I am not saying the quality will look good at all, but is 160x576 compliant ? Also how about 320x576 ?

I have found the KDVD templates to be both great and also slightly weird. As I can often fit 4 movies per DVD in FULL mode but then I find it hard sometimes to fit 5 hours on to a DVD in HALF mode. I am guessing 10 hours can only be reached on ultra widscreen movies ? I am trying to get between 7 and 8 hours of fullscreen footage PAL on to 1 DVD using a KDVD template, but it isn't proving easy (without the footage looking real bad). Transcoding using IC8 can help a lot though.

Does it make a difference what type of file I encode from ? Like VCD to KDVD or AVI to KDVD ? Does resulting file size change dependant on the file type ?

No. Those resolutions are not DVD compliant. Not full screen
You can get ~10 hours at half D-1, but only with wide screen material. Forget recompression
A re-compression of a VCD to KDVD will have quality loss.
Same from AVI (DivX) to KDVD, unless the source is extremely high bitrate, and exceptional quality.

-kwag

Thanks for the reply. Funny thing about 160x576 is that it will work (or it does via DVD Workshop and my normal DVD player) but it is quite bad quality. So does this mean it is compliant, sort of ? As usually DVD workshop is very strict, but it went straight through without re-encoding the footage. Put it in to my Cyberhome DVD player and it played, but like I said, not overly great on quality (subtitle text on screen couldn't be read clearly). But may be good for those desperate to cram footage on (but it is worse then EP mode). I haven't tested 320x576 yet but if that works too, then great, even if it is only on Cyberhomes (not tested on others yet).

I will keep fiddling

This sounds quite interesting to me, since I have downloaded some anime fansubs which are 640x480 DivX.
I will give the 320x480 resolution a try, using NTSC 29fps, for this is exactly half the resolution of the source. And "640 to 320" sounds better than "640 to 352,704 or even 720" to me.