Video and Timeline

I have an issue concerning videos and timelines. I have a video based course that involves images/shapes to appear at certain points on the timeline. Everything runs well until I load to LMS. The video playing sometimes buffers, the timeline continues while the video is buffering. Then once the video plays again my timeline has already moved on and everything is out of sync. Even if it is a 1 or 2 second buffer that occurred this causes major issues when triggers are set based on what is happening in the video.

Is there a way to set triggers based on Video time opposed to slide timeline? Since the video does have controls in it that shows the actual time being played in the video, can we not execute certain cues based on video timeline opposed to  the slide timeline?

8 Replies
Brian Dennis

I've created video time triggering systems for clients, but the solution involve third party video players which expose programmatic interfaces to their players. JWPlayer is one such player, as well as FlowPlayer. Triggering at specific millisecond accuracy can be tricky as network congestion can induce jitter in the video playback with most players opting to drop video frames vs. audio if bandwidth hiccups.

Walt Hamilton

You may not want to do it, but shortening the video can help. Cutting the video into chunks of no more than a couple of minutes per slide helps a couple of ways.

Loading a smaller chunk is likely less vulnerable to buffering problems.

SL may be pre-loading a couple of slides at a time, if I understand correctly how it operates. That means that by the time you get halfway through one video, you may have the next one or two mostly loaded, which gives you quite a bit of leeway.

And if you do have buffering issues, it all gets reset when the next slide starts if you jump when media ends. ("When media ends" is the only SL trigger based on actual media timelines.) If you lose a second in the early part of a 30 minute video, you are lost forever; if you lose it in a 1 minute video, you're back on track in less than a minute.

Just an idea, and you may not want to be that serious about it all.

Philippe Siwinski

Hi Ashley,

I was wondering about your statement : the video time is not the timeline timing.

When the video starts when the timeline starts, we kind of expect the video time and the timeline timing to be synchronized.

Could you please point me to the page where this difference is documented ?

Thank you :)

Ashley Terwilliger

Hi Philippe,

Although a video and a timeline may have the same length and play for a certain period of time, if you're users were to pause the video the slide timeline will keep playing. You could look at methods like disabling the video controls so that they can't pause or covering the video with a transparent shape so that they can't click on the video or the controls to pause. 

So a video may start automatically when the slide timeline starts, but they're not necessarily always in sync depending on your set up and options enabled.

If you've run into something that you'd like help on, feel free to share a copy of the .story file here with us so that we can take a look! 

Walt Hamilton

If you absolutely MUST have the video pause at a certain time, you cannot depend on the delivery system (LMS, Network, user's computer). Changes in any of those can throw off the timing. You are always at the mercy of buffering vagrancies, and they are unpredictable and out of our control.

Break your video into a one minute portion, and a three minute portion and do your pause when the first portion ends.