Audio from 25 fps in 23,976 fps video always out of sync even if converted

[Huggy]

Hello everyone!

I searched the forum, I found similar issues, but I have yet to find a solution to this particular one.
In the past, I successfully exported audio from PAL 25 fps videos in my language and add it to NTSC 23.976 fps (after converting the 25 fps audio track to 23.976).

However, this time is different. I tried several tools and realized that the issue was not in the tool used to convert 25 fps audio to 23.976 fps, but rather in the video itself.

Basically, after conversion and checking in Avidemux that I needed to slightly anticipate the audio of -1200 ms, the audio and video were synchronized only in the first 20 minutes. The remaining 20 minutes circa (it's an episode) are out of sync: I suspect a black screen between 2 scenes is slightly longer in the 23.976 fps version, which"ruins" the sync between the 2.

Is there a tool that allows us to quickly fix this that is NOT time-consuming, if any? I am asking this because I am afraid I will have to add this extra step to all other episodes... and if it's too complicated or too long, I would honestly give up.

Just for the record, these are the steps I took so far:

1. Collected video 1 (low-quality PAL 25 fps with the audio track in my language) and video 2 (good quality NTSC 23.976 fps only in the English language)
2. Used MediaInfo to compare fps between the 2 videos.
3. Used TFM Audio Tool to extract and convert video 1's audio to 23.976 fps.
4. Imported converted video 1's audio and video 2 inside MKVToolNix to create a new single video.
5. Checked in Avidemux the aforementioned new video the time difference between audio and video.
6. Adjusted the audio timing in MKVToolNix as per Avidemux's result and saved the file again.


Thanks to anyone in advance.

[johns0]

https://forum.videohelp.com/threads/409365-Transplanting-audio-track-from-25fps-movie-...76#post2688020 read here.

[poisondeathray]

Edit them to match. There is no easy way if there are different cuts

There is no tool that will figure out if a scene is deleted or added and fix them automatically

[Huggy]

@johns0 thank you.That thread was actually the first one I read, but it seems like the OP did not find any solution to the issue.

@poisondeathray thanks, this is what I suspected. I am not actually looking for a tool that fixes them automatically, but is there any process that is quick enough to be repeated without making the whole process too long, since this is going to be applied to several episodes? Which tool or process would you use in my place (assuming the issue is only in a longer black screen between scenes)?

[davexnet]

Avisynth and stackhorizontal

[Huggy]

Thank you davexnet!