i think i'll try this "-ao alsa:pcm=default".
but as i already mentioned, the softdevice complains about the ac3
stream. perhaps something like "-ao alsa:pcm=default#ac3=default#" will
do the job.
so, my real problem was, that i hadn't found any information in how to
build up this "-ao whatever" line.
it would be nice to know, how this whole '-ao alsa:"description"' thing
is working. e.g. where can if find out, what to use as $dev_name in:
vdr mailing list