Camtasia to sync audio from two sources

  • 1
  • Question
  • Updated 4 years ago
I used Camtasia to record a video conference call with two audio sources, system audio and a microphone. At the beginning of the call the microphone and system audio are in sync but as the call progresses, more and more "echo" appears in the call and judging by the audio waves in both audio tracks, it's clear that one is moving ahead of the other. By the end of the call they are off by 4 or 5 100ths and the "echo" is very distracting. 

Is there a way to stretch one of the audio tracks so that over the course of this one hour session the audio will remain lined up? Or, is there a way to use one track to remove the audio from the other. 

Couple items of note, the microphone track has mostly my voice on it, but it's picking up the speakers so there is the system audio in the background of that track. It's enough that it creates this echo effect noticeable from midway through the call and getting worse over time. The other item is that the system audio is devoid of anything from my microphone. That track alone has dead air whenever I'm talking. 
Photo of Chris Charette

Chris Charette

  • 5 Posts
  • 0 Reply Likes

Posted 4 years ago

  • 1
Photo of kayakman

kayakman, Champion

  • 7016 Posts
  • 2277 Reply Likes
perhaps try applying clip speed adjustment to the longer audio track?

I'd try initially 101%?  this will shorten it slightly

don't know of something like 100.5% would work?

after applying the speed adjustment, as I recall, you can grab end of clip and drag in/out to change/fine tune the adjustment

you didn't say how long the clips are [duration], so you may need to split the clip and apply adjustment to the separate sections?

I assume removing one of the audio tracks is not an option?
Photo of Timbre4

Timbre4, Champion

  • 680 Posts
  • 273 Reply Likes

Hello,

That's a tough situation. Since the delay was gradually introduced, I'm thinking at least one cellphone was involved? In addition to the modification to the overall clip speed, you might consider cutting the clip around the midway mark where the problem starts. This would leave the first portion exactly where it is (playing fine) but also give you some leeway to move the remainder of the audio to better align and make the echo less evident.

All of this is conjecture without actually hearing what you have there. However I would suggest the split idea (non-destructive editing = means changing it on timeline not harming the original asset).

TIP: When recording from a microphone, always kill the system speakers until finished.

Photo of Chris Charette

Chris Charette

  • 5 Posts
  • 0 Reply Likes
I did try that first but the percentages that I was allowed to use were not granular enough. They didn't allow fractions of a percent. 

The clips are just over an hour long, but I only need to stretch the audio by about 0:00:00:06. At the beginning, the audio waves line up great, but at the end, they are off. 
(Edited)
Photo of Joe Morgan

Joe Morgan

  • 7135 Posts
  • 3873 Reply Likes
I would export the audio and change the duration using audio editing software. I use Adobe Audition myself. A lot of people use the free program Audacity.

If you're using Camtasia 8 you can "Lock" the audio tracks you don't want to export.
To export the audio see the Image Below, Click to Enlarge. Yo will want to export the audio as a .wav file to preserve it's quality.

Regards, Joe



Camtasia is finicky with audio  files. To avoid any conflicts you want to render the new audio files using these settings. See Image Below.

Photo of Chris Charette

Chris Charette

  • 5 Posts
  • 0 Reply Likes
I have a microphone, but it's not part of a headset. It's a Blue Yeti microphone with only the forward (Cardioid) microphone active and it sits in front of my monitors. The speakers are behind the monitors. The captured speaker audio is very weak on the microphone track, but enough to be troublesome. Without a headset, I have no choice but to use the speakers. 
Photo of kayakman

kayakman, Champion

  • 7016 Posts
  • 2277 Reply Likes
Joe's approach sounds reasonable, although I've never tried it before

believe you said you needed to "stretch the audio by about 0:00:00:06" in a 1 hour clip?

if you mean by 6 seconds, that's 180 frames

maybe [add or] slice that much out of the audio clip, cutting dead space between spoken words; spread them out over a lot of short snips? lock the other tracks so you don't cut their content

just an idea ...
Photo of Chris Charette

Chris Charette

  • 5 Posts
  • 0 Reply Likes
Thanks to all. I'm going to try the either Audition or Audacity just to see if those do a better job and make things easier for future recordings, but I was able to use Camtasia by splitting the longer audio track during silent moments and repositioning the clips over the shorter track to that the audio waves between them lined up. This allowed me to make enough corrections that the echo, or repeated audio, was not noticeable. 

I'm disappointed that Camtasia has this issue in the first place or that as long  as they've been creating this software, that there isn't a built in tool for performing this critical edit. It appears that the core functionality is there, but there is not enough granularity to allow such slight corrections as I needed. I could see that I was a fraction of a time period off, but the software only allowed huge swipes at the problem, seconds at a time, and I needed small tweaks or fractions of a second here and there. 

Thanks for all of the input