svcd header ratio 4:3>16:9 change?? how???

[starlight-kitty]

How do i change the 4:3 ratio to 16:9 without reencoding the mpeg2.
I have a perfect mpeg2 480x576 25 fps, but it should have a ratio of 16:9 instead of 4:3
i do have some 16:9 ratio 480x576 mpeg2 files that play perfectly 16:9 when the keep ratio is on.
however, i also do have a 4:3 ratio mpeg2 that should have been 16:9, but something went wrong, so now it said aspect ratio 4:3 when it should have said 16:9
is there a way to change the vcd headers in such a way, that only the ratio is changed, not the actual video data?

[wkc]

Have you tried DVDPatcher?

Make sure you just patch the "Frist header only".