Dave has posted a tutorial at his site on
using Quicktime to create video files with 5.1 sound. Taking video files he captured with an Elgato EyeTV, he uses mAC3dec and Quicktime Pro to separate the sound into the six
channels of 5.1 sound. It looks pretty straight forward, but I don't have an EyeTV, so I couldn't try it out. Thanks
for sharing, Dave!