Subject: [linux-audio-dev] Re: Latency test (RTcmix/Linux)
From: Gary Scavone (gary_AT_ccrma.Stanford.EDU)
Date: Sat Jul 29 2000 - 04:42:18 EEST
Hi David,
This is not exactly along the same lines as your previous email, but I
did an audio i/o latency test a few weeks ago here at CCRMA for the
Midiman Delta 1010 card (8 channels analog i/o plus S/PDIF). I had a
scope hooked up to both the input and the output of the card and used
a square-wave generator for input (patched through the scope). I
wrote a simple STK program that read in a buffer of data and
immediately read it out. At 22 KHz, I was able to get down to about
18 ms i/o delay. At 44.1 KHz, however, I got it down to about 10 ms.
I was, of course, using the ALSA driver. I tried doing some
FIFO_SCHED priority stuff, but that didn't really affect the latency
(I didn't expect it would).
*******************************************************
* Gary Scavone *
* Center for Computer Research in Music & Acoustics *
* Stanford University *
* gary_AT_ccrma.stanford.edu *
* http://www-ccrma.stanford.edu/~gary/ *
*******************************************************
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