Synchronize audio and video in Subtitle Edit and save

[loninappleton]

I have out of synch audio and video in an mkv. Tried a number of things but I simply cannot read lips to get a good mark.

Subtitle Edit can show the video and audio and then use the hairline guide to adjust where the beginning is visually. Usually it is to go back a few millisecs.

This mkv has no subtitle file for it. I loaded an SRT from elsewhere to get it going. Can I simply save video and audio in Subtitle Edit?

On that issue, is there an audio and video editor to do this visually? It's not VLC or the usual suggestions. AVIDemux should do this but again, I want to see the waveform. I'll check with Audacity or Goldwave audio editor as well.

[loninappleton]

Progress.
Here is a method I used to get audio and video synched using both Subtitle Edit and AviDemux with this
help link for Step Two:

https://www.simplehelp.net/2018/05/29/how-to-fix-out-of-sync-audio-video-in-an-mkv-mp4-or-avi/

Step One:
In Subtitle Edit load video and click on 'load the wave form' in the audio box lower screen.
Find your preferred index sound such as a loud noise. Use the hairline slider to shift to the beginning of the sound.
Note the millisecond _count_ displayed as you move the slider.

Step Two:
Use that millisecond number in AVIDemux. AVIDemux should be here on Videohelp free software. Use the instruction on adding a delay with help in the link above. Save in AVIDemux--

Further note: I don't think AVIDemux will recognize a subtitle file.

I'll mark Solved on this after I run it a few more times.

[loninappleton]

A further problem with this. What I've said above is accurate to get the synchronization. But the synchronization goes off as the playback continues from AVIDemux. It's a frames per second problem I've asked AVI demux about. So on first look, the synch added looks perfect but drifts off. If there is an incorrect "default' in AVIdemux I don't know what it is or how to correct yet.

[johns0]

If the subtitle was for a different version of the video it might have added/reduced scene changes and fixing that will take a lot of editing,basically what you do is start the first scene and when it changes correct that part and do so for the next scenes changes.

[davexnet]

If the subtitle was for a different version of the video it might have added/reduced scene changes and fixing that will take a lot of editing,basically what you do is start the first scene and when it changes correct that part and do so for the next scenes changes.

Is the OP talking about sync of the video and audio OR video and subtitle?

Perhaps a mediainfo report showing the details (text view) would help

[johns0]

Is the sound going gradually out of sync or just after a while or in certain parts?

[october262]

A further problem with this. What I've said above is accurate to get the synchronization. But the synchronization goes off as the playback continues from AVIDemux. It's a frames per second problem I've asked AVI demux about. So on first look, the synch added looks perfect but drifts off. If there is an incorrect "default' in AVIdemux I don't know what it is or how to correct yet.

try with mkvtoolnix - https://www.reddit.com/r/mkvtoolnix/comments/kzzw1k/how_to_sync_audio_w_mkvtoolnix/
and try here for the audio drifting - https://www.reddit.com/r/VideoEditing/comments/140p4o/audio_and_slowly_drift_out_of_sync/

[loninappleton]

Thanks for replies. I mentioned earlier someplace I can't read lips worth a hoot. No, no subtitles. I was just using that to get the delay numerically.
This all started b/c I did an edit of the various parts: part one, intermission feature, part two. Someone spotted the out of sync and told me
since I could not see the problem in the first couple minutes of that part two.

I will look at the MKV toolnix tip above but I already tried their delay box with a 'baseline' or original part two where the problem is.
Perhaps someone knows if the free editing software like this introduces some time shifts.

I've looked at MediaInfo and can make an attachment. In MediaInfo it will sometimes show a delay number in the readout.
I didn't see any for this. Please say of you want the original unedtited content for the MediaInfo and I'll look for the original I had used.

[davexnet]

Thanks for replies. I mentioned earlier someplace I can't read lips worth a hoot. No, no subtitles. I was just using that to get the delay numerically.
This all started b/c I did an edit of the various parts: part one, intermission feature, part two. Someone spotted the out of sync and told me
since I could not see the problem in the first couple minutes of that part two.

I will look at the MKV toolnix tip above but I already tried their delay box with a 'baseline' or original part two where the problem is.
Perhaps someone knows if the free editing software like this introduces some time shifts.

I've looked at MediaInfo and can make an attachment. In MediaInfo it will sometimes show a delay number in the readout.
I didn't see any for this. Please say of you want the original unedtited content for the MediaInfo and I'll look for the original I had used.

Post the mediainfo of both. Please state clearly which is which

[loninappleton]

I looked at the source. Not three pieces, just two. But I separated a short interview with an edit that I do often with stage plays. I can post the MediaInfo from the second part shortly. But I think the editing process screwed this up, not the original. Something that AVIDemux effected.

I'll just say I was confused by those reddit discussions. I can't pick out what's important in someone elses discussion if indeed there's any solution stated.

[october262]

I looked at the source. Not three pieces, just two. But I separated a short interview with an edit that I do often with stage plays. I can post the MediaInfo from the second part shortly. But I think the editing process screwed this up, not the original. Something that AVIDemux effected.

I'll just say I was confused by those reddit discussions. I can't pick out what's important in someone elses discussion if indeed there's any solution stated.

might also try using ffmpeg to synchronize audio & video - https://www.geekyhacker.com/2020/05/17/synchronize-audio-and-video-with-ffmpeg/

[loninappleton]

I am not familiar with ffmpeg.

But what I'll do is start from scratch--- download the original part two from my source. The source is a screen capture which may be another variable. Then make a simple edit-- no fade ins fade outs-- just MKVtoolnix. If that shows the problem is gone it will answer this inquiry.

[loninappleton]

Here are the two MediaInfo text views in Attachments. First is the MP4 original. I thne converted to MKV in MKVToolnix for a working copy. Then loaded that MKV into MKV Cutter to make a 7 minute trim. I have not viewed any of it so far. But I consider this all new work and hopefully problem is gone.

Failed today. I'll try this another time. Just now the upload attachment failed. Both were simple text copied to a notepad text file. I even tried changing the name. Perhaps the media info is too long. I have used the attachment option before. It just marked the uploads as failed.

[davexnet]

This site filters our files with unknown filename extensions, for example, something from
Notepad should be *.txt

[loninappleton]

This site filters our files with unknown filename extensions, for example, something from
Notepad should be *.txt

Yes the usual stuff. I'll check again and do the upload now:

Ok, I just simply redid the procedure and it went in.

Will add the other again with no special naming...

[loninappleton]

and the edit in MKV

[loninappleton]

I hope that's not too confusing. Let me know any of your findings. And again, this is new work, not the old tinkered version.

What I'll be looking for in the edit is being able to skip to any part of it and not see out-of-synch
dialog. Will do that when I'm in a quiet place.

[davexnet]

I don't see any obvious issue, but to increase the chance of success I would create a copy of the original file with PCM
audio. Open it in Avidemux, leave video as copy and set audio to PCM. Save.
Use that for your edits and keep it as PCM until your final edit is good.

[loninappleton]

That's an interesting procedure. I may try it if needed. My first look at the edit portion showed everything looks ok yet but I'll have to at least go through some tests or watch it through completely. If the sync holds I'd leave it as is without AVIDemux.

In using MKV Cutter I just used the arrows to go to an obvious key frame (which I understand the double arrows in it to do)
then made begin edit and then tagged the end followed by 'save'.

AVIDEmux I have used for things like fade outs fade ins which in free programs is rare. This whole edit business I did
originally to get rid of 'countdowns' 20 mins long between acts which are onscreen in the source.