Sometime back, PathPartner‘s skype demo at MWC was covered by engadget. This was a demo, running on OMAP4+android, doing 720p (1280×720) between two boards. Skype on OMAP4+Android might be our flagship demo, but its not the only SoC/OS on which PathPartner has skype running.
With boards, We have accelerated video encoders and decoders which make achieving 720p relatively easy. With a PC, the story is slightly different.
Skype defines HD as upto 720p (1280×720 ) and High Quality as upto VGA (640×480).
There are Skype HD webcams available in the market today. These webcams use a special USB-UVC extension to send H.264 encoded video from the camera to the PC. So the PC just has to encrypt and stream this video. This reduces a lot of CPU load and has performance benefits.
I’m only aware of certain facevision and freetalk webcams which utilize this USB extension. I haven’t been able to achieve 720p calls with any other camera.
A skype call will usually start at a lower resolution, say QVGA or VGA and then switch up to 720p over time, depending on bandwidth availability, CPU load of hardware etc. Also, the video probably reaches about 22fps with these cameras at about 1-2MBPS bitrate.
Initial versions of these skype HD webcams might not switch to 720p. Nothing lacking in the hardware: There were firmware updates that were released later which allowed the 720p switch to happen.
Skype will also insist on using tlatest versions for making HD calls (5.0+ on windows and 2.2 beta on linux).
Recently, skype opened up an updated UVC extension specification. Hopefully, this encourages a lot more vendors to manufacture skype enabled HD webcams, bring down webcam costs and also improve performance to 30fps@720p.