you can also use the edl feature of mplayer for cutting out parts of a video, f.e. commercial breaks.
Start mplayer like this "mplayer -gui 1 -edlout video.edl video" then start playing the video, and press "i" everytime to mark the beginning and the end of a part which should be cut out.
Now quit mplayer and start it like this "mplayer -gui 1 -edl video.edl video", this won't cut the movie it just skips the marked parts to see if you marked the correct parts!
To cut the movie, you have to use mencoder "mencoder -edl video.edl -ovc copy -oac copy video -o newvideo".
Its fast, because the video isn't reencoded, only the marked parts will be cut out.
I have created some small scripts for this and put them in ambient video mimetype for easy access. I also have a small converter script to convert cutlists (for onlinetvrecorder cutlists) to edl format.
