Avc Basic Conferencing Parameters - Polycom realpresence 1800 Administrator's Manual

● The display aspect ratio is 4x3 or 16x9.
● Site (endpoint) names, skins, message overlay etc. are not supported in Video Switching.
● Video forcing is enabled at the conference and participant levels.
● To connect to a Video Switching conference via Entry Queue, the Profile assigned to the Entry Queue
must be set to Video Switching. It is recommended to use the same profile for both the destination
conference and Entry Queue.
● Telepresence Mode is unavailable in Video Switching conferences.
● In RealPresence Collaboration Server (RMX) 2000/4000 with MPMRx media cards, each participant
connecting to a VSW conference consumes one HD720 port.
● The HD_THRESHOLD_BITRATE flag must be set in the System Configuration. The value of this flag
is the system minimum threshold bit rate for HD resolutions. The line rate selected in the conference
Profile must be the same as or higher than that specified by the HD_THRESHOLD_BITRATE flag.
Note: Threshold bit rate
The HD_THRESHOLD_BIT RATE flag is responsible for negotiation only, It does not guarantee that
the endpoint will open an HD channel or transmit on an opened HD channel.
The HD_THRESHOLD_BITRATE flag line rate value ranges from 384kbps to 4Mbs, default is
768kbps. For more information, see
AVC
Basic Conferencing Parameters
The main parameters that define the quality of an AVC-based video conference and its display are:
● Line (Bit) Rate - The transfer rate of video and audio streams. The higher the line (bit) rate, the better
the video quality. The MCU supports the following line rates:
 Collaboration Server 2000/4000 with MPMRx card
 Collaboration Server 1800 - 64kbps to 6144kpbs
● Audio Algorithm - The audio compression algorithm determines the quality of the conference audio.
● Video protocol, video format, frame rate, annexes, and interlaced video mode - These
parameters define the quality of the video images. The RealPresnce Collaboration Server will send
video at the best possible resolution supported by endpoints regardless of the resolution received
from the endpoints.
 When Sharpness is selected as the Video Quality setting in the Conference Profile, the
RealPresnce Collaboration Server will send 4CIF (H.263) at 15fps instead of CIF (H.264) at 30fps.
 H.264 High Profile protocol provides better compression of video images in line rates lower than
384 Kbps and it will be automatically selected for the endpoint if it supports H.264 High Profile. If
the endpoint does not support H.264 High Profile, the RealPresnce Collaboration Server will try
H.264 Base Profile which provides good compression of video images in line rates lower than
384 Kbps (better than H.263 and not as good as H.264 High Profile).
 When working with RealPresnce Collaboration Servers at low bit rates (128, 256, or 384Kbps),
HDX endpoints will transmit SD15 resolution instead of 2CIF resolution.
When using a full screen (1x1) conference layout, the RealPresnce Collaboration Server transmits
the same resolution it receives from the endpoint.
● Video resolution:
Polycom®, Inc.
Modifying System Flags.
- 64kbps to 6144kpbs
Conferencing Modes Overview
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