internet Speech Audio Codec
From Infogalactic: the planetary knowledge core
Internet media type | audio/isac[1] |
---|---|
Developed by | Global IP Solutions, now Google Inc |
Type of format | Audio compression format |
Developer(s) | Global IP Solutions, now Google Inc |
---|---|
Written in | C |
Operating system | Cross-platform |
Type | Audio codec, reference implementation |
License | formerly proprietary, now 3-clause BSD |
Website | www.webrtc.org |
internet Speech Audio Codec (iSAC) is a wideband speech codec, developed by Global IP Solutions (GIPS) (acquired by Google Inc in 2011).[2][3] It is suitable for VoIP 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. It was formerly a proprietary codec licensed by Global IP Solutions. As of June 2011, it is part of open source WebRTC project,[4] which includes a royalty-free license for iSAC when using the WebRTC codebase.[5]
Parameters and features
- Sampling frequency 16 kHz[1] (or 32 kHz according to WebRTC)[6][7]
- Adaptive and variable bit rate (10 kbit/s to 32 kbit/s) (or 10 kbit/s to 52 kbit/s according to WebRTC)[6][7]
- 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
See also
References
- ↑ 1.0 1.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ sites.google.com/site/webrtc/faq#TOC-What-is-the-iSAC-audio-codec-.
- ↑ sites.google.com/site/webrtc/license-rights/additional-ip-grant.
- ↑ 6.0 6.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 7.0 7.1 Lua error in package.lua at line 80: module 'strict' not found.
External links
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