(1) (Common Intermediate Format) A standard video format used in videoconferencing. CIF formats are defined by their resolution, and standards both above and below the original resolution have been established. The original CIF is also known as Full CIF (FCIF). The bit rates in the chart below are for uncompressed color frames.
Bit Rate
at 30 fps
CIF Format Resolution (Mbps)
CIF (Full CIF, FCIF) 352 x 288 36.5
QCIF (Quarter CIF) 176 x 144 9.1
SQCIF (Sub Quarter CIF) 128 x 96 4.4
4CIF (4 x CIF) 704 x 576 146.0
16CIF (16 x CIF) 1408 x 1152 583.9
(2) (Common Image Format) A standard frame size for digital video. Common Image Format, not to be confused with Common Intermediate Format in #1 above, defines 720x480 and 720x576 as the two standard SDTV frames. See CDR.
(3) (Cells In Frames) A networking technology developed by Cornell University that allows ATM backbones to be used with Ethernet LANs. CIF utilizes the inherent quality of service in ATM, which allows for real-time voice and video, all the way to the Ethernet end station by placing the ATM cell within the Ethernet frame. It differs from LAN Emulation, in which Ethernet packets are encapsulated into LAN Emulation packets and then converted into ATM cells.
CIF is implemented by replacing the Ethernet hub with a switch or multiplexor known as a CIF Attachment Device (CIF-AD). CIF drivers are used in the client stations.
