G.711.1 Annex D and G.722 Annex B - New ITU-T superwideband codecs

This paper presents high quality monaural superwideband extensions to G.711.1 and G.722, recently standardized as Recommendations ITU-T G.711.1 Annex D and G.722 Annex B. The superwideband (50-14000 Hz) functionality is achieved using embedded scalable structure that adds extension layers on top of the wideband core codecs. The bit rates are extended to 96/112/128 and 64/80/96 kbit/s for G.711.1 and G.722, respectively. The main technologies include lower and higher band (0-4 kHz and 4-8 kHz) enhancements, 8-14 kHz bandwidth extension and transform coding based on algebraic vector quantization. The codecs' performance is illustrated with listening test results extracted from formal ITU-T Characterization tests.