Subject: RE: [linux-audio-dev] re: [linux-audio-user] A bit of goodnews--paper now available for your viewing pleasure and/or comments
From: Fernando Pablo Lopez-Lezcano (nando_AT_ccrma.stanford.edu)
Date: Fri May 28 2004 - 22:38:03 EEST
> Hmm, it would be a fun project then to come up with a profiler of various
> audio cards by recording and then capturing a specific buffer of audio data.
> Then by comparing them (assuming that this drift is constant) see how many
> empty samples there are (or if the playback is slower, how many samples are
> missing), and then create a framework that allows real-time resampling in
> order to compensate for that discrepancy whenever multiple soundcards are
> being used :-D
Yes, of course that is doable. I don't think you need to profile them.
Just measure the drift between the hardware pointers for both cards as
you play.
> Of course this would be relatively pointless as for any serious work one
> should always resort to a better card rather than experimenting with this.
> Nonetheless it may prove to be a fun project sometime down the road ;-)
A long time ago (98/98 or so) I _have_ used two sb128 soundcards without
sample sync to play back four channel pieces under linux. If the cards
are of the same model and manufacturing batch the drift will be small.
Small enough to play a 10 or 15 minute 4 channel piece without clicks[*]
:-)
Guilty :-)
-- Fernando
[*] but either the front or back speakers will slowly drift away from
you as the piece progresses, not a real problem :-)
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