High Definition (HD) Videoconferencing
HD and JVCS
The JANET Videoconferencing Service (JVCS) is now able to offer true High Definition (HD) videoconferencing through their new core infrastructure equipment for those organisations with HD CODECs, HD cameras and HD displays. This equipment also includes ClearView software which helps improve the image sent by both legacy and up-to-date Standard Definition (SD) endpoints.
The new MCUs are capable of bridging between HD and SD by IP or ISDN endpoints seamlessly allowing organisations with legacy or cutting edge equipment to videoconference with each other.
Benefits of HD
Higher resolution and better picture quality mean:
- Less eye and mental fatigue
- Easier to maintain attention and focus in meeting
Enhanced clarity with natural movement leads to:
- Crisper images
- Better experience for large groups and classrooms
Sharper, more true-to-life colours means:
- Better interaction during colour-critical conferences, e.g. medical diagnostics or textile manufacturing
What is HD Videoconferencing?
High definition videoconferencing generally refers to any videoconferencing system that provides a higher resolution video image than standard definition (SD) videoconferencing.
Three of the most noteable features of HD are:
Display resolution: the most common HD display resolutions are 1280×720 (720p) or 1920×1080 (1080i or 1080p). The number 720 (or 1080) stands for the 720 (or 1080) horizontal scan lines of display resolution, the letter p stands for progressive scan or non-interlaced, and the letter i stands for interlaced. This is compared to SD which commonly operates at 640x480 (480p). A 720p image has 3 times the number of pixels of a 480p image.
Aspect ratio: Standard definition displays at a 4 x 3 (traditional TV) aspect ratio and high definition displays at a 16 x 9 (widescreen TV) aspect ratio. For an SD system to use an HD display, it will either not use the entire screen and will have two vertical black bars either side of the image, or it may use the full screen but stretch the image which looks unnatural. True high definition provides up to 40% more viewing area and will make best use of a 16 x 9 display.
Network Bandwidth requirements: H.323 endpoints preferably require a minimum of 1.5 Mbps network speed connection to run HD videoconferences. If an organisation's network bandwidth does not support the preferred speed, JVCS's infrastructure can auto negotiate the best speeds possible with H.323 endpoints but videoconferences might not be HD quality.
Looking For Advice?
Please email the JANET Video Technology Advisory Service (VTAS) with any queries or for advice about HD videoconferencing. Also, unbiased evaluations of HD products are available on the VTAS Product Evaluations page.