G.722.1 or SIREN 7
G.722.1 or SIREN 7 describes a digital wideband coder algorithm that provides an audio bandwidth of 50 Hz to 7 kHz, operating at a bit rate of 24 kbps or 32 kbps. G.722.1 is useful for hands-free operation in HD VoIP systems with low frame loss.
It exists also the G.722.1 Annex C or SIREN 14 that provides an audio badwith up to 14 Khz operating at a bir rate of 24, 32, y 48 kbit/s.
G.722.2 o AMR-WB ("Adaptive Multirate Wideband")
The Adaptive Multi-Rate Wideband Codec (AMR-WB) is a speech coder standard introduced by the 3rd Generation Partnership Project (3GPP), The AMR-WB Codec has been approved by the ITU-T standards body and is referred to as G.722.2.This speech coder is mainly used for speech compression in the 3rd generation mobile telephony.
This codec has nine basic bit rates, 23.85, 23.05, 19.85, 18.25, 15.85, 14.25, 12.65, 8.85 and 6.6 kbit/s. This codec works on the principle of Algebraic Code Excited Linear Prediction (ACELP) for all bit rates. To reduce average bit rate, this codec supports the discontinuous transmission (DTX), using Voice Activity Detection (VAD) and Comfort Noise Generation (CNG) algorithms.
The coder works with a framesize of 20 msec and the algorithmic delay for the coder is 25 msec.
references:
http://www.en.voipforo.com/codec/new-codecs-g7111-g7291.php
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