CIF = Common Intermediate Format and

QCIF = Quarter-CIF

Definitions:

CIF is based on a progressively scanned format with 360 x 288pixels/frame at 30 frames/sec, while QCIF uses 176 x 144pixels/frame at 30 frames/sec. QCIF compatibility is required bythe ITU H.261 videoconferencing standard, which mandates that allcodecs must be able to operate with QCIF. In contrast, the higherquality CIF compatibility is optional.

Usage:

CIF is used primarily for videoconferencing, while QCIF isbetter suited for applications like desktop videophones.