Why is 480x480 not full screen on the DVD player?

[Mike Schoenborn]

Why is 480x480 not full screen on the DVD player?

I've used the "fiddle Tivo's bitrates" shortcut to get streams off the
Tivo, and massaged them enough to produce an MPG that is acceptable to
NTI's CD-Maker Pro's SVCD requirements (480x480, 4:3, 2600kbps, 192kbps,
44.1KHz, etc). The SVCD plays on a Pioneer 440 DVD player, but the
image is vertically compressed (and perhaps horizontally expanded a bit,
though I haven't measured it). The results are watchable, but a line of
noise/data along the top edge of the image (is this what is called
"dot crawl"?) is awfully annoying.

Any hints why I'm not getting my money's worth in the vertical?

Thanks,
Mike

(BTW, results from a full, 8 x realtime, TMpegEnc conversion fill the
screen, so that tends to suggest it's not the DVD player itself).

(I'm purposely not mentioning the exact steps I took because that level
of detail would probably belong in a more SVCD-related forum. I felt
a brief description might be enough to identify an obvious problem by
those folks here who have expertise down in the guts of MPEG streams).