Need to know how to permanently sync audio with video in an mp4 file

[phrohg]

I have a video I recorded on my phone in 2017 of my daughter meeting with a princess in the hospital. The audio has been 2.2 seconds off from the video ever since it was imported to my PC. I can't seem to find any way to actually permanently sync up the audio with the video. I've used VLC, but that only syncs it temporarily when I tell it to. When I use the VLC record function on the video after I've sync'd it, the output file still ends up having the original out of sync issue. I've tried using a version of Cyberlink PowerDirector 10 that came with my BD burner when I got it, and can't find any way of achieving this. I've downloaded Lightworks and some HD Video Converter Factory Pro app that claim they can fix the issue, but it seems to be false advertising in both cases.

I don't have the first clue how video files are coded, but it doesn't seem like it would be that difficult of a thing to do. Especially since VLC already does it, but doesn't allow it to be saved that way permanently. I have no issue with spending a little bit of money on something to do this, but I'm not going to spend money on something that false advertises or doesn't fix this issue. I'm trying to organise and fix all the photos and videos of her since she passed, but getting very frustrated that I can't find anything to fix the videos of her. It's an MP4 file if that makes any difference.

 

[gardenman]

Hi, have you tried [Avidemux]?

Download, install it, and open the file in it.

Set Video Output and Audio Output (on the left) to Copy.
Check the Shift option below that.

This is where you'll have to guess. Use either a positive number or a negative number for the ms (milliseconds) amount. 1000 ms is equal to one second. So you'll likely need a number anywhere from -2000 to 2000.

Try a few different values and press the Play/Pause button below. Keep changing the value until the audio/video syncs up.

Once you got it synced up, choose the Output Format. You can use MP4 Muxer if you like that format, however, if you re-save it and that doesn't work, try the MP4v2 Muxer.

When ready to save, click on File / Save.

Important: Often when you re-save videos/images you loose a small amount of quality. Just keep the original in case you ever want to try to find a better way with slightly less quality loss at a later time.

I found this information on [this] page and I tried it myself before posting here. I shifted the audio/video sync on a video by 2 seconds and it saved and works right. I hope this works for you.

 

[phrohg]

Hi, have you tried [Avidemux]?

Download, install it, and open the file in it.

Set Video Output and Audio Output (on the left) to Copy.
Check the Shift option below that.

This is where you'll have to guess. Use either a positive number or a negative number for the ms (milliseconds) amount. 1000 ms is equal to one second. So you'll likely need a number anywhere from -2000 to 2000.

Try a few different values and press the Play/Pause button below. Keep changing the value until the audio/video syncs up.

Once you got it synced up, choose the Output Format. You can use MP4 Muxer if you like that format, however, if you re-save it and that doesn't work, try the MP4v2 Muxer.

When ready to save, click on File / Save.

Important: Often when you re-save videos/images you loose a small amount of quality. Just keep the original in case you ever want to try to find a better way with slightly less quality loss at a later time.

I found this information on [this] page and I tried it myself before posting here. I shifted the audio/video sync on a video by 2 seconds and it saved and works right. I hope this works for you.

Exactly what I was needing. Thank you so much. I'm not sure why this never came up in all of my searching.

 

[gardenman]

I'm sorry for your loss. I'm glad you got the video fixed. Take care.