How to fix out of sync audio track?

[Bsmooth]

I'm putting all my blurays on hard drive. I'm older so I always use subtitles, but some of the vocal audio tracks are near impossible to hear. On the more quiet ones I am actually redoing the audio tracks using Audacity. Trouble is sometime and I don't know why yet it gets out of sync with the video.
The way I do it is; seperate the audio track using MkvToolInc, then adjust in Audacity. Put it back in by using MKVToolInc, and everything is usually fine.
I have found a workaround by watching the movie with VLCMedia Player and in tools there is a resync option where its adjustable. Then I find the amount usually in ms and then in Audacity, add or take away the amount of time and it usually works... after a few tries.
Would anyone have any idea what would cause the delay while I adjust in Audacity or with the add or remove option using MKVToolInc?
Its driving me crazy.

[cholla]

I believe you mean you use MKVtoolnix.
In it there is this setting you could try:
"Timestamps and default duration
Delay (in ms):"
You can use -(negative) also depending on which direction the "out of sync is".
This corrects the video sync as far as I can tell.
You can use VLC to determine the setting in ms.
In VLC use the hotkeys k & j for this.

Can I assume you are working with ,MKV files after using MKVtoolnix?
This is an unusual fix for some problems with .MKV files & it has fixed an out of sync problem sometimes.
I do not know why.
Multiplex the file as is with MKVtoolnix.
Then "Chapterize" the file with MKV-Chapterizer-v2.4.
Uncheck overwrite old files. That way you keep the old file as is.
And get a new file also.

[Bsmooth]

Sorry yes MKVtoolnix is correct. I tried that delay feature in it, but it just immediately goes to 100% finished without doing anything. Yes using MKV files. Weird problem indeed

[cholla]

I will have to give mkvtoolnix a try on an .mkv to see if it immediately goes to 100% finished without doing anything.
I have not use the delay feature much if any.

You could give the MKV-Chapterizer-v2.4 a try.
At worst it just won't help.

[Bsmooth]

What I would really like to do is find out why its happening in the first place.

[ProWo]

What I would really like to do is find out why its happening in the first place.

Use mediainfo to see the original delay. Note it and mux the new created audiostreams with the same delay.


[Attachment 88387 - Click to enlarge]

[cholla]

Use mediainfo to see the original delay. Note it and mux the new created audiostreams with the same delay.

What MediaInfo reports should be the "delay" already in the a/v file.
Some formats do not show this.
Audio can be either lead or lag so delay can be positive or negative.

I use both VLC & MPC-BE to check the audio or video sync.

[videoAI]

try clever FFmpeg-GUI

[Bsmooth]

I have mediainfo, didn't even think of that ! Great info I'll look into it and let you know. Does anyone else have the issue with soft vocals> Otherwise I wouldn't have this problem in the first place. I have to say they really do a lousy job with vocals in movies.
You'd think with those cool in the ear devices they have for bands and musicians, that they could come up with some better mics in movies. I realize they are different but they still both have audio in common.

[cholla]

A lot of movies have "soft vocals"(dialog).
They also seem to have much louder music that drowns out the dialog.
Some amps have a dialog setting where the dialog can be turned up.
This helps some but not as much as it should.

I did this short video using mkvtoolnix.
I added both audio lag & audio lead.
The original had already been synced with audio lead(negative delay).

[ProWo]

I have mediainfo, didn't even think of that ! Great info I'll look into it and let you know. Does anyone else have the issue with soft vocals> Otherwise I wouldn't have this problem in the first place. I have to say they really do a lousy job with vocals in movies.
You'd think with those cool in the ear devices they have for bands and musicians, that they could come up with some better mics in movies. I realize they are different but they still both have audio in common.

You can use clever FFmpeg-GUI.
Load your video, click main page, click encode audio stream.
Click on extra, then on volume detection.


[Attachment 88398 - Click to enlarge]

Wait until is finished.
You'll get a message of the gain found. Click OK.
On the left click on Audio filter.
On the top you see the found gain in dB.


[Attachment 88399 - Click to enlarge]

Remember the value and cancel the field.
Check the clevernorm filter and enter the remembered value. Click OK.
Select your encoder and the bitrate, then click encode.
If finished, click on multiplex.
The new created audiostream is shown in green. Deselect the old audiostream on the left; all other streams should be selected.


[Attachment 88400 - Click to enlarge]

Set your container and click multiplex. Done.
Listen at your new video and report, if the vocals are better for you.

[Bsmooth]

I've tried twice to get that program to work, with no luck, plus all the warnings I keep getting. Appreciate the help but no joy with Clever FFmpeg-GUI.