My iBooks client wants to embed a YouTube tutorial video in an iBook. It is one long video, so he wants to break it into 4 video widgets by starting it at a different point for each one. (Video Tutorial Part 1 starts at 00:00, then Part 2 at 4:38, Part 3 at 12:34, etc.)
I've successfully made a widget that will play Part 1, and modified the code as shown below for the next parts. But when I test the iBook on my iPad, they all start at 0:00.
This is the embed code for Part 2:
iframe width="1024" height="768" src="https://www.youtube.com/embed/I9N2Q4587D4?t=4m38s" frameborder="0" allowfullscreen=""
(I added ?=4m38s to the embed code.)