Prezi Public accounts are free for use, and require no annual fee. Each Public account is limited to 100MB of presentation storage space. Public users also have access to the Prezi offline player software, subject to the end user license agreement associated with that software.
You can insert audio in prezis in MP3, M4A, FLAC, WMA, WAV, OGG, AAC, MP4, and 3GP format. Follow the link below to see how.
You can insert the following video file formats to Prezi: FLV, F4V, AVI, MOV, WMV, F4V, MPG, MPEG, MP4, M4V, 3GP. Follow the link below to see how to use these different formats with your Prezi.