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Why 23.976 FPS?

Posted: Wed Jun 14, 2017 6:33 pm
by saribex
Hi, i copied serveral of my Blu-Rays to a MKV-File but I get 23.976 FPS... not 24.00 FPS. Why? I would like to preserve the original framerate of my blurays..

Re: Why 23.976 FPS?

Posted: Wed Jun 14, 2017 6:46 pm
by Woodstock
Because the nominal value "24fps" is actually 23.976 on average. The same thing for "30fps", "50fps", and "60fps"; the nominal isn't exact.

Re: Why 23.976 FPS?

Posted: Wed Jun 14, 2017 9:17 pm
by saribex
Hmm... it should be exact. Probably because of the 3:2 pulldown to convert to analog tv stuff in NTSC..
But I'm from europe and I really don't know why they don't stick with 24.0 FPS like it should be.. at least here in europe, we don't have NTSC.

Re: Why 23.976 FPS?

Posted: Wed Jun 14, 2017 9:39 pm
by Woodstock
If you're worried about the difference, you'll have to talk to the author of the particular BD, and ask them why they chose that frame rate.

Just know that 23.976 is a particularly popular frame rate for Bluray.

Re: Why 23.976 FPS?

Posted: Sat Jun 17, 2017 5:24 pm
by trumpet205
saribex wrote:Hmm... it should be exact. Probably because of the 3:2 pulldown to convert to analog tv stuff in NTSC..
But I'm from europe and I really don't know why they don't stick with 24.0 FPS like it should be.. at least here in europe, we don't have NTSC.
When people talk about 24.0 fps, they are referring to 23.976 (24000/1001) fps.

Precisely speaking, both 23.976 fps and 24.0 fps exist in Blu-ray standard. I only know 1 Blu-ray release that actually uses the exact 24.0 fps, Evangelion 3.33.

23.976 fps was a compromise back in the old days when the industry was transitioning from black and white to color video. Since bandwidth was very limited at that time to make color video works the industry decided to slow down the video slightly, hence 23.976 fps. Not a problem these days but the industry saw no need to move back to 24.0 fps.

The future will probably be more focused on high frame rate anyway (48.0 fps or above).

Re: Why 23.976 FPS?

Posted: Sat Jun 17, 2017 5:55 pm
by angelgraves13
99% of films are at 23.976, which is otherwise known as 24p. On the PC this setting is often called 23hz. Very few discs are made at exactly 24fps.