Lossless Compression of Mapped Domain Linear Prediction Residual for ITU-T Recommendation G.711.0

Summary form only given. The ITU-T Rec. G.711 is widely used for narrowband telephony applications, including PSTN/GSTN and packet-based network applications such as VoIP, and has been used for many decades because of its proven voice quality, ubiquity, and utility. ITU has just established a lossless coding technology for G.711 encoded payloads, ITU-T Rec. G.711.0-Lossless compression of G.711 pulse code modulation. This paper introduces some coding technologies proposed and applied to the G.711.0 codec, such as Plus-Minus zero mapping for the mapped domain linear predictive coding and escaped-Huffman coding combined with adaptive recursive Rice coding for lossless compression of the prediction residual. The proposed and conventional algorithms were implemented and the coding performances of the codec were evaluated using large speech corpus in various conditions in terms of the computational complexity/compression performance trade-off. Since the distribution of the prediction residual signal sometimes does not follow the expected Laplacian PDF model of Rice coding, E-Huffman coding can improve the compression performance for relatively smaller Rice quotients of residual and Recursive Rice coding can improve the compression performance for relatively larger Rice quotients of residual. It is shown that the PM zero mapping improves the compression performance by 0.2% for ?-law input. The E-Huffman coding combined with adaptive recursive Rice coding improves the compression by 0.16% while the complexity was increased by 0.046 WMOPS for the encoder/decoder pair, averaged for all test conditions, compare to the conventional Rice coding scheme. The worst-case complexity was increased by 0.079 WMOPS. Average computational complexity is 1.071 WMOPS for the encoder/decoder pair and the worst-case complexity is 1.667 WMOPS in total.