SND_DUMMY(4)

📦
version 15.1 · 2 versions
, in freebsd 15.1

🎀 SND_DUMMY(4) 🎀

okay bestie, welcome to the Kernel Interfaces Manual page for SND_DUMMY(4) — yes, the dummy audio driver is the main character today, and she's lowkey iconic for testing. 💅✨

💖 NAME 💖

snd_dummy — Dummy audio driver. literally the virtual sound-card vibe, no physical hardware required. 🫶

✨ SYNOPSIS ✨

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

snd_dummy_load="YES"

🦋 DESCRIPTION 🦋

okay so the snd_dummy driver implements a virtual testing device, meaning it does not correspond to a physical sound card. she's not a real sound card, bestie — just a testing device doing her thing. 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. no cap, that's the whole point. 🫶

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

Playback works by discarding all input, and recording by returning silence (zeros). so playback is like “not me throwing your audio away 💀”, and recording gives you silence — literally 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. it's giving convenience, honestly. 💖

🌈 SEE ALSO 🌈

👑 AUTHORS 👑

The snd_dummy driver was implemented by Christos Margiolis <christos@FreeBSD.org> under sponsorship from the FreeBSD Foundation. we love a sponsored icon. 🫶

💀 CAVEATS 💀

Because the driver automatically attaches once the module is loaded, it can only be attached once. so like, one attach only, bestie — no double-dipping. 🙈

Debian, October 22, 2025, SND_DUMMY(4) — bye bestie, go run your tests and slay 💖✨

📦 where this page comes from