Modification of the ADPCM Codec Based on a Modification of the Khurgin-Yakovlev Algorithm

A modification of the adaptive differential pulse-code modulation (ADCM) codec based on a modification of the Khurgin-Yakovlev algorithm is considered. Studies of the proposed modification of the ADPCM codec for various orders of the predictor and various transmission rates have been carried out. It is shown that the use of this algorithm for various ADPCM codecs provides a speech quality gain at the output by 0.2 … 0.4 points according to GOST R 5084095. A joint implementation of the predictor for decimated signal samples and derivative is proposed, which will reduce computational costs by 20%. An algorithm for separate quantization of the signal samples and the derivative is proposed, which makes it possible to obtain the quality of the restored speech by 0.3 … 0.5 points higher than in similar ADPCM codecs.