Huawei V100R001 User Manual page 141

HUAWEI TE30 Videoconferencing Endpoint
User Guide
H.261
H.263
H.264
H.323
half-duplex
hang up (site)
Issue 01 (2013-03-27)
H.3xx-series terminals". Practical importance of this recommendation
is its setting forth a way to have multiple video channels (for
example, one for conferencing, another for presentation) within a
single session (call).
H.261 is a 1990 ITU-T video coding standard originally designed for
transmission over ISDN lines on which data rates are multiples of 64
kbit/s. It is one member of the H.26x family of video coding
standards in the domain of the ITU-T Video Coding Experts Group
(VCEG). The coding algorithm was designed to be able to operate at
video bit rates between 40 kbit/s and 2 Mbit/s. The standard supports
two video frame sizes: CIF (352x288 luma with 176x144 chroma)
and QCIF (176x144 with 88x72 chroma) using a 4:2:0 sampling
scheme. It also has a backward-compatible trick for sending still
picture graphics with 704x576 luma resolution and 352x288 chroma
resolution (which was added in a later revision in 1993).
H.263 is a video codec standard originally designed as a low-bitrate
compressed format for videoconferencing. It was developed by the
ITU-T Video Coding Experts Group (VCEG) in a project ending in
1995/1996 as one member of the H.26x family of video coding
standards in the domain of the ITU-T. H.263v2 (H.263+) added
support for flexible customized picture formats and custom picture
clock frequencies. Previously the only picture formats supported in
H.263 had been Sub-QCIF, QCIF, CIF, 4CIF, and 16CIF, and the
only picture clock frequency had been 30000/1001 (approximately
29.97) clock ticks per second.
H.264/AVC/MPEG-4 Part 10 (Advanced Video Coding) is a standard
for video compression. The final drafting work on the first version of
the standard was completed in May 2003. H.264/AVC is the latest
block-oriented motion-compensation-based codec standard developed
by the ITU-T Video Coding Experts Group (VCEG) together with the
ISO/IEC Moving Picture Experts Group (MPEG), and it was the
product of a partnership effort known as the Joint Video Team (JVT).
The ITU-T H.264 standard and the ISO/IEC MPEG-4 AVC standard
(formally, ISO/IEC 14496-10 - MPEG-4 Part 10, Advanced Video
Coding) are jointly maintained so that they have identical technical
content. H.264 is used in such applications as Blu-ray Disc, videos
from YouTube and the iTunes Store, DVB broadcast,
direct-broadcast satellite television service, cable television services,
and real-time videoconferencing.
H.323 is a recommendation from the ITU Telecommunication
Standardization Sector (ITU-T) that defines the protocols to provide
audio-visual communication sessions on any packet network. The
H.323 standard addresses call signaling and control, multimedia
transport and control, and bandwidth control for point-to-point and
multi-point conferences.
A transmitting mode in which a half-duplex system provides for
communication in both directions, but only one direction at a time
(not simultaneously). Typically, once a party begins receiving a
signal, it must wait for the transmitter to stop transmitting, before
replying.
Hang up a remote site and remove the site from the conference.
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