| 词条 | Extended Adaptive Multi-Rate – Wideband |
| 释义 |
| name = Extended Adaptive Multi-Rate - Wideband (AMR-WB+) | icon = | logo = | caption = | extension = | mime = audio/amr-wb+, audio/3gpp | type code = | uniform type = | magic = | owner = | genre = Audio | container for = | contained by = 3GP | extended from = AMR-WB | extended to = | standard = }} 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 kHz, AMR-WB+ also supports various internal sampling frequencies ranges from 12.8 kHz to 38.4 kHz. AMR-WB uses 16 kHz sampling frequency with a resolution of 14 bits left justified in a 16-bit word. AMR-WB+ uses 16/24/32/48 kHz sampling frequencies with a resolution of 16 bits in a 16-bit word.[1] 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 (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, 3GPP-defined ISO-based multimedia file format defined in 3GPP TS 26.244.[2] The AMR-WB+ codec has a wide bit-rate range, from 5.2–48 kbit/s. Mono rates are scalable from 5.2–36 kbit/s, and stereo rates are scalable from 6.2–48 kbit/s, reproducing bandwidth up to 20 kHz (approaching CD quality). Moreover, it provides backward compatibility with AMR wideband. Software supportIn September 2005, VoiceAge Corporation announced availability of AMR-WB+ decoder in Helix DNA Client.[3][4] Licensing and patent issuesAMR-WB+ compression incorporate several patents of Nokia Corporation, Telefonaktiebolaget L. M. Ericsson and VoiceAge Corporation.[5][6] VoiceAge Corporation is the License Administrator for the AMR and AMR-WB+ patent pools. VoiceAge also accepts submission of patents for determination of their possible essentiality to these standards.[7][8] 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.[5][6] AMR-WB+ monoural 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.[5][6] See also
References1. ^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 2. ^RFC 4352, page 30 3. ^{{cite web |author= |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 |accessdate=2009-09-11}} 4. ^{{cite web |author= |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 |accessdate=2009-09-11}} 5. ^1 2 {{cite web |author=VoiceAge Corporation |url=http://www.voiceage.com/amrwbplus_licterms.php |title=AMR-WB+ Licensing Terms |date=2007-10-14 |accessdate=2009-09-12 |archiveurl=https://web.archive.org/web/20071014161444/http://www.voiceage.com/amrwbplus_licterms.php |archivedate=2007-10-14}} 6. ^1 2 {{cite web|author=VoiceAge Corporation |publisher=VoiceAge Corporation |url=http://www.voiceage.com/amrwbplus_licterms.php |title=AMR-WB+ Licensing Terms |date=November 2006 |accessdate=2009-09-12 |deadurl=yes |archiveurl=https://web.archive.org/web/20071014161444/http://www.voiceage.com/amrwbplus_licterms.php |archivedate=2007-10-14 |df= }} 7. ^{{cite web |author=VoiceAge Corporation |publisher=VoiceAge Corporation |url=http://www.voiceage.com/licpatentcalls.php |title=Licensing - Patent Calls |date= |accessdate=2009-09-12 |deadurl=yes |archiveurl=https://web.archive.org/web/20071014161420/http://www.voiceage.com/licpatentcalls.php |archivedate=2007-10-14 |df= }} 8. ^{{cite web |author=VoiceAge Corporation |publisher=Archive.org |url=http://www.voiceage.com/licpatentcalls.php |title=Licensing - Patent Calls |date=2007-10-14 |accessdate=2009-09-12 |archiveurl = https://web.archive.org/web/20071014161420/http://www.voiceage.com/licpatentcalls.php |archivedate = 2007-10-14}} External links
2 : Audio codecs|Speech codecs |
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