We recommend that you create videos in .mp4 format if you’ll be uploading them to VoiceThread. Other formats may work, but there’s no guarantee.
There are a number of “container” formats like QuickTime, WMV, and AVI that are like an envelope containing the video. A QuickTime movie, for example, can be encoded by close to 40 different codecs. VoiceThread can convert the vast majority of them, but not all.
Also, you can embed a YouTube video into your VoiceThread presentation via its link. VoiceThread’s Importing Media From Another Website page explains how.
