On Sat, Dec 13, 2008 at 04:53:21PM +0900, Colin Didier wrote: > * Jacob Meuser <jake...@sdf.lonestar.org> [2008-12-13 07:02:29 +0000]: > > On Sat, Dec 13, 2008 at 03:36:35PM +0900, Colin Didier wrote: > > > Hi, > > > > > > I've a similar problem on my IBM X31 with my USB DAC (a StyleAudio > > > Carat-Peridot) using mplayer with the libsndio backend. The audio > > > stutters and crackles a lot, but only when playing movies. If I play > > > audio files, if I use the sun audio backend, or if I use the integrated > > > sound-card of my laptop, everything is fine. > > > > that is quite interesting. can you show us what "audioctl blocksize" > > gives you when the sound is strange? > > $ audioctl -f /dev/audioctl1 blocksize > blocksize=24000 > > > > When I plug the USB DAC, I see the following lines in my dmesg: > > > > > > uaudio0 at uhub2 port 1 configuration 1 interface 0 "Burr-Brown from TI > > > USB Audio DAC" rev 1.10/1.00 addr 2 > > > uaudio0: audio rev 1.00, 2 mixer controls > > > audio1 at uaudio0 > > > uhidev0 at uhub2 port 1 configuration 1 interface 2 "Burr-Brown from TI > > > USB Audio DAC" rev 1.10/1.00 addr 2 > > > uhidev0: iclass 3/0 > > > uhid0 at uhidev0: input=1, output=0, feature=0 > > > > > > So I use mplayer with the following command > > > env AUDIODEVICE=/dev/audio1 mplayer my_movie.avi > > > > > > I tried to use "aucat -l -f /dev/audio1" but it doesn't work and ends > > > with the following error: > > > > > > /dev/audio1: Device not configured > > > safile_new: can't open device > > > > aucat -l runs in full-duplex mode by default. you can change it to > > play only with '-m play'. > > Oh I see. Now "aucat -l -m play -f /dev/audio1" works and there is no > more stutters nor crackles in movies. But the audio sounds robotic (even > using the integrated sound-card). >
The current resampling algorithm is poor quality; depending on the combination of the movie rate, device rate and DAC hw, you'll hear more or less "metallic" noise. If you care about quality, the simpler is to avoid resampling when possible until this gets fixed. -- Alexandre
