Audio Drift on mp4 files

[SilentScreamer]

Hello Everyone,

I started learning video edition and I wanted to try and fix some videos I have. A friend of mine gave me an usb drive with an onld tv show from the 90's that I used to watch as a kid. most episodes have some audio drift issues but on some the sound goes off by 7 to 10 seconds by the end of the video (roughly 45 minutes episodes). I tried to fix this in different ways using tools such as Handbrake to fix the fps and even in DaVinci. No matter what I do it always drifts overtime. Video and Audio are synchronized at first but never remains so. As it's an old show I don't mind that much but I'm very interested in techniques to try and fix this. I have watched several videos and tried several methods but could never achieve any tangible result.

If you have any good information for me, I'd be verry happy!

Cheers from Japan.

[ProWo]

Upload such an episode to a hoster and post the download link here, so we can take a look.
The audio track probably comes from a different source.

[SilentScreamer]

There you go:
https://drive.google.com/file/d/1Mwp8nmoDaJywlSvXGrbPabDELHzlGN2h/view?usp=sharing

Thanks for the help

[ProWo]

There you go:
https://drive.google.com/file/d/1Mwp8nmoDaJywlSvXGrbPabDELHzlGN2h/view?usp=drive_link
Thanks for the help

The link requires registration.
Post a shared link.

[Dooby]

What is this "Google" thing?

[Alwyn]

@Silentscreamer, could you set the sharing to "anyone with the link" (right-click on the file in Google Drive>Share>Share>General Access).

[SilentScreamer]

@Silentscreamer, could you set the sharing to "anyone with the link" (right-click on the file in Google Drive>Share>Share>General Access).

Sorry I totall forgot to do that when I shared it. It's done.

[Alwyn]

My editor (Magix Movie Studio) allows stretching of the audio track. In this case, the audio appears pretty-well synced at the start, but at the end, is 10sec 8 frames too short. Interestingly, almost all of the audio that needs to be chopped off is blank. So a possible solution would be to open the audio in an audio editor, trim off the blank end bit, then remux it with the video.


[Attachment 85449 - Click to enlarge]

There's a good timing point at 44:24:06, as the halo starts; a big kick in the audio:


[Attachment 85450 - Click to enlarge]

[ProWo]

That's a problem with a messed muxing.
You can fix it with clever FFmpeg-GUI.
Load your file, click main page, click various, click fix framerate, set 23.976 as framerate and click fix.
Done.

Instead of clicking on fix, you could also click on to batch.
Then click on batch tasks, drag all other episodes into the grid and click execute.
This way all your episodes are fixed in one go.


[Attachment 85451 - Click to enlarge]

[SilentScreamer]

That's a problem with a messed muxing.
You can fix it with clever FFmpeg-GUI.
Load your file, click main page, click various, click fix framerate, set 23.976 as framerate and click fix.
Done.

Instead of clicking on fix, you could also click on to batch.
Then click on batch tasks, drag all other episodes into the grid and click execute.
This way all your episodes are fixed in one go.


[Attachment 85451 - Click to enlarge]

Wow I am so grateful. I tried Handbrake and other options to fix the frame rate but nothing worked. Your option did! I'm happy to think I'll sleepd a little less stupid tonight! Thank you so much!