Syncing audio & video - app?

se2020

A while ago I transfered a wedding video from an old vhs tape to digital.

I basically plugged a vhs video player into a pc and played it back in full-screen using a screen grab to save it into an mp4 file.

I thought it had all worked fine but have since noticed the audio and video are way out of sync.
The audio is lagging around 5 seconds behind the video (and has a constant background noise)

I've tried downloading a few apps to resync but they all seem to be designed to work when the audio and video are recorded as 2 separate files.

Is there a simple app available where I can just open the mp4 file and adjust?
If I could remove the background noise/static as well that would be a bonus!

oldernonethewiser

You would have been better using a video capture/convertor intitially to connect from VHS to PC.  I did this with lots of old tapes. 

You could try using Handbrake to sort your sync issues. 

Neil_Jones

If the drift is constantly 5 seconds, you can import the audio into something like Audacity, knock five seconds off the file, export it back to WAV or MP3 or whatever and then just use what you've found to rebuild it.

If the drift varies and its not a fixed 5 second lag, this option may not work. so the solution there depends on how bad the lag is.  If its totally out of whack with the whole video its probably going to be better just to remake it properly - ie capture directly, not from a screen recorder.

The sound issue - depends where its been introduced.  If its on the original tape you may be able to effect/limit it in Audacity, but if it was introduced by your screen grab program because you left microphone open (for example), then it may be more prevalent.

forgotmyname

Try different software to play the video.  Even different versions of the same software can affect audio sync issues.

I had a big problem with VLC a while back, everything I played was out of sync, sometimes just a fraction of a second and
sometimes upto 7 seconds out of sync.  Reinstalled an older version and everything was back to normal.

You can adjust the playback sync using VLC or similar and select the always remember so it will always be in sync
when you play that file.

Heedtheadvice

There are several issues as posted above and different ways to sort or just improve.

Answering if the delay is constant will help (one solution above) and hearing a sample of the audio can help to determine the type of unwanted sound and best way to improve it, if possible.

Both assume you cannot or do not want to do a proper capture  ( also as posted above).

Can I suggest you share a small sample of the video and audio and you might get some good responses? Otherwise it is difficult to be specific as to what to do.

PHK

.mp4 is a container format, so this is going to depend what is actually in the file. 

Personally, I would start again using proper capture software that will enable you to get best quality and sync audio amongst other things.