From a recent post:
If you want to make it behave more along the lines of what I think you are
after here is another method.
Assuming you have a video clip of say 60 seconds on the slide and it plays
automatically.
Create an object (doesn't really mater what, lets say a circle) and it to
"Appear" "After Previous" with a time of zero seconds. That means it will
appear immediately after the video is done playing. Now set the outline and
fill of the object (circle?) to invisible (none).
Next step is to set the slide transition to advance automatically after zero
seconds.
Sounds goofy I know so let me walk you through how it works.
The slide can't transition untill all appear animations for objects have
happened. The appear animation can't happen until the video is done
playing. Once both are completed the transition happens zero seconds after
the object has appeared (even though you don't see it.)
The advantage of this is that your transition to the next slide will happen
*almost* instantly after the video plays regardless of the machine the
presentation is played on or video length. (length = duration)
Austin Myers
MS PowerPoint MVP Team
Solutions to Multimedia in PowerPoint
www.pfcmedia.com
