Independent ALSA and linux audio support site

OSS emulation

From the ALSA wiki

Jump to: navigation, search


OSS Emulation in Alsa

One of the aims of ALSA is to provide full OSS compatibility for OSS applications. ALSA has an OSS emulation which supports all of the OSS devices listed below.

There are two different OSS emulation methods in ALSA (and several not in ALSA itself; see the "Alternatives" section below):

  1. Kernel-level OSS emulation via the snd-pcm-oss and snd-mixer-oss and snd-seq-oss modules
  2. The aoss script from the alsa-oss package.

The latter has the advantage of being able to use any device from ALSA's PCM plugin layer during the emulation. This enables software-based mixing of streams for OSS apps. See the DmixPlugin page for more details of how to do software mixing.

Note that neither method works for all OSS apps.

Issues and Limitations

Particular issues include:

OSS Emulation Topics

More Info

Much of this page and it's sub-topic pages is derived from\~iwai/OSS-Emulation.html from the official ALSA docs. It may be more frequently updated or contain more extensive information than this wiki.

DmixPlugin includes some tips on using dmix with OSS.

OSS and dmix by Richard is an a step by step guide on how to use xmms while playing Unreal Tournament. It probably will also help with Enemy Territory, Quake3, and other things that use OSS, fopen(), and/or mmap.


ALSA is not the first sound system (and probably not the last) to have a need to capture and convert output from programs written for OSS. If ALSA's OSS Emulation is not doing it for you, you can look into:

Retrieved from ""

Category: OSS