Device attributes

The configuration file can be used to configure device attributes.

Valid device types are defined in Definitions in audio_manager_device.h.

You can configure the following device attributes:

Attribute Description
audioconfig Configuration of the audio output channels (e.g., "2.0", "5.1"). Note that this is used only by the hdmi device.
audioprocessing 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): true or false.
BUTTONS The number of buttons the device supports. If not present, the default 0 is assumed.
connected This type of device is connected to the system: true or false.
controlpps 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 Indicates whether this device depends on another device (this device has no effect unless the other is also connected).
hwinchans Total number of input channels on the hardware.
inchans 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).
input.mixer 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:
  • BT A2DP In
  • BT SCO In
  • HDMI In
  • Input Gain
  • Tones In
  • TosLink In
  • USB In
  • Voice In
  • WIFI In

For details about audio drivers, see the io-audio manager and the deva-* entries in the QNX Neutrino Utilities Reference.

input.path Path for the audio stream input; for example /dev/snd/pcmPreferredc.
keepalive Indicates whether the output device is to be kept alive when no audio stream is active: true or false.
mixer 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:
  • BT A2DP Out
  • BT SCO Out
  • HDMI Out
  • Output GaOut
  • Tones Out
  • TosLOutk Out
  • USB Out
  • Voice Out
  • WIFI Out

For details about audio drivers, see the io-audio manager and the deva-* entries in the QNX Neutrino Utilities Reference.

mutable The output device can be muted: true or false.
numchans Number of audio channels supported.
order The first audio channel; see list of audio channels definitions in Definitions in audio_manager_device.h.
path Path for the audio stream output; for example, /dev/snd/pcmPreferredp.
public Indicates whether the device can be heard publicly (e.g., the value for a speaker would be true).
supported Set to true if this device type is supported: true or false.
suspended Indicates whether the device is temporarily disabled by the system.: true or false.
vadsupport Voice Activity Detection (VAD) is supported: true or false.
volumecontrol The type of volume control; see AUDIO_VOLUME_CONTROL_NAMES in Definitions in audio_manager_device.h.