How do I fix audio drift in video?

[Cmclernon]

Hi,

I've downloaded "More Wild Wild West 1980" in English from YouTube, but the picture quality was not very good. I therefore downloaded a French language version where the video quality was better. I then tried muxing the English audio with the French video using MKVToolnix, but the audio was out of sync. I was able to use the offset facility in MKVToolnix to sync the Video and audio at one point. The audio was out of sync with the video elsewhere, however.

Any ideas on how to fix this? A solution would come in handy with other videos with the same problem.

[davexnet]

first thing to check is the running time (hours, minutes and seconds) of both versions.
The you can check the frame rate (frames per second).
Open the files with mediainfo and check it

[jagabo]

Try changing the frame rate of the video from 25 to 23.976.

[Cmclernon]

According to Mediainfo the duration of the audio is 1:34 & the video is 1:30

Am using Handbrake to change the framerate to 23.976. Should I select variable (peak) framerate or constant frame rate?

[jagabo]

According to Mediainfo the duration of the audio is 1:34 & the video is 1:30

Am using Handbrake to change the framerate to 23.976. Should I select variable (peak) framerate or constant frame rate?

I would use constant frame rate.

But don't use handbrake, use MKVToolNix so you don' have to reencode the video. It will just tell the player to play the video at 23.976 fps rather than 25. Not all players will obey the frame rate flag though.

[Cornucopia]

First you need to figure out if you are working with exact same sequence. Are the edits the same? If not, you will need to edit.
Next, you should figure out which one is closer to the master source. Was it shot on film (23.976 or 24fps)? Or was it shot in NTSC video (29.97/59.94) or PAL video (25/50)? You should attempt to get the version that has had the LEAST amount of changes done to it.
Next, if you have to time compress/expand one stream or the other, there is less overall error doing it to the audio as it has a finer timebase.

Scott

[Cmclernon]

The original English language file is 29.975 fps NTSC, duration 1:34. The French language file is 50 fps video standard unknown, duration 1:30. I used MKVToolnix to change the French language video to 29.975 fps, but the duration of the video is still only 1:30.

I guess the French version is a different edit.

[davexnet]

It could be, or it could be sped up to 25 frames per second, typical PAL handling of Hollywood movies.
What is the exact length of the NTSC version, including the seconds?

[Cmclernon]

My apologies, the French version is 25 fps, duration 1:30:47. The English version is 29.975 fps, duration 1:34:52

Please find attached full specs of original downloaded files'

[davexnet]

1:34:52 = 8092 seconds. When sped up for PAL you get 8092/25*23.976 equals about 1:29:20 -
so it still doesn't match - perhaps the French version has extra credits at start or end..

To do the conversion with the as-is French video and speeded up NTSC audio, open the French video in Avidemux.
Then select "audio" at the top and load the english audio. Choose the output type, bitrate and set
Filter/frame rate change/Film to PAL. Resampling 48000. OK out.

By default it creates an MKV, leave it like this and save the new file. Then see if you can sync it