Thanks for your reply Jan,
My windows version is 32bits.
I can't find any revision number on the "about" of avidemix.
I downloaded it from here: http://www.clubic.com/telecharger-fiche30172-avidemux.html
When i talked about preview, it is in the filters window, indeed.
"When you use view filtered output and play the video, you should see the end result. Only whilst playing."
--> When i close the filters window i see the original video. I only see it filtered on the filters window and i can't really play it but just move the cursor and see it frame per frame if you know what i mean.
"You did use the 1st save icon? "
"The filtered view is the last icon on the top right. Both underscored in red."
--> I cant find it!
If it does not work with mp4 muxer, try mp4v2 muxer.
--> Should i download this? I dont get what you mean sorry
Thanks again anyways