Late last year, I needed to convert a 29.97 fps video to 25 fps. I tried transcoding in Vegas Pro 20, in daVinci Resolve Studio and in Handbrake. The best result was in Vegas Pro 20 using the Under-sampling rate field in Properties to bring the video event back to 25 fps and selecting the Optical Flow resampling selection - which I don't think is available in VP18 - if it is, all the better.

BTW, even Resolve free allows rendering with optical flow. Sometimes with a particular video, one NLE/app gets better transcoding results than with others, but another video gets better transcoding results with another NLE/app. Test and trial to see which works best for you.

Also, iPhones typically don't record in Constant Frame Rate (CFR) but rather in a Variable Frame Rate (VFR) - ditto with most Android phones. The actual fps may vary wildly within the one shot. Use the free MediaInfo app to ascertain what fps you are actually getting in your iPhone videos.

Just curious - why the aversion to resampling?

@3POINT | @Dexcon | Thanks guys for your help. I will have to do a trial test and see how it works out. Just one thing @Dexcon, I may be incorrect, but it appears from my own experience, that third-party camera apps like Filmic Pro and ProCamera film a Constant Frame Rate (CFR). I’ve only ever seen my videos filmed in a Variable Frame Rate (VFR) when using iOS’ native camera app. Thanks for pointing that out though. 🙂👍

... but it appears from my own experience, but third-pard camera apps like Filmic Pro and ProCamera seem to film a Constant Frame Rate (CFR)

Sorry, but I have no idea about these apps - I've never used them. If they result in CFR from a VFR source, presumably there's some sort of transcoding going on which may or may not involve resampling. There doesn't seem to be any details on their websites as to how they process VFR to CFR.

Even with the advantage of Optical flow resampling, your best bet is still 60->30p because of the common factor, (which is 30). And that gives you the added advantage of an easy path to perfect slow motion, should you wish to use it in spots.

Late last year, I needed to convert a 29.97 fps video to 25 fps. I tried transcoding in Vegas Pro 20, in daVinci Resolve Studio and in Handbrake. The best result was in Vegas Pro 20 using the Under-sampling rate field in Properties to bring the video event back to 25 fps and selecting the Optical Flow resampling selection - which I don't think is available in VP18 - if it is, all the better.

I use optical flow (in Vegas available since VP20) only for converting from a lower framerate to a higher framerate and not viceversa. Optical flow is ideal for generating the new (missing) frames from existing frames. Converting from a higher framerate to a lower framerate probably works best with blend fields (mixing fields) but will give some ghosting of moving objects. If slowing down of speed is not a problem, I prefer importing at projects framerate as described earlier, which gives best quality and renders fastest.

Optical flow in Vegas is terribly slow compared to Davinci Resolve.

VEGAS 20 has optical flow resampling. It's the best way to convert framerates.

VEGAS 20 has optical flow resampling. It's the best way to convert framerates.

And the slowest way (more 10 times slower than with DVR). Also depending on moving content you will see no difference between optical flow and blending fields.

I'm still able to crank out renders in decent times when using it. Optical flow has far less ghosting than the other resample modes, and less jitter.

I did several tests comparing optical flow with Vegas and DVR. Results of DVR were far superior and in a fraction of the time Vegas needed. As soon Vegas optical flow reaches this level, I will recommend to use optical flow in Vegas.

Just curious - why the aversion to resampling?

Well, with the typical VEGAS Pro resampling, you get a lot of ghosting and I have an aversion to that. That’s why. However, if I am able to get much less ghosting (possibly even next to none) with another resampling option, then I’d be all for it.

Just curious - why the aversion to resampling?

Well, with the typical VEGAS Pro resampling, you get a lot of ghosting and I have an aversion to that. That’s why. However, if I am able to get much less ghosting (possibly even next to none) with another resampling option, then I’d be all for it.

In Vegas you have 4 options each with advantages and disadvantages:

1. Import at projectframerate, + no ghosting, no hickups, fast rendering - not original speed.

2. no resampling, + no ghosting, fast rendering, original speed - hickups.

3. frame blending, + fast rendering, original speed, no hickups - ghosting.

4. optical flow, + less ghosting, no hickups, original speed - extremly slow rendering, strange artifacts in some situations.

For me option 1 gives best results, option 2 I don't like at all, option 3 is my second choice (better have some ghosting, looks actually as motion blur) and option 4 is far from perfect in Vegas (compared to results I achieve with Davince Resolve).

In this clip, 1. 60fps played in a 25fps project no resample 2. optical flow is used 3. difference between the 1. and 2.

This is maybe not the best choice because at 25fps the cyclist so close is not going to be smooth, it is equivalent of panning too fast. At lower frame rates you pan slower. But to my eye the optical flow is smoother, especially look at the front wheel as it goes past.

@Former user 1. is with hickups, because no resampling, 2 is ofcourse smoother by using resampling (but looks also unnatural because lack of motion blur).

@3POINT I don't think frame blend works there, because of the same problem with non resampled 'hickups' , it will use pin sharp frames where it can, and create new blended frames to create the smoothness, so it's still sort of a hickup, alternating between perfect sharp frames and blended blurred frames

I guess as long as the optical flow is working well for the particular scene, you could dial in the perfect amount of motion blur as an FX. Still on the subject of optical flow resample. it's just not perfect yet, everything has to transfer over to AI, and even then AI model optical resample currently isn't perfect either but it's better.

1.no resample 2.optical flow 3. blended frames

@Former user | @3POINT | Thanks guys for your helpfulness re this. And @Former user, I’m just wondering what would be the best option for fast motion vs that kind of slow - medium motion in your video example (of which I do appreciate, BTW, thank you)?

I always start with optical flow, then work my way back to other resampling methods from there.

@Dexcon | If DaVince Resolve (free) would allow me to use Optical Flow without upgrading to VP 20, then that would be great. Given that Optical Flow is apparently not so great in VEGAS vs DV. But, on that very note, given that I will have to download DaVinci Resolve (no problem), and also being somewhat new to DaVinci Resolve, how would I go about converting a 60fps video down to 50fps or less using optical flow inside of DaVinci Resolve?

Thanks in advance for your help or anyone else's re this.

@MH7  ... In the Master Settings window of Project Settings, scroll down to the last settings topic which should be 'Frame Interpolation' - then change the 'Retime Process' field from its default 'Nearest' selection to 'Optical Flow'. Pages 128 &129 of Resolve's User Manual cover the basics of Frame Interpolation, but there's hundreds of other references to Optical Flow in Resolve's 4,000+ page user manual.

Notwitthstanding the above, why not get the trial version of Vegas Pro 20 and see how that performs with Optical Flow. And in any case, Vegas Pro 20 build 326 is a leaps and bounds improvement on Vegas Pro 18 in so many ways.

@MH7  ... In the Master Settings window of Project Settings, scroll down to the last settings topic which should be 'Frame Interpolation' - then change the 'Retime Process' field from its default 'Nearest' selection to 'Optical Flow'. Pages 128 &129 of Resolve's User Manual cover the basics of Frame Interpolation, but there's hundreds of other references to Optical Flow in Resolve's 4,000+ page user manual.

Thanks for that. I greatly appreciate it. 👍

Notwithstanding the above, why not get the trial version of Vegas Pro 20 and see how that performs with Optical Flow.

Well, it’s interesting you say that. I have trialed the previous build of VEGAS Pro 20 (Build 214 IIRC). I believe that, even with a new build, you cannot trial VEGAS Pro 20 again when you’ve already trialed it for the set 30 day trial period with creating another account (of which I don’t really want to). I never actually thought to trial Optical Flow in my trial period but I now realise that I should’ve.

And in any case, Vegas Pro 20 build 326 is a leaps and bounds improvement on Vegas Pro 18 in so many ways.

I definitely have not ruled out buying it. On that note though (so I don’t have to create another thread, but I will if necessary), I do believe it’s automated, but do you think they’d be any problem with buying VEGAS Post 20 on a weekend, would it process my purchase?

The purchase should process regardless of the date.

The purchase should process regardless of the date.

Thank you! I actually remembered I’ve asked a similar question on here before. I also came across an email to MAGIX asking about this back in 2018 where I asked MAGIX directly. This was their reply:

DATE: 26/03/2018 (MM/DD/YYYY)

We have an automated order system.

If you purchase an instant download version, you order is processed automatically and you'll receive the download link and serial number directly in the confirmation email within a few minutes. 

For physical box versions, they are shipped from our warehouse in Germany. We operate Mon-Fri.

Based on this, it’s quite obvious that anyone can order anything at any time, which is good, nice, and convenient.

@MH7 Davinci Resolve (is free version, the non free version is Davinci Resolve Studio) has optical flow.

The difference between optical flow of Vegas and Davinci Resolve is best seen not when conforming from example 60fps to 24fps but when conforming from 24fps to 60fps or when creating slow motion. Actually when missing frames have to be added/created and not when unnecessary frames have to be removed.