Does anyone know if there is an app for mac similar to dvdpatcher for PC?
That would be an app that lets you change the vertical and horizontal resolution and aspect ratio of an mpeg2 or vob file (i.e. change the header information, not the actual content of course).
And as in DVDpatcher it should have an option to patch the whole file, not just the first header.

I know I can edit the files "manually" with hexedit, but it doesn't work well with files over 2GB, and it's very messy.

Wouldn't this be a pretty simple app to code? Anyone? (I wish i could do it myself)