Exactly ten years ago, I wrote a blog post entitled "The Problem With Video Clips." A full decade of technological advances later and the problematic elements I mentioned then remain a problem today.
If you use a web conferencing technology that relies on screen sharing to display content to attendees, you don't want to rely on that for showing a full-motion video clip. It is impractical to believe that the software can scan your screen frequently enough, ship all the pixels over the many pathways of the internet, and reassemble them on attendee computers with enough speed to create a smooth and unbroken audio/video playback experience for attendees.
So let's turn our attention to technologies that let you upload or pre-cache video files to show during your webinar. The two big problems remain:
1) Local Buffering. AKA: "When do I start talking again?"
Imagine you are talking to your audience. You set up your video and say, "Okay - Let's watch this together, then we can discuss what you saw." You hit the play button. When do you start talking again? When the video finishes? Just because it finished for you, it hasn't necessarily finished for all attendees. They might have had a slower network and the video may have paused for buffering. So you start talking, assuming the video is done, but they hear you speaking over the end of the video. If you sit there and wait after the video has finished, you have dead air for viewers with faster networks. And you still don't know how long to wait.
A corollary to this problem is 1a) Synchronous Pausing. AKA: "Look at this!"
I have worked with lots of presenters who want to pause the video at a certain point and talk about the frozen image on the screen before continuing the video. If the software doesn't pause on the same frame for all attendees, it can lead to confusion and misunderstandings.
One solution approach comes from the old "outbound webcasting" school of thought. The vendor buffers up all content and concentrates on making sure that all attendees see and hear it as the presenter delivered it, but without regard to keeping synchronization between different attendees. It's akin to everybody watching a "tape delayed" broadcast of the live content… Each person sees and hears a nice, unbroken stream of content, but user 1 may be a few seconds ahead of or behind user 2, and neither is in sync with the presenter. That works fine as long as your content is outbound only. But as soon as you want to make your session more interactive - asking your participants for responses to questions or polls - you have a problem. You ask a question… You wait for the question to arrive on the consumption side… You wait for responses… You see the responses and reply… There is another delay while your response goes out to the audience. It's like carrying on a conversation with astronauts on the moon. Very unnatural and a real conversation killer.
2) Telephone Audio. AKA: "Please turn on your speakers."
I always prefer web conferencing technologies that give participants a choice of using computer audio or telephone audio. You will never satisfy all members of an audience by forcing one or the other listening method. Unfortunately you run into the same problems of synchronization that we mentioned above. If the software picks up the audio from the video as it is transmitted, will that match up with the video stream on each attendee's computer as it is received and played? Probably not. For phone audio to work properly for all attendees, they must be in perfect sync with each other and with a lock-step playback of the visual content. I can't think of a technology that can guarantee that kind of synchronization. So most vendors throw up their hands and tell telephone users to turn on their computer speakers once a video starts playing.
Ten years ago I asked vendors to write in with comments about how they coordinate video playback with telephone audio. None did (although KRM was nice enough to suggest a workaround they use). Are there any takers now?
