Until last world update I was happily using the following .asoundrc [1] to duplicate stereo sound from front to rear channels (the former is connected to a 2.1 system, the latter to a hi-fi equipment):
pcm.ch40dup { type route slave.pcm surround40 slave.channels 4 ttable.0.0 1 ttable.1.1 1 ttable.0.2 1 ttable.1.3 1 } and then "mplayer -channels 4 -ao alsa:device=ch40dup" gave me the duplicated stereo sound on 4 channels. After last update alsa-lib went from 1.0.19 to 1.0.20 and kernel 2.6.29 to 2.6.30 and mplayer sound stopped working from any channel with the following error: Trying preferred audio driver 'alsa', options 'device=ch40dup' alsa-init: requested format: 48000 Hz, 2 channels, 9 alsa-init: using ALSA 1.0.20 alsa-init: setup for 1/2 channel(s) alsa-init: using device ch40dup alsa-init: pcm opened in blocking mode [AO_ALSA] Unable to get initial parameters: Invalid argument Failed to initialize audio driver 'alsa:device=ch40dup' Could not open/initialize audio device -> no sound. If I remove the "-ao alsa:device..." bit from the mplayer command line I get stereo sound from the front speakers only. This is with HDA-intel driver on Nvidia nForce430/AD1986 chipset, icewm desktop. I just read from the kernel doc [2] that there is a "model name" parameter that defaults to '6stack' while my model is '3stack' so tonight I will try that. Any other hints before I try upstream? thanks, raf [1] http://alsa.opensrc.org/index.php/Playing_stereo_on_surround_sound_setup_%28Howto%29 [2] /usr/src/linux/Documentation/sound/alsa/HD-Audio-Models.txt