Adding Borders to an mpeg1 (VCD) for DVD authoring possible?

[schamp]

I have these old VCD's (or better PAL xVCD's) with a Resolution of 720 by xxx, where xxx is just the height of the actual movie. I never added any borders to make up to the full 576, cause my Sony DVD Player just ate it like that. But now I would like to burn some of these movies on DVD's and the Authoring software doesn't take an mpg with say 720x320, so I patched the headers to 720x576, but then the whole movie shows in the upper part of the TV screen and not in the middle which is not very nice to look at. I there any way to add those missing borders to the mpeg-1 file or an authoring tool that will do the correct letterboxing automatically?

I know I could reencode the whole stuff, but thats exactly what I don't want to do, cause of quality loss and time.

I searched everywhere and so far I couldn't find an answer to this problem. I know that an mpg can't be resized without encoding, but I don't want to resize, just wanna add some borders at the top and bottom.

PS: I also repatched the finished VOB's back to 720x320 and tried that and my Sony player does fine with that (as it does with the according VCD's), but other players won't deal with that of course. I hope someone can help me, cause I really would hate to reencode everything again just cause of some missing black.

[SaSi]

Can you write a simple program to read one file, look for values and replace some, writing output to another? If so, perhaps there's an easy way out.

Let us know.

[schamp]

I don't think I know what you mean.

[SaSi]

If you can write a small program, then perhaps there's a way to add to the vide stream the information it needs to center the actual video frame on screen. It's a wild guess but will likely succeed.

Since the video is made up of slices, each 16 pixels high, the idea is to insert empty slices to the top and bottom (say 3 slices each side) so that the full 576 (or 480) vertical resolution is filled. The existing slices must also be renumbered (i.e. 1,2,3,4... must become 4,5,6,7,... if you add 3 empty slices to the top).

This approach would not involve re-encoding the files you have and the process should be fast. One only needs to write the code.

How many files do you have?

[schamp]

OK, now I am sure what you mean , but I don't have the knowledge nor the time to program something like that, so thats why I was wondering if there is already a tool arround, that would fix this, or maybe a DVD Authoring Software that doesn't care about the vertical size of the mpg and adds the missing portion automatically.

I have around 50 or more vcd's that I would like to convert like this, but in order to write a program I would have to have perfect knowledge about the way an mpeg1 file is built up and that I truely don't have.