Proper Tools and Method to Sync Audio from Different Video Source

[danswano]

Hello,
I have a video recorded from TV with a specific language that i want to export it as an ac3 audio track and sync with my already owned DVD as an extra audio language.
What are the proper tools and method to sync them because they are out of sync and duration is a bit different as well like intro and credits stuff.

Thank you.

[Baldrick]

There is no simple way to do this.

You can cut/stretch audio with audio editors like audacity but you can't preview it together with the video. You could try compare it against the other synced audio track.

Or get an advanced video editor like vegas so you can both preview the video with the audio. But it might be tricky to import the ac3 audio and dvd video in the video editor.

Extract audio with demultiplexers: https://www.videohelp.com/tools/sections/video-de-multiplexers

[danswano]

I'm using a trial of TMPGEnc Video Mastering Works 5 but i'm unable to sync properly, i can stretch and move the audio on the timeline but if it was good at the beginning at the end it gets out of sync or in the middle and if i fix it from the end it gets out of sync in the beginning again. :/

[videobruger]

As said There is no simple way to do this.

But have you considered dividing your audio into segments and making a piecewise sync.

[danswano]

No i didn't, how to do that?

[hech54]

With an audio editor.

[videobruger]

I don't know about TMPGEnc Video Mastering Works but it's normally quite strait forward. You make cuts on your audio track at appropriate points and try to sync the segments.

[danswano]

Ok i will try the dividing method, thank you.
@hech54, you don't say!

[Budman1]

It is possible to create a video of the soundtrack using LAV filter and display against the video.



Above shows the sound is delayed approximately 100 ms

You can also view as lines instead of points:

[danswano]

Can you explain further please, i'm not an expert.

[Budman1]

This is done with FFMpeg and AVISynth. If you are familiar with these then use the following script, making sure it is same size, format, etc as the original:

ffmpeg -ss 00:00:00.000 -f lavfi -i "amovie=../../../../../../../../../Users/Bud/Desktop/NameOfVideo.mp4,asplit[out0],showwaves=r=29.970=640x320:mode=line[out1]" -r 29.970 -s 640x320 -vcodec libx264 -vsync 1 -y "C:\Users\Bud\Desktop\NameOfVideoLAV.mp4"

Then just Stack them using AVISynth:

v1=DirectShowSource("C:\Users\Bud\Desktop\mpg test\NameOfVideo.mp4", Pixel_Type="yuy2")
v2=DirectShowSource("C:\Users\Bud\Desktop\mpg test\NameOfVideoLAV.mp4", Pixel_Type="yuy2")
stackvertical(v2, v1)
Subtitle("NameOfVideoLAV.mp4", font="Arial", size=24, text_color=$ff0000, align=9)
Subtitle("NameOfVideo.mp4", font="Arial", size=24, text_color=$ff0000, align=3)
ShowFrameNumber(scroll=true, x=10, y=27, font="Arial", size=24, text_color=$ff0000)
ShowTime(x=72, y=44, font="Arial", size=24, text_color=$ff0000)
ShowSMPTE(fps=30, x=68, y=61, font="Arial", size=24, text_color=$ff0000)

I am currently debugging beta that does it for me:

[hech54]

This is done with FFMpeg and AVISynth.

Just what every newbie needs.....yet another suggestion involving AviSynth.

[danswano]

I used some avs inside Virtualdub scripts but i'm not expert in the code itself, anyway i understand from your suggestion that it's comparing both video frame by frame to sync the audio?

[Budman1]

Yes, I UNDERSTOOD from your post that you were not an expert but were somewhat familiar with scripts. Thars why I said it is POSSIBLE . Yes the ffmpeg script creates a video of the audio portion and you only need avisynth to stack them as in my example. Do you use either ffmpeg or avisynth?

[danswano]

I'm not sure but all i have used in the past is an avs scripts that allows me to open an mkv file inside VirtualDub natively, i don't even know if those apps has a gui or just encoders so if you properly guide me i would be appreciated.

[turk690]

I'm using a trial of TMPGEnc Video Mastering Works 5 but i'm unable to sync properly, i can stretch and move the audio on the timeline but if it was good at the beginning at the end it gets out of sync or in the middle and if i fix it from the end it gets out of sync in the beginning again. :/

This is not uncommon with audio and video clips of the same program that came from different sources. But like baldrick said you have to use something proper like vegas or premiere.
What I'd do in premiere is this: lay audio and video on tracks in a sequence. Preview and note where there are stretches of silence or parts of audio like incidental music (these do not critically have to be in sync); cut/splice on them, ending with separate shorter clips, ideally each no more than 5 to 10mins long. Play the timeline and attempt to move these clips so they sync with the corresponding video. Export when satisfied. What was achieved here included

• no stretching/compressing of audio
• easy to sync short cut clips to corresponding video at that timeline point
• out-of-sync is no more than 1 to 3 frames worth (hopefully) anywhere for the duration of the movie, not noticed

BTW this is exactly what videobruger above is saying

[danswano]

Awesome details, thank you turk690