This directory contains all the supported audio devices
| Device name | Description |
|---|---|
| a2dp | Bluetooth A2DP connection. When selected, the default input (onboard mic) is selected. |
| btsco | Bluetooth SCO/HFP connection. |
| hac | HAC telecoil used for hearing aids. When selected, the default input (onboard mic) is selected. |
| handset | The handset on the device phone receiver. When selected, the default input (onboard mic) is selected. |
| hdmi | HDMI audio connection. When selected, the default input (onboard mic) is selected. |
| headphone | Headphone with no mic input. When selected, the default input (onboard mic) is selected. |
| headset | Headset with mic input. |
| lineout | An output device connected through the headset jack. When selected, the default input (onboard mic) is selected. |
| speaker | The main speaker on the device (handsfree on mobile phones). |
| tones | A virtual audio device for the system tones. |
| toslink | Optical audio device ("Toshiba Link") used by some receivers. |
| tty | Telecommunications device for the deaf (connected through the headphone jack). |
| usb | Used for USB audio devices. |
| voice | A virtual audio device for voice content. |
| wifidisplay | Wireless connection to TVs for A/V playback. |
The status of the default audio device is published to the /pps/services/audio/devices/default object.
The default device has the following attributes:
| Attribute | Description |
|---|---|
| device | Name of the default audio device used for playback (e.g., speaker). |
| input.device | The current default audio device for capture (e.g. handset). |
| input.path | The mountpoint to access the input device (e.g., /dev/snd/pcmPreferredp). |
| path | Path to the actual audio interface for input and output (e.g., /dev/snd/pcmPreferredp). |
Each device has the following attributes:
| Attribute | Data type | Description |
|---|---|---|
| audioconfig | String | Configuration of the audio output channels (e.g., "2.0", "5.1"). Note that this is used only by the hdmi device. |
| audioprocessing | Boolean | Indicates whether the device can do some audio processing that the system won't need to handle (e.g., a headset may be able to do noise cancellation). |
| connected | Boolean | Indicates whether a given device is connected. |
| controlpps | String | The path of the device's PPS control object. If this object exists, then the device is controlled by a PPS interface instead of an actual audio driver. |
| dependency | Boolean | Indicates whether this device depends on another device (this device has no effect unless the other is also connected). |
| hwinchans | Number | Total number of input channels on the hardware. |
| inchans | Number | Default number of channels that the client should use for multimedia audio capture. For
example, for a device with four microphones, the client might use two for multimedia, in which case
inchans would be 2 (hwinchans would be
4).
Note:
If inchans is 0, then no input is supported for this device.
|
| input.device | String | The current default audio device for capture (e.g. handset). This attribute appears only in the default object. |
| input.mixer | String | Name of the mixer group implemented by the input device for volume control. Values depend on
the particular audio drivers and on the Audio Manager configuration. Default names are:
For details about audio drivers, see the io-audio manager and the deva-* entries in the QNX Neutrino Utilities Reference. |
| input.path | String | The mountpoint to access the input device (e.g., /dev/snd/pcmPreferredc). |
| keepalive | Boolean | Indicates whether the output device is to be kept alive when no audio stream is active. |
| mixer | String | Name of the mixer group implemented by the output device for volume control. As for
input.mixer, values depend on the particular audio drivers and on the Audio Manager configuration. Default names are:
|
| mutable | Boolean | Indicates whether the device can be muted. During audio transitions from one device to another, the Audio Manager may mute both devices until the transition is complete so as to avoid sound leaks. |
| numchans | Number | Number of audio channels supported by the device. |
| order | String | The channel order (e.g., FL,FR) for two channels. Note that this is used only by the hdmi device. |
| path | String | Path to the actual audio interface for input and output (e.g., /dev/snd/pcmPreferredp). |
| public | Boolean | Indicates whether the device can be heard publicly (e.g., the value for a speaker would be true). |
| supported | Boolean | Indicates whether the device is physically installed on the target. |
| suspended | Boolean | Indicates whether the device is temporarily disabled by the system. |
| volumecontrol | String | Type of volume control supported:
|