The mp3 audio which appears to be most of your content would be no trouble at all, you would have to transcode any video to h.264 following the various discussions on this site about the best practices, generally 29.97 fps or 23.97 fps, AAC audio being the most important. Video stored on youtube won't work (actually, it will work, but you can't legally use it on Roku at the moment). You could use something like blip.tv to store your content or Vimeo.
- J.
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