H.263

A standards-based video compression technique (circa 1988) used primarily for videoconferencing systems, given its low-latency and low-bandwidth requirements. ITU-T H.261 is the first member of the H.26x codecs recommended by the ITU-T Video Coding Experts Group (VCEG). Primarily used in 64Kbps increments on ISDN B channels (from 64- and 128-kbps residential lines all the way up to PRI lines (T-1 parsed in to a number of B channels) allowing video transmission rates of 40 to 2000 kbps. at CIF (352x288 luma with 176x144 chroma) and QCIF (176x144 with 88x72 chroma) rates using 4:2:0 chroma sub-sampling.