HTCondorWiki: Hosting Video

 You can use ffmpeg to do lossless trimming of files (say, to break a single video into multiple videos, or to trim off dead time).  {link: http://askubuntu.com/questions/35605/splitting-an-mp4-file source }
 
 {code}
-# START and LENGTH are seconds or hh:mm:ss.
-ffmpeg -acodec copy -vcodec copy -ss START -t LENGTH -i ORIGINALFILE.mp4 OUTFILE.mp4
+ffmpeg -ss START -t LENGTH -i ORIGINALFILE.mp4 -codec copy OUTFILE.mp4
 {endcode}
 
 {subsection: Cropping}