Does QuickTime player inaccurately display time for 23.98 FPS files?

Question

Does QuickTime player inaccurately display time for 23.98 FPS files?

When I create a 1-hour 23.98 FPS file in Final Cut, export a ProRes master, and open in QuickTime player, QuickTime (and the Finder, and VLC) displays the total running time as "1:00:04" (1 hour, 4 seconds). Is QuickTime player displaying inaccurate runtime? Where is it getting this number? This makes no sense to me, if QuickTime were playing my 23.98 movie at 24.0 FPS, then the overall duration would be shorter, not longer.

When I export a 24.0 FPS file and open it in QuickTime player, it displays the runtime correctly.

MacBook Pro (Retina, Mid 2012), OS X Mountain Lion (10.8.3)

Posted on Oct 25, 2018 3:30 AM

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Answer 1

Tom Wolsky

Level 10

152,815 points

Oct 25, 2018 11:25 AM in response to Chris Tipton-King

It's because of the frame count. Editing applications count each frame of 23.976 as one frame, as if it's 24. It doesn't use any drop frame scheme to compensate for the difference between 23.976 and 24, so at the end of the hour you have this discrepancy. At 24fps ten minutes of video is 14,400 frames. At 23.976 over 10 minutes it's 16,7865.6 frames.

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Answer 2

Oct 25, 2018 11:27 AM in response to Tom Wolsky

Thanks, I get it now. How can I tell the actual runtime of a project edited in 23.98 without exporting it first? Could I use a timecode generator clip sped up by XYZ amount?

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Does QuickTime player inaccurately display time for 23.98 FPS files?

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