Takashi Iwai wrote: > 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 you little beauty :) The sound is infinitely better. I'll add a note to the docs. Hmm. Now I have no excuses when people ask to hear my music though ;) -- Patrick Shirkey - Boost Hardware Ltd. For the discerning hardware connoisseur Http://www.boosthardware.com Http://www.boosthardware.com/LAU/guide/ ======================================== "Um...symbol_get and symbol_put... They're kindof like does anyone remember like get_symbol and put_symbol I think we used to have..." - Rusty Russell in his talk on the module subsystem ------------------------------------------------------- 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
