Here's how I processed some digital camera videos for uploading to Flickr. The things I wanted to adjust were:

• Shortening the length
• Removing the original Audio track
• Adding new music, using a sound loop

Nothing particularly that seems like it should be hard. (Details after the break)

First, I found a sound loop from SoundSnap.com.

By installing Audacity and using "Effect: Repeat", I was easily able to make the sound loop repeat enough times to cover the video.

Next, I stripped out the original audio using ffmpeg, while converting the file to the the MPEG format, and preserving the quality:


ffmpeg -i MVI_3876.AVI -an -sameq out.mpg


Finally, I added in my new music, while also truncating the video to be 16 seconds:


ffmpeg -i out.mpg -i my.mp3 -sameq -t 16 final.mpg


While I would happy to know about graphical ways to accomplish what ffmpeg was doing, it wasn't particularly hard to read the documentation for ffmpeg and come up with these commands.