View source for Extended Adaptive Multi-Rate – Wideband

{{Short description|Audio codec}}
{{Infobox file format
| name = Extended Adaptive Multi-Rate – Wideband (AMR-WB+)
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| mime = audio/amr-wb+, audio/3gpp
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| genre = Audio
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| contained by = [[3GP]]
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'''Extended Adaptive Multi-Rate – Wideband''' ('''AMR-WB+''') is an audio [[codec]] that extends [[AMR-WB]]. It adds support for stereo signals and higher sampling rates. Another main improvement is the use of transform coding (transform coded excitation – TCX) additionally to [[ACELP]]. This greatly improves the generic audio coding. Automatic switching between transform coding and ACELP provides both good speech and audio quality with moderate bit rates.

As AMR-WB operates at internal sampling rate 12.8&nbsp;kHz, AMR-WB+ also supports various internal sampling frequencies ranges from 12.8&nbsp;kHz to 38.4&nbsp;kHz. AMR-WB uses 16&nbsp;kHz sampling frequency with a resolution of 14 bits left justified in a 16-bit word. AMR-WB+ uses 16/24/32/48&nbsp;kHz sampling frequencies with a resolution of 16 bits in a 16-bit word.<ref name="3gpp-amr-wb+">[http://www.3gpp.org/ftp/Specs/html-info/26290.htm 3GPP TS 26.290; Audio codec processing functions; Extended Adaptive Multi-Rate – Wideband (AMR-WB+) codec; Transcoding functions], Page 10, Retrieved on 2009-07-08</ref>

[[3GPP]] originally developed the AMR-WB+ audio codec for streaming and messaging services in Global System for Mobile communications ([[GSM]]) and Third Generation ([[3G]]) cellular systems.
Its primary target applications are Packet-Switched Streaming service ([[3GPP PSS|PSS]]), [[Multimedia Messaging Service]] (MMS) and Multimedia Broadcast and Multicast Service (MBMS).

File storage of AMR-WB+ encoded audio is specified within the [[3GP]] [[container format (digital)|container format]], 3GPP-defined [[ISO base media file format|ISO-based]] multimedia file format defined in 3GPP TS 26.244.<ref>{{Cite IETF |title=7.1. RTP Payload Format for the Extended Adaptive Multi-Rate Wideband (AMR-WB+) Audio Codec |rfc=4352 |sectionname=Media Type Registration |section=7.1 |page=31}}</ref>

The AMR-WB+ codec has a wide bit-rate range, from 5.2 to 48&nbsp;kbit/s. Mono rates are scalable from 5.2 to 36&nbsp;kbit/s, and stereo rates are scalable from 6.2 to 48&nbsp;kbit/s, reproducing bandwidth up to 20&nbsp;kHz (approaching CD quality). Moreover, it provides backward compatibility with AMR wideband.

== Software support ==
In September 2005, VoiceAge Corporation announced availability of AMR-WB+ decoder in [[Helix DNA Client]].<ref name="helix-voiceage">{{cite web |publisher=sys-con |url=http://www.sys-con.com/node/135572 |title=State-of-the-art AMR-WB+ Hi-fi Audio Compression is Now Available for Helix |date=2005-09-28 |access-date=2009-09-11}}</ref><ref name="helix">{{cite web |publisher=Helix Community mailinglist |url=http://lists.helixcommunity.org/pipermail/helix-client-announce/2005-September/000018.html |title=AMR-WB+ audio codec being integrated into Helix |date=2005-09-28 |access-date=2009-09-11}}</ref>

== Licensing and patent issues ==
AMR-WB+ compression incorporate several [[patent]]s of [[Nokia Corporation]], [[Telefonaktiebolaget L. M. Ericsson]] and VoiceAge Corporation.
<ref name="voiceage-amrwbplus_licterms">{{cite web |author=VoiceAge Corporation |publisher=VoiceAge Corporation |url=http://www.voiceage.com/amrwbplus_licterms.php |title=AMR-WB+ Licensing Terms |date=2007-10-14 |access-date=2009-09-12 |url-status=dead |archive-url=https://web.archive.org/web/20071014161444/http://www.voiceage.com/amrwbplus_licterms.php |archive-date=2007-10-14}}</ref>
VoiceAge Corporation is the ''License Administrator'' for the AMR and AMR-WB+ [[patent pool]]s. VoiceAge also accepts submission of patents for determination of their possible essentiality to these standards.
<ref name="voiceage-licpatentcalls">{{cite web |author=VoiceAge Corporation |publisher=VoiceAge Corporation |url=http://www.voiceage.com/licpatentcalls.php |title=Licensing – Patent Calls |access-date=2009-09-12 |url-status=dead |archive-url=https://web.archive.org/web/20071014161420/http://www.voiceage.com/licpatentcalls.php |archive-date=2007-10-14 }}</ref>

The initial fee for applications using "real-time channels" with AMR-WB+ is $6,500. Minimum annual royalty shall be $10,000, excluding the initial fee in year 1 of the license agreement.<ref name="voiceage-amrwbplus_licterms"/>

AMR-WB+ monaural decoder in a category of personal computer products is licensed for free. Stereo AMR-WB+ decoder for personal computer products is licensed for $0.30.<ref name="voiceage-amrwbplus_licterms"/>

== See also ==
* [[Adaptive Multi-Rate]] (AMR)
* [[Adaptive Multi-Rate Wideband]] (AMR-WB)
* [[3GP]]
* [[Comparison of audio coding formats]]
* [[RTP audio video profile]]

==References==
<references/>

==External links==
* [http://www.3gpp.org/ftp/Specs/html-info/26-series.htm 3GPP codecs specifications; 3G and beyond / GSM, 26 series]
* [http://www.3gpp.org/ftp/Specs/html-info/26290.htm 3GPP TS 26.290; Audio codec processing functions; Extended Adaptive Multi-Rate – Wideband (AMR-WB+) codec; Transcoding functions]
* {{IETF RFC|4352|link=no}} – RTP Payload Format for the Extended Adaptive Multi-Rate Wideband (AMR-WB+) Audio Codec
* {{IETF RFC|4281|link=no}} – The Codecs Parameter for "Bucket" Media Types

{{Compression formats}}
{{Audio broadcasting}}

{{DEFAULTSORT:Extended Adaptive Multi-Rate - Wideband}}
[[Category:Audio codecs]]
[[Category:Speech codecs]]