Technical Q&As

QTMCC 01 - How to Get the First Video Frame (1-May-95)

Q Stepping through QuickTime movie video frames in the order they appear in the movie is simple using GetMovieNextInterestingTime, except for getting the first frame. If I set the time to 0 and rate to 1, I get the second frame, not the first. In addition, the video may start later than at 0. How do you suggest finding this first frame of video?

A To get the first frame under the conditions you describe, you have to pass the flag nextTimeEdgeOK to GetMovieNextInterestingTime. What this flag does is make the call return the current interesting time instead of the next, if the current time is an interesting time. You need to do this because there's no way to go negative and then ask for the next interesting time.

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