Polycom 8 manual 10-25

	MGC WebCommander User’s Guide
Table 10-3: Basic Conference Parameters
Option	Description
Video Protocol	H264 - The H.264 standard provides better
(con’t)	compression of video images in lower line rate
	connections and is part of the Highest Common
	mechanism in Video Switching conferences.
	When the conference line rate is up to 384 Kbps,
	and the Video Protocol is set to Auto (in both VSW
	and CP conferences) the system tries to connect the
	participant using H.264 video protocol first. Only if
	the endpoint does not support H.264, the system
	tries to connect the participant using H.263 or H.261.
	When H.264 is selected, the Video Format is
	disabled and set to Auto.
Video Format	CIF and QCIF are video formats used in video
	conferencing systems. Video Format specifies the
	data rate (in number of frames per second) and the
	resolution of each frame (number of lines in a frame
	and the number of pixels in each line).
	Video Format is enabled only in Video Switching
	mode and when the Video Protocol is set to H.261 or
	H.263.
	CIF (Common Intermediate Format) - Each frame
	contains 288 lines and 352 pixels per line. The data
	rate is up to 30 frames per second (FPS)
	QCIF (Quarter Common Intermediate Format) -
	Each frame contains 144 lines and 176 pixels per
	line (it is one-fourth the resolution of CIF).
	This field is disabled if the Video Protocol field is set
	to Auto.
	• Using the H.261 protocol, you can select Auto,
	QCIF, or CIF.
	Select Auto to allow the system to select the
	video format for the conference according to the
	participants' capabilities and enable the dynamic
	adjustment of the highest common video
	resolution. In such a case, the system will
	connect all the participants in CIF format.
	If one of the participants' endpoints does not
	support CIF, the conference video format will
	change to QCIF for all the participants.

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