Converting to 24fps

[Sycho]

I want to make a video with a DV cam, and convert it to 24fps, how would i do this? (could i use motion blur?)

[sh0dan]

I've done a series of tests using AviSynth, and I got the best results using the following (simple) script:

AVISource("620.AVI", pixel_type="yuy2")
fielddeinterlace()
decimate(cycle=25)


It gives a very "movielike" look. It requires the Decomb package from Donald Graft.

A "sharper", but also more choppy looking video can be achieved by using:


AVISource("620.AVI", pixel_type="yuy2")
SmoothDeinterlace(tff=true, doublerate=true)
decimate(cycle=25, mode=1)
selecteven()

This furthermore requires SmoothDeinterlace. It is much slower than the script above - and personally I much more prefer the first one anyway. But it depends on the source material.

You should be able to get anything you need from avisynth.org (http://avisynth.org).

[theReal]

Wouldn't it be better to slow down the framerate and keep all frames instead of deleting every 25th frame?

I never tried this, but what I'd do was to load the video in VDub, save the audio as PCM, then change the framerate of the video to 24 fps and save it. Then I'd use Besweet to change the PCM audio to 24 fps as well and mux everything together.
OK, I'll give it a try and tell you if it works this way :)


EDIT: It does work perfectly.
I was using HuffYUV to save the new video because I don't think you can save to DV using 24 fps.

[Chez_Wimpy]

Originally posted by theReal
I never tried this, but what I'd do was to load the video in VDub, save the audio as PCM, then change the framerate of the video to 24 fps and save it. Then I'd use Besweet to change the PCM audio to 24 fps as well and mux everything together.


The best result would be to incorporate the FieldDeinterlace() command from the decomb package in addition to your method. This way each of the 24 fps would not be so liney, that is, unless PAL video cameras now produce a progressive 25fps picture?

A sample script:

AVISource("620.AVI", pixel_type="yuy2")
fielddeinterlace()
AssumeFPS(24) #or AssumeFPS(23.976) for NTSC compat.

BeSweet the audio using the "frame change" method: 25000->24000 or 25000->23976 for NTSC friendliness.

The combination of these two techniques is the typical approach for Video Cinema (and most "movies" shot on DV as independent features).

[theReal]

I didn't deinterlace because nobody said the result had to be 24fps progressive (but oh well, what would be the purpose of 24 fps interlaced - I didn't think about that...)

I didn't realize that Assumefps in avisynth does the same as the framerate conversion in VDub - so you're right, it's easier that way (no intermediate HuffYUV files)

But you could just as well deinterlace the resulting HuffYUV 24 fps video and get something like film (but then, why not just leave it at 25 fps and deinterlace - I guess it's the progressive mode that makes the difference of the "film-look", not the 24 fps against 25 fps)

[DDogg]

Chez_Wimpy, if you have it easily available, any chance you could paste in the command line from Besweet to do the 23.976 operation you mentioned above? Else, I will puzzle through the docs. Besweet command lines can be a little painful for me.

[Mindhunter93]

I use a Canopus-ADVC 1394 to capture and have found that simple IVTC using the Decomb405Legacy version works fine to convert 29.97 fps material down to 24 fps. I also tested using Doubleweave and pulldown and found the results were fine as well.

IVTC example:
Telecide(reverse=false,swap=false,firstlast=false,post=true,threshold=15,dthreshold=9,blend=true,chroma=false,y0=0,y1=0)
Decimate(cycle=5,mode=0,threshold=0)

Doubleweave Example:
Doubleweave()
Pulldown(0,2)
Fieldeeinterlace()

[theReal]

Mindhunter93, what are you capturing with your Canopus card? TV, VHS, or DVcam material? If it's TV or VHS sources, then the ivtc with Decomb might work very well because the source is telecined.

If it's DV video from a camcorder, it's true 29.97fps (or 25fps for PAL), then you can't get acceptable results with telecide(), I think.

[BlueCup]

Originally posted by sh0dan
...
AVISource("620.AVI", pixel_type="yuy2")
fielddeinterlace()
decimate(cycle=25)


It gives a very "movielike" look. It requires the Decomb package from Donald Graft.
....

When I try this and bring the AVS into VDub, the framerate says to be 28.771.