Variable frame rate issue (from DVD) when upscaling

Video AI General
1

I want to upscale some Star Trek Voyager and Deep Space nine episodes using Topaz video AI but have run into the same problem other people have had. The NTSC raw DVD SD files are variable frame rate. Some sections of each episode are at 23.976 and others (the CGI sections) are 29.97 frame rate. For example the overall frame rate of one episode might be 24.66.
This creates a problem for smooth playback of all parts of an episode, and is the same when upscaled…

I have got hold of some other Topaz upscales of these shows other people have done and they have somehow managed to make a whole episode 23.976 frame rate. They look good, - no judder etc.

Does anyone have any ideas of the best way to address this?

I think the best way would be to get the variable frame rate SD source file (ripped from the DVD) transposed to 23.976 instead of variable frame rate, but how do you do that for mixed footage at different frame rates?

This is a long shot and I’m probably dreaming, but is there any kind of program that could scan a video file with mixed 23.976 and 29.97 footage, and identify the 29.97 portions and then convert those parts 23.976 without quality loss?, and leave the parts that were originally 23.976 untouched.

I’m guess that a long shot, but wanted to ask. Or are there other good days to sort this out.

If anyone is familiar with this problem and has a way around it, any advice would be really appreciated.

2

Pretty sure I’ve seen two blogs about doing this to this exact show and explaining how they deal with that frame rate issue. It shouldn’t be too hard to find them.

3

I agree with @ForSerious and would recommend looking through this chapter of ExtremeTech.com’s series about upscaling the Deep Space 9 DVDs.

We’re working to improve the VFR experience within the app, but it seems to be an issue that can be seen across multiple different video processing tools specifically when working with interlaced content that flips between 23.976 and 29.97fps.

4

so does your reply that its an issue with your competitors programs code for Topaz is not going to address it? IT should be the opposite. The first program that can convert video correctly back to 23.97 will very quickly corner the market. Topaz Video Enhance AI latest version 4.1.0 cannot change the frame rate back to 23.97 if the video was a DVD ripped at 29.97, it comes up juttery on pans and looks terrible. That means Topaz does not know which frames were the injected duplicates when the studio pulled down the 23.97 footage to produce their DVD. Please get on this Topaz. I like the product, but its defective still in some very important areas.

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5

You didn’t read the blog, did you? Reducing the frame rate of Deep Space Nine has a unique issue.
Besides, ffmpeg does as good of job as I have seen at dropping the correct duplicate frames. You just have to open the command prompt from within TVAI. Copy the ffmpeg command that gets generated when you click 'Show Export Command, add -r 23.976 after the -i "path/to/input.file" line, and paste that into the command line. That should do it correctly for 90% of DVDs.

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There are LOTS of programs that correctly inverse telecine 29.97 back to 23.976.

7

which one? it seems like all of them I have seen including Adobe merely use an assumed sequence of frames and they delete away. That is not going back from 29.97 to 23.97 if there is a variable rate here and there in the clip. Do you have a software program you use for this that works? can you share it so I can buy it?

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I thought TVAI has a built-in function to telecine the source. can he not use this instead?

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I’m saying that a garden-variety 2:3 pulldown can be inverse telecined back to 23.976 by the likes of Handbrake, Hybrid, Shutter Encoder, etc.

If you meant variable frame rate IVTC, that is a different can of worms. (And you would be correct, that there is no program that does that).

But, straight 29.976—>23.976 can be done easily.

11

For those that did not read the blog. Deep Space Nine has a unique frame rate situation: It’s filmed normally in 23.976 fps except for the scenes with computer generated visual effects. They are in 29.97 fps.
It sounds like tntman is just talking about average DVDs, so I guess they just don’t know about all the software that can undo that frame rate.

If I am wrong and they were talking about frame rates that change substantially throughout a video, sure, an interpolation model that could ignore the higher rate frames and perfectly replace the lower frame rate ones to match the higher rate, would be valuable.

From my understanding though, most variable frame rate videos just mean the frame rate goes down when there is little to no motion—to save storage space. In that case we’re back to all: those programs mentioned before can convert those to a constant frame rate no problem.