Hybrid QTGMC with Bob vs Frame Interpolation

Hi there

I am now planning to prepare my videos with Hybrid QTGMC and save as a ProRes file prior to upscaling with Topaz, however I have a question (naturally).
I see suggestions around the internet to use Bob in Hybrid QTGMC when deinterlacing, In Video AI Frame Interpolation doubles the frame rate as well, creating new frames in the process. From my understanding Bob isn’t doing this when it doubles the frame rate, but rather improves on the deinterlacing feature of QTGMC. If I use Bob & Frame Interpolation that would make my final video 100 fps (if the original is only 25fps).

What settings do people on here actually use in order to get the best out of their video at double the framerate?

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The way I understand it, it depends on where the video originally came from. If it was film, bob just adds a bunch of duplicate frames. If it was something like my old family videos recorded straight onto a VHS tape, bob is needed to make every frame of motion.

My experience that TVAI produce better, sharper and detailed output HD when converting Interlaced SD / Video8 footage (Sony TRV-45E), when using the built-in Interlaced → DV/TV option (DV gives slightly more details and sharpness in the expense of a bit more noise, but very subtle).
When I de-interlaced the original file 1st (losless) to QTGMC / bob / “Slower” preset, using hybrid and then used the Progressive option in TVAI (tried: Artemis, Proteus, Theia & Gaia in all sort of combinations/options - I spent hours testing all type of combinations), it yielded less quality video then using Direct TVAI → Interlaced → DV/TV, with the original interlaced file.
Even though my QTGMC output file I fed TVAI with was really good quality compared to the original interlaced video.
So my conclusion with my testing, the best is to go Direct with TVAI with your interlaced video and upscale/deinterlace in one shot, you would get better quality output, more sharp and more details then upscaling your QTGMC progressive file. with the Progressive upscaling, the output HD file was a bit muddy, while the Interlaced Upscale was much cleaner and sharp/more details.

For me personally it’s a clear winner, Direct TVAI De-Interlace + Upscale. the best results

Did you only try QTGMC “Slower”?

Also “fast” preset I tried (didn’t see much difference honestly).
But it doesn’t matter, as I mentioned above , the video quality output of hybrid (after de-interlacing my file) was better quality then the original interlaced, if I playback them both side by side (before TVAI processing of course).
That means in theory TVAI should had output a greater quality video of my QTGMC progressive video, but it didn’t. it was muddy looking and not clear and sharp compared when I Directly fed TVAI with my original interlaced file using the interlaced option → Dione: TV/DV in TVAI . not by much, but enough for me to notice the difference.
BTW “Dione: Dehalo” was bad quality output, so it was disqualified for my videos to be used.

P.S. the Dione: DV output a slightly more detailed video then Dione: TV, but very subtle difference. Even though my video files are Analogue Video8 (1998 Sony TRV-45E Camcorder), which make sense to use the “Dione: TV” based on TVAI Dione module description. but “Dione: DV” performed a bit better.


I am starting to think along those lines as well since I have tried using QTGMC via Hybrid and when I set it on highest quality settings for all formats (ie Placebo), ProRes 422HQ was not as sharp as what I had with X264, which surprised me.

Everyone tends to go on about how perfect QTGMC is, but Topaz always seems to do a marvellous job anyway. Maybe it’s down to the fact that these other free programs don’t actually make it easy to work out the correct settings?

I’ll give Hybrid a miss.

I’m a bit confused with what you say here? Are you saying you got better results using QTGMC first? If so, what method do you actually use before using TVAI?

A lot of my source material is of 60s and 70s TV shows (Mostly UK and Europe), including rock concerts. I always prefer to give my videos that smooth frame interpolation l, especially as I have a video projector and I see a big difference!

no, what i was saying is that if I compare the original interlaced video to the QTGMC Hybrid de-interlaced , the QTGMC vs Original, the QTGMC was higher quality on playback (still original size, no Topaz involved yet for any).
but once I process/upscale the QTGMC with Topaz, the upscaled file quality is less good then if I upscale with Topaz the original untouched interlaced files.
the method I use for QTGMC is on my 1st post…nothing special pretty standard.


I follow you now.

My previous experience was not exactly the same (I did not upscale, just deinterlaced). Dione DV gave some artifacts on the final output albeit the footage was clean. I must check what you wrote about Dione DV denterlacing and upscaling in one step.
By the way, which Dione version have you used and in which VEAI version? I use 2.4.0 since it does not create any ghosting.
Another question, how to insert certain script to VEAI?

So VEAI wins when you upscale later on. Hmm, for many of use higher resolution footage is the goal so it could make sense.

I am using TVAI v3.1.x, Dione DV v3 / Dione TV v4 were involved in the testing. I haven’t tried VEAI, so i can’t comment on the results you might be getting on VEAI.
if you only need to deinterlace without upscaling, then QTGMC is a perfect solution. no need to involve Topaz in that matter. Having said that, if you also want to upscale, then the above is relevant.

If no problem, I could send you one day a short file and would be grateful if you could both deinterlace and upscale using 3.1 version, ok? Short, 10-12s Full HD file. In general in future I would like to upscale these files so Dione DV could be the way to go…

sure, upload it to a drive and share the link and I’ll do it

I would like to throw some mud in the water.

Turns out, 99% of DVDs are interlaced with bottom field first. Ffmpeg deinterlaces them automatically, so I didn’t notice it was doing that and I thought there weren’t interlaced. It does a good job, so no complaints there.

Now for the mud. One of my favorite shows as a kid was the original Star Trek. I was gifted season 1 not long ago. After reading what is stated in the posts of this topic, I ran a section of an episode through Doine TV. It looked perfect! I got distracted figuring out how to add Vapoursynth to my script that calls TVAI and a few other processing programs. The goal was to feed my sources through the QTGMC filter before they got to TVAI for deinterlacing and denoising. Once I found good settings for denoising on that same episode, I ran it through the QTGMC deinterlace, and EZDenoise of the same filter. Then Proteus manual with only Revert Compression turned up to 50 and everything else at 0. It came out great! Then I remembered how well Dione TV looked and how that would be much less effort. I ran it again on several sections of the episode, and well. It makes things more painting-like and adds fake detail patterns to things like grass and dirt and rocks and leaves and… you get the idea. I tried the other deinterlacing models in TVAI too. Similar results. All of those issues can be avoided by turning things down in Proteus.

My conclusion: QTGMC deinterlacing WITH an adequate amount of denoising is better than anything TVAI can do on its own.

I have yet to try it on those direct-to-VHS family videos I have that were digitized to DVDs. I might find that TVAI is better for those.


can you post your exact settings you did both on Hybrid (I assume you used Hybrid for QTGMC) with all denoising parameters and values? i’ll give it a shot

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The bottom half of the settings with all the presets and source matching… I didn’t try any other values with those, since I don’t really know what they’re supposed to do.
These settings are for a grainy TV show from 1966. (Not Star Trek. That was less grainy.)
On a more modern show (2005), I settled with keeping the EZDenoise at 2.00, but I put the Final Temporal Smoothing to 1.