I have two videos from youtube which are part of the same file. However youtube encoded them in mp4 format with two different resolutions. I want to join the files using AviDemux.

So I resized one of the videos to match the size of the other using AviDemux. (Mencoder Lanzcos3).

When I append in AviDemux and view the joined videos they play seamlessly. However I save as mp4 and try to open with VLC and the Video stops at the point where the files merged. The audio is ok.

Also when I inserted the resized file AviDemux prompted the index was not up to date and wanted to rebuild frame. I tried that and it crashed.

Info on the files:


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I also tried joining the files with Yamb but VLC opened a software RGB Direct X output window and played both clips simultaneously instead of concatenating them.


I believe there is a problem with the rencoded file not matching the original, but I can't figure out what the problem is.

Can anyone assist me in joining these two files?