Best method for converting 29.97fps to 23.976fps?

[fearmyrage]

I have an idea for an experimental short film I want to make and it uses old video cameras. The old cameras obviously run at 29.97 and I want to get rid of that "video" look. I know you can never make the 29.97 look like genuine 23.976 but every method of conversion I have tried has left me with stuttering video. Is there any way to reduce this or fix it? I have been mostly experimenting in Adobe Premiere with different combinations of "interpreting" the foot as 23.976 and just re-encoding to 23.976 with different time interpolation.

If anyone here knows any tricks or better methods I am all ears. Thanks in advance.

[manono]

The obvious answer is to use a film camera and not a video camera. Using interpolation after the fact to get it down to 23.976fps is just asking for trouble. Doing that will leave you with jerky and artifacted video. Why try to fit a round peg into a square hole?

As for better methods, AviSynth. Bob it using QTGMC and then reduce it to 23.976fps perhaps with some motion blur added to make it look and play a little more smoothly. There are several ways to do that framerate reduction but none will be as satisfactory as shooting at film speed to begin with. Rethink your plan.

[DB83]

You might wish to try, if not so already, the method explained here

https://www.avidemux.org/admWiki/doku.php?id=using:video_filter_decomb_telecide

[smrpix]

??? If you want to get rid of the video look, why are you using old video cameras?
??? If you want to use old video cameras, why do you want to get rid of the video look?

As manono suggested -- you may want to rethink your plan?

FWIW, back in the day, many people tried to achieve the film look by changing the frame rate, adjusting the gamma and contrast, and adding grain. It was rarely convincing.

[jagabo]

Most of the film look is knowing how to set up the shot, lighting, etc. And how to use the camera (depth of field, exposure, stedicam,etc.)

As for frame rate, try converting to 30p. That will look almost as jerky/flickery as 24p.

If you really need 24p you can try using motion flow techniques. Try a good smart bob to 60p followed by motion flow to 24p. AviSynth's QTGMC is the best smart bobber. So you might as well do the motion interpolation there too. But motion interpolation like this often leads to weird distortions.

[fearmyrage]

I shoot video professionally for a living. I understand the difference between 30 and 24 fps. I want to shoot a short film using a variety of older cameras. I want to get the unique look that each camera provides but with as little of the "tv look" as possible. My "plan" is fine. I would like to know the best way to make 30fps content look like 24fps.

Thanks for the replies.

[manono]

I want to get the unique look that each camera provides but with as little of the "tv look" as possible.

You don't see the contradiction in that statement? You shoot using a video camera, you get the television look, keeping in mind the qualifications jagabo mentioned.

For smoothest playback from different framerate sources forced to use the same output framerate, it's isn't 23.976fps, but 59.94fps (or interlaced 29.97fps if for DVD). And Adobe Premier is inferior for doing that.

[Cornucopia]

If you are a pro videographer as you say, and want to shoot 24p style using an older video camera, you should already know to use a Panasonic DVX100b in Advanced 24p mode (or HVX200 for HD). End of story.

Of course, if you are married to using many different cams each with their own characteristics, that option isn't possible. But so isn't "the film look" possible. There are tools to help with DoF, and transfer characteristics can be cheated, but bokeh is a function of lens, you still won't have true low noise high sensitivity or latitude of large sensor. And false telecine of 29.97 stuff will never look like true telecine because in order to retain true motion speed, you have to take out true frames and add back in extra dup frames, thereby DOUBLING the jerkiness of a true telecined cadence (which only adds the dup frames).

Also, goes against the point of showing each cam's "characteristics".

Scott

[fearmyrage]

You don't see the contradiction in that statement? You shoot using a video camera, you get the television look, keeping in mind the qualifications jagabo mentioned.

What part of this is complicated for you? Every camera in the world has many characteristics outside of framerate. Resolution, color accuracy, compression rate, low light performance, rolling shudder, dynamic range... I am trying a to make, I will say it again, an EXPERIMENTAL film. I want use the the different look that each camera provides and incorporate into a film but I do not want the motion of 30fps to make it look like TV. I want to make it look as much as I can like film.

I found a solution that seems to work pretty well actually. I use "optical flow" when rendering the video to 24fps and an effect I found called "Reel Smart Motion Blur" that blurs the movement across the screen and really helps to hide the judder. Best solution I have found so far.

http://revisionfx.com/products/rsmb/

[johnmeyer]

Google "film look", with the quotes. You will find that having 24 events per second (film) instead of 60 events per second (interlaced NTSC video) is only part of what makes at theatrical movie look like it does. In addition to the gamma, grain, and color issues already mentioned, there is the depth of field. Most video cameras use a sensor that is smaller than the 35mm or 70mm "sensor" that you have with traditional film. Because of the physics of how optics work, the smaller the sensor, the greater the depth of field. What this means is that it is extremely difficult to achieve shallow depth of field or "selective focus" when shooting video on a traditional video camera.

If you really want to get the film look, you'll get a DSLR that shoots video, making sure that it has a "full frame" (35mm) sensor, or larger. Then, purchase lenses that let you get the optical look of professional movies. Use this camera to shoot directly to 24p.

As others have said, if you are starting with 60i "traditional" video, and you simply decimate it down to 24p, there are lots of AVISynth scripts that will do a nice job of that conversion. If you use one of these scripts, you will achieve that "once removed" temporal feel that lower frame rates impart, but it still won't feel like film.

Finally, modern "movies" are almost all shot digitally. This means you no longer have dirt, grain, and gate weave (the residual "bounce" you see when film is projected). Despite this, the movies you watch in the theater still look like old fashioned movies, especially since most older movies you now see on Blu-Ray, DVD, and OTA TV have been digitally restored to remove those artifacts. But even with all these traditional film artifacts removed, the new movies still look like movies, and it is because of gamma, color, 24p, and depth of field.

I haven't used this script for a long time, but I think it works:

source=AviSource("e:\fs.avi")

#Create 60p from 60i
QTGMC( Preset="Slower", SubPel=2, EdiThreads=4,ThSCD1=180, ThSCD2=98, Blocksize=32,Overlap=4)  
super = MSuper(levels=1, pel=2)

#Create 48p from 60p
MFlowFps(super, QTGMC_bVec1, QTGMC_fVec1, num=48000, den=1001,ThSCD1=180, ThSCD2=98) #Change scene detection to match QTGMC
blur(0.0,1.0)
sharpen(0.0,0.75) #Adjust 2nd value between 0.5 and 1.0 to taste

#Create 24p
selecteven()

[manono]

I found a solution that seems to work pretty well actually. I use "optical flow" when rendering the video to 24fps and an effect I found called "Reel Smart Motion Blur" that blurs the movement across the screen and really helps to hide the judder. Best solution I have found so far.

Already mentioned by me and others, and using the freeware AviSynth:

Bob it using QTGMC and then reduce it to 23.976fps perhaps with some motion blur added to make it look and play a little more smoothly. There are several ways to do that framerate reduction...

One of the framerate reduction methods I was thinking of was the frame interpolation also mentioned by jagabo later and with a complete script provided by johnmeyer just above this post. The 'Reel Smart Motion Blur' effect is easily created by QTGMC's motion blur setting. From the QTGMC page at the AviSynth site and its doc:

For smoother playback of single-rate output there are settings to add light motion blur to simulate different shutter angles (shutter speeds)

[Tomaswhite]

Search "best video frame rate converter", select an easy-to-use one to change frame rate.