Script to get media files that are used in the active sequence

I have a script that replaces all the media in a project, which is great. Except when you have 600 movie files to go through!  I would like to provide the user the option to just replace the footage used in the active sequence, but I can't figure out how to get the file names associated with the clips in a sequence.

The closest I've gotten to the video clips is "app.project.activeSequence.videoTracks". I've used the object browser and the getProps and getMethods function from the PProPanel sample, and I can't locate a way to the media file info for a sequence.

Thanks for your time!