-----Original Message----- From: Michael Lechasseur [mailto:mlecha@music.mcgill.ca] Is there a simple way to test for a driver's full-duplex capabilities outside of pd? I've tried mixing several inputs sources such as line-in, cd audio in, and playing an mp3, which can all heard via the sound cards output. This suggests to me that my sound card and drivers are full-duplex capable outside of pd. Or is this a naive assumption?
Be careful here. Most of the times, the output you hear is the monitor output from the soundcard. This means, the cd in for examples doesnŽt even go through the adc - dac section. This is all done by the analog mixer of the card.
Most of the times full-duplex - not full-duplex is a feature of the card, every more or less serious driver would then support that mode (The full duplex mode of standard SoundBlaster cards is an exception here - full duplex drivers use a sort of "crippled" 8 bit mode for either record or playback).
What makes pd that critical about it, is latency. Pd tries to allocate audiobuffers as small as possible. There are certain limitations for this audiobuffer size.
The doc's for OSS/Free suggest that these drivers arehalf-duplex only. I didn't actually try it outside of pd before I bought the commercial drivers. Are you getting full-duplex audio outside of pd using OSS/Free?
The PCI128 is definitely full duplex :), so yes I get full duplex with OSS/Free and large audiobuffer size.
I am unfamiliar with the audiobuffer size parameter. DoI want to set this for the driver or loading pd?
just start pd with:
# pd -audiobuf 100
for example, where 100 is the length of the audiobuffer in milli seconds.
I have found the OSS email tech support to be excellentand really fast. Which is why I paid for the commercial drivers. Why don't you get in touch with them?
Well, if I really started to comment on this topic ...... Basically, my opinion is, that Linux got that stable because of open source ... see ? Still I want to support OSS/Linux too, itŽs just not high priority for me ..
Hey, I still have my old SB16. Maybe I can use that asan input device and use my PCI128 as output. I doubt that win95 would like that configuration, but ALSA supports it. Thanks for the idea.
Mhmm .. yes could work.
I found that the ALSA drivers sounded better than the OSSones, but have no testing gear to prove it.
I can only imagine that some filters and/or 3D support are set differently, otherwise the sound is a feature of the card, not the driver. ALSA lets you control this settings, whereas IŽm not sure if OSS does. Check out the ALSA mixer.
ha! I have the ambition, but I doubt the technical knowledge yet.There are people in the know here at school though. Maybe between I can convince them to give a hand for a good cause.
Convinve them to play around with pd, maybe they will start to get interested then.
Guenter