HUAWEI VP9050 Executive Video Terminal

 

 

User Guide

DGlossary

dual stream

During a conference, two channels of video streams can be sent or received

 

 

 

simultaneously. For example, one channel is used for transmitting video (such as

 

 

 

video captured by a camera) and the other channel is used for transmitting

 

 

 

presentation (such as a computer desktop). The two channels of videos can be

 

 

 

displayed on two displays.

 

 

G

 

 

 

G.711

G.711, also known as Pulse Code Modulation (PCM), is a very commonly used

 

 

 

waveform codec. G.711 uses a sampling rate of 8,000 samples per second, with the

 

tolerance on that rate 50 parts per million (ppm). Non-uniform quantization

 

 

 

(logarithmic) with 8 bits is used to represent each sample, resulting in a 64 kbit/s bit

 

rate. There are two slightly different versions; μ-law, which is used primarily in

 

 

 

North America, and A-law, which is in use in most other countries outside North

 

 

 

America.

 

 

G.722

G.722 is a ITU-T standard 7 kHz wideband speech codec operating at 48, 56 and 64

 

kbit/s. It was approved by ITU-T in November 1988. Technology of the codec is

 

 

 

based on sub-band ADPCM (SB-ADPCM).

 

 

G.728

G.728 is an ITU-T standard for speech coding operating at 16 kbit/s. It is officially

 

described as Coding of speech at 16 kbit/s using low-delay code excited linear

 

 

 

prediction.

 

 

give floor

After the chair site gives floor to a site, the other sites view and hear the site. All the

 

sites, except the chair site and the site that is given the floor, are muted.

 

 

H

 

 

 

H.239

H.239 is an ITU-T recommendation from the H.32x Multimedia Communications'

 

macrofamily of standards for multimedia communications over various networks.

 

 

 

The H.239 recommendation is titled "Role management and additional media

 

 

 

channels for 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

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

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.

 

 

 

 

 

 

Issue 03 (2011-12-10)

Huawei Proprietary and Confidential

110

 

 

Copyright © Huawei Technologies Co., Ltd

 

 

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Huawei VP9050 manual Dual stream, 711, 722, 728, Give floor, 239, 261, 263