Take a look at the Video with Dynamic Panel page in this demo:
Video-Examples-2.rp (286.1 KB)
When you load videos in an inline frame, you are more or less at the mercy of the browser–however it handles video is what you get. Blessing and a curse… If you load videos as embedded objects via javascript injection you can get more control, including hiding the default controls, autoplay/not, jumping to a specific frame, creating your own external controls, etc. (for example, i like to build some keyboard shortcuts in the OnPageKeyUp event to play/pause, reload videos etc.)
If you need to keep using your inline frame widgets, then you could create a new page in your prototype and point the inline frame to it. On that page, place a dynamic panel (or any widget, really) and load the video into it. Size the widget based on dimensions you need for your video/iFrame and you should be good to go.