Short description: Audio codec standard
internet Speech Audio Codec| Internet media type | audio/isac[1] |
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| Developed by | Global IP Solutions, now Google Inc |
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| Type of format | Audio compression format |
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Codec| Developer(s) | Global IP Solutions, now Google Inc |
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| Written in | C |
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| Operating system | Cross-platform |
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| Type | Audio codec, reference implementation |
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| License | formerly proprietary, now 3-clause BSD |
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| Website | webrtc.org |
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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 of 16 kHz (wideband) or 32 kHz (superwideband)[1][6][7]
- Adaptive and variable bit rate of 10 kbit/s to 32 kbit/s (wideband) or 10 kbit/s to 52 kbit/s (superwideband)[1][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
- iLBC
- Opus (audio codec)
- SILK
- G.722
- Speex
- List of codecs
References
- ↑ 1.0 1.1 1.2 Grand, Tina le; Jones, Paul; Huart, Pascal; Shabestary, Turaj Zakizadeh; Alvestrand, Harald T. (2013). "RTP Payload Format for the iSAC Codec". https://tools.ietf.org/html/draft-ietf-avt-rtp-isac-04.
- ↑ Dana Blankenhorn (2010-05-18). "Why Google bought Global IP Solutions". http://www.zdnet.com/blog/open-source/why-google-bought-global-ip-solutions/6501.
- ↑ "iLBC Freeware". http://www.webrtc.org/ilbc-freeware.
- ↑ webrtc.org/faq/#what-is-the-isac-audio-codec .
- ↑ webrtc.org/license/additional-ip-grant/.
- ↑ 6.0 6.1 "WebRTC FAQ - What are the parameters of iSAC?". http://sites.google.com/site/webrtc/faq#TOC-What-are-the-parameters-of-iSAC-.
- ↑ 7.0 7.1 "WebRTC components". http://www.webrtc.org/reference/webrtc-components#TOC-iSAC.
External links
- WebRTC codecs - GIT- source code for iSAC and other codecs
Multimedia compression and container formats |
|---|
Video
compression | | ISO, IEC, MPEG |
- MJPEG
- Motion JPEG 2000
- MPEG-1
- MPEG-2
- MPEG-4
- Part 2 / ASP
- Part 10 / AVC
- MPEG-H
- MPEG-I
|
|---|
| ITU-T, VCEG |
- H.120
- DCT
- H.261
- H.262
- H.263
- H.264 / AVC
- H.265 / HEVC
- H.266 / VVC
- DV
|
|---|
| SMPTE | |
|---|
| TrueMotion | |
|---|
| Others |
- Apple Video
- AVS
- Bink
- Cinepak
- Daala
- DVI
- EVC
- FFV1
- Huffyuv
- Indeo
- Lagarith
- Microsoft Video 1
- MSU Lossless
- OMS Video
- Pixlet
- ProRes 422
- ProRes 4444
- QuickTime
- RealVideo
- RTVideo
- SheerVideo
- Smacker
- Sorenson Video/Spark
- Theora
- Thor
- WMV
- XEB
- YULS
|
|---|
|
|---|
Audio
compression | | ISO, IEC, MPEG |
- MPEG-1 Layer II
- MPEG-1 Layer I
- MPEG-1 Layer III (MP3)
- AAC
- MPEG Surround
- MPEG-4 ALS
- MPEG-4 SLS
- MPEG-4 DST
- MPEG-4 HVXC
- MPEG-4 CELP
- MPEG-D USAC
- MPEG-H 3D Audio
|
|---|
| ITU-T |
- G.711
- G.718
- G.719
- G.722
- G.722.1
- G.722.2
- G.723
- G.723.1
- G.726
- G.728
- G.729
- G.729.1
|
|---|
| IETF | |
|---|
| 3GPP |
- AMR
- AMR-WB
- AMR-WB+
- EVRC
- EVRC-B
- EVS
- GSM-HR
- GSM-FR
- GSM-EFR
|
|---|
| ETSI | |
|---|
| Others |
- ACELP
- ALAC
- Asao
- ATRAC
- AVS
- CELT
- Codec 2
- DRA
- FLAC
- iSAC
- Monkey's Audio
- TTA
- MT9
- Musepack
- OptimFROG
- OSQ
- QCELP
- RCELP
- RealAudio
- RTAudio
- SD2
- SHN
- SILK
- Siren
- SMV
- SVOPC
- TwinVQ
- VMR-WB
- VSELP
- WavPack
- WMA
- MQA
- aptX
- aptX HD
- aptX Low Latency
- aptX Adaptive
- LDAC
- LHDC
- LLAC
|
|---|
|
|---|
Image
compression | IEC, ISO,
IETF, W3C,
ITU-T, JPEG |
- CCITT Group 4
- DCT
- HEIF
- HEVC
- JPEG
- JPEG XR
- JPEG XT
- TIFF/EP
- Arithmetic
- JPEG-LS
- JPEG 2000
- LZ
- TIFF
- TIFF/IT
|
|---|
| Others |
- APNG
- BPG
- DjVu
- EXR
- FLIF
- ICER
- MNG
- PGF
- QTVR
- WBMP
- WebP
|
|---|
|
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| Containers | | ISO, IEC |
- MPEG-ES
- MPEG-PS
- MPEG-TS
- ISO base media file format
- MPEG-4 Part 14 (MP4)
- Motion JPEG 2000
- MPEG-21 Part 9
- MPEG media transport
|
|---|
| ITU-T | |
|---|
| IETF | |
|---|
| SMPTE | |
|---|
| Others |
- 3GP and 3G2
- AMV
- ASF
- AIFF
- AVI
- AU
- BPG
- Bink
- BMP
- DivX Media Format
- EVO
- Flash Video
- IFF
- M2TS
- Matroska
- QuickTime File Format
- RatDVD
- RealMedia
- RIFF
- MOD and TOD
- VOB, IFO and BUP
|
|---|
|
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| Collaborations |
- NETVC
- MPEG LA
- HEVC Advance
|
|---|
| Methods |
- Discrete cosine transform
- Entropy
- Arithmetic
- Huffman
- Modified
- FFT
- LPC
- Lossless
- Lossy
- LZ
- PCM
- Transform
- Wavelet
|
|---|
| Lists |
- Comparison of audio coding formats
- Comparison of video codecs
- List of codecs
|
|---|
See Compression methods for techniques and Compression software for codecs |
Data compression software |
|---|
Archivers with
compression
(comparison) | | Free software |
- 7-Zip
- Archive Manager
- Ark
- Expander
- FreeArc
- Info-ZIP
- KGB Archiver
- PAQ
- PeaZip
- tar
- XAD (decompression only)
- Xarchiver
- Zipeg
- ZPAQ
|
|---|
| Freeware |
- Filzip
- LHA
- StuffIt Expander (decompression only)
- The Unarchiver (decompression only)
- TUGZip
- ZipGenius
|
|---|
| Commercial |
- ARC
- ALZip
- Archive Utility
- ARJ
- BetterZip
- JAR
- MacBinary
- PKZIP/SecureZIP
- PowerArchiver
- StuffIt
- WinAce
- WinRAR
- WinZip
|
|---|
|
|---|
Non-archiving
compressors | | Generic |
- bzip2
- compress
- gzip
- lzip
- lzop
- pack
- rzip
- Snappy
- XZ Utils
|
|---|
| For code | UPX |
|---|
|
|---|
Audio
compression
(comparison) | | Lossy |
- Fraunhofer FDK AAC
- Nero AAC Codec
- Freeware Advanced Audio Coder (FAAC)
- Helix DNA Producer
- l3enc
- LAME
- TooLAME
- libavcodec
- libcelt
- libopus
- libspeex
- Musepack
- libvorbis
- Windows Media Encoder
|
|---|
| Lossless |
- ALAC
- FLAC
- libavcodec
- Monkey's Audio
- mp4als
- OptimFROG
- Shorten
- TTA (True Audio)
- WavPack
|
|---|
|
|---|
Video
compression
(comparison) | | Lossy | | MPEG-4 ASP |
- 3ivx
- DivX
- Nero Digital
- FFmpeg
- HDX4
- Xvid
|
|---|
H.264 /
MPEG-4 AVC |
- CoreAVC
- Blu-code
- DivX
- FFmpeg
- Nero Digital
- OpenH264
- QuickTime
- x264
|
|---|
| HEVC | |
|---|
| Others |
- CineForm
- Cinepak
- Daala
- DNxHD
- Helix DNA Producer
- Indeo
- libavcodec
- Schrödinger (Dirac)
- SBC
- Sorenson
- VP7
- libtheora
- libvpx
- Windows Media Encoder
|
|---|
|
|---|
| Lossless |
- FFV1
- Huffyuv
- Lagarith
- MSU Lossless
- YULS
|
|---|
|
|---|
- See also: compression methods and compression formats
|
 | Original source: https://en.wikipedia.org/wiki/Internet Speech Audio Codec. Read more |
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