FPS inconsistancy questions

For every movie I have imported into VEAI, it reads the FPS as:
29.970 FPS
And that corresponds with what MPC properties details tab, witch says:
“Video: MPEG2 Video 720x480 (4:3) 29.97fps [V: English [eng] (mpeg2 main, yuv420p, 720x480)]”
However, there is another frame rate of the video that is found in the Media Info tab under video:
“Frame rate mode : Variable
Frame rate : 23.939 FPS
Original frame rate : 29.970 (30000/1001) FPS”

Now, I don’t know what Variable means for this. I just know that if I process the movie in VEAI at 29.970FPS like it defaults to, the resulting movie comes out with jerks and stutters all through it. That’s even with the Chronos model.

I can try to fix it by using MKVToolNix to set the Default Duration/FPS to 24000/1001p. Then VEAI loads the FPS as 23.976. That’s really close to 23.939, and the result after processing is much smoother. I have not checked if the audio goes out of sync by the end of the movie, but I think it will be acceptable since this particular example movie I’m using is only 25 minutes long.

I just don’t know enough about this to know if there’s something I’m missing or doing wrong.
For example, I noticed that when the movie loads at 29.970FPS in VEAI, there are 45913 total frames, but when I load the version set to 23.976FPS, there are 36730 total frames. By changing the default FPS am I just dropping those extra frames?

Is there a way to get VEAI to load the lower frame rate instead of the default one?

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Time lapse drops frames, slow motion adds frames. That is what CHRONOS is supposed to do. That is why audio gets out of sync because the length of audio is longer/shorter than the length of the converted movie.

Your video is variable frame rate. It is recommended to use ffmpeg command utility to convert it to constant frame rate before processing it in VEAI. Also you can use a free utility called Shutter Encoder, choose function ‘Conform’, then select your desired frame rate.

Thanks guys. After making a few tests setting the constant frame rate with ffmpeg, that does seem to fix everything.
I think I understand more about it after reading a bit of that blog, someone mentioned on this forum, about enhancing Deep Space 9.
Sadly, the show I’m working on, seems to have a different frame rate for each episode!
Anyway, maybe I’ll take the time, sometime, to make a python script that will automate at least the ffmpeg portions needed.

The issue is much bigger than this. Topaz often misinterprets the input frame rate, regardless of whether it is constant or variable. I’m desperate for a solution but can’t find one.

For most DVDs, I have found that passing them through ffmpeg with -r set to the correct FPS works perfectly.
Top-field first interlaced DVDs do not work that way. So far, the best solution I have seen is deinterlacing and converting them to image files, then sizing the folder just right so that you can drag-select all the fifth frames and delete them. Then use a batch rename program to give them the correct number sequence.
Even though the interpolation models now have the Replace Duplicate Frames check box, it has not worked yet. And even though ffmpeg has similar filters, they somehow have a hard time removing the correct duplicates.