Very familiar with tmpgenc for VCD and just got a DVD burner. Few quesitons.

When putting a VCD file on a DVD the only thing I need to change is the audio. It seems tmpgenc DVD author does this automatically when adding a vcd compliant file to a DVD, is this right?

Doom 9's SVCD header trick seems to work to put a SVCD compliant file on a DVD for me. Is there any difference here and if re-encoding an SVCD file to DVD whats the best setting? I assume no need to up the bitrate since it's the same codec, but maybe if increasing the resolution (if is this even advisable) I should?

Most importantly, I know there is no direct correlation b/t a Divx, Xvid, etc. video bitrate and an mpeg-2 when re-encoding for a DVD, but is it the same for the audio? I know there are different audio codecs in those, but if encoding to layer II with tmpgenc, what is the normal target audio bitrate, or is it totally dependent on the source? Any agreed upon default?