Hi, I read in the forum: http://www.kinovea.org/en/forum/viewtopic.php?id=155 It's a request for saving dual video. I started to work on this during this weekend. I got so far that I was able to create a Videofile containing the combined video files. I still have some problem with creating the videofile. I also need to look a bit more into adding keyframes etc. Hopefully I will have time tonight to create a branch with that code. /Erik