Best DVD-compliant MPEG settings?

I cannot get a good MPEG video quality out of my exports; everything that I do export ends up looking very blocky, and I don't think it is very DVD-worthy :cry:

Currently I am exporting the file at the m2t HDV 720 30p option (2nd-best*); then I am building a DVD in QDVDAuthor, which remasters (read: loses quality) the mpeg into a DVD-compliant mpeg. The results are decent but not great; still blocky. My experience with the straight-to-vob in KDEnlive has had very poor quality (this is better but not great).

Any suggestions? I am using the 20080412 svn of the local build of KDEnlive, ffmpeg, mlts; my video is Raw DV (NTSC) captured in Kino. I can get a decent AVI/DV final product with this Custom Export parameter string:
format=dv deinterlace=1 pix_fmt=yuv411p size=720x480 profile=dv_ntsc
but nothing of quality with MPEG. Sadly, QDVDAuthor doesn't recognize the output of that custom format.

*2nd-best, because I don't have enough time to spend at the highest quality :)

Forums:

Same problem here. I'm using the KDE4 SVn version, but can't find out how to render to DVD quality 16:9 NTSC....

I'm not too familiar with KDenlive yet, but HDV 720 refers to Hi-Def 1280x720 resolution (progressive) while dvd's use NTSC 720x480/486 (interlaced) resolution. So I'm assuming your upscaling the video by quite a bit. Additionally you might check what order the deinterlace takes place in relation to the scaling.