нашел в FAQ такие строчки ( http://www.lavrsen.dk/twiki/bin/view/Motion/FrequentlyAskedQuestions#How_do_I... )
How can I get a big movie per day, not all the small ones? There is no builtin feature to do this in motion, but it's still quite easy:
If you are using MPEG1 format you can cat them directly:
cat *.mpg > daily.mpg or
cat newmpeg.mpg >> daily.mpg
If you are using another MPEG format then you need a tool to cat them.
...