CS 8.4.4 audio not synced with rendered video

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  • Problem
  • Updated 4 years ago
  • (Edited)
I'm using Camtasia Studio 8.4.4 to render an mp4 in a web-based format and the audio becomes out of sync later in the video.

Spec of original video
The video was created by a media organization, in which they shot the video and then edited it in Final Cut. The video is in an mp4 format, 55 minutes long, 29 fps, 1280x720, and 2.5 GB.

My workflow when rendering
I imported the original video into CS, put it on the timeline with no other assets and rendered it using the MP4 with Smart Player (up to 720p) setting.

The syncing problem
The rendering process worked without incident and initially the video played fine. But when I used the seek bar to jump ahead in the video, the audio/voice of the person talking on camera gradually become out of sync with the video. I started to notice it at the around 26 minutes in. By the end of the video, it's completely out of sync. I played it in multiple browsers (Firefox, Chrome) and the behavior was the same in each.

Edit: Forgot to mention that the audio remains synced when I view the video at different points on the timeline in CS.

My troubleshooting so far
  1. I checked the mp4 that CS creates, and the syncing problems exist in that file. I double-checked the original mp4, and there aren't any syncing issues.

  2. I tried rendering the video again, but this time changing the frames per second to 29, since CS was rendering it as 30 fps. The problem was still present.

  3. Finally, I rendered just the last 31:20 of the video to see if "chunking" might work as a way around the problem. The audio stayed synced for the most part until right at the end when it was noticeably out of sync. I imagine chunking it further will might eliminate the problem altogether, but that will complicate matters by delaying the project due to the extra work (we have more than 1 video) and having to coordinate this among three people in different organizations.

My computer specs
  • Dell Precision T1650 workstation
  • Core i7 processor
  • 16 GB RAM
  • Intel HD Graphics 4000 card
  • Windows 7 Professional (64-bit)
  • Flash player 16.0
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Tim Danner

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Posted 5 years ago

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kayakman, Champion

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your 3rd party video may not be compatible with the CS production engine

can you play the video in a viewer

if so, capture it with Recorder while it's playing; set Recorder to capture system audio; turn off your speakers

use the new capture in a project; does it produce with in-sync audio?
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Tim Danner

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The audio is synced fine when playing the video in the CS viewer.

Tried what you suggested using the 31:20 clip. After I rendered the project with the recording, the problem was still present but a little less noticeable until the very end.
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kayakman, Champion

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sorry; what I meant was for you to play the video in a non-CS [3rd party] viewer, while capturing with Recorder; sounds like you captured off of the CS canvas?

the CS editor [editor viewer = canvas] can fall a little behind when trying to process and display a large format video w/audio as it will try to process everything in real time

anyway, there are many things that could be causing the issue you see; the original 29 frames per second being one

if you cannot resolve, suggest you contact free tech support; they may be able to give you better guidance
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Tim Danner

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Yeah, that's what I thought you meant by "viewer." I'm recording again with the video playing in Windows Media Player.
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Tim Danner

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Audio was in sync with the rendered video from the recording of the original mp4 playing in WMP.
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kayakman, Champion

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glad to hear that!
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Tim Danner

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Unfortunately, it doesn't solve my problem. I need CS to render correctly using the original video imported into the program, instead of a recording of it playing in a media player. Cutting up the video (and some of the others) into smaller parts seems to resolve the syncing, while keeping everything consistent. For me, it will be the lesser of two evils.

Thanks for all the help. I really appreciate you taking time out of your day to help resolve my issue.
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Elísabet Ólafsdóttir

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This is bugging me alot. I have used camtasia  for a long time and I can ́t now. i put a mp4 file in or a mov file and if the file plays for longer than 20 minutes the sync is off. I have old recordings that are completely fine whilst im working on them in camtasia. I view them. I cut them up. All looks fine. Then I render and I have tried every setting...been rendering for hours but it always goes out of sync. Help!!! 
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taketwo.info

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Has anyone found a fix to this?  

My workflow is similar: I record on camera 1080i 25fps, edit in Premiere CC, export H.264/mp4, import into Camtasia 8.5.1 add a few markers and export out a smart player.

Audio and video are in sync during the whole process except when it exports out of Camtasia.  

My current work around is to replace the smartplayer video with the Premiere export.  This works as long as I don't make any changes to the video in Camtasia.

Could it have something to do with my frame rate?  I use Automatic as there's no option to pick 25fps.  
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Emre Çelik

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thank you very much.. this for ..My troubleshooting so far
  1. I checked the mp4 that CS creates, and the syncing problems exist in that file. I double-checked the original mp4, and there aren't any syncing issues.

  2. I tried rendering the video again, but this time changing the frames per second to 29, since CS was rendering it as 30 fps. The problem was still present.

  3. Finally, I rendered just the last 31:20 of the video to see if "chunking" might work as a way around the problem. The audio stayed synced for the most part until right at the end when it was noticeably out of sync. I imagine chunking it further will might eliminate the problem altogether, but that will complicate matters by delaying the project due to the extra work (we have more than 1 video) and having to coordinate this among three people in different organizations.
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t.andrews

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I too am becoming increasing frustrated with the audio not syncing with the video. Plus I also get my audio going 'slow-motion' and sounding like an old man!  As an institution we were told Camtasia was going to make everything easier for our teaching - but it's not! The amount of time I waste re-recording things is ridiculous. And I'm only talking about a 4 minute webcam video. I'm not editing anything - just record and produce. It shouldn't be this hard...
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wride.matthew

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I just recorded a 26 minute screen recording of me just talking over a power point presentation, I didn't do any editing, just produced it and the audio is out of sync. Is there a fix for this?
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Kevin Mojek, Employee

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With the current version, audio may gradually drift out of sync on long unedited clips, usually becoming noticeable after about 15-20 minutes and getting progressively worse. The current workaround is to add a few splits to those clips; one every 10 minutes or so should correct the problem. Sorry for the trouble; we'll have a new version available soon that will not require this workaround.
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Kevin Mojek, Employee

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Camtasia Studio 8.6 is available now. It includes a fix for the problem where audio can gradually drift out of sync on long (15 minutes+) unedited clips.
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Frank

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Sorry Kevin, I too am still having audio syncing issues as mentioned in this post and am running 8.6. The audio issues seems  to be focusing around when I record my webcam at the same time. The screen audio seems fine but not my webcam audio. It falls behind.
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kayakman, Champion

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when you record webcam, audio is part of the webcam clip

try this ...

select webcam clip, right click, separate audio from video

right click webcam video clip, apply clip speed adjustment of 101%

grab end of webcam video clip and drag it in/out until it more closely matches audio clip [this adjusts the clip speed itself]

does that work?
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Frank

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Good thought, but it will put it out of sync with the screen recording and sound track.
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kayakman, Champion

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I thought the sound matched the screen recording clip OK?  and only webcam audio was off from the webcam video?

if necessary, adjust the screen recording clip the same way with clip speed tweak
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brianmt68

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other programs had similar issues as this before they fixed the software to account for it.

I suspect that it is the different sampling rates being mixed together in camtasia that could be causing this problem.

For example your camera may record audio at 48khz. 16bit. a music track may have a rate of 44khz 16 bit and your voice narration may be at 32khz. When you export, the program has to choose. So if you have multiple audio files for example, it might not hurt to check the properties and see what the various sampling rates are before you edit. If you convert your imported audio assets and videos to the same formats, you'll likely get the same sampling rate in the end.
to my knowledge, Camtasia only lets you choose the recording bitrate when exporting. Not the sampling rate. However, if your files are all the same type when you export everything, the sampling rates should be the same. . It happens in all editing programs to one degree or another.
Brian.

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