Synchronizing separate recordings from same source

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baudoinia
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Synchronizing separate recordings from same source

Post by baudoinia » Tue Apr 06, 2021 5:18 pm

What I am trying to do: obtain 1 track without commercial interruptions from any 2 consecutive tracks of the same (classical) work on a streaming platform.

Is there a way to "analyze" 2 tracks to find identical moments in what should be identical takes from the same source (as long as I adjust for amplification/peak dB level, assuming I can do that accurately?)
(same piece, same performance)

I discovered the need when quality-controlling a stream I saved and attempted to cut the commercial interruptions out of. So I did another take, figuring (correctly) that on different occasions, the commercial breaks might not interrupt between the same tracks all the time. The problem is the way the piece is written, there are never actually silences between the sections.
Another problem is that the source volume and recording level in Audacity were not the same.

Is there an analysis tool I can use, or can anyone recommend a work flow that would allow me to do this (stitch them together)? Want to sound as seamless as possible, so far can get very close but not without a resulting reverb effect.

jademan
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Re: Synchronizing separate recordings from same source

Post by jademan » Wed Apr 07, 2021 7:30 pm

baudoinia wrote:
Tue Apr 06, 2021 5:18 pm
Is there a way to "analyze" 2 tracks to find identical moments in what should be identical takes from the same source (as long as I adjust for amplification/peak dB level, assuming I can do that accurately?)
(same piece, same performance)
I would say try zooming all of the way out. Since you are comparing classical music, the differences and similarities should be fairly easy to spot.
baudoinia wrote:
Tue Apr 06, 2021 5:18 pm
Another problem is that the source volume and recording level in Audacity were not the same.
Since you are using classical music, this will be a little tougher. :) ;) If you can find two identical passages, select those passages to find how much amplification would be required to bring them up to say, 0. Then manually use those numbers on each entire track. (Later, you will want to bring them back down again).
baudoinia wrote:
Tue Apr 06, 2021 5:18 pm
Is there an analysis tool I can use, or can anyone recommend a work flow that would allow me to do this (stitch them together)? Want to sound as seamless as possible, so far can get very close but not without a resulting reverb effect.
Try Crossfade Tracks

I hope this helps. :D

baudoinia
Posts: 43
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Operating System: macOS 10.15 Catalina or later

Re: Synchronizing separate recordings from same source

Post by baudoinia » Thu Apr 08, 2021 3:34 pm

jademan wrote:
Wed Apr 07, 2021 7:30 pm

I would say try zooming all of the way out. Since you are comparing classical music, the differences and similarities should be fairly easy to spot.
jademan wrote:
Wed Apr 07, 2021 7:30 pm
Try Crossfade Tracks

I hope this helps. :D
Bingo on the crossfade, that occurred to me too the more I thought about it, after I posted of course. :roll:
But I don't get zooming all the way out. Seems like if I zoomed close in, and especially using spectrogram view, I might be able to more accurately align the tracks. It's times like this when I wish there were a 'magnify' kind of zoom, as well as microsecond-by-microsecond view of the tracks!

I like the idea, too, of amplifying tracks at different volumes up to 0, then readjusting back downward.
I also thought maybe if I could run the "find silences" on both tracks, the lines (or clumps of lines) next to the [S]'s would be easier to use as reference points. (The silences are too brief, at 0.001, for me to use aurally).

Thanks for the ideas!

jademan
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Re: Synchronizing separate recordings from same source

Post by jademan » Thu Apr 08, 2021 7:17 pm

baudoinia wrote:
Thu Apr 08, 2021 3:34 pm
I don't get zooming all the way out. Seems like if I zoomed close in, and especially using spectrogram view, I might be able to more accurately align the tracks. It's times like this when I wish there were a 'magnify' kind of zoom, as well as microsecond-by-microsecond view of the tracks!
Perhaps I didn't make myself clear. I'm thinking that if you zoom all the way out, you should get a pretty good picture of what is going on. Line up the tracks so the identical sections are above each other then zoom in and repeat.

So you can keep zooming in with View > Zoom > Zoom In (I just use the icon of a magnifying glass with the plus sign), then aligh your waveforms with each zoom as necessary. BTW, you can zoom in all the way to the "microsecond-by-microsecond view", and you can even zoom in all the way to the sample level!

baudoinia
Posts: 43
Joined: Wed Jul 08, 2020 12:43 pm
Operating System: macOS 10.15 Catalina or later

Re: Synchronizing separate recordings from same source

Post by baudoinia » Thu Apr 08, 2021 8:08 pm

jademan wrote:
Thu Apr 08, 2021 7:17 pm
baudoinia wrote:
Thu Apr 08, 2021 3:34 pm
I don't get zooming all the way out. Seems like if I zoomed close in, and especially using spectrogram view, I might be able to more accurately align the tracks. It's times like this when I wish there were a 'magnify' kind of zoom, as well as microsecond-by-microsecond view of the tracks!
Perhaps I didn't make myself clear. I'm thinking that if you zoom all the way out, you should get a pretty good picture of what is going on. Line up the tracks so the identical sections are above each other then zoom in and repeat.

So you can keep zooming in with View > Zoom > Zoom In (I just use the icon of a magnifying glass with the plus sign), then aligh your waveforms with each zoom as necessary. BTW, you can zoom in all the way to the "microsecond-by-microsecond view", and you can even zoom in all the way to the sample level!
I can get really close to exact, and I have to be zoomed in quite far to do it. If I'm zoomed all the way out, then when I time-shift with the mouse, it's moving too far one way or the other. Perhaps that's just my mouse dexterity.
At any rate, I've succeeded in making the notes sound like they're being played at the same instant in both tracks, but there's a teensy bit of resulting reverb.
On other occasions it sounds almost perfect, but some out-of-phase artifacts.
I think once I incorporate the cross-fade, that'll be the ticket.

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