Removing the original frame rate

[Nico Darko]

Hello,

So I've converted a bunch of mkv files from 25 fps to 23.976 fps, setting them at 24000/1001p with MKVToolNix. They play fine on my computer but the playback is very jumpy on my Sony blu-ray player. What I don't get is that I have some old mkv files that were also slowed down to 23.976 and those play fine on the same player.

The only difference I notice is that jumpy mkv files indicate 25.000 fps as the Original frame rate, while the ones that play fine only indicate the new Frame rate.
Is there a way to remove the Original frame rate flag? I'm thinking that would fix the issue. I've tried with JMkvpropeedit but I couldn't do it.

Than you.

[sneaker]

Try ticking "Fix bitstream timing info" when remuxing in MKVToolNix GUI. (It's slightly below where you set the fps.)

How are you handling the audio?

[Nico Darko]

That did the trick, thank you!

I ended up finding this command line for the audio, and it worked great:

for %%a in (*.ac3) do ffmpeg -y -i "%%a" -map 0:0 -af asetpts='25025/24000*(PTS-STARTPTS)',aresample=48000:async=1:min_comp=0.01:c omp_duration=1:max_soft_comp=100000000:min_hard_co mp=0.3 -vn -c:a ac3 -b:a 640k -ar 48000 "%%~na.new.ac3"

[Nico Darko]

A couple of those mkv files were incorrectly ripped at 23.976 fps instead of 25 though, which results in a jerky playback, but I'm also unable to slow them down to the correct speed with MKVToloNix since 24000/1001p won't change the frame rate. Is there a way to fix those files by any chance?

[ProWo]

You have to reencode the video to 23.976 FPS.

[sneaker]

A couple of those mkv files were incorrectly ripped at 23.976 fps instead of 25 though, which results in a jerky playback, but I'm also unable to slow them down to the correct speed with MKVToloNix since 24000/1001p won't change the frame rate. Is there a way to fix those files by any chance?

If you encode 25 frames as 23.976 frames without changing the speed you drop ~1 frame per second or have ugly blended frames. This is difficult to reverse so there is no easy fix short of re-ripping the DVDs (or whatever it is you are ripping from).

[Nico Darko]

A couple of those mkv files were incorrectly ripped at 23.976 fps instead of 25 though, which results in a jerky playback, but I'm also unable to slow them down to the correct speed with MKVToloNix since 24000/1001p won't change the frame rate. Is there a way to fix those files by any chance?

If you encode 25 frames as 23.976 frames without changing the speed you drop ~1 frame per second or have ugly blended frames. This is difficult to reverse so there is no easy fix short of re-ripping the DVDs (or whatever it is you are ripping from).

Yeah I didn't think it was fixable, just wanted to be sure, thanks.