Best way to convert 29.97 fps to 25 fps

PeterDuke wrote on 5/20/2016, 1:12 AM

"Best" needs qualification. What are your criteria, and how do you weight them against each other? Everyone would not agree on what is meant by "best"

If you mean within Vegas alone, then right-click on the 29.97 video clips and set the properties to force resample. Also try setting it to disable resample - it will be more jumpy but sharper - you may like that better. If your source is interlaced, set deinterlace method to interpolate.

If you have something like Twixtor, you could generate new frames by interpolating between the old frames each side of the new ones.

megabit wrote on 5/20/2016, 2:47 AM

Bob has had a good method for that - if I recollect correctly, it comprised on putting the footage on a 30 fps time first, checking the exact time (on the ruler), then changing the project to 25 fps and Ctrl+dragging the clip's end to the same point in time exactly.

BTW, how's Bob? Haven't seen him here for a while...

Piotr

Grazie wrote on 5/20/2016, 3:04 AM

I SKYPE-ed with Ozzie-Bob only last week. He's fine. Much better than his twinkling dead pixeled Skype cam! Been meaning to send him a new one.....

Yes, I use Bob's method when needed.

Grazie

PeterDuke wrote on 5/20/2016, 5:35 AM

That method works OK for converting between 24 and 25 fps, but 25 and 30 is quite a change and will give a noticeable slowdown. It preserves the number of frames.

K-Decisive wrote on 5/20/2016, 6:31 AM

you can also try Resolve and use optical flow for speed changes, optical flow should be available in the free version

aboammar wrote on 5/21/2016, 9:24 AM

PeterDuke, thanks for your feedback. What I meant by best, is best quality regardless of the method, or software.

I have about 20 progressive clips at 29.97 fps. I converted them to 25 fps using Vegas Pro by simply rendering them to 25 fps. Then I used Twixtor to slow down the clips to 35%, but I got that ghosting like effect .. not acceptable.

Should I try the force resample and disable resample ?

aboammar wrote on 5/21/2016, 9:29 AM

Thanks megabit .. I will give that a try, and hopefully will work.

aboammar wrote on 5/21/2016, 9:29 AM

Thanks K-Decisive .. Will try tat out after I try the Vegas way.

PeterDuke wrote on 5/21/2016, 6:19 PM

"I have about 20 progressive clips at 29.97 fps. I converted them to 25 fps using Vegas Pro by simply rendering them to 25 fps. Then I used Twixtor to slow down the clips to 35%, but I got that ghosting like effect .. not acceptable."

No, I meant you to use Twixtor to change the frame rate. I haven't tried it so you should experiment or search the web. In principle you would slow down by a factor of 10 and then speed up by a factor of 12 (i.e. speed up by a factor of 1.2), and then adjust the frame rate from 29.97 to 25 using Bob's method. Megabit is not quite right: adjust to have the same number of frames not time.

NickHope wrote on 5/21/2016, 11:14 PM

You could try this free and high-quality motion-interpolation method that I use...

1. Install Debugmode Frameserver (note minor bugs with VP13)
2. Install VirtualDub (try 64bit if you like but 32bit more likely to succeed)
3. Install MagicYUV
4. Install AviSynth 2.6.0
5. Install SEt's 2015.02.20 MT build of AviSynth (simply overwrite the previously-installed avisynth.dll file)
6. Install MVTools2
7. Save the script below as changefps.avs
8. Match your Vegas project properties to your 29.97 footage properties
8. Frameserve your 29.97 footage in RGB24 format to, for example, fs.avi
9. Open changefps.avs in VirtualDub
10. Render to MagicYUV .avi file at MagicYUV's default settings
11. Put rendered file back on a 25fps Vegas timeline
12. Check for weird motion-interpolation artifacts
13. Let us know how it goes

Options:
1. You could render an uncompressed or lossless intermediate instead of frameserving
2. You could render other formats instead of MagicYUV. e.g. Cineform, DNxHD, UT Video Codec etc.)
3. There are lots of additional options avaliable if you need them for lines 6-9 in the following script
4. The script assumes your source footage is progressive, not interlaced
5. I'm actually using a fork of MVTools, version 2.6.0.5, from here, but the developer has taken up development of the official version recently so best start with that one I think.

SetMemoryMax(2048) #For high-memory systems. Try for example 1024 if you have trouble

SetMTMode(3, 10) #For high-memory systems. Try for example (3, 6) if you have trouble

AviSource("d:\fs.avi") #Change to the name of your frameserved file

SetMTMode(2)

ConvertToYV12()

super = MSuper(pel=2)

backward_vec = MAnalyse(super, isb=true)

forward_vec = MAnalyse(super, isb=false)

MFlowFps(super, backward_vec, forward_vec, num=25, den=1, ml=100)

Note that in my tests, Vegas is detecting the final rendered file as interlaced, even though it is progressive, and matching the project accordingly. Don't know why that is. So I'm manually setting the project to progressive.

Once you get into AviSynth, all sorts of other "better-than-Vegas" processing is possible... noise reduction, deinterlacing, slomo, resizing, sharpening etc. etc..

megabit wrote on 5/22/2016, 2:34 AM

"Megabit is not quite right: adjust to have the same number of frames not time."

Sure thing; I stand corrected - the idea is to avoid messing up with frame resampling :)

Piotr

aboammar wrote on 5/23/2016, 7:50 AM

Guys, thank you very much for your feedback and help.

I tried Bob's way and the result was not good enough.

K-Decisive, your way worked perfectly .. Resolve indeed produced amazing results with its optical flow turned on. In fact the 35% slomo clips looks like as if they was native 25 fps, not 29.97 fps :)

Nick Hope, thank you for your comprehensive feedback, but I already solved the problem with a much simpler method by using only Davinci Resolve.

Thanks again for everyone who shared their experience.