Sorry, I misread the docs. There is NTSC support.
I have one small request thought
Could you add I420 and YV12 support?
The only free avi2yuv tool I could find:
http://www.ee.surrey.ac.uk/Personal/S.Worrall/dloads/
converts uncompressed RGB stuff (= tried XviD encoding, didn't work) to I420.