From ITU-T G.722.1 to ITU-T G.722.1 Annex C: A New Low-Complexity 14kHz Bandwidth Audio Coding Standard

Abstract

This paper describes the low-complexity 14kHz bandwidth audio coding algorithm which has been recently standardized by ITU-T as Recommendation G.722.1 Annex C (“G.722.1C”). The algorithm is an extension to ITU-T Recommendation G.722.1 and a doubled form of the G.722.1 algorithm to permit 14 kHz audio bandwidth using a 32 kHz audio sample rate, at 24, 32, and 48 kbit/s. The G. 722.1C codec features very high audio quality, extremely low computational complexity, and low algorithmic delay compared to other state-of-the-art audio coding algorithms. This codec is suitable for use in video conferencing and teleconferencing, and Internet streaming applications as well as a general-purpose 14 kHz audio codec. Subjective test results from the Characterization phase of G 722.1C are also presented in the paper.