At Sat, 07 Sep 2002 05:40:02 +0900, Patrick Shirkey wrote: > > Takashi Iwai wrote: > > >>the Tascam US-428 driver (copied / changed from snd-usb-audio ) showed a > >>similar problem. > >>I worked around it by not using ASYNC_UNLINKing of the urbs. > > > > > > yes, this could be the problem. > > this happend once and i thought it fixed on the alsa side, but it > > seems that there is something wrong on usb driver itself. > > why it happened on jack is because jack caused xrun - and the driver > > tries to stop the stream and unlinks urbs with ASYNC_UNLINK flag. > > > > anyway, i changed the code on cvs to use SYNC unlink mode as default. > > this may have a drawback that the urbs still exist even if the driver > > stops the stream after detection of xrun. but usually this doesn't > > matter so much. > > > > i've tested normal playbacks and it seems working. > > > > > > I have actually managed to get a stream from alsaplayer through without > a hang but the sound is choppy. > > I will make a test signal so you can hear what I am getting. It's > similar to what was happening before the driver was fixed last time. > > I got this output from jackd. this happened after I started jack and > didn't connect any other apps. Maybe it timed out but I don't think it > is supposed to. > > ---- > $ jackd -v -d alsa -d q4 > jackd 0.37.1 > Copyright 2001-2002 Paul Davis and others. > jackd comes with ABSOLUTELY NO WARRANTY > This is free software, and you are welcome to redistribute it > under certain conditions; see the file COPYING for details > > 512 waiting for signals > creating alsa driver ... q4|1024|2|48000|swmon
the resolution of usb-audio device is 1ms. this value is fixed. thus you need to adjust the period size according to the sample rate if you want to achieve the real-time response with a small period size. that means: - the sample rate should be 48kHz (or 32kHz), which can be divided by 1000, and should not be 44.1kHz. - the period size should be aligned to (rate / 1000). in the case of 48kHz, the period size should be 48, 96, 192, ... please try this combination. Takashi ------------------------------------------------------- This sf.net email is sponsored by: OSDN - Tired of that same old cell phone? Get a new here for FREE! https://www.inphonic.com/r.asp?r=sourceforge1&refcode1=vs3390 _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
