Audio Questions

[Aim]

When I added a webcam last night my audio stopped working. I was very surprised.

I got it working again but have no clue what I did. In loader.conf I did the following changes:

# Original
# hint.hdac.0.cad0.nid17.config="as=1 seq=15"
# hint.hdac.0.cad0.nid22.config="as=1 seq=0"
# end of original
hint.hdac.0.cad0.nid21.config="as=1 seq=15"
hint.hdac.0.cad0.nid28.config="as=1 seq=0"

Is there something I can read that explains all these elements? What is a NID, for example? I just guessed after reading dmesg.