Difference between 23.976 fps and 23.98 fps ???

[wasimismail]

I want to author the DVD and apply the 3:2 pulldown option for NTSC compatibility.

First, I converted VOB to Huffyuv DV AVI in VirtualDub. VirtualDub indicated the original video to be 23.976 fps, which is normal.

Then I took this DV file into Adobe Premiere 6.0 but I found the Adobe Premiere will only export the file as 23.98 fps.

Is there a difference between the two frame rates or are they must different ways of saying the same thing? If there is a difference, will it affect the finished product, specifically, the authored DVD with the 3:2 pulldown option?

BTW, I sadly discovered that Ulead DVD Workshop 2 does not support the 3:2 pulldown, quite a shame. I am thinking of getting Roxio DVDit Pro, what do you guys think of that software?

It says that is has 3:2 progressive scan pulldown support under Professional Timeline:

http://www.roxio.com/enu/products/dvdit/hd/features.html

Thanks.

[edDV]

It should be just a different way (rounded) to say the same thing.

The math is 29.97 fps / (5frames/4frames) = 23.976 fps

[Chris K]

Is there a difference between the two frame rates or are they must different ways of saying the same thing?

Both is true. Some software displays 23.976 fps as 23.98 fps but when you encode e.g. with FFmpeg to 23.976 and 23.980, Gspot surely reports the difference. If you would mux true 23.98 fps video with a 23.976 fps audio track or vice-versa you'd get audio sync problems.

Conclusion... use Gspot if you want to be sure of the frame rate.

[SLK001]

Actually, it is just lazy programming on the part of the programmers of these types of programs. A MPEG file has the frame rate listed as a number from 1 to 15 inside the file itself.

Here are the frame rates that correspond to the numbers:

• 1 = 24000/1001 (23.976...)
  2 = 24
  3 = 25
  4 = 30000/1001 (29.97...)
  5 = 30
  6 = 50
  7 = 60000/1001 (59.94)
  8 = 60
  9 thru 15 = reserved

[jagabo]

And in an AVI file the frame rate is given as two numbers, a numerator and a denominator. Each can be anywhere from 1 to ~4 billion. So the frame rate can be anwhere from 1/4,000,000,000 fps, to 4,000,000,000/1 fps.

Different programs may use different pairs to represent the same frame rate. For example, 24000/1001 or 240000/10010 are exactly the same rate. But some will use 23976/1000 which is slightly different.

[PuzZLeR]

When you round 23.976 to two decimal digits it would be none other than 23.98 since the 3rd decimal digit is 5 or greater. Both are "relatively" equal (similar to what edDV was referring to).