Sigil - ebook editor. PDFUnlock! Audio & Video in ePub v3. One of the most obvious and impressive advantages that electronic books have over their print counterparts is the ability to contain moving images and sound.
While at first the EPUB spec didn't contemplate multimedia much at all, Apple's decision to use the new HTML5 video and audio elements in order to incorporate multimedia in ebooks clearly pushed the EPUB spec in that direction. Barnes & Noble now also supports these same tags for creating enhanced ebooks in its NOOK Color.