I finally got some time off and have been working on this the last
couple of days. I put some wave files on an SD card and have been
trying aplay. I still get ticks and pops, but not as often as when
playing from squeezeplay. I tried killing jive_alsa and jive so there
was not much going on and that didn't make much difference. 

I also did a lot of work playing around with different thread
priorities, especially the USB driver and that made almost no
difference.

I also tried many different alsa buffer properties through aplay
switches and was never able to get it any better. I can make it worse
by playing with these parameters, but I can't make it better. 

So the issue is not just something to do with squeezeplay, its in the
alsa/USB driver hierarchy. I'm not getting any xruns from alsa so it
might be something to do with the generic USB driver. 

Leaving the priorities alone and going back to squeezeplay the rate of
clicks and pops goes up significantly for 44.1 and 88.2, much lower for
48 and 96. This sounds like a difference between internal and external
clocks, which would mean that the async is not working right. BUT when
using just aplay there is no difference in the rate of clicks and pops
with different sample rate. Async is handled in the alsa usb audio
driver so it should work the same from either squeezeplay or aplay. 

I also ran the Touch with my hacked in much newer alsa USB audio driver
and got the same results, so I don't think its an issue with the async
handling.

At this point I'm running out of ideas. 44.1 and 88.2 are much worse
than 48 and 96, but I can't figure out why. 

With aplay I still have clicks and pops, but I don't know where they
are comming from, thread/interrupt priorities don't seem to be the
issue, neither does buffer size. I also tried different nrpacks and
that didn't make any difference to the click/pop behavior. 

Does anybody else have any thoughts for possible places to look? I'm
kind of at a standstill right now. 

John S.


-- 
JohnSwenson
------------------------------------------------------------------------
JohnSwenson's Profile: http://forums.slimdevices.com/member.php?userid=5974
View this thread: http://forums.slimdevices.com/showthread.php?t=82110

_______________________________________________
Touch mailing list
[email protected]
http://lists.slimdevices.com/mailman/listinfo/touch

Reply via email to