[MEncoder-users] Joining different video files together

[Dennis Duggen]

Hi list

I've tried to search the web up and down to look for a solution. I have 
a lot of different video files i want to put into one single video file.

The files are different in fps and dimension. Some are 4:3, some 16:9 
and so on.

I've tried:

mencoder -ovc copy -oac copy -o out.avi file1.avi file2.avi

and something similar with ffmpeg. But none of the solutions give the 
desired result.
Mencoder stops with the error that fps and dimension must be the same.

Here now my idea:

Is it possible to put every video file into one frame. Lets say 4:3 is 
my targettet ratio. So if the next file is in 16:9 there are simply 
added som black rows in top and bottom. In the end every file has the 
same dimension.

Is this possible? And if how?

Thanks in advance for any help.

Dennis