Syncing video and animation - SL2

Hi there, I am working on a project that requires me to have a video on the left of the screen, and to display animated content (text, bullet, images, etc) on the right side, which is synced to the video.

I currently do all of that using the timeline (no cue points or triggers) and everything is timed perfectly and precisely if I just watch the whole slide from A to Z.

However, when jumping back or forth by clicking on the seekbar, there is a couple seconds delay between the video and the animations. Sometimes just 1-2 seconds, sometimes up to about 6-7.

Anyone here is aware of a work-around for that?

Thanks a lot!!

8 Replies
Walt Hamilton

When you jump around in a slide like that, SL tries to calculate where everything should be, and what it should look like. It gives it a gallant effort, but just doesn't have enough fingers. BTW the same thing happens if you try to preview starting in the middle of the timeline. The only way to synch everything is to preview (or preview) from the beginning, without jumping around in the timeline.

Sorry :)

P-Y Beaulieu

Hey thanks for the reply.

But I would still like to understand better the "not enough fingers" part. As a former flash developer working with video a lot, I know that Flash can return the precise time of a given video and seek to that time. So I am not sure where in the technical process this can't be precisely synced, say to the nearest second...or is it because the SL video compression doesn't generate enough keyframes?

Ashley Terwilliger-Pollard

Hi P-Y,

I'm not entirely sure what Walt meant in regards to his analogy, so I'll let him respond to that part - but as he mentioned, you may want to preview the slide as a whole to see how elements are synced up vs. previewing from the timeline or choosing a spot on the timeline to begin playing. 

Walt Hamilton

I really don't have any idea how it works, but here is how I imagine it.  When the user starts playing at 30.6 seconds, SL starts at the beginning of the timeline, and counts to 30.6 and says,"The video will be on this frame."  On the way, it watchers triggers and animations, so it can say,"Animation 1 has not started yet, animation 2 has finished, and animation 3 is .3 seconds into a .75 animation." The trouble is, it cannot keep track of everything, not even if it uses fingers and toes to count on. Instead of counting by .01 seconds, it may count by 5's or 10's.

Maybe it does not work that way, but as an explanation, it covers all the behavior we observe. "Counting on fingers and toes" is just my way of saying that somewhere, somehow, there is not enough computing power to keep track of where every entrance, trigger, and animation should be at a given point on the timeline. I have no idea where the problem is, or whose fault it is, and I suspect it only manifests when you are trying to sync actions to a video, but Ashley's advice is the best work around.

P-Y Beaulieu

Hey guys, thanks a lot for the input. Walt is right, in that the problem has some organic feel to it.

Ashley, just to be sure, I am not talking about my capacity to properly sync the material when editing my timeline, that would definitely not be a problem....I am talking about playback. If the learner uses the seekbar, then the video and animation will display off-sync by a couple of seconds....just wanted to clarify to make sure that you get my issue.

Thanks again and let me know if you have any more thoughts/insights :)



Ashley Terwilliger-Pollard


Thanks for the clarification as I did think you were talking about the set up of previewing/syncing as an author. 

Are you seeing this out of sync behavior when you're previewing the entire course or viewing the published output within the intended environment? I think we'd want to take a look at the course you've set up to see how it's behaving and if it's something we need to report to our QA team. For example, if you've also enabled the video seekbar, the video and slide timeline are not synced together and using the slide seekbar could cause the behavior you're seeing and therefore would be as expected.