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 a human vocal communication using language. Each language uses phonetic combinations of vowel and consonant sounds that form the sound of its words (that is, all English words sound different from all French words, even if they are th ...

codec A codec is a device or computer program 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 on a signal or ...

, 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 IP networks, before it was acquired by Google in May 2010. The company delivered embedded software th ...

(GIPS) (acquired by

Google Inc Google LLC () is an American multinational technology company focusing on search engine technology, online advertising, cloud computing, computer software, quantum computing, e-commerce, artificial intelligence, and consumer electronics. I ...

in 2011). It is suitable for

VoIP Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. The terms Internet t ...

applications and

streaming audio Streaming media is multimedia that is delivered and consumed in a continuous manner from a source, with little or no intermediate storage in network elements. ''Streaming'' refers to the delivery method of content, rather than the content it ...

. 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, 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 ...

. 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 the source code, design documents, or content of the product. The open-source model is a decentralized so ...

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 to wor ...

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 In signal processing, sampling is the reduction of a continuous-time signal to a discrete-time signal. A common example is the conversion of a sound wave to a sequence of "samples". A sample is a value of the signal at a point in time and/or s ...

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