Join / Concatenate / Glue mp4 files to one file using mencoder

I tried to concatenate some mp4 videos using mencoder like this:

mencoder -ovc copy -oac pcm P10408*.mp4 -o new.mp4

When trying to play the new video I was asked to install some additional decoder ITU H.264 Of course, I could install it but on the other hand manpage for mencoder claims that -ovc copy just copies the original without re-encoding.

So, apparently -ovc copy changed the format of the original mp4 (which I can replay without that H.264 decoder).

I also tried -ovc raw -vf format=mp4 which generates a file I can replay without problems but is blown up to 10 GB (oroiginal files in sum are about 200 MB).

And I tried -ovc lavc -lavcopts vcodec=mpeg4 which generates a file I can replay without problems but lacks in video quality.

By the way, concatenating .mov files with -ovc copy produces a new file I can replay without problem.

Question:

Is there a way to use -ovc copy to produce a new file of the same format as the original files?