aligning audio tracks

ade_m wrote on 4/13/2014, 3:58 PM
Hi looking for some advice on this.. I've multiple camera recordings of the same event. I've created the required extra video and audio tracks and put the video/audio in rough placement.

I'm prepping to make them composite to switch the video around and mute all but one audio.

However, getting them aligned is a problem. I'm trying to use the waveform in the audio to line them up visually, but if you're a smidgen out then it makes a difference.

It occurred to me that there might be a better method, or, a tool to automatically align the tracks better.

The audio levels between tracks will differ slightly, but it should have very similar peaks and drops, so maybe something a computer could align faster than me.

I'm putting together 4 cameras over 4 hours of video - so any way to speed this up would be good.

Any ideas?

Comments

musicvid10 wrote on 4/13/2014, 5:17 PM
The audio tracks are not going to be in sync, regardless. Good you will use one audio track in the end.
Audio tracks can be aligned to each other in Vegas Pro using Pluraleyes ($300), but it is not a way to sync video.

Lacking Vegas Pro and genlocked, smpte synced timecode, the best you will do is by aligning the video tracks visually, looking for reference motion points. The best you can achieve is one-frame precision, do not misalign frame boundaries; i.e.., leave "Quantize to Frames" and "Snapping" turned On in a properly matched project.
richard-amirault wrote on 4/13/2014, 8:29 PM
When aligning be sure to sufficiently *expand* the timeline to make it easier to see the peaks and valleys, but don't overdo it.

With four tracks over that long a time period .. yes, it is *very* unlikely that what was synced at the beginning will still be synced at the end.

What I have done (with two or three .. never four tracks) is find which audio track is going to be your "master" track .. and then edit the other tracks when they get too far out of sync. To do that it is easier to shorten those tracks (make a cut then slightly overlap the ends) than lengthen them. Obviously you do this when you are not using that video as an active track ... and it is unlikely that the other three tracks will go out of sync by the same amount.
UKharrie wrote on 4/26/2014, 8:13 AM
FWIW, don't forget that sometimes a bit of silence works wonders, - or you can drop in music (but some filming may have that). When you cut to non-performers say folks at a table, the music sync is not important, so you can reset any alignment at the next cut.

Chose the best recording for Master Audio - Yes, I expect you know that.
( brighterside explains this better too.)
Chienworks wrote on 4/26/2014, 11:05 PM
What i usually do is find some common cut point at both the beginning and end. For one wedding i did this was when the organist walked across the platform before starting, choosing when her foot hit the top step in all four videos. Then at the end someone went up to blow out the candles after the recessional was over. I trimmed all three sets of video to these points and then snapped the beginnings to align with each other. After deciding which one was the master version, i then held down the Ctrl key while stretching/shinking the others to match the end point of the master track. Any track that had changed speed, i'd go into the audio media properties and change the pitch change method to 'lock to stretch'. This is vitally important to make sure they end up all matching pitch with each other.

At this point they were all in perfect sync. I could then trim the extra unwanted material.