High-Definition PC Video Conferencing?

dsginter asks: "This year's spring Networld+Interop has ended with little fanfare. However, I noticed that a small nugget slipped between the cracks - HD video-conferencing. Two different manufacturers demonstrated such products which means that we'll probably have interoperability soon. After seeing the massive pricing estimates for such products, I couldn't help but think that I should try my hand at my own HD product (a Mac Mini, some H.264, a pinch of AAC and the glue that is H.323 or SIP). However, I'm missing one piece - a small, 720P camera for video acquisition. I've scoured Google but can't come up with anything suitable. Is there an answer? HD video-conferencing is an important step in complete communication between remote parties. While there will be those that joke about the possibilities, it is important to remember that the bulk of business travel still happens for the sake of face-to-face communication. HD video-conferencing might prove to be a panacea."

Comments

A Mac mini?

[WombatControl]

Trying to decode an HD stream on a Mac mini is probably not that good of an idea - a single G4 doesn't have quite enough power to manage it.

H.264 is designed to scale down to various processor architectures, so a lower-resolution stream would probably play acceptably, but I rather doubt that you'd get enough horsepower out of a Mac mini to acceptably decode HD content encoded with H.264 in realtime.

For more, see Apple's H.264 FAQ.

An iMac G5 should have the horsepower, however.

Re:Potential difficulties

[Anonymous Coward]

The bitrate of the MPEG-2 transport stream of the Sony 1080i camera is 25 Mbps. Hardware real-time MPEG-4 Part 10 (aka H.264, aka AVC) encoders do exist, but they're aimed at commercial broadcasters. As the parent pointed out, software encoding, even on the latest and greatest CPU, is *much* slower than real-time.

The other problem you'll run into is the quality of the lens. On a small webcam, it wouldn't help you much to put a high-res CCD in it. The lens would be the bottleneck.

The market is the problem

[gillbates]

As an engineer who recently wrapped up a video camera project, here's are the problems we ran into:

• The CCD sensor can easily do full-motion XGA or SXGA video, but:
• The DSP has a very difficult time encoding MPEG video at full-motion frame rates for anything larger than VGA resolutions.
• 100 Mbit ethernet is just barely capable of supporting a VGA or D1 bitstream, and,
• XGA has ~twice the number of pixels as D1; SXGA is even more bandwidth intensive.

Now granted, we do build boards which could probably handle HDTV video conferencing. But the problem is that the 4 processors alone cost more than the average low-end PC. From a technical perspective, HDTV video conferencing is possible, but the hardware required is far more expensive than what the market would tolerate.

Are you willing to pay $10k for HDTV versus a few hundred for a QVGA webcam setup?

I'd love to be building HDTV cameras, but the problem is that we can't find customers willing to pay the extra expense for the higher resolution.