Audio drivers again?

Michal Seta mis at
Thu Mar 25 20:25:03 CET 1999

On Wed, 24 Mar 1999, Miller Puckette wrote:

|Hi list,
|I'm now running Pd under Red Hat Linux, and (like everybody else) I've
|run into some questions about audio/MIDI drivers.

Welcome to the club :)

|1.  I've got an OplSa3 soundcard and so far I've been using the OSS drivers
|(the free ones from the RedHat 5.2 CDROM).  I notice that the ADC noise
|floor (measured in the test tone patch) is around 45 dB, whereas the
|SAME HARDWARE gets a noise floor of 20 dB under NT.  I've got a wild
|guess that this might be related to which of the two "DMA channels" I assign
|to "DMA0" and "DMA1"...  any other wild guesses out there?

I have noticed the noise in the OplSa3 but haven't been able to deal with
it.  In my case the DMA0 and DMA1 must have the same parameters as they
have in Windoze.  Otherwise I don't have full duplex.  And I'm using the
commercial version of OSS.  I've noticed that when OSS probes the
soundcard it often returns different values for the DMA and IRQ settings.
It seems to be safer to set it up manually.

|2.  I also want to test the ALSA drivers.  I note in the ALSA FAQ (part
|of the release) that ALSA comes with an OSS compatibility package.  So
|is there any advantage to using the ALSA drivers "natively" (as s_alsa.s
|does) rather than just using s_linux.c and having ALSA emulate OSS audio?

I had problems compiling and getting ALSA to work on my machine.  It was a
IBM thinkpad so I assume there must be a problem right there.  As I don't
have much more access to that machine I can't even give any more insight.
ALSA refused to work with with OplSa3 and I haven't really tried it with
the OSS emulation.  

However if you find a way around I'd like to know ;)

.....                            ....
     ......   Michal Seta  ......
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