my first frame on my video jumps before it starts
I added a movie to a Keynote slide. However, when I transition to it, the thumbnail isn't the "first" frame ... so you see that briefly - then it jumps to the beginning and starts to play.
Question marked as
Check the poster frame setting, if it is not set to the first frame, change it as follows:
Select the video on the slide then go to Format Inspector - Movie tab then drag the poster frame slider to the first frame, which will be 00:00:00:000