i followed minion's advice in another thread. I extracted the audio file and changed the length to the exact length of the video file. then a multiplexed the two files, which were equal lengths, but the video starts out good but ends up out of synch. what did I do wrong? Another thing: why is it when i de-mulitplex a file, the video file is shortened by about 8 seconds compared to the original? thanks in advance for any help.