Synching with a recording

alpalmer wrote on 12/1/2015, 1:41 PM
I am using Movie Studio Platinum 13.0 with Windows 10. I have a video shot with a Canon camcorder. I also have a sound track recorded on a separate audio recorder. Is there a way to synchronize the two? The audio recording runs a bit longer than the camcorder sound track. If I line everything up at one point, down the line, the audio is behind the sound track and gets further behind the farther down the line you go. Any thoughts would be appreciated.

Comments

Chienworks wrote on 12/1/2015, 6:12 PM
Pretty easy to fix, with a bit of practice. Trim both audio and video as close to the part you're going to keep as possible so you don't have a lot of extra head and tail to deal with. Line up the beginning as best you can. Now go to the end and make a good guess how much longer the audio is than the video. Place your mouse pointer at the end of the audio track just as if you were going to trim it, but hold down the Ctrl key and drag the end to the left by the amount of time you guessed. This speeds up the clip instead of trimming it. Check to see how close the end is and adjust again as necessary.

Now, unfortunately, Vegas defaults to "preserving pitch" when you change the speed of the audio, which is the wrong thing in this case. Since the audio ran longer the pitch is off, so it needs to be corrected, not preserved. Right-mouse-button click on the audio and from the popup menu choose properties. In the window that opens change the Time stretch / pitch shift method to "lock to stretch" or "none" depending on which version of Vegas you're using. This tells Vegas to adjust the pitch to match the new speed.

Now, something to watch out for: if the initial sync point you chose wasn't very close to the beginning then it may have shifted significantly to the left and you'll have to line that point back up again, which means you'll have to adjust the pitch again, which means it'll shift again, which means you need to line it up and adjust ... well, you get the idea. So, it's important to choose your initial sync point as close to the beginning as possible. If you can't ...

If your initial sync point has to be somewhere far from the beginning then you can follow this slightly more complex procedure to avoid having to adjust too many times. After getting that point in sync put the cursor on that spot in the audio clip and press S to split. Vegas will break the audio clip into two pieces at that point. Now when you go to the end to adjust the speed Vegas will keep that split spot at the same point on the timeline and it won't shift back. Now when you get the speed right turn off auto-ripple, delete the first part of the audio clip, and then drag (without the Ctrl key) the beginning of the second part back to the beginning. This will extend it to restore the part you split off while keeping it at the new speed. Don't forget to turn auto-ripple back on, if you want it.
musicvid10 wrote on 12/3/2015, 9:57 AM
I cut the audio into 9-10 minute chunks, but ONLY in quiet spots precisely at zero-crossings, lock the reference audio track (from the camera), and tell Pluraleyes to line them up. Teeny gaps or crossfades should not be audible in the final mix.

Any stretch/pitch adjustments create artifacts that are audible to me, when compared side-by-side with the more time-consuming method I use.
D7K wrote on 12/3/2015, 11:58 AM
I second PluralEyes as a great multicamera/sound mixer
alpalmer wrote on 12/6/2015, 7:31 AM
Actually, there was another solution that my son, a professional photojournalist, suggested. The sample rates were different. When I ran the audio tracks through Sound forge and resampled them to 48,000 everything came out fine. They had been recorded at 44,100. Thanks for all of the suggestions.
Chienworks wrote on 12/6/2015, 11:00 AM
That shouldn't have mattered. Vegas resamples on the fly already.
alpalmer wrote on 12/8/2015, 9:43 AM
Perhaps not but, that was how I solved it. The two audio recordings were recorded at 44,100. When I resampled them in Sound Forge to 48,000 and brought them into Movie Studio, they lined up perfectly.