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.
5 #ifndef MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_
6 #define MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_
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/synchronization/lock.h"
16 #include "media/audio/audio_manager.h"
18 #include "media/audio/audio_output_dispatcher.h"
21 #include "base/win/scoped_com_initializer.h"
30 class AudioOutputDispatcher;
32 // AudioManagerBase provides AudioManager functions common for all platforms.
33 class MEDIA_EXPORT AudioManagerBase : public AudioManager {
35 // TODO(sergeyu): The constants below belong to AudioManager interface, not
36 // to the base implementation.
38 // Name of the generic "default" device.
39 static const char kDefaultDeviceName[];
40 // Unique Id of the generic "default" device.
41 static const char kDefaultDeviceId[];
43 // Input device ID used to capture the default system playback stream. When
44 // this device ID is passed to MakeAudioInputStream() the returned
45 // AudioInputStream will be capturing audio currently being played on the
46 // default playback device. At the moment this feature is supported only on
47 // some platforms. AudioInputStream::Intialize() will return an error on
48 // platforms that don't support it. GetInputStreamParameters() must be used
49 // to get the parameters of the loopback device before creating a loopback
50 // stream, otherwise stream initialization may fail.
51 static const char kLoopbackInputDeviceId[];
53 virtual ~AudioManagerBase();
55 virtual scoped_refptr<base::MessageLoopProxy> GetMessageLoop() OVERRIDE;
56 virtual scoped_refptr<base::MessageLoopProxy> GetWorkerLoop() OVERRIDE;
58 virtual string16 GetAudioInputDeviceModel() OVERRIDE;
60 virtual void ShowAudioInputSettings() OVERRIDE;
62 virtual void GetAudioInputDeviceNames(
63 AudioDeviceNames* device_names) OVERRIDE;
65 virtual void GetAudioOutputDeviceNames(
66 AudioDeviceNames* device_names) OVERRIDE;
68 virtual AudioOutputStream* MakeAudioOutputStream(
69 const AudioParameters& params,
70 const std::string& device_id,
71 const std::string& input_device_id) OVERRIDE;
73 virtual AudioInputStream* MakeAudioInputStream(
74 const AudioParameters& params, const std::string& device_id) OVERRIDE;
76 virtual AudioOutputStream* MakeAudioOutputStreamProxy(
77 const AudioParameters& params,
78 const std::string& device_id,
79 const std::string& input_device_id) OVERRIDE;
81 // Called internally by the audio stream when it has been closed.
82 virtual void ReleaseOutputStream(AudioOutputStream* stream);
83 virtual void ReleaseInputStream(AudioInputStream* stream);
85 // Creates the output stream for the |AUDIO_PCM_LINEAR| format. The legacy
86 // name is also from |AUDIO_PCM_LINEAR|.
87 virtual AudioOutputStream* MakeLinearOutputStream(
88 const AudioParameters& params) = 0;
90 // Creates the output stream for the |AUDIO_PCM_LOW_LATENCY| format.
91 // |input_device_id| is used by unified IO to open the correct input device.
92 virtual AudioOutputStream* MakeLowLatencyOutputStream(
93 const AudioParameters& params,
94 const std::string& device_id,
95 const std::string& input_device_id) = 0;
97 // Creates the input stream for the |AUDIO_PCM_LINEAR| format. The legacy
98 // name is also from |AUDIO_PCM_LINEAR|.
99 virtual AudioInputStream* MakeLinearInputStream(
100 const AudioParameters& params, const std::string& device_id) = 0;
102 // Creates the input stream for the |AUDIO_PCM_LOW_LATENCY| format.
103 virtual AudioInputStream* MakeLowLatencyInputStream(
104 const AudioParameters& params, const std::string& device_id) = 0;
106 // Listeners will be notified on the AudioManager::GetMessageLoop() loop.
107 virtual void AddOutputDeviceChangeListener(
108 AudioDeviceListener* listener) OVERRIDE;
109 virtual void RemoveOutputDeviceChangeListener(
110 AudioDeviceListener* listener) OVERRIDE;
112 virtual AudioParameters GetDefaultOutputStreamParameters() OVERRIDE;
113 virtual AudioParameters GetOutputStreamParameters(
114 const std::string& device_id) OVERRIDE;
116 virtual AudioParameters GetInputStreamParameters(
117 const std::string& device_id) OVERRIDE;
119 virtual std::string GetAssociatedOutputDeviceID(
120 const std::string& input_device_id) OVERRIDE;
125 // Shuts down the audio thread and releases all the audio output dispatchers
126 // on the audio thread. All audio streams should be freed before Shutdown()
127 // is called. This must be called in the destructor of every AudioManagerBase
131 void SetMaxOutputStreamsAllowed(int max) { max_num_output_streams_ = max; }
133 // Called by each platform specific AudioManager to notify output state change
134 // listeners that a state change has occurred. Must be called from the audio
136 void NotifyAllOutputDeviceChangeListeners();
138 // Returns user buffer size as specified on the command line or 0 if no buffer
139 // size has been specified.
140 int GetUserBufferSize();
142 // Returns the preferred hardware audio output parameters for opening output
143 // streams. If the users inject a valid |input_params|, each AudioManager
144 // will decide if they should return the values from |input_params| or the
145 // default hardware values. If the |input_params| is invalid, it will return
146 // the default hardware audio parameters.
147 // If |output_device_id| is empty, the implementation must treat that as
148 // a request for the default output device.
149 virtual AudioParameters GetPreferredOutputStreamParameters(
150 const std::string& output_device_id,
151 const AudioParameters& input_params) = 0;
153 // Returns the ID of the default audio output device.
154 // Implementations that don't yet support this should return an empty string.
155 virtual std::string GetDefaultOutputDeviceID();
157 // Get number of input or output streams.
158 int input_stream_count() { return num_input_streams_; }
159 int output_stream_count() { return num_output_streams_; }
162 struct DispatcherParams;
163 typedef ScopedVector<DispatcherParams> AudioOutputDispatchers;
165 class CompareByParams;
167 // Called by Shutdown().
168 void ShutdownOnAudioThread();
170 // Max number of open output streams, modified by
171 // SetMaxOutputStreamsAllowed().
172 int max_num_output_streams_;
174 // Max number of open input streams.
175 int max_num_input_streams_;
177 // Number of currently open output streams.
178 int num_output_streams_;
180 // Number of currently open input streams.
181 int num_input_streams_;
183 // Track output state change listeners.
184 ObserverList<AudioDeviceListener> output_listeners_;
186 // Thread used to interact with audio streams created by this audio manager.
187 scoped_ptr<base::Thread> audio_thread_;
188 mutable base::Lock audio_thread_lock_;
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_;
195 // Map of cached AudioOutputDispatcher instances. Must only be touched
196 // from the audio thread (no locking).
197 AudioOutputDispatchers output_dispatchers_;
199 DISALLOW_COPY_AND_ASSIGN(AudioManagerBase);
204 #endif // MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_