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Resyncing audio from completely different masters, potential automation?

7 Replies, 630 Views

Hello, as the title suggests, I am wondering if there is any way I can somehow make audio synchronisation of two (almost)completely different sources a little easier, or if it really is completely necessary to do it all shot by shot, frame by frame? I know a programme that does this with subtitles that I have used with great success, I thought that would be harder than this, so I am a bit puzzled. Thanks in advance to whoever responds.
If you want an accurate sync it’s got to be frame by frame. With two different masters you could have lots of differences, even if it’s just a frame off every so often it starts to add up over a 150k frame movie.
Let's say, Mad Max style, that the length of all the different masters are the same (with no cuts), and the delay only being at the beginning.

Could the initial delay be automated by some software?

After, FCPX can align multi-angles automatically.
(2021-10-28, 09:03 AM)Stamper Wrote: Let's say, Mad Max style, that the length of all the different masters are the same (with no cuts), and the delay only being at the beginning.

Sadly it's often not true...

Apart the obvious delay at the beginning, usual differences are around reel change (about every 20 minutes) one or two frames.

So, in the best case, no frame difference and only delay; in worst case (of the same cut) several frames missing from one or both sources.

Easiest sync based on frames; most accurate sync based on waveforms.
Sadly my projects are lost due to an HDD crash... Sad
Fundamental Collection | Vimeo channel | My blog
Thanks for the replies. Yea, I've already started doing a waveform sync. I seem to be stuck with a worse than worst case scenario where multiple frames are missing from every shot, so I'm just going to have to trudge through here.
(2021-10-28, 02:20 PM)Mediahead Wrote: multiple frames are missing from every shot

Dodgy  I guess there's something wrong... check these things:
  • one source could be variable frame rate
  • blended frames due to bad IVTC
  • wrong conversion from NTSC to PAL
Sadly my projects are lost due to an HDD crash... Sad
Fundamental Collection | Vimeo channel | My blog
(2021-10-28, 02:20 PM)Mediahead Wrote: Thanks for the replies. Yea, I've already started doing a waveform sync. I seem to be stuck with a worse than worst case scenario where multiple frames are missing from every shot, so I'm just going to have to trudge through here.

I often follow this process for problem syncs where there are a lot of frame differences:

https://forum.fanres.com/thread-2776.html
(2021-10-28, 02:38 PM)spoRv Wrote:
(2021-10-28, 02:20 PM)Mediahead Wrote: multiple frames are missing from every shot

Dodgy  I guess there's something wrong... check these things:
  • one source could be variable frame rate
  • blended frames due to bad IVTC
  • wrong conversion from NTSC to PAL

Nope, it's just a really really bad transfer. That's why I'm only using the audio from it.

Edit: to clarify, there are jumps, reel change marks, or splices at these missing frames.
(This post was last modified: 2021-10-28, 03:39 PM by Mediahead.)

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