Desktop video conferencing is moving into the mainstream as enterprises look for ways to save money, reduce their carbon footprint and better utilize their workforces. At the same time, many organizations are investing in high-definition, room-based video conferencing systems, which raises questions about how to extend HD support to the desktop. Do you have high-quality Web cameras? What are the PC requirements? How about the bandwidth demands?
HD requires cameras that can support higher resolution, but it is more complicated than that. The main number manufacturers use to market their products is the resolution when the camera is in a still/photographic mode and not in motion video mode. In general, as the video resolution goes up the frame rates drops dramatically. What you need to look for is high resolution, such as 960x720 or 1280x720, along with a frame rate approaching 15 to 30 frames per second (fps).
Additionally, a glass lens is preferred over a plastic one because it minimizes distortion and will provide more image detail and clarity. With HD the quality of the lens is significantly more important than with standard-definition video because the goal is to have the highest quality source image with the least amount of optical artifacts. The video codecs won’t waste cycles encoding and decoding irrelevant pixels.
Desktop video will likely be used at home and on the road where the lighting is typically not as good as in an office setting. The camera’s gain control should be able to increase image brightness and remove shadows from a face without overexposing the image. Another important feature is auto-focus because desktop users tend to move around in front of their PCs and many cameras have a limited distance range where the focus is accurate, especially in situations with less than optimal lighting. What’s more, everyone will appreciate the fact that remote users won’t have to constantly place their fingers in front of the camera to focus.
In terms of PC support, H.264 is the video codec that most standards-based conferencing endpoints support. Before HD, the typical resolution for desktop video conferencing was either QCIF (176 x 144) or CIF (352 x 288), with some applications also supporting a second video stream of presentation data. A single processor system (2.0GHz CPU) could support this level of video quality for both send and receive. HD 720p (1280 x 720) is roughly nine times more resource intensive than CIF — there is simply nine times more data to encode and decode.
What these increased processing requirements you need at least a dual-core CPU (2.0GHz). One core encodes the video while the other decodes, leaving enough CPU to process audio and other PC tasks. A typical dual-ore system will have enough horsepower for receiving HD at 30 fps, but not quite enough to encode or send HD video at 30 fps. Most dual core systems will top out at 15 to 30 fps. Achieving 30 fps of encoded HD video requires a quad core machine – two cores for encoding, splitting the workload in half, and one core for decoding.