Open Sound System
Open Sound System provides an audio mixer device to mix multiple audio streams being played to the same audio device. Recoring and full duplex is supported too with most devices.
The vmix driver is a 2nd generation virtual mixing driver. Similar functionality is provided by the older softoss driver.
Unlike softoss the vmix driver doesn't create visible audio devices. Instead the driver creates "hidden" audio engines that will be automatically used when some application opens the master device. However the ossinfo program shows these virtual engines with the -e option. Also the -a and -A options will show these engines if the -v (verbose) option is used.
The vmix driver doesn't create dedicated mixer (volume control) device. Instead it hooks to the mixer of the parent (master) device. The parent device will have few vmix specific volume and peak meter controls attached.
vmix.conf Device configuration file