Last week I wrote a post about Unique Webinar Features. I invited vendors to write to me if they had a unique functionality in their webinar/webcast software that I should mention.
Ryan took up the challenge on behalf of InterCall Webcast Studio. He pointed to a press release they issued in July, claiming to be the first webcasting product to “support organic HD through a webcam. It provides resolution up to 720p.”
The press release included a provocative quote from Mike Nessler, executive vice president of InterCall Event Services: “While other webcasting tools claim to be HD and use HD tools on the broadcast end, they’re still delivering just standard video to the desktop. InterCall Webcast Studio breaks that barrier by delivering a full HD experience to users on their devices.”
I have to admit, I’m not sure of my footing with this issue. HD (High Definition) video started as a television broadcast concept, where the term was initially rather loosely applied to any TV electronic scanning format with more scanning lines than previous mechanical systems could handle. Modern broadcast standards have attempted to put a more rigorous definition on HDTV, saying that it should either be 1080 or 720 lines of vertical display resolution. The letter “p” mentioned in the press release (720p) indicates progressive scanning, as opposed to interlaced scanning. Look it up… I have already lost half my readers and we haven’t even gotten to the good stuff. There’s another statistic called Frame Rate that enters the equation, and I don’t intend to lecture you about that either.
The problem with talking about HD video is that many vendors have indeed used the phrase in a non-rigorous context. Some companies play up their “HD video” as just another way to say their video is subjectively of a high quality. But others seem to use the phrase to mean true 720p internet videocasting. For instance, I found a Citrix newsletter from 2010 that includes this quote about GoToMeeting with HDFaces: “Multistream video feeds can accommodate six participants at once, and can run at 720p for a true HD experience.”
The other problem with talking about resolution as the functional differentiator for your webcast video is that it isn’t sufficient to describe the user experience that event attendees will have. Other things strongly influence the way your video comes across. You see, there are certain absolutes that can’t be avoided… webcasting a moving video image requires shoving a heck of a lot of bits through those pipes in the interwebs. Vendors are all looking for ways to cut corners in order to reduce the number of bits needed to reconstruct that image on the far end.
The frame rate I glossed over earlier is one of those items. You can have a nice high resolution image that looks jerky and juddery because it doesn’t update itself often enough. Compression algorithms are another component. You can throw away small bits of the picture “that don’t matter” or use fancy programming to compress and reconstruct the image on either end. And different processes can produce more or less pleasing results.
Then the vendor can play games with trading off audio bandwidth for video. I might not value a great looking video if it was achieved by sending audio that sounds like a tin can.
And how does the software deal with individual attendees who can’t process the signal fast enough – because of an old, slow computer; or too many programs running; or a slow/overloaded internet connection? Some products elect to reduce frame rate, others reduce resolution, others buffer the image. How often do they do this? Do they keep checking and re-raise performance if things get better, or do they assume they should stay at the “low and slow” settings?
Nobody shares these details publicly. As you can see from this high-level overview, it quickly gets too technical. And it often depends on other underlying software that might change independently of the webcast vendor (Adobe Flash Player is famous for this). And the vendors often experiment with different algorithms and approaches to see if they can improve performance. So making a valid objective comparison between different products’ “HD video” performance is likely to be a frustrating and futile exercise.