Two novel speech coders , called flag modulo pulse code modulation GMPCM and enhansened flag modulo pulse code modulation EGMPCM , are presented. The coders are designed for medium and high bit rate applications. These coders use the modulo PCM principle. A flag bit is used to indicate changing in speech segments. The coders have small modulo amplitude and hence better SNR. Dynamic quantization and bit allocation are also used in these coders in effect these coders function as dynamic quantizers.
EGMPCM coders use a new technique to reduce the modulo amplitude by modifying the input speech files. Both coders do not use predictors neither in coding nor in decoding stages. The coders depend only upon the actual difference between conp.