I have a M-Audio Delta 410 and I seem to have it working in 4xstereo mode. Now I'm trying to refine my technique, as right now the only way I know to send MP3s to a specific device (or channel) is:
mpg123 -s test.mp3 | aplay --device=channel2 --channels=2 -f cd --buffer-time=1000000 - But the problem is that aplay takes up a huge amount of CPU time. Here is output from 'top' with two such processes running on different channels: PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND 4229 root 15 0 1876 1616 1476 R 32.6 0.4 0:38 aplay 4235 root 15 0 1876 1616 1476 R 30.6 0.4 0:38 aplay 4228 root 0 -20 3500 3500 3304 S < 5.5 0.9 0:06 mpg123 4234 root 0 -20 3436 3436 3240 S < 4.7 0.8 0:05 mpg123 Note that each 'aplay' is taking over 30% of my CPU time while the actual MP3 decoder is only taking around 5%. If I just let mpg123 play the MP3 directly, it uses ESD and I get: PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND 4701 root 15 0 1036 1032 828 S 5.7 0.2 0:00 mpg123 4703 root 15 0 440 440 356 S 3.8 0.1 0:00 esd Note the significantly reduced CPU usage. I'm hoping to be able to play four streams on this system while it is performing other tasks as well. So I'm looking for help on how to get this down. I see two approaches I can take: 1) Figure out how to reduce aplay's CPU usage and/or implement a bigger buffer to avoid skips. 2) Find another way to play MP3s on all four channels at once. My requirements are: 1) Must be able to run from the command line (or at least control it from the command line, like I think I could do with xmms if I was to run it in a fake X Window session). 2) Must be able to play to any of the four stereo outputs of my sound card. A big plus is if the program can control the output volume directly so that I can mix in speech over the music when necessary. Question -- when mpg123 uses esd, is it basically using the OSS compatibility layer? -- Kirk Bauer <[EMAIL PROTECTED]> http://linux.kaybee.org | www.autorpm.org | www.logwatch.org ------------------------------------------------------- SF.Net is sponsored by: Speed Start Your Linux Apps Now. Build and deploy apps & Web services for Linux with a free DVD software kit from IBM. Click Now! http://ads.osdn.com/?ad_id=1356&alloc_id=3438&op=click _______________________________________________ Alsa-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-user
