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 24 namespace media { 25 26 class AudioOutputDispatcher; 27 28 // AudioManagerBase provides AudioManager functions common for all platforms. 29 class 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::SingleThreadTaskRunner> GetTaskRunner() OVERRIDE; 52 virtual scoped_refptr<base::SingleThreadTaskRunner> GetWorkerTaskRunner() 53 OVERRIDE; 54 55 virtual base::string16 GetAudioInputDeviceModel() OVERRIDE; 56 57 virtual void ShowAudioInputSettings() OVERRIDE; 58 59 virtual void GetAudioInputDeviceNames( 60 AudioDeviceNames* device_names) OVERRIDE; 61 62 virtual void GetAudioOutputDeviceNames( 63 AudioDeviceNames* device_names) OVERRIDE; 64 65 virtual AudioOutputStream* MakeAudioOutputStream( 66 const AudioParameters& params, 67 const std::string& 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) OVERRIDE; 75 76 // Called internally by the audio stream when it has been closed. 77 virtual void ReleaseOutputStream(AudioOutputStream* stream); 78 virtual void ReleaseInputStream(AudioInputStream* stream); 79 80 // Creates the output stream for the |AUDIO_PCM_LINEAR| format. The legacy 81 // name is also from |AUDIO_PCM_LINEAR|. 82 virtual AudioOutputStream* MakeLinearOutputStream( 83 const AudioParameters& params) = 0; 84 85 // Creates the output stream for the |AUDIO_PCM_LOW_LATENCY| format. 86 virtual AudioOutputStream* MakeLowLatencyOutputStream( 87 const AudioParameters& params, 88 const std::string& device_id) = 0; 89 90 // Creates the input stream for the |AUDIO_PCM_LINEAR| format. The legacy 91 // name is also from |AUDIO_PCM_LINEAR|. 92 virtual AudioInputStream* MakeLinearInputStream( 93 const AudioParameters& params, const std::string& device_id) = 0; 94 95 // Creates the input stream for the |AUDIO_PCM_LOW_LATENCY| format. 96 virtual AudioInputStream* MakeLowLatencyInputStream( 97 const AudioParameters& params, const std::string& device_id) = 0; 98 99 // Listeners will be notified on the GetTaskRunner() task runner. 100 virtual void AddOutputDeviceChangeListener( 101 AudioDeviceListener* listener) OVERRIDE; 102 virtual void RemoveOutputDeviceChangeListener( 103 AudioDeviceListener* listener) OVERRIDE; 104 105 virtual AudioParameters GetDefaultOutputStreamParameters() OVERRIDE; 106 virtual AudioParameters GetOutputStreamParameters( 107 const std::string& device_id) OVERRIDE; 108 109 virtual AudioParameters GetInputStreamParameters( 110 const std::string& device_id) OVERRIDE; 111 112 virtual std::string GetAssociatedOutputDeviceID( 113 const std::string& input_device_id) OVERRIDE; 114 115 virtual scoped_ptr<AudioLog> CreateAudioLog( 116 AudioLogFactory::AudioComponent component) OVERRIDE; 117 118 // Get number of input or output streams. 119 int input_stream_count() const { return num_input_streams_; } 120 int output_stream_count() const { return num_output_streams_; } 121 122 protected: 123 AudioManagerBase(AudioLogFactory* audio_log_factory); 124 125 // 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 128 // implementation. 129 void Shutdown(); 130 131 void SetMaxOutputStreamsAllowed(int max) { max_num_output_streams_ = max; } 132 133 // 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 135 // thread. 136 void NotifyAllOutputDeviceChangeListeners(); 137 138 // Returns user buffer size as specified on the command line or 0 if no buffer 139 // size has been specified. 140 int GetUserBufferSize(); 141 142 // 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; 152 153 // 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(); 156 157 private: 158 struct DispatcherParams; 159 typedef ScopedVector<DispatcherParams> AudioOutputDispatchers; 160 161 class CompareByParams; 162 163 // Called by Shutdown(). 164 void ShutdownOnAudioThread(); 165 166 // Max number of open output streams, modified by 167 // SetMaxOutputStreamsAllowed(). 168 int max_num_output_streams_; 169 170 // Max number of open input streams. 171 int max_num_input_streams_; 172 173 // Number of currently open output streams. 174 int num_output_streams_; 175 176 // Number of currently open input streams. 177 int num_input_streams_; 178 179 // Track output state change listeners. 180 ObserverList<AudioDeviceListener> output_listeners_; 181 182 // Thread used to interact with audio streams created by this audio manager. 183 base::Thread audio_thread_; 184 185 // The task runner of the audio thread this object runs on. Used for internal 186 // tasks which run on the audio thread even after Shutdown() has been started 187 // and GetTaskRunner() starts returning NULL. 188 scoped_refptr<base::SingleThreadTaskRunner> task_runner_; 189 190 // Map of cached AudioOutputDispatcher instances. Must only be touched 191 // from the audio thread (no locking). 192 AudioOutputDispatchers output_dispatchers_; 193 194 // Proxy for creating AudioLog objects. 195 AudioLogFactory* const audio_log_factory_; 196 197 DISALLOW_COPY_AND_ASSIGN(AudioManagerBase); 198 }; 199 200 } // namespace media 201 202 #endif // MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_ 203
