The first post in this series on webcams was historical. This one is as well, but it highlights the performance offered by the very first HD-capable webcam that was recommended for use in UC/video conference solutions.
There was a time when I was pursuing the ability to deploy HDVoice for my home office. If this were possible then it would improve not only my working life, but also that of my US co-workers.
This little quest harkens back to the summer of 2008. The idea was inspired by some time spent using the then newly released new Polycom SoundPoint IP550 & IP650 desk phones. Small Net Builder had asked me to review those phones and I found that using them was positively addictive.
While I might have the lovely Polycom hardware there was no way that I could convince my employer to replace our existing IP phones en masse. At the time they had around a dozen older SoundPoint models in service.
However, some of our staff also used soft phones on Windows laptops. I saw this as a way to sneak HDVoice into the operation for minimal cost. The trick was to find a good, G.722-capable soft phone for a reasonable price.
Unfortunately, there just wasn’t any such thing to be found at the time. This fact I found very frustrating.
Some time later I discovered that HDVoice, while not at all common in software phones built for purely voice applications, was in fact a standard feature in an emerging new class of soft clients targeting video conferencing. This I discovered while trying the newly released LifeSize Desktop v1.0.
In support of my experimentation with the LifeSize Desktop I purchased a Logitech Webcam Pro 9000 (pictured above). It was the current state-of-the-art in webcams, and the only one then capable of 720p video. It was in fact recommended by the LifeSize sales staff.
One of the major features of the Webcam Pro 9000 was the fact that it included a microphone. Thus when added to any PC with speakers it provided a complete web-chat solution.
The Webcam Pro 9000 was release in Q2 2009 and has long since been discontinued. It replaced the Quickcam Pro 9000, a model introduced two years prior, which is a bit confusing. Setting aside that specific model, it’s worth examining some basic properties common to most webcams.
What set the Webcam Pro 9000 apart from the crowd was it’s ability to deliver “HD video.” But what does that mean exactly?
In this case, it means that the Webcam Pro 9000 could deliver a frame size of 1280 x 720 pixels, aka 720p. This is essentially the baseline frame size that is considered to be genuine HD video.
The camera had a 2 megapixel sensor that was actually capable of “video” at up to 1600 x 1200 pixels. However, that’s an odd frame size, more common to a desktop computer display than any kind of media industry offering.
There’s much more to “video” than just the size of the frame. The frame rate is also very important.
Very early webcams could only output a frame every few seconds, making their use more like time lapse than fluid video. Hence, one of their earliest applications was to post periodic images online, perhaps updating the status activity in a room.
In fact, for several years I took a couple of webcams to the annual NAB conference so that we could share a visual sense of the activity on the show floor with co-workers in the UK. These webcams posted a VGA resolution frame to a web server every minute or two. If I reduced the frame resolution I could put up a new frame perhaps as fast a a few frames a minute.
From the perspective of professional video production & broadcast activities “video” implies delivering frame rates that create the impression of continuous motion. Film and the SDTV standards defined this as 24-30 frames/second. Modern HD standards vary, but 720p is typically conveyed at 50 or 60 frames/second, depending upon where you are in the world.
The HD broadcast standards are actually a large suite of frame rates & sizes. In North America this generally breaks down into two camps; 720p60 and 1080i30. The smaller 720 pixel format streams at 60 frame/second and the larger 1920 x 1080 pixel format streams at 30 interlaced frames/second.
ABC and FOX adopted 720p, trading spatial resolution for improved temporal resolution, resulting in better conveyance of motion. CBS and NBC selected 1080i for its increased sharpness of picture.
A Current Day Sample Of Performance
Recovering my old Logitech Webcam Pro 9000 from a junk drawer, I made this sample video to illustrate its performance when used to capture a 720p video stream.
While the Webcam Pro 9000 does output a 720p stream, it clearly doesn’t manage the sort of frame rate that I’d hope for when deploying a video calling solution for a home office worker. The image quality isn’t bad, but the frame rate of <10 frames/second is simply too slow to be acceptable.
When the camera is set to deliver 854×480 pixel frames (YouTube recommended size for 480p widescreen) the Webcam Pro 9000 easily delivers 30 frame/second. That’s the kind of frame rate necessary to ensure fluid conveyance of motion, even from just a talking head.
I suspect that many early HD-capable video conference solutions based upon webcams rarely actually managed to pass real HD video at acceptable frame rates. Anything that was 16:9 aspect ratio, like the 854×480 YouTube example, had the same overall shape as HD video, giving the impression of being better.
Coming in Webcams 3: Understanding the limits of USB 2.0, and working around them
*In so many ways IP communications is the new HAM radio.