internet Speech Audio Codec (iSAC) is a

wideband In communications, a system is wideband when the message bandwidth significantly exceeds the coherence bandwidth of the channel. Some communication links have such a high data rate that they are forced to use a wide bandwidth; other links ma ...

speech Speech is the use of the human voice as a medium for language. Spoken language combines vowel and consonant sounds to form units of meaning like words, which belong to a language's lexicon. There are many different intentional speech acts, suc ...

codec A codec is a computer hardware or software component that encodes or decodes a data stream or signal. ''Codec'' is a portmanteau of coder/decoder. In electronic communications, an endec is a device that acts as both an encoder and a decoder o ...

, developed by

Global IP Solutions Global IP Solutions (also known as GIPS) was a United States–based corporation that developed real-time voice and video processing software for Internet Protocol, IP networks, before it was acquired by Google in May 2010. The company delivered ...

(GIPS) (acquired by Google Inc in 2011). It is suitable for

VoIP Voice over Internet Protocol (VoIP), also known as IP telephony, is a set of technologies used primarily for voice communication sessions over Internet Protocol (IP) networks, such as the Internet. VoIP enables voice calls to be transmitted as ...

applications and streaming audio. The encoded blocks have to be encapsulated in a suitable protocol for transport, e.g. RTP. It is one of the codecs used by AIM Triton, the Gizmo5, QQ, and

Google Talk Google Talk was an instant messaging service that provided both text and voice communication. The instant messaging service was variously referred to colloquially as Gchat, Gtalk, or Gmessage among its users. Google Talk was also the name o ...

. It was formerly a proprietary codec licensed by Global IP Solutions. As of June 2011, it is part of

open source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use and view the source code, design documents, or content of the product. The open source model is a decentrali ...

WebRTC WebRTC (Web Real-Time Communication) is a free and open-source project providing web browsers and mobile applications with real-time communication (RTC) via application programming interfaces (APIs). It allows audio and video communication and ...

project, which includes a royalty-free license for iSAC when using the WebRTC codebase.webrtc.org/license/additional-ip-grant/
.

Parameters and features

* Sampling frequency of 16 kHz (wideband) or 32 kHz (superwideband) * Adaptive and variable

bit rate In telecommunications and computing, bit rate (bitrate or as a variable ''R'') is the number of bits that are conveyed or processed per unit of time. The bit rate is expressed in the unit bit per second (symbol: bit/s), often in conjunction ...

of 10 kbit/s to 32 kbit/s (wideband) or 10 kbit/s to 52 kbit/s (superwideband) * Adaptive packet size 30 to 60 ms * Complexity comparable to G.722.2 at comparable bit-rates * Algorithmic delay of frame size plus 3 ms

References

External links

WebRTC codecs - GIT- source code for iSAC and other codecs
Speech codecs Free audio codecs Formerly proprietary software {{multimedia-software-stub

Parameters and features

See also

References

External links