How to pass from 24.000 fps to 23.976 fps properly

[kalemvar1]

Hello guys

I was wondering what would be the best option to pass from 24.000 fps to 23.976 fps.

The streamers I got from put some of his movies/series in 24.000 fps instead of 23.976 fps. I would love your opinion on how to put them back to 23.976 fps.

This only half answer I found if using :

FDecimate

If so, what wound be the perfect command line for it ?

Thanks

Kalemvar1

[dannyboy48888]

In avisynth do changefps("ntsc_film") some may disagree and have more elegant methods but for me I've not had any motion issues etc with it.

[kalemvar1]

Thanks for the reply,

And I guess it’s similar passing from 30.000 fps to 29.970 fps too ?

Yeah some streamer really do that (don’t ask me why)

[manono]

ChangeFPS(23.976) removes frames. 1 in every 1001 (I think). Not really optimum since it does it in a non-selective way.

AssumeFPS(23.976) slows the video down but you'd also need to slow the audio.

If for DVD you can use DGPulldown to slow it easily with no need to adjust the audio.

But one might wonder why change from 24fps at all.

[dannyboy48888]

Yes. For video it would be changefps("ntsc_video")

[Sharc]

for 24->23.976:
AssumeFPS(24000,1001,sync_audio=true)

for 30->29.97:
AssumeFPS(30000,1001,sync_audio=true)

if you want a standard sampling rate for the audio, add:
SSRC(44100) #for 44.1kHz audio sampling rate

See:
http://avisynth.nl/index.php/AssumeFPS
or
https://avisynthplus.readthedocs.io/en/latest/avisynthdoc/corefilters/fps.html

[kalemvar1]

Well it’s for live show, reality show, digitally from last few years . It’s the same pretty sure. (30.000 fps to 29.970 fps)

[Vidd]

If your video has a specific pattern of a duplicate frame every 40 seconds, this link would be useful:

https://forum.doom9.org/showthread.php?t=184909

[kalemvar1]

Thanks all of you for the answers, and links for more details.

Last 2 cases I have to deal with are :

-Episodes shot digitally and native 23.976 fps but were encoded in 30.000 fps (why I don’t know but it’s the only source I have), how to going back to the original 23.976 fps ? AssumeFPS(30000,1001,sync_audio=true) too ?

-Episodes encoded in 25.000 fps and need to be slow down at 23.976 fps ? (Still digital stuff 1080p) option ChangeFPS is a good one to make the episode a bit longer and match 23.976 fps and make the audio and subtitle to follow ?

Thanks

[Sharc]

-Episodes shot digitally and native 23.976 fps but were encoded in 30.000 fps (why I don’t know but it’s the only source I have), how to going back to the original 23.976 fps ? AssumeFPS(30000,1001,sync_audio=true) too ?

It's most probably telecined (pattern of combed and clean frames). The reason is to make 24fps film frames NTSC TV compliant. You have to inverse-telecine it, like:

TFM().TDecimate()  #should give 24fps progressive frames
AssumeFPS(24000,1001,sync_audio=true) #slowdown to 23.976fps

It could also be field blended crap, then something like

bob()  #or use a better bobber of your choice
sRestore()

may help.

-Episodes encoded in 25.000 fps and need to be slow down at 23.976 fps ? (Still digital stuff 1080p) option ChangeFPS is a good one to make the episode a bit longer and match 23.976 fps and make the audio and subtitle to follow ?

It depends.
- If it is just speed up you could try:

AssumeFPS(24000,1001,sync_audio=true)

- If it is Euro-pulldown (patterns of combed and clean frames), you would have to inverse-telecine it as well.

Above is speculative without seeing samples of the sources. You may want to upload samples (few seconds with motion of your unprocessed sources) for obtaining more specific help.