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.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 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 Multimedia Messaging Service (MMS) is a standard way to send messages that include multimedia content to and from a mobile phone over a cellular network. Users and providers may refer to such a message as a PXT, a picture message, or a multimedia ...

(MMS) and Multimedia Broadcast and Multicast Service (MBMS). File storage of AMR-WB+ encoded audio is specified within the

3GP 3GP (3GPP file format) is a multimedia container format defined by the Third Generation Partnership Project (3GPP) for 3G UMTS multimedia services. It is used on 3G mobile phones but can also be played on some 2G and 4G phones. 3G2 (3GPP2 ...

container format A container format (informally, sometimes called a wrapper) or metafile is a file format that allows multiple data streams to be embedded into a single file, usually along with metadata for identifying and further detailing those streams. Notab ...

, 3GPP-defined ISO-based multimedia file format defined in 3GPP TS 26.244. The AMR-WB+ codec has a wide bit-rate range, from 5.2 to 48 kbit/s. Mono rates are scalable from 5.2 to 36 kbit/s, and stereo rates are scalable from 6.2 to 48 kbit/s, reproducing bandwidth up to 20 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 A helix () is a shape like a corkscrew or spiral staircase. It is a type of smooth space curve with tangent lines at a constant angle to a fixed axis. Helices are important in biology, as the DNA molecule is formed as two intertwined helice ...

Licensing and patent issues

AMR-WB+ compression incorporate several patents of Nokia Corporation, Telefonaktiebolaget L. M. Ericsson and VoiceAge Corporation. 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. 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. 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.

References

External links

3GPP codecs specifications; 3G and beyond / GSM, 26 series

* – RTP Payload Format for the Extended Adaptive Multi-Rate Wideband (AMR-WB+) Audio Codec * – The Codecs Parameter for "Bucket" Media Types {{DEFAULTSORT:Extended Adaptive Multi-Rate - Wideband Audio codecs Speech codecs

Software support

Licensing and patent issues

See also

References

External links