00001 #include "d_lpc10.h" 00002 00003 /**********************************************************/ 00004 /* De-emphasize output speech with 1 / ( 1 - .75z**-1 ) 00005 cascaded with 200 Hz high pass filter 00006 ( 1 - 1.9998z**-1 + z**-2 ) / ( 1 - 1.75z**-1 + .78z**-2 ) */ 00007 00008 static FLOAT dei1 = 0.0, dei2 = 0.0; 00009 static FLOAT deo1 = 0.0, deo2 = 0.0, deo3 = 0.0, deo4 = 0.0; 00010 00011 VOID deemp( FLOAT x[], INDEX n ) 00012 { 00013 FLOAT dei0; 00014 INDEX k; 00015 00016 for (k = 0; k < n; k++) { 00017 dei0 = x[k]; 00018 x[k] += (FLOAT)(-1.9998 * dei1 + dei2 + 2.75 * deo1 - 2.93 * deo2 00019 + 1.48 * deo3 - 0.312 * deo4); 00020 dei2 = dei1; 00021 dei1 = dei0; 00022 deo4 = deo3; 00023 deo3 = deo2; 00024 deo2 = deo1; 00025 deo1 = x[k]; 00026 } 00027 } 00028 00029 /**********************************************************/
1.5.6