GIPS语音编解码器家族
转自http://kware.blogbus.com/logs/16564260.html
1. GIPS 语音编解码器家族 Family of Codecs
1) High Quality Codecs
GIPS (Global IP Sound) offers a full set of codecs that are tailored to meet your VoIP
communications needs. The codec suite includes wideband and narrowband codecs that produce a
robust, clear sound, even under heavy packet loss. When this sound clarity is combined with
GIPS NetEQ?, delay and jitter are managed to produce the highest quality VoIP coversation
available.
窄带 Narrowband 宽带 Wideband
---------------- ----------------------- -------------------
拨号网 Dial-up iLBC 13.3/15.2kbps iSAC 10 - 32 kbps
宽带网 Broadband Enhanced G.711 64 kbps iPCM-wb 80 kbps
2) What is iSAC?
iSAC is a wideband, adaptive codec designed to deliver high quality sound in both high-bit-
rate and low-bit-rate condition. GIPS iSAC makes VoIP communications possible using a dial-
up modem, automatically adjusting transmission rates to deliver better-than-PSTN voice
quality.
iSAC is an adaptive VoIP codec that is specifically designed to deliver wideband sound
quality in both low- and high-bit rate applications. Even at dial-up modem data rates, iSAC
delivers better than PSTN sound quality by adjusting transmission rates to give the best
possible listening experience for the existing connection speed.
Features
·Excellent trade-off between bit-rate and audio quality for low rate connections such as
modems
·Automatically adjust the bit rate for best quality or use a bit rate set to a fixed value
·Efficient speech codec; good quality for any audio signal
·Packet-loss robustness that exceeds current standards
·Uses the full 8 kHz available audio bandwidth for 16 kHz sampling
3) What is iPCM-wb?
iPCM-wb is a high-quality, low-complexity wideband codec that provides excellent resiliency
against packet loss, resulting in significantly higher sound quality than PSTN. When
deployed in end-to-end IP communication, iPCM-wb ensures excellent speech quality for high-
end telephony and for special user requirements (such as conference calls) where excellent
sound is required.
Key benefits
·Higher basic speech quality than current standards, such as G.722.1 and G.722.2
·Packet-loss robustness that significantly exceeds current standards
·Lower delay than standard solutions when combined with NetEQ
·Compatible with GIPS Enhanced G.711
·Allows more efficient network provisioning
3) What is RUP?
The GIPS Redundant Coding Unit (RCU) is a robustness enhancement unit that provides
increased packet loss robustness for low bit-rate codecs in IP telephony products. GIPS RCU
is generic and support any low bit-rate codec, such as iLBC, G.729 and G.723.1
4) 市场信息
* Skype uses GIPS codecs.
iLBC was created by Global IP Sound(GIPS). Skype is wideband capable. Therefore Skype uses
wideband iLBC.
* 互联网和移动增值服务供应商腾讯公司日前宣布，该公司选择了Global IP Sound(GIPS)的VoiceEngine
PC Advanced 语音处理技术软件，为在中国的超过1.5亿互联网即时信息(instant messaging, IM)服务
QQ用户提高语音服务质量。
* 腾讯即时通讯产品部总经理卢山表示：“对于腾讯2005年最新版QQ来说，选择 GIPS VoiceEngine 技术
确保了为国内的客户提供最高质量的语音服务。 IM是一个竞争非常激烈的市场， 我们的用户都要求最
好的语音质量。 然而，这并不单单是选择技术平台这么简单的事情， 腾讯要寻找的是一家了解中国市
场，并象我们一样充满热诚及灵活的合作伙伴。GIPS已多次证明了本身的实力，而且随着该公司最近于
香港设立亚太区销售办事处，保证了以本地语言提供最高质量的工程支持，对这样一个快速发展并不断
推陈出新的市场来说，这是至关重要的。”