| is used by unified IO to open the correct input device.
88  virtual AudioOutputStream* MakeLowLatencyOutputStream(
89      const AudioParameters& params,
90      const std::string& device_id,
91      const std::string& input_device_id) = 0;
92
93  // Creates the input stream for the |AUDIO_PCM_LINEAR| format. The legacy
94  // name is also from |AUDIO_PCM_LINEAR|.
95  virtual AudioInputStream* MakeLinearInputStream(
96      const AudioParameters& params, const std::string& device_id) = 0;
97
98  // Creates the input stream for the |AUDIO_PCM_LOW_LATENCY| format.
99  virtual AudioInputStream* MakeLowLatencyInputStream(
100      const AudioParameters& params, const std::string& device_id) = 0;
101
102  // Listeners will be notified on the AudioManager::GetMessageLoop() loop.
103  virtual void AddOutputDeviceChangeListener(
104      AudioDeviceListener* listener) OVERRIDE;
105  virtual void RemoveOutputDeviceChangeListener(
106      AudioDeviceListener* listener) OVERRIDE;
107
108  virtual AudioParameters GetDefaultOutputStreamParameters() OVERRIDE;
109  virtual AudioParameters GetOutputStreamParameters(
110      const std::string& device_id) OVERRIDE;
111
112  virtual AudioParameters GetInputStreamParameters(
113      const std::string& device_id) OVERRIDE;
114
115  virtual std::string GetAssociatedOutputDeviceID(
116      const std::string& input_device_id) OVERRIDE;
117
118  virtual scoped_ptr<AudioLog> CreateAudioLog(
119      AudioLogFactory::AudioComponent component) OVERRIDE;
120
121  virtual void FixWedgedAudio() OVERRIDE;
122
123 protected:
124  AudioManagerBase(AudioLogFactory* audio_log_factory);
125
126  // Shuts down the audio thread and releases all the audio output dispatchers
127  // on the audio thread.  All audio streams should be freed before Shutdown()
128  // is called.  This must be called in the destructor of every AudioManagerBase
129  // implementation.
130  void Shutdown();
131
132  void SetMaxOutputStreamsAllowed(int max) { max_num_output_streams_ = max; }
133
134  // Called by each platform specific AudioManager to notify output state change
135  // listeners that a state change has occurred.  Must be called from the audio
136  // thread.
137  void NotifyAllOutputDeviceChangeListeners();
138
139  // Returns user buffer size as specified on the command line or 0 if no buffer
140  // size has been specified.
141  int GetUserBufferSize();
142
143  // Returns the preferred hardware audio output parameters for opening output
144  // streams. If the users inject a valid |input_params|, each AudioManager
145  // will decide if they should return the values from |input_params| or the
146  // default hardware values. If the |input_params| is invalid, it will return
147  // the default hardware audio parameters.
148  // If |output_device_id| is empty, the implementation must treat that as
149  // a request for the default output device.
150  virtual AudioParameters GetPreferredOutputStreamParameters(
151      const std::string& output_device_id,
152      const AudioParameters& input_params) = 0;
153
154  // Returns the ID of the default audio output device.
155  // Implementations that don't yet support this should return an empty string.
156  virtual std::string GetDefaultOutputDeviceID();
157
158  // Get number of input or output streams.
159  int input_stream_count() { return num_input_streams_; }
160  int output_stream_count() { return num_output_streams_; }
161
162 private:
163  struct DispatcherParams;
164  typedef ScopedVector<DispatcherParams> AudioOutputDispatchers;
165
166  class CompareByParams;
167
168  // Called by Shutdown().
169  void ShutdownOnAudioThread();
170
171  // Max number of open output streams, modified by
172  // SetMaxOutputStreamsAllowed().
173  int max_num_output_streams_;
174
175  // Max number of open input streams.
176  int max_num_input_streams_;
177
178  // Number of currently open output streams.
179  int num_output_streams_;
180
181  // Number of currently open input streams.
182  int num_input_streams_;
183
184  // Track output state change listeners.
185  ObserverList<AudioDeviceListener> output_listeners_;
186
187  // Thread used to interact with audio streams created by this audio manager.
188  base::Thread audio_thread_;
189
190  // The message loop of the audio thread this object runs on. Used for internal
191  // tasks which run on the audio thread even after Shutdown() has been started
192  // and GetMessageLoop() starts returning NULL.
193  scoped_refptr<base::MessageLoopProxy> message_loop_;
194
195  // Map of cached AudioOutputDispatcher instances.  Must only be touched
196  // from the audio thread (no locking).
197  AudioOutputDispatchers output_dispatchers_;
198
199  // Proxy for creating AudioLog objects.
200  AudioLogFactory* const audio_log_factory_;
201
202  DISALLOW_COPY_AND_ASSIGN(AudioManagerBase);
203};
204
205}  // namespace media
206
207#endif  // MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_
208