23.967 fps to 25 or 50 fps converter wanted

[jack616]

Does anyone know of a program that can convert 23.976 to 25fps without the 3:2 frame judder
without having to save everything out a few times and re-encode? A one click process if you like?
(without causing audio sync problems) or even an ffmpeg sequence that would do it all in one go maybe?
It's trickier than it sounds.

[manono]

It's trickier than it sounds.

Not tricky at all. Quite easy, in fact. But I know of no 1-step process for it.

First, 23.976fps has no '3:2 frame judder'. You're referring to 29.97fps NTSC DVDs perhaps? Converting 23.976fps to 25fps by adding a duplicate frame every second will create judder, but it's not 3:2 judder.

Speed up the video to 25fps, speed up the audio to match. I suppose the two can be done together in a single AviSynth script, but I always do it separately (going 25->23.976fps).

One can only ask 'why'? Keep it at 23.976 (which is film speed, after all) and reencode it for something other than DVD, if that's your source. x264 inside of an MKV, for example. I don't really know what MakeMKV does about 3:2 Pulldown.

[jack616]

If anyone knows the answer to the question I actually asked please ignore the above response and let me know.

Thanks

jack

[Cornucopia]

Listen to manono, he answered your question directly.

The proper way to do this is to not reencode at all but just modify the time base in the header. In essence, speeding up the video. You must then adjust the audio to match.* This is usually done with time-compression filters/plugins in a DAW/audio editor separately (demuxing and remuxing as necessary). There is loss/change in the audio stream, but if done correctly with good tools it is usually quite acceptable.

1-click step? Not likely. There are AVISynth scripts (see http://forum.doom9.org/archive/index.php/t-163949.html and http://avisynth.nl/index.php/FPS, http://avisynth.nl/index.php/TimeStretch) & ffmpeg scripts (see https://trac.ffmpeg.org/wiki/How%20to%20speed%20up%20/%20slow%20down%20a%20video) that could be used, however.

Scott

*Without adjust the audio correspondingly, yes, you WOULD have audio sync issues.
That is unavoidable with this method - but this method is MUCH preferable to the alternatives which would muddle up the frames of the video AND require video re-encoding (and loss).

[manono]

If anyone knows the answer to the question I actually asked please ignore the above response and let me know.

Cute. Maybe if you had provided more details you might have gotten an answer more to your liking. For example, if you're converting an NTSC film DVD to a PAL film DVD you'd use AVSToDVD, which does the conversion properly. An NTSC film DVD source is the only one where '3:2 frame judder' even comes into play. But you didn't say whether or not this is DVD-to-DVD. For every other kind of output, some kind of judder might be possible, but it won't be 3:2.

The real answer to the question:

Does anyone know of a program that can convert 23.976 to 25fps without the 3:2 frame judder

is that no 23.976 to 25fps conversion you can possibly do will leave you with '3:2 frame judder'.

So, stop with the uninformed questions and the insulting responses if you really want help.

[_MrC_]

If the OP wants a NTSC film based source to be converted to PAL DVD w/o the 3:2 pulldown method, he can use the PAL SpeedUp option using AVStoDVD. Both video and audio timings are reduced by 4% approx and audio frequency is adjusted to 48khz within the same AviSynth script. Sort of 1.5 click step.



Bye