media/audio/audio_manager_base.h

   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/synchronization/lock.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 base {
  25 class Thread;
  26 }
  27
  28 namespace media {
  29
  30 class AudioOutputDispatcher;
  31
  32 // AudioManagerBase provides AudioManager functions common for all platforms.
  33 class MEDIA_EXPORT AudioManagerBase : public AudioManager {
  34  public:
  35   // Name of the generic "default" device.
  36   static const char kDefaultDeviceName[];
  37   // Unique Id of the generic "default" device.
  38   static const char kDefaultDeviceId[];
  39
  40   virtual ~AudioManagerBase();
  41
  42   virtual scoped_refptr<base::MessageLoopProxy> GetMessageLoop() OVERRIDE;
  43   virtual scoped_refptr<base::MessageLoopProxy> GetWorkerLoop() OVERRIDE;
  44
  45   virtual string16 GetAudioInputDeviceModel() OVERRIDE;
  46
  47   virtual void ShowAudioInputSettings() OVERRIDE;
  48
  49   virtual void GetAudioInputDeviceNames(
  50       media::AudioDeviceNames* device_names) OVERRIDE;
  51
  52   virtual AudioOutputStream* MakeAudioOutputStream(
  53       const AudioParameters& params,
  54       const std::string& input_device_id) OVERRIDE;
  55
  56   virtual AudioInputStream* MakeAudioInputStream(
  57       const AudioParameters& params, const std::string& device_id) OVERRIDE;
  58
  59   virtual AudioOutputStream* MakeAudioOutputStreamProxy(
  60       const AudioParameters& params,
  61       const std::string& input_device_id) OVERRIDE;
  62
  63   // Called internally by the audio stream when it has been closed.
  64   virtual void ReleaseOutputStream(AudioOutputStream* stream);
  65   virtual void ReleaseInputStream(AudioInputStream* stream);
  66
  67   // Creates the output stream for the |AUDIO_PCM_LINEAR| format. The legacy
  68   // name is also from |AUDIO_PCM_LINEAR|.
  69   virtual AudioOutputStream* MakeLinearOutputStream(
  70       const AudioParameters& params) = 0;
  71
  72   // Creates the output stream for the |AUDIO_PCM_LOW_LATENCY| format.
  73   // |input_device_id| is used by unified IO to open the correct input device.
  74   virtual AudioOutputStream* MakeLowLatencyOutputStream(
  75       const AudioParameters& params, const std::string& input_device_id) = 0;
  76
  77   // Creates the input stream for the |AUDIO_PCM_LINEAR| format. The legacy
  78   // name is also from |AUDIO_PCM_LINEAR|.
  79   virtual AudioInputStream* MakeLinearInputStream(
  80       const AudioParameters& params, const std::string& device_id) = 0;
  81
  82   // Creates the input stream for the |AUDIO_PCM_LOW_LATENCY| format.
  83   virtual AudioInputStream* MakeLowLatencyInputStream(
  84       const AudioParameters& params, const std::string& device_id) = 0;
  85
  86   // Listeners will be notified on the AudioManager::GetMessageLoop() loop.
  87   virtual void AddOutputDeviceChangeListener(
  88       AudioDeviceListener* listener) OVERRIDE;
  89   virtual void RemoveOutputDeviceChangeListener(
  90       AudioDeviceListener* listener) OVERRIDE;
  91
  92   virtual AudioParameters GetDefaultOutputStreamParameters() OVERRIDE;
  93   virtual AudioParameters GetInputStreamParameters(
  94       const std::string& device_id) OVERRIDE;
  95
  96  protected:
  97   AudioManagerBase();
  98
  99
 100   // Shuts down the audio thread and releases all the audio output dispatchers
 101   // on the audio thread.  All audio streams should be freed before Shutdown()
 102   // is called.  This must be called in the destructor of every AudioManagerBase
 103   // implementation.
 104   void Shutdown();
 105
 106   void SetMaxOutputStreamsAllowed(int max) { max_num_output_streams_ = max; }
 107
 108   // Called by each platform specific AudioManager to notify output state change
 109   // listeners that a state change has occurred.  Must be called from the audio
 110   // thread.
 111   void NotifyAllOutputDeviceChangeListeners();
 112
 113   // Returns the preferred hardware audio output parameters for opening output
 114   // streams. If the users inject a valid |input_params|, each AudioManager
 115   // will decide if they should return the values from |input_params| or the
 116   // default hardware values. If the |input_params| is invalid, it will return
 117   // the default hardware audio parameters.
 118   virtual AudioParameters GetPreferredOutputStreamParameters(
 119       const AudioParameters& input_params) = 0;
 120
 121   // Get number of input or output streams.
 122   int input_stream_count() { return num_input_streams_; }
 123   int output_stream_count() { return num_output_streams_; }
 124
 125  private:
 126   struct DispatcherParams;
 127   typedef ScopedVector<DispatcherParams> AudioOutputDispatchers;
 128
 129   class CompareByParams;
 130
 131   // Called by Shutdown().
 132   void ShutdownOnAudioThread();
 133
 134   // Max number of open output streams, modified by
 135   // SetMaxOutputStreamsAllowed().
 136   int max_num_output_streams_;
 137
 138   // Max number of open input streams.
 139   int max_num_input_streams_;
 140
 141   // Number of currently open output streams.
 142   int num_output_streams_;
 143
 144   // Number of currently open input streams.
 145   int num_input_streams_;
 146
 147   // Track output state change listeners.
 148   ObserverList<AudioDeviceListener> output_listeners_;
 149
 150   // Thread used to interact with audio streams created by this audio manager.
 151   scoped_ptr<base::Thread> audio_thread_;
 152   mutable base::Lock audio_thread_lock_;
 153
 154   // The message loop of the audio thread this object runs on. Used for internal
 155   // tasks which run on the audio thread even after Shutdown() has been started
 156   // and GetMessageLoop() starts returning NULL.
 157   scoped_refptr<base::MessageLoopProxy> message_loop_;
 158
 159   // Map of cached AudioOutputDispatcher instances.  Must only be touched
 160   // from the audio thread (no locking).
 161   AudioOutputDispatchers output_dispatchers_;
 162
 163   DISALLOW_COPY_AND_ASSIGN(AudioManagerBase);
 164 };
 165
 166 }  // namespace media
 167
 168 #endif  // MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_