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The aoss script for OSS emulation

One of the aims of ALSA is to provide full OSS compatibility for OSS applications. ALSA does this by emulating the old OSS sound driver. ALSA has two alternative methods of emulating the old OSS sound driver:

For example, to use the xmms media player program, which in some old version is only an OSS application, you can start it using aoss:

   aoss xmms

together with the OSS output plugin of xmms. Usage of aoss is preferred over kernel-level OSS emulation because if you need use the PCM plugin layer, enabling the use of the DmixPlugin or asym. If you don't need software-mixing of streams or any other PCM layer functionality, then go with the kernel-level emu (modules), since they are much easier to set up: Just load them.

For details of how to use the kernel modules see the OSSEmulation page.

You can define PCM devices in the .asoundrc which will then get used by the aoss script (pcm.dsp0). See the man page of aoss. Also I think that you can tell it which mixer to use; use a "ctl.mixer0" entry for that.


Important It seems that aoss does not support libc's fopen() function calls. So all OSS apps that use the sound devices by calling fopen() won't work with aoss. The sox program, for example, won't work. I don't know of any others though I suspect that there are quite a few.

Teamspeak uses fopen() too in the current version. Teamspeak 3.x is supposed to have native ALSA support though. Maybe aoss will be adapted to catch calls to libc's fopen() and other related functions.

For alsa-oss-1.0.5 there's a patch available which should fix the fopen stuff:\~tapas/alsa-oss-fopen.patch

this one builds on the above one:\~tapas/alsa-oss-fopen2.patch

and fixes some minor issues..

\ Please test and let me know tapas.

Update: the fix should be in alsa cvs now.. please grab from there. dunno when it will come into the next release.. Update2: seems as if the fix is official since release 1.0.6a

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Category: OSS