On Wed, 26 Mar 2008, Helge Fredriksen wrote: > Ok, here's what I found out: > > Since these cards seem to lack the support for doing frequency conversion in > HW, you simply need to use the alsa plugin > plughw instead of hw when referring to the card: > > arecord -Dplughw:0 test.wav > aplay -Dplughw:0 test.wav AFAIK, alsa frequency conversion is pretty primative ( linear interpolation) which produces a huge amount of noise/distortion. See www.theory.physics.ubc.a/soundcard/resample.html for a comparison of various rate conversion routines on a sound sample roughly similar to real music (pink noise type spectrum) The problem is that better conversion routines require a longer time and thus have a longer latency than the simplest techniques. Mind you I have no idea how the sound cards with hardware conversion do it either, so they might be just as nasty as the linear software routines. > > Then alsa do the conversion for you... Strange though that giving hw the > argument > -r 48000 didn't seem to work either. > > Credit to Florian Bomers for helping me out. > > Regards, > Helge Fredriksen > > On Wed, Mar 19, 2008 at 8:41 PM, Darrell Bellerive <drbellerive@xxxxxxxx> > wrote: > >> Helge >> >> Please document what ever you do and post it here. There are others with >> these >> cards who would also like to read configuration how-to's. >> >> Darrell >> >> >> On Wednesday 19 March 2008 03:29, Helge Fredriksen wrote: >>> I just bought a couple of MAudio cards to test out (Revolution 5.1 and >>> Audiophile 2496). I'm trying to test the sound using arecord and aplay, >> but >>> no matter which format I choose I get the message: >> >> >> -- >> Darrell Bellerive >> >> ------------------------------------------------------------------------- >> This SF.net email is sponsored by: Microsoft >> Defy all challenges. Microsoft(R) Visual Studio 2008. >> http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ >> _______________________________________________ >> Alsa-user mailing list >> Alsa-user@xxxxxxxxxxxxxxxxxxxxx >> https://lists.sourceforge.net/lists/listinfo/alsa-user >> > -- William G. Unruh | Canadian Institute for| Tel: +1(604)822-3273 Physics&Astronomy | Advanced Research | Fax: +1(604)822-5324 UBC, Vancouver,BC | Program in Cosmology | unruh@xxxxxxxxxxxxxx Canada V6T 1Z1 | and Gravity | www.theory.physics.ubc.ca/ ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
