About 15 years ago, video conferencing technology was considered to be somewhat of a sci-fi. Average people could not afford virtual communication, during which you could not only hear, but see other people.
Today, video conferencing is widely used in fields such as health care, education, law and business. Many users install software solutions at home for personal communication with distant friends and family.
From CIF to Full HD. The history of video formats used in the conferencing field starts with the simplest video resolutions, which are currently considered obsolete and out of use: SQCIF (128x96) and QCIF (176x144). They were implemented in video conferencing systems for slow communication channels, the speed of which did not exceed 64 Kbit/s.
CIF video format (Common Intermediate Format) was first used in mobile TV of DVB-H standard. It should be noted that the first video conferencing systems emerged simultaneously with the DVB-H, which is why CIF video resolution is considered to be the ancestor of the formats used in video conferencing. This format is supported in video conferences conducted at speeds of standard quality (up to 512 Kbit/s). CIF resolution implies a 320x240 image size and is a standard quality format. Its variations, labeled as 2CIF, 3CIF and 4CIF, indicate the resolution of N x 240 x 320. Consequently, 2CIF (640x480) is a format for high-quality or HQ, 3CIF — 960x720, and 4CIF — 1280x960.
Many people think that the 4CIF format equals high definition (HD), because the size of images obtained from their use, are almost the same. However, the HD resolution gives a more pleasing image to the human eye with 16:9 aspect ratio, whereas 4CIF resolution is designed to broadcast the 4:3 images. In 2007, Sony introduced a new format — Full HD (1920x1080). The company has used this resolution as a promotion for a new high-quality video media format — Blu-ray, as well as for screens that can display a picture of that resolution. Now almost all manufacturers produce equipment with an aspect ratio of 16:9 HD or Full HD resolution.
Today, the most widely used resolution in video conferencing is HD (1280x720), as the transmission of video images in real time is a very time-consuming task for computers and network resources. That is why a Full HD resolution is considered to be the prerogative of video conferencing products of upper price segment.
However, you should not think that the formats used in video conferencing are limited to Full HD resolution. There is a class of premium solutions, referred to as immersive telepresence. Such systems are able to transmit high quality images in full size. The total resolution of such products can reach up to 3 Full HD images (5760x1080) broadcasted simultaneously on three separate screens.
Author: TrueConf Team