Polycom RealPresence 800s, Руководство администратора

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RealPresence Collaboration Server (RMX) 800s/Virtual Edition Administrator’s Guide
Polycom®, Inc. 10
 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 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 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 Collaboration Server transmits the same
resolution it receives from the endpoint.
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Video resolution :
 H.261 CIF/QCIF – Supported in Continuous Presence (CP) conferences at resolutions of 288 x
352 pixels (CIF) and 144 x 176 pixels (QCIF). Both resolutions are supported at frame rates of up
to 30 frames per second.
 H.263 4CIF - A high video resolution available to H.263 endpoints that do not support H.264. It is
only supported for conferences in which the video quality is set to sharpness and for lines rates
of 384kbps to 1920kbps.
 Standard Definition (SD) - A high quality video protocol which uses the H.264 and H.264 High
Profile video algorithms. It enables compliant endpoints to connect to Continuous Presence
conferences at resolutions of 720 x 576 pixels for PAL systems and 720 x 480 pixels for NTSC
systems.

High Definition (HD) – HD is an ultra-high quality video resolution that uses the H.264 and H.264
High Profile video algorithms. Depending on the Collaboration Server’s type, compliant endpoints
are able to connect to conferences at the following resolutions:

720p (1280 x 720 pixels) - all Collaboration Server types

1080p (1920 x 1080 pixels) in Collaboration Server (RMX) 1500/1800/2000/4000
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Lost Packet Recovery (LPR) - LPR creates additional packets that contain recovery information
used to reconstruct packets that are lost during transmission.
Supplemental Conferencing Features
In addition to basic parameters that determine the quality of the video, additional features can be enabled,
adding capabilities to the conference, or enabling special conferencing modes:
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Content Sharing (H.239) – Allows compliant endpoints to transmit and receive two simultaneous
streams of conference data to enable Content sharing. H.239 is also supported in cascading
conferences. Both H.263 and H.264 Content sharing protocols are supported. If all endpoints
connected to the conference have H.264 capability, Content is shared using H.264, otherwise
Content is shared using H.263.
For more information, see
Sharing Content During Conferences .
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Encryption – Used to enhance media security at conference and participant levels. For more
information, see Implementing Media Encryption for Secured Conferencing ..
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Conference Recording - The Collaboration Server enables audio and video recording of
conferences using Polycom RSS recording system.
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Lecture Mode (CP Conferences only) – The lecturer is seen by all participants in full screen while
the lecturer views all conference participants in the selected video layout.
For more information, see Lecture Mode (AVC CP Only) .