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. Would anyone already know the answers to these?
- 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 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?
- Same question for MIDI... is it likely to be worth the trouble of
rewriting the MIDI I/O code to address ALSA natively?
If any of you have any experience that might suggest answers to these I'd be grateful!
Miller
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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Michal Seta -
Miller Puckette