IAudioDeviceManager

Audio device management methods.

IAudioDeviceManager provides methods for audio device testing. You can call the queryInterface method to get the IAudioDeviceManager interface.

enumeratePlaybackDevices

Enumerates the audio playback devices.

virtual IAudioDeviceCollection* enumeratePlaybackDevices() = 0;

Details

Attention: This method is for Windows and macOS only.

This method returns an IAudioDeviceCollection object that includes all audio playback devices in the system. With the IAudioDeviceCollection object, the application can enumerate video devices. The application must call the release method to release the returned object after using it.

Returns

  • Success: Returns an IAudioDeviceCollection object that includes all audio playback devices in the system.
  • Failure: NULL.

enumerateRecordingDevices

Enumerates the audio capture devices.

virtual IAudioDeviceCollection* enumerateRecordingDevices() = 0;

Details

Attention: This method is for Windows and macOS only.

This method returns an IAudioDeviceCollection object that includes all audio capture devices in the system. With the IAudioDeviceCollection object, the application can enumerate video devices. The application must call the release method to release the returned object after using it.

Returns

followSystemLoopbackDevice

Sets whether the loopback device follows the system default playback device.

virtual int followSystemLoopbackDevice(bool enable) = 0;

Details

Since
v4.0.1

This method is for Windows and macOS only.

Parameters

enable
Whether to follow the system default audio playback device:
  • true: Follow the system default audio playback device. When the default playback device of the system is changed, the SDK immediately switches to the loopback device.
  • false: Do not follow the system default audio playback device. The SDK switches the audio loopback device to the system default audio playback device only when the current audio playback device is disconnected.

Returns

  • 0: Success.
  • < 0: Failure.

followSystemPlaybackDevice

Sets the audio playback device used by the SDK to follow the system default audio playback device.

virtual int followSystemPlaybackDevice(bool enable) = 0;

Details

Attention: This method is for Windows and macOS only.

Parameters

enable
Whether to follow the system default audio playback device:
  • true: Follow the system default audio playback device. The SDK immediately switches the audio playback device when the system default audio playback device changes.
  • false: Do not follow the system default audio playback device. The SDK switches the audio playback device to the system default audio playback device only when the currently used audio playback device is disconnected.

Returns

  • 0: Success.
  • < 0: Failure.

followSystemRecordingDevice

Sets the audio recording device used by the SDK to follow the system default audio recording device.

virtual int followSystemRecordingDevice(bool enable) = 0;

Details

Attention: This method is for Windows and macOS only.

Parameters

enable
Whether to follow the system default audio recording device:
  • true: Follow the system default audio playback device. The SDK immediately switches the audio recording device when the system default audio recording device changes.
  • false: Do not follow the system default audio playback device. The SDK switches the audio recording device to the system default audio recording device only when the currently used audio recording device is disconnected.

Returns

  • 0: Success.
  • < 0: Failure.

getLoopbackDevice

Gets the current loopback device.

virtual int getLoopbackDevice(char deviceId[MAX_DEVICE_ID_LENGTH]) = 0;

Details

Since
v4.0.1

This method is for Windows and macOS only.

Parameters

deviceId
Output parameter, the ID of the current loopback device.
The maximum length is MAX_DEVICE_ID_LENGTH_TYPE.

Returns

  • 0: Success.
  • < 0: Failure.

getPlaybackDevice

Retrieves the audio playback device associated with the device ID.

virtual int getPlaybackDevice(char deviceId[MAX_DEVICE_ID_LENGTH]) = 0;

Details

Attention: This method is for Windows and macOS only.

Parameters

deviceId
Output parameter. The device ID of the audio playback device. The maximum length is MAX_DEVICE_ID_LENGTH_TYPE.

Returns

  • 0: Success.
  • < 0: Failure.

getPlaybackDeviceInfo [1/2]

Retrieves the information of the audio playback device.

virtual int getPlaybackDeviceInfo(char deviceId[MAX_DEVICE_ID_LENGTH], char deviceName[MAX_DEVICE_ID_LENGTH]) = 0;

Details

Attention: This method is for Windows and macOS only.

Parameters

deviceId
Th ID of the audio playback device. The maximum length is MAX_DEVICE_ID_LENGTH_TYPE.
deviceName
Output parameter; the name of the playback device. The maximum length is MAX_DEVICE_ID_LENGTH_TYPE.

Returns

  • 0: Success.
  • < 0: Failure.

getPlaybackDeviceInfo [2/2]

Get the information and type of the audio playback device.

virtual int getPlaybackDeviceInfo(char deviceId[MAX_DEVICE_ID_LENGTH], char deviceName[MAX_DEVICE_ID_LENGTH], char deviceTypeName[MAX_DEVICE_ID_LENGTH]) = 0;

Details

Since
v4.3.1

This method applies to macOS only.

Parameters

deviceId
Th ID of the audio playback device. The maximum length is MAX_DEVICE_ID_LENGTH_TYPE.
deviceName
Output parameter; the name of the playback device. The maximum length is MAX_DEVICE_ID_LENGTH_TYPE.
deviceTypeName
Output parameter; indicates the type of audio playback devices, such as built-in, USB and HDMI. The maximum length is MAX_DEVICE_ID_LENGTH_TYPE.

Returns

  • 0: Success.
  • < 0: Failure.

getPlaybackDeviceMute

Retrieves whether the audio playback device is muted.

virtual int getPlaybackDeviceMute(bool *mute) = 0;

Parameters

mute
Whether the audio playback device is muted.
  • true: The audio playback device is muted.
  • false: The audio playback device is unmuted.

Returns

  • 0: Success.
  • < 0: Failure.

getPlaybackDeviceVolume

Retrieves the volume of the audio playback device.

virtual int getPlaybackDeviceVolume(int *volume) = 0;

Parameters

volume
An output parameter. The volume of the audio playback device. The value range is [0,255].

Returns

  • 0: Success.
  • < 0: Failure.

getRecordingDevice

Gets the current audio recording device.

virtual int getRecordingDevice(char deviceId[MAX_DEVICE_ID_LENGTH]) = 0;

Details

Attention: This method is for Windows and macOS only.

Parameters

deviceId
An output parameter. The device ID of the recording device. The maximum length is MAX_DEVICE_ID_LENGTH_TYPE.

Returns

  • 0: Success.
  • < 0: Failure.

getRecordingDeviceInfo [1/2]

Retrieves the information of the audio recording device.

virtual int getRecordingDeviceInfo(char deviceId[MAX_DEVICE_ID_LENGTH], char deviceName[MAX_DEVICE_ID_LENGTH]) = 0;

Details

Attention: This method is for Windows and macOS only.

Parameters

deviceId
Th ID of the audio playback device. The maximum length is MAX_DEVICE_ID_LENGTH_TYPE.
deviceName
Output parameter; the name of the playback device. The maximum length is MAX_DEVICE_ID_LENGTH_TYPE.

Returns

  • 0: Success.
  • < 0: Failure.

getRecordingDeviceInfo [2/2]

Get the information and type of the audio capturing device.

virtual int getRecordingDeviceInfo(char deviceId[MAX_DEVICE_ID_LENGTH], char deviceName[MAX_DEVICE_ID_LENGTH], char deviceTypeName[MAX_DEVICE_ID_LENGTH]) = 0;

Details

Since
v4.3.1

This method applies to macOS only.

Parameters

deviceId
Th ID of the audio playback device. The maximum length is MAX_DEVICE_ID_LENGTH_TYPE.
deviceName
Output parameter; the name of the playback device. The maximum length is MAX_DEVICE_ID_LENGTH_TYPE.
deviceTypeName
Output parameter; indicates the type of audio capturing devices, such as built-in, USB and HDMI. The maximum length is MAX_DEVICE_ID_LENGTH_TYPE.

Returns

  • 0: Success.
  • < 0: Failure.

getRecordingDeviceVolume

Retrieves the volume of the audio recording device.

virtual int getRecordingDeviceVolume(int *volume) = 0;

Details

Note: This method applies to Windows only.

Parameters

volume
An output parameter. It indicates the volume of the audio recording device. The value range is [0,255].

Returns

  • 0: Success.
  • < 0: Failure.

setLoopbackDevice

Sets the loopback device.

virtual int setLoopbackDevice(const char deviceId[MAX_DEVICE_ID_LENGTH]) = 0;

Details

Since
v4.0.1

The SDK uses the current playback device as the loopback device by default. If you want to specify another audio device as the loopback device, call this method, and set deviceId to the loopback device you want to specify.

You can call this method to change the audio route currently being used, but this does not change the default audio route. For example, if the default audio route is microphone, you call this method to set the audio route as a sound card before joinging a channel and then start a device test, the SDK conducts device test on the sound card. After the device test is completed and you join a channel, the SDK still uses the microphone for audio capturing.

Note:

This method is for Windows and macOS only.

The scenarios where this method is applicable are as follows:

Use app A to play music through a Bluetooth headset; when using app B for a video conference, play through the speakers.
  • If the loopback device is set as the Bluetooth headset, the SDK publishes the music in app A to the remote end.
  • If the loopback device is set as the speaker, the SDK does not publish the music in app A to the remote end.
  • If you set the loopback device as the Bluetooth headset, and then use a wired headset to play the music in app A, you need to call this method again, set the loopback device as the wired headset, and the SDK continues to publish the music in app A to remote end.

Parameters

deviceId

Specifies the loopback device of the SDK. You can get the device ID by calling enumeratePlaybackDevices. Connecting or disconnecting the audio device does not change the value of deviceId.

The maximum length is MAX_DEVICE_ID_LENGTH_TYPE.

Returns

  • 0: Success.
  • < 0: Failure.

setPlaybackDevice

Sets the audio playback device.

virtual int setPlaybackDevice(const char deviceId[MAX_DEVICE_ID_LENGTH]) = 0;

Details

Attention: This method is for Windows and macOS only.

You can call this method to change the audio route currently being used, but this does not change the default audio route. For example, if the default audio route is speaker 1, you call this method to set the audio route as speaker 2 before joinging a channel and then start a device test, the SDK conducts device test on speaker 2. After the device test is completed and you join a channel, the SDK still uses speaker 1, the default audio route.

Parameters

deviceId

The ID of the specified audio playback device. You can get the device ID by calling enumeratePlaybackDevices. Connecting or disconnecting the audio device does not change the value of deviceId.

The maximum length is MAX_DEVICE_ID_LENGTH_TYPE.

Returns

  • 0: Success.
  • < 0: Failure.

setPlaybackDeviceMute

Mutes the audio playback device.

virtual int setPlaybackDeviceMute(bool mute) = 0;

Parameters

mute
Whether to mute the audio playback device:
  • true: Mute the audio playback device.
  • false: Unmute the audio playback device.

Returns

  • 0: Success.
  • < 0: Failure.

setPlaybackDeviceVolume

Sets the volume of the audio playback device.

virtual int setPlaybackDeviceVolume(int volume) = 0;

Details

Note: This method applies to Windows only.

Parameters

volume
The volume of the audio playback device. The value range is [0,255].

Returns

  • 0: Success.
  • < 0: Failure.

setRecordingDevice

Sets the audio capture device.

virtual int setRecordingDevice(const char deviceId[MAX_DEVICE_ID_LENGTH]) = 0;

Details

Attention: This method is for Windows and macOS only.

You can call this method to change the audio route currently being used, but this does not change the default audio route. For example, if the default audio route is microphone, you call this method to set the audio route as bluetooth earphones before joinging a channel and then start a device test, the SDK conducts device test on the bluetooth earphones. After the device test is completed and you join a channel, the SDK still uses the microphone for audio capturing.

Parameters

deviceId

The ID of the audio capture device. You can get the Device ID by calling enumerateRecordingDevices. Connecting or disconnecting the audio device does not change the value of deviceId.

The maximum length is MAX_DEVICE_ID_LENGTH_TYPE.

Returns

  • 0: Success.
  • < 0: Failure.

setRecordingDeviceVolume

Sets the volume of the audio capture device.

virtual int setRecordingDeviceVolume(int volume) = 0;

Details

This method is for Windows and macOS only.

Parameters

volume
The volume of the audio recording device. The value range is [0,255]. 0 means no sound, 255 means maximum volume.

Returns

  • 0: Success.
  • < 0: Failure.

startAudioDeviceLoopbackTest

Starts an audio device loopback test.

virtual int startAudioDeviceLoopbackTest(int indicationInterval) = 0;

Details

This method tests whether the local audio capture device and playback device are working properly. After starting the test, the audio capture device records the local audio, and the audio playback device plays the captured audio. The SDK triggers two independent onAudioVolumeIndication callbacks at the time interval set in this method, which reports the volume information of the capture device (uid = 0) and the volume information of the playback device (uid = 1) respectively.

Attention:
  • This method is for Windows and macOS only.
  • You can call this method either before or after joining a channel.
  • This method only takes effect when called by the host.
  • This method tests local audio devices and does not report the network conditions.
  • When you finished testing, call stopAudioDeviceLoopbackTest to stop the audio device loopback test.

Parameters

indicationInterval
The time interval (ms) at which the SDK triggers the onAudioVolumeIndication callback. Agora recommends setting a value greater than 200 ms. This value must not be less than 10 ms; otherwise, you can not receive the onAudioVolumeIndication callback.

Returns

  • 0: Success.
  • < 0: Failure.

startPlaybackDeviceTest

Starts the audio playback device test.

virtual int startPlaybackDeviceTest(const char* testAudioFilePath) = 0;

Details

This method tests whether the audio device for local playback works properly. Once a user starts the test, the SDK plays an audio file specified by the user. If the user can hear the audio, the playback device works properly.

After calling this method, the SDK triggers the onAudioVolumeIndication callback every 100 ms, reporting uid = 1 and the volume information of the playback device.

The difference between this method and the startEchoTest method is that the former checks if the local audio playback device is working properly, while the latter can check the audio and video devices and network conditions.

Attention: Call this method before joining a channel. After the test is completed, call stopPlaybackDeviceTest to stop the test before joining a channel.

Parameters

testAudioFilePath
The path of the audio file. The data format is string in UTF-8.
  • Supported file formats: wav, mp3, m4a, and aac.
  • Supported file sample rates: 8000, 16000, 32000, 44100, and 48000 Hz.

Returns

  • 0: Success.
  • < 0: Failure.

startRecordingDeviceTest

Starts the audio capturing device test.

virtual int startRecordingDeviceTest(int indicationInterval) = 0;

Details

This method tests whether the audio capturing device works properly. After calling this method, the SDK triggers the onAudioVolumeIndication callback at the time interval set in this method, which reports uid = 0 and the volume information of the capturing device.

The difference between this method and the startEchoTest method is that the former checks if the local audio capturing device is working properly, while the latter can check the audio and video devices and network conditions.

Note: Call this method before joining a channel. After the test is completed, call stopRecordingDeviceTest to stop the test before joining a channel.

Parameters

indicationInterval
The interval (ms) for triggering the onAudioVolumeIndication callback. This value should be set to greater than 10, otherwise, you will not receive the onAudioVolumeIndication callback and the SDK returns the error code -2. Agora recommends that you set this value to 100.

Returns

  • 0: Success.
  • < 0: Failure.
    • -2: Invalid parameters. Check your parameter settings.

stopAudioDeviceLoopbackTest

Stops the audio device loopback test.

virtual int stopAudioDeviceLoopbackTest() = 0;

Details

Attention:
  • This method is for Windows and macOS only.
  • You can call this method either before or after joining a channel.
  • This method only takes effect when called by the host.
  • Ensure that you call this method to stop the loopback test after calling the startAudioDeviceLoopbackTest method.

Returns

  • 0: Success.
  • < 0: Failure.

stopPlaybackDeviceTest

Stops the audio playback device test.

virtual int stopPlaybackDeviceTest() = 0;

Details

This method stops the audio playback device test. You must call this method to stop the test after calling the startPlaybackDeviceTest method.

Attention: Call this method before joining a channel.

Returns

  • 0: Success.
  • < 0: Failure.

stopRecordingDeviceTest

Stops the audio capturing device test.

virtual int stopRecordingDeviceTest() = 0;

Details

This method stops the audio capturing device test. You must call this method to stop the test after calling the startRecordingDeviceTest method.

Note: Call this method before joining a channel.

Returns

  • 0: Success.
  • < 0: Failure.