[MPlayer-users] Strange problem when merging two avi

[Fabio S.]

Hi all,

I have a strange problem when merging two avi.
First, let me say that the two files have the same parameters: both are 
produced from two quicktime clips produced by my videocam using the 
commands

mencoder -oac mp3lame -lameopts cbr -ovc lavc -lavcopts
   vcodec=mpeg4:vbitrate=3000:vpass=1:mbd=2:trell:v4mv:autoaspect:cmp=3:subcmp=3:mbcmp=3
   -demuxer lavf -ffourcc DIVX    in.mp4 -o out.avi

mencoder -oac mp3lame -lameopts cbr -ovc lavc -lavcopts
   vcodec=mpeg4:vbitrate=3000:vpass=2:mbd=2:trell:v4mv:autoaspect:cmp=3:subcmp=3:mbcmp=3
   -demuxer lavf -ffourcc DIVX    in.mp4 -o out.avi

Done this, I merge the two 1.avi 2.avi with

mencoder -oac copy -ovc copy -o 1-2.avi 1.avi 2.avi

Well, what happens is that when I look the merged file 1-2.avi, then in 
the point where the two files join for a few seconds the second one looks 
somewhat "corrupted", like if it where taken with a much lower resolution. 
After 3-4 seconds, then it looks good again.

What can I do?

Another try I did, is to use avimerge to merge the two files, but then the 
second one gets the audio out of sync, and I couldn't resolve this.
I have seen this is a FAQ, but I didn't find an answer for my case...  :-(((

Thanks a lot

Fabio