Polycom RealPresence 2000, Руководство администратора

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Chapter 4-Additional Conferencing Information
Polycom, Inc.
4-9
Table 4-4 summarizes the Maximum Resolution of Content and Frames per Second (fps) for Bit
Rate Allocations to the Content Channel .
SVC Only and Mixed CP and SVC Content Setting
The Content channel is transmitted in Graphics mode only.
Content Protocols
Two Content Protocols can be used for sharing content:
• H.263 (CP and mixed CP and SVC)
• H.264 (all conferencing modes)
H.264 offers higher quality content, but is not supported by legacy endpoints. Depending on
the endpoints capabilities, you can determine the content sharing experience by selecting
the appropriate protocol and system behavior from the Content Protocol list:
• H.263 & H.264 Auto Selection
(
AVC CP Only)
• H.263 (AVC CP Only)
• H.264 HD (AVC CP Only)
• H.264 Cascade and SVC Optimized (all conferences)
H.263 & H.264 Auto Selection (AVC CP Conferences)
The H.263 & H.264 Auto Selection option should be selected when Content is to be shared
using a mix of H.263 -supporting and H.264 -supporting endpoints. (In versions up to and
including 7.6, this is named Up to H.264 .)
Bit rate allocation to the Content channel by the Collaboration Server is dynamic according
to the conference line rate and Content Setting selected for the conference.
If an endpoint that supports only H.263 for Content Sharing connects to a conference with
Content Protocol set to H.263 & H.264 Auto Selection :
• Content is shared using H.263 even if H.264 -supporting endpoints are connected.
• Content is shared using H.264 if all connected endpoints have H.264 capability.
• If the first endpoint to connect to the conference only supports H.263, the H.263 protocol
is used for Content for all conference participants.
• If Content is already being shared using the H.264 protocol when a H.263 endpoint
connects, Content sharing is stopped and must be manually restarted using H.263 (i.e.
the endpoint using H.263 Content Protocol must connect first), for all participants to
receive content. If the H.263 endpoint disconnects, Content sharing must be manually
stopped and restarted and will automatically upgrade to the H.264 protocol.
Table 4-4 Content - Maximum Resolution, Frames/Second per Bit Rate Allocation
Bit Rate Allocated to Content
Channel (Kbps)
Content
Maximum Resolution Frames/Second
From 64 and less than 512 H.264 HD720p 5
From 512 and up to 768 H.264 HD720p 30
From 768 and up to 1536 H.264 HD1080p 15