Patent ID: 8576927
Filing Date: 2013-11-05
Classification: G10L,H03M

Abstract:
1. An encoding method comprising: a decision step of accepting input code words encoded with an encoding mode in which two different types of code words are assigned one-to-one to two smallest quantization intervals, and judging whether a frame formed of a plurality of the code words contains just the two types of code words assigned to the two smallest quantization intervals; a first encoding step of outputting a code obtained by lossless encoding of the frame containing just the two types of code words when it is judged that the frame contains just the two types of code words; and a second encoding step of performing encoding differing from the encoding in the first encoding step on a frame that includes a code word other than the two types of code words, wherein the encoding mode is non-uniform PCM (pulse code modulation); and the second encoding step comprises a step of converting first non-uniform PCM codes of signals formed of code words encoded with the non-uniform PCM, to uniform PCM codes, converting prediction values obtained by using prediction coefficients obtained by applying linear prediction analysis to the uniform PCM codes, to second non-uniform PCM codes, and encoding respective residuals between the first non-uniform PCM codes and the second non-uniform PCM codes.