sync two audio tracks

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I have created multiple recordings of the same session.  From a zoom meeting, I have screen capture along with audio from the mics in the room.  I also used a lavalier mic and a pocket recorder to capture the main speaker, and a video camera (with its audio recording) to capture some whiteboard portions of the presentation.  Now i want to combine these into one recording.  In particular, I want to synchronize the audio tracks so that I can switch between them.  For the portions where the presenter is speaking, the audio track from the lavalier mic is much cleaner.  When questions get asked from the audience, or there is a discussion within the group, the room mics picks this up better (albeit with background noise).  I searched, but can't find an answer.  Does Camtasia allow me to automatically sync the audio tracks?
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pauls

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Posted 2 months ago

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Joe Morgan

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No, unfortunately. Camtasia doesn't have that as a feature.

If you bang on a table or make some other noise that will put a defined spike in the audio waveform. You can line up those spikes on the timeline.

Regards,Joe
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bill.raymond

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Unfortunately, this is not an option for you, but here is how I resolve this problem, specifically when I am recording with a Zoom meeting. Stop the recording. When everyone is ready to start, begin the recording anew. If you use Zoom's Record a separate audio file for each participant option, then you will get a set of audio recordings that are already aligned. As for synching audio that may not be recorded by Zoom, yeah, I think the bang the table or using a clicking device option is a good option. 

Once you get the beginning of each audio lined up, you should be good to go. Add each audio item to their own track in Camtasia and when you need to remove sections, CUT the segment (the scissors or use the proper keyboard shortcut for your OS) and then Camtasia will not only remove the segment for everything (keeping things in sync) but will automatically move the audio on the right so it lines up with that on the left.

Hope this helps.
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Paul Middlin, Employee

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Just to make sure you know what you can do...
You definitely CAN sync the two audio tracks effectively. There just isn't an *automatic* way to do it, without your help, though that would be cool.

To line them up, place both recordings on the timeline. Drag one of the recordings left/right until they are in sync. If the sync drifts, it is because one recording is longer than the other. That might sound weird, since they were literally recorded at the same time, however different devices encode the audio in different ways, and as such, when they get to a computer, one can be a few seconds longer than the other even though they should have been synchronous. To correct that, make use of the "clip speed" effect to tug it into place.

Hope that helps.
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pauls

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Thanks for the info.  My hope is this is a product request that might be completed in the near term future?  This is something that I will be doing on a regular and repeated basis, and should be relatively easy to do programmatically.  I know other products include this feature.
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bill.raymond

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Out of curiosity, how would you expect the product to work specifically with auto-sync? As a podcaster, I totally get the need to line up audio but am curious how you picture that working in a product.
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pauls

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Sure.  You would select two audio tracks, right-click and select an option to synch audio.  I suspect you would have to confirm which one is the driver (primary sound track).  i.e.  adjust the secondary track to map to the primary sound track.  The product would analyze the two tracks and adjust the position of the secondary track to map to the primary one (and potentially adjust clip speed as noted above).  The reason choosing which is primary matters, is because the primary track is the one that is connected to the video, so i need to keep these in synch.  
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Joe Morgan

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So, Adobes Premier Pro automatically syncs audio tracks.
Multiple cameras, audio tracks, etc. If you had 10 audio track to sync, it would do it.
Plus, it only takes a couple of seconds to apply. If you have several tracks of audio, it will take a little longer for Premiere Pro to analyze and sync.

Heres somebody elses video, not mine. Jump to the 1 minute and you will see it work very quickly.

Regards,Joe


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bill.raymond

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Just like the guy said in the video, I've been using Premiere Pro wrong all that time :-). Thanks for sharing and now that I understand there is some logic in there to smartly synch, I can understand how you would want it to function in Camtasia. Thanks.

As a side note, my tip on stopping recording in zoom and re-starting will be really valuable for you if you use multiple audio channel output files. They will all align for you much easier with that method. The reason Zoom does not sync easily is that if I dial into the session and then you dial in a minute later, then the audio is off by a minute. If you stop recording and start recording, the new multiple audio files will be in synch because for the recording we are all starting at the same time.
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pauls

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Thanks all.  Yeah, the guy sitting beside me at work is using Adobe Premier, so I knew the feature was there.  It feels like such an obvious and useful feature that I am surprised Camtasia doesn't do it, and I am hoping they are about to add it.  Otherwise, I might have to make the switch.
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davemillman

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Pauls, from what you described, the sync step is something you will do once per project. Then you will spend a lot of time inserting cuts when the one track is cleaner than another, deleting unused segments, etc. So at best, the autosync feature you described will not save very much time.

In addition, re-read Paul Midlin's reply above, about how two recordings of the same material can end up different lengths. This is quite common. One of your audio tracks comes directly from mics in the room, so it gets encoded only once. Another track goes through multiple digital conversions across telephone and Zoom networks, being encoded and re-encoded all the way, each to a different timebase. I never bother with the clip speed feature solution that Paul described because it is simpler just to cut the clips, drag them into place and move on.

My advice: Practice visually aligning waveforms. This will take you a few minutes to master, at which point you will be able to quickly sync anything you need. Do it long enough and you'll start to recognize words by their waveforms. "Ummm" looks like a football (rugby ball if you are from that part of the world).
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pauls

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Thanks for the feedback everyone.  I have to admit, now that i have done it, you were right.  lining them up was easier and quicker than i had thought.  and agreed, switching between the audio tracks is the bigger job.  can anyone point to any best practices on managing multiple audio tracks.  I want to be able to switch back and forth between them.  the mic on the presenter is much cleaner when the presenter talks.  but when the discussion moves to the room, the lapel mic doesn't pick up the conversation very well.  I think an audio track is either heard or not heard.  to I chop up the audio tracks portions and move them to a new track switching between the sources?
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Joe Morgan

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Keep all the audio tracks in place, stacked together on separate tracks. Until your positive you have the audio just the way you want it. That way you can easily make changes.


Then select all the audio and group it. That gives you the flexibility to change anything you chose later. With minimal fuss.

Un-group the audio and it will be in the state it was during editing.

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pauls

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What I have is two complete audio recordings from the same session.


One of the tracks contains audio from a lapel mic.  the other track contains audio from room mics.   The room mics are pretty noisy.  So when the presenter speaks (most of the time), i am using the audio from the lapel mic.  When there is a discussion in the room, I am using the audio from the room mics.  What I am currently doing is splitting the tracks at points where I want to switch audio tracks and moving them up to a primary audio track.  Seems finicky, but I haven't come up with a better approach.  I tend to not want to throw the other audio away in case I realize i made a mistake in where i cut the files, i can switch back.  Is there a different approach that others have used?

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davemillman

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Joe Morgan described how to manage them. Here's how to cut them. Nothing fancy...


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cbkr.team

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I just thought I'd share an experience for interest, which does have some relevance to what you're doing, and I also think shows that Camtasia is a lot more versatile & useful than some users on here give it credit for, present company excepted of course. I had a video that I was doing for work, where I had two speakers addressing an audience, and two cameras - the primary one facing the speakers, and the secondary one facing the audience. This was the first time I had shot this kind of scenario.

The primary camera had a microphone on top, and a feed from two lavalier microphones on the two speakers. The secondary camera had a feed from a boom microphone, which was held near an audience speaker when they were asking a question, as you would expect. The original intention was to have both the recorded camera tracks, with audio, lined up in Camtasia from the start, and cut between them, similar to what you're doing. To do this, I would put the secondary camera track at zero opacity, and the audio level from it at zero. Then I would "Split All at Playhead" when I wanted to switch between cameras, then play on until I wanted to switch back again, and split at the playhead again. Then I would select the primary camera track for the section I'd just made, make that opacity & audio zero, and then select the secondary camera track for that section, and bring up the opacity & audio to 100%. I would then keep doing that every time there was an audience contribution. Doing it this way means everything remains on the same tracks, so it's easier to see where you are. I'm used to manually editing reel-to-reel audio tapes, so I find laying it out like this to be the most natural way.

As it turned out, there were technical difficulties during the shooting, whereby the secondary camera (which was borrowed from another department), that was just being left to roll on its own, kept switching itself off every 30 minutes, which I spotted, and kept switching it on again, but it also failed to record any audio, for some reason that I still don't know, and which I didn't spot. Additionally, the person with the (unknowingly redundant) boom microphone, kept walking across the shot on both cameras, in such a way that it was often impossible to simply block them out just by switching to the other camera track. I learned two lessons from this. Firstly, don't use a borrowed camera for your secondary; get your own, so that you know it works properly! :-) Secondly, using a boom microphone is difficult to manage, unless you're the BBC! :-) Hence, after this, in these situations, I mike the audience with a matched stereo pair of Rode M5 microphones, on fixed stands, and I've made sure that the secondary camera problem has been addressed.

However, I still had to rescue the output of this shoot at the time, and Camtasia was a great help. I stuck with the basic technique that I'd planned, as above, but separated the audio from both tracks, and deleted the useless audio track from the secondary camera. When I had an audience speaker asking a question, I still split the primary audio at the playhead, at the beginning and end of their question, then amplified that section, as the camera microphone had picked up the audience sufficiently to do that, albeit with more noise. In terms of the person walking across the cameras, I used a combination of split screen, picture in picture, and replacing the moving image with a still frame for a few seconds where needed. I was also able to duplicate sections from the second camera convincingly, where it had cut out altogether. Luckily, most of the questions had come from the same two people, and it was running for the others. I ended up with a pretty decent final product and, although it did take a bit of time to edit (it was a three hour video), it was pretty straightforward to do in Camtasia.

I use Camtasia 2 for Mac at work and, I liked it so much, that I got Camtasia 3 for Mac at home. Once I've got all of my current Camtasia 2 projects finished at work, we'll be moving to Camtasia 2019, but I'll be sticking with Camtasia 3 for Mac at home, as it already does way more than what I need, and does it reliably. 

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pauls

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Thanks for the feedback.  I finished the editing on the video i was working on already.  I used the split and move things between tracks approach.  I think your idea of playing with opacity and volume levels within the existing tracks is interesting, and i will play with that next time, as it feels like it might be a bit less finicky.