Adaptive Multi-Rate Wideband

G.722.2
Wideband coding of speech at around 16 kbit/s using Adaptive Multi-Rate Wideband (AMR-WB)
StatusIn force
Year started2002
Latest version(08/18)
August 2018
OrganizationITU-T
CommitteeITU-T Study Group 16
Domaintelecommunication
LicenseFreely available
Websitehttps://www.itu.int/rec/T-REC-G.722.2

Adaptive Multi-Rate Wideband (AMR-WB) is a patented wideband speech audio coding standard developed based on Adaptive Multi-Rate encoding, using a similar methodology to algebraic code-excited linear prediction (ACELP). AMR-WB provides improved speech quality due to a wider speech bandwidth of 50–7000 Hz compared to narrowband speech coders which in general are optimized for POTS wireline quality of 300–3400 Hz. AMR-WB was developed by Nokia[1] and VoiceAge and it was first specified by 3GPP.[2]

AMR-WB is codified as G.722.2, an ITU-T standard speech codec, formally known as Wideband coding of speech at around 16 kbit/s using Adaptive Multi-Rate Wideband (AMR-WB). G.722.2 AMR-WB is the same codec as the 3GPP AMR-WB. The corresponding 3GPP specifications are TS 26.190 for the speech codec[3] and TS 26.194 for the Voice Activity Detector.[4]

The AMR-WB format has the following parameters:[5]

A common file extension for the AMR-WB file format is .awb. There also exists another storage format for AMR-WB that is suitable for applications with more advanced demands on the storage format, like random access or synchronization with video. This format is the 3GPP-specified 3GP container format, based on the ISO base media file format.[7] 3GP also allows use of AMR-WB bit streams for stereo sound.

  1. ^ "Nokia Research Center: AMR-WB and the Nokia Voice Experience - Istanbul". Archived from the original on 2013-02-10.
  2. ^ "G.722.2: Wideband coding of speech at around 16 kbit/s using Adaptive Multi-Rate Wideband (AMR-WB)". ITU Telecommunication Standard Sector. Archived from the original on 2021-06-14. Retrieved 2021-12-14.
  3. ^ "Specification # 26.190: Speech codec speech processing functions; Adaptive Multi-Rate - Wideband (AMR-WB) speech codec; Transcoding functions". 3GPP Portal. 3GPP. Retrieved 2021-12-14.
  4. ^ "Specification # 26.194: Speech codec speech processing functions; Adaptive Multi-Rate - Wideband (AMR-WB) speech codec; Voice Activity Detector (VAD)". 3GPP Portal. 3GPP. Retrieved 2021-12-14.
  5. ^ "Wideband Speech Coding Standards and Applications" (PDF). Archived from the original (PDF) on 2007-10-13. Retrieved 2012-02-22.
  6. ^ "Specification # 26.976: Performance characterization of the Adaptive Multi-Rate Wideband (AMR-WB) speech codec; Chapter 25: Transmission Delay". 3GPP Portal. 3GPP. Retrieved 2021-12-14.
  7. ^ "AMR and AMR-WB Storage Format". RTP Payload Format and File Storage Format for the Adaptive Multi-Rate (AMR) and Adaptive Multi-Rate Wideband (AMR-WB) Audio Codecs. p. 35. sec. 5. doi:10.17487/RFC4867. RFC 4867.