SND_DUMMY(4)

NAME
snd_dummy - Dummy audio driver

SYNOPSIS
To load the driver at boot time, place the following line in loader.conf(5):

    snd_dummy_load="YES"

DESCRIPTION
The snd_dummy driver implements a virtual testing device, meaning it does not correspond to a physical sound card. It is intended for testing, so that test programs do not need to rely on hardware being present in the machine in order to run.

The driver attaches as a regular sound(4) device, with two channels (one playback and one recording), as well as a mixer.

Playback works by discarding all input, and recording by returning silence (zeros).

FILES
/dev/dsp.dummy
    Alias to the device's /dev/dsp%d file created by sound(4). This makes it easy for tests to open the dummy device when there are more devices present in the system.

SEE ALSO
sound(4), loader.conf(5), loader(8)

AUTHORS
The snd_dummy driver was implemented by Christos Margiolis <christos@FreeBSD.org> under sponsorship from the FreeBSD Foundation.

CAVEATS
Because the driver automatically attaches once the module is loaded, it can only be attached once.