Audio and Video out of sync when using Seekbar

I have a number of different courses where I have recorded video using Storyline. I have then exported the video, converted it to an audio file, edited the audio with Audacity, and then inserted the audio file back into the slide. When I play the video everything works fine until I use the seekbar. If I try to use the seekbar the video jumps to the right part but the audio doesn't jump with the video. The audio just keeps on playing. I'm sure there is an easy solution to this but I'm a new user and don't know what it is. Please help Storyline experts.


126 Replies
Michael Maier

Cool. I created a work around for this.

  1. Put a 50% transparent rectangle over the seekbar.
  2. Create separate start/stop controls that sit on top of the start/stop controls of the seekbar.
  3. Create triggers assigned to the "faux" stat/stop controls that would start and stop the timeline. 


  • Still get to see the seekbar advance and the time indicator
  • Starting and stopping timeline doesn't throw any animated effects out of wack


  • Not a true seekbar since you can't jump around in the movie. 

Hope this helps. 

- Michael 

Kevin Mc

Thanks Ashley and to your team for looking into the issue and providing extra detail.

Another potential workaround that I can think of would be to add additional keyframes to your video. This will increase the video file size but depending on the content you may be able to sacrifice other settings (bit rate) to keep the file size down.

Best to do this at the output point to get the best quality rather than using already compressed video.

In an application such as Adobe Media Encoder you can set the keyframe distance to 1, for example and re-output your video. 

In a 29 Frames Per Second video this would insert 29 keyframes every second. This should keep  the sync very close. You could set the keyframe distance to a larger number eg 15, that would mean there would be keyframe every half second.

I am sure there are  other video rendering tools out there that would let you add keyframes but always best to do it from the Hi Res source.

I have to test this theory but I am certain it will work.

Ashley Terwilliger-Pollard

Thanks Kevin for sharing that here as well - it's a bit beyond my expertise, but it sounds easy enough to do if you've got access to another video encoder tool. Keep us posted on how your test goes - and if you're able to document the steps you've taken I'm sure that'll be helpful to other users who come across this thread. 

Ashley Terwilliger-Pollard

Hi Bernard, 

We don't have a date yet for the update - but once we know we'll update this thread immediately. I know our team is still hard at work on it and going through some additional testing before we push it out. 

As far as updating the existing files, I haven't tested the update myself yet, so I can't say for certain but based on how similar fixes/updates in the past have worked I would expect that to be the case. I'll reach out to see if I can get any more information. 

Bernard Sandler

Hi Ashley,

Providing substantive information about a long awaited and frequently requested fix to flaw in the software was an excellent start.  I fear that we are dipping back into the pattern of non-response that characterizes this thread.

1. Please confirm whether re-publishing existing content with an updated version of Storyline will correct the syncing problem you have identified above.  If you don't have the answer, please get one from the development team.

2. Please provide at least an approximate schedule for this update so that the Articulate community can plan a our development cycles effectively.




Ashley Terwilliger-Pollard

Hi Bernard,

Sorry if I wasn't clear about the answer to question 1. You will want to republish existing content once there is an updated version to correct the syncing problem. There is not (that I know of yet) an "updater" similar to what we've been able to do for the issue with iOS9 that goes and updates code within the published output. 

I was speaking with our team the other day, and we don't have or share a schedule or timeline for updates (or even new products). The rationale behind this, is that during the testing phase and while we're confirming all the elements of any new update we may run into unexpected issues that could take longer or cause a delay. We don't want to promise or offer a target date as it may get pushed back and therefore we wouldn't be true to what was previously shared. I can see how this is perceived - but from my stance I'd say it's the lesser of two evils. 

I hope that helps clarify and if you have any other questions please feel free to let me know. I'll always offer as much as I'm able and if it's something I can reach out to our team regarding I'm happy to do so. 

Dan Graham

The sync issue stems from a limitation with the way Flash handles video. It is only possible to sync playback to the nearest video keyframe. Keyframes may occur multiple times per second, but in some videos it may be several seconds between keyframes. If the seek bar is moved to a position that does not correspond to a keyframe, the timeline will play from the precise position selected but video will only play back from the nearest keyframe, causing the sync issues described above.

Hi Ashley!  I'm having issues with this problem in a current course , and I reeeeeaaalllly wanted this to be a fix, so I tested it.  I didn't get very good results though.  

I went ahead and created two versions of the same video, one with keyframes at 90 and one with keyframes at 5.  And i published both courses at 29.97fps (pretty standard).   I separated the audio from the video and posted each video on a separate slide under the exact same conditions.  I got what looks to be the exact same amount of ... ummm... 'un-synced-ness?'.  And it's pretty big chunks of time, even though a video at 30fps with keyframes at every 5 should have 6 keyframes/second, and therefore only a .2 second disconnect with the audio at most.  I posted my test version here.

I'm attaching the source file as well.  To me, it was really weird that video lag was pretty much exactly the same at each point when comparing the videos, BUT, the lag was longer at the first point than it was at the second and third.  

The html5 version is spot on though!

So, I guess with that said, I'm wondering if there might be some additional information regarding the keyframe issue that was left out?  Or maybe I'm missing something?  I'm pretty handy with Adobe Premier Pro, so any further insight would be helpful.  

P.S.... Much appreciation for your peaceful moderation of these kinds of issues!  It seems like you're always moderating the issues with no end in site.  I'm sure it's a tough position to be in.  :(

Thanks Ashley!

Ashley Terwilliger-Pollard

Hi Dan,

Thanks for sharing the files and steps you went through here. I sent this directly along to our QA lead who let me know about the technical specifics of the sync issue to see if they're able to take a look at how your file is behaving as they continue testing the mentioned fix. I suspect as you surmised there may be a bit more "under the hood" that isn't included in my post above - the behind the scenes elements that we can't share, which I don't even know all of - likely because it's a bit more technical than I understand! ;) But your test file is really well organized so it will be a good one for them to test - and I appreciate you sharing it. 

It's a tough position, but one we're happy to take on in advocating for all of you here in the forums and through support cases. I'll be back in touch soon! :-) 

Dan Graham


I can't believe I didn't know that setting was there.  So yeah, I set it to not compress, and it works like gang-busters.

Adjusting keyframes may not be an option for the average developer, but maybe I'll put a little tutorial together on how to do it in Adobe Premier.

Thanks again for all your help Ashley.  Problem...solved. 

Oh, it's also worth noting that adding additional keyframes to these videos didn't increase video size at all.  

Leslie McKerchie

Hi all,

I wanted to provide an update here, as Storyline 2 Update 8 was just released, and included a number of fixes which you can see in the release notes available here. The item you all may be particularly interested in is how it fixed an issue where a video would no longer be synced with the slide's timeline after using the seekbar to scrub back and forth through the video. You can download the latest update here, and after downloading and installing the latest update you’ll want to republish any existing content to ensure that the updates and fixes are applied.

Let us know if you have any questions, either here or by reaching out to our Support Engineers directly.