24fps to 23.976 - how?

[neil wilkes]

Here's the problem.
For some reason best known to themselves, I have been supplied with 2 video files at 24fps instead of 23.976 with the inevitable result that once the 24fps material is accessed on the disc, the TV set promptly switches frame rate on me causing glitching at the start.
How can I change the frame rate from 24 to 23.976 please, instead of the 24 supplied so it matches the rest of the disc?

Can do this on the Quicktime 10-bit file or the .264 file, it matters not. needs to be done though.

[kabelbrand]

How can I change the frame rate from 24 to 23.976 please

You can use this modified version of ffmpeg to quickly change fps of the raw h264 file:
http://forum.doom9.org/showthread.php?t=152419

ffmpeg -i input24fps.264 -vbsf h264_changesps=fps=24000:1001 -vcodec copy -y output23976.264

[EDIT] Playback speed of the video will be slightly different so you have to adjust the audio as well.

[setarip_old]

Why don't you simply return the discs to the place of purchase in exchange for new ones with the proper framerate?

[Video Dude]

Why don't you simply return the discs to the place of purchase in exchange for new ones with the proper framerate?

My interpretation of the question is the original poster did not purchase a disc, but is creating the disc from supplied video files from a client (DVD Authoring in the signature). The video files are 24fps instead of 23.976fps.

[huhn]

you can load the 24 hz file in avisynth and use the ffmpegsource2 plugin:

ffvideosource("yoursource",fpsnum=24000,fpsden=1001)

this adds or removes frame from the source to make it true 24000/1001. playback is not 100% smooth anymore and the video needs an reencode.

you can load both audio and video(or a fake 24 fps video) in avisynth and do this:
AssumeFPS(24000, 1001, sync_audio=true)

this slows playback down to 24000/1001 and resamples the audio to match the video speed so you can decode it to LPCM or what ever codec your disk can hold.

you can't simply change the FPS of the file it will run our of sync.

[Ghitulescu]

Before getting into speculations, one has first to establish how the 24fps has been obtained?
If it was in fact a 24/1.001 file that was wrongly flagged, then patching the fps would do the trick.
If it was a 24/1.001 but stretched then the video fps can still be patched but the audio has to be "stretched".
If it was 24/1.001 but resampled, then the audio would fit, but the video has to be restored.
Damn NTSC, it plagues us also today.

[SeeMoreDigital]

Here's the problem.
For some reason best known to themselves, I have been supplied with 2 video files at 24fps instead of 23.976 with the inevitable result that once the 24fps material is accessed on the disc, the TV set promptly switches frame rate on me causing glitching at the start.
Out of interest, what's the duration of these two files? For every 60 seconds the difference between 24.000 (1440.00 frames) and 23.976 (1438.56 frames) is 0.06 seconds (1.5 frames), which is very slight.

Obviously, the longer the duration of the sources, the more creative you'll have to be. You could either adjust the audio to match the new video duration. Or remove frames where appropriate to match the original audio duration ;)

[srfscenar]

Hi,
If you have a MAC & Pro Apps (FCP 7 etc) then you should have Cinematools.
Open Cinematools and go to File->Batch Conform.
Select the 10bit video you want to conform as it is not working with lossy codecs, Prores will do also,(be careful, it will change fps to ALL videos in the same folder, so maybe put just the video you want alone to a folder)
click OPEN and select the desired fps to the next window.
Click Conform.

It will take almost a second to complete.
Open the newly created folder "Conformed 23.98" and find inside the new file.

Hope it works!