Tip: Syncing audio tracks

farss wrote on 5/29/2008, 4:36 AM
Matching waveforms makes this easy. Except if some tracks are 20dB different there's a problem. You can magnify the waveform but that doesn't help, they all get bigger. As I just realised though the Gain Envelope reduces a tracks Gain and hence waveform height.
So, use Shit + Up Arrow to make the low level track nicely visible. Drag the Gain Envelope down on the tracks that are now too magnified to get them at around the same height.

Now you can see the patterns and match easily.

The Gain Envelope is the thin blue line at the top of every audio track. It's hard to see and very usefull. A Volume Envelope will not change a waveforms height.

Bob.

Comments

rs170a wrote on 5/29/2008, 6:24 AM
Great tip!!
Thanks Bob.

Mike
alltheseworlds wrote on 5/29/2008, 6:55 AM
+1 :-) thanks
baysidebas wrote on 5/29/2008, 7:30 AM
"You can magnify the waveform but that doesn't help, they all get bigger. " But why can't you just resize the track? I do that all the time.
rs170a wrote on 5/29/2008, 7:36 AM
baysidebas, I do that a lot as well but there are times (low original track volume) that Bob's tip will be more useful.

Mike
baysidebas wrote on 5/29/2008, 9:47 AM
Maybe so, but to my tired eyes, reducing the size of waveforms in order to make them match is counterproductive. But I'd be giving away my age if I mentioned doing film editing with wet cement splices, and audio editing with grease pencil, cutting block, splicing tape and a single edge razor blade.
rs170a wrote on 5/29/2008, 10:03 AM
Who said anything about reducing the size of the waveform?
My 57 year old eyes are getting tired as well :-)
That's why a combination of these two suggestions works VERY well for me.
I also use the F11 hotkey to show only the timeline and nothing else.
On a 24" monitor, my eyes need all the viewing space they can get.

Mike
TGS wrote on 5/29/2008, 11:04 AM
I see the 'up' arrow.
I know I have one of those other keys somewhere here.
UlfLaursen wrote on 5/29/2008, 11:35 AM
Thanks for sharing Bob :-)

/Ulf
baysidebas wrote on 5/29/2008, 1:32 PM
Sop my tired old eyes saw this: "Drag the Gain Envelope down on the tracks that are now too magnified to get them at around the same height." but didn't see this: "So, use Shit + Up Arrow to make the low level track nicely visible."

So pray tell, how is this an advantage over just increasing the track size for the low level signal? In fact, I see a serious drawback in Bob's method. If you forget to restore the gain on the reference track... On the other hand, a magnified track view has absolutely no effect on the output. I'm sure that Bob's method works for him and may be the answer to many others. I was just presenting an alternative that has worked for me on more occasions than I care to remember.
farss wrote on 5/29/2008, 2:53 PM
I've tried increaing the track size but that didn't quite help when the track your're trying to sync to is over 20dB lower than the other track you're trying to sync to. Also you've got to have the room to make the track bigger.
I find the visual patterm matching works better for me at least if the tracks are the same height and the waveform are also pretty close to being the same height within those tracks. If you're trying to sync from slates doesn't matter much but here I didn't have slates and really didn't have a clue where I was. I'd recorded around 90 mins of audio and only 70 mins of vision as the audio recoder was left to just record as it was a long way from the camera and could record for hours before it ran out of HDD space. My camera on the other hand I buttoned off at every scene change which took minutes.
Worse still this wasn't music, just speech from a play and it wasn't in English and a lot of it had repeated phrases, so I needed to view say a minutes worth of waveforms to get a matched pattern.
Once I was in the right ballpark, the final sync to frame accurate was easy.

Bob.