got 2 alsa "cards" : nforce 2 (onboard, card 0) and bt878 (tv card, card 1)

alsa works well with both cards

when using gst-recorder, using alsasrc as audio source, it probes the following
device name and fails :

ALSA lib pcm_hw.c:1057:(snd_pcm_hw_open) open /dev/snd/pcmC1D0p failed: Aucun
fichier ou répertoire de ce type

the problem is that card 1 (bt878) has no playback /dev/snd entry
it has 2 capture dev ( pcmC1D0c and pcmC1D1c, first digital and second analog)

i don't know how alsa capabilities are probed for now (alsa-lib doing it himself
 or gstreamer having it's own code)

so, device=hw:1,0 or hw:1,1 depending on what audio input we want for bt878

<BBB> osssrc checks the element type
<BBB> by going through all pads in our padlist
<BBB> if we contain a source pad, it opens using RDONLY
<BBB> if we contain a sinkpad, WRONLY
<BBB> if we contain none, it tries the mixer
<BBB> alsa should do the same