Combine videos with mencoder

[daviddoria]

I'm trying to concatenate a bunch of videos in a directory. I've used this before:

mencoder -of mpeg -nosound -ovc lavc -lavcopts vcodec=mpeg2video -o combined.mpg *

but I'm getting 'New video file has different resolution or colorspace than the previous one". I'm assuming thats because they aren't all the same size, etc. Is there anyway to tell it "convert with padding" to make them all the same size by padding with black space? Or is there a better way to do this?

Thanks,
Dave