00001 #include "c_lpc10.h" 00002 00003 /**********************************************************/ 00004 /* Preemphasize speech, using a couple of zeros at 0.5 +- 0.387i. 00005 Previous version used ( 1 - .9375z**-1 ) [old preemphasis] cascaded 00006 width ( 1 + .2z**-1 ) / ( 1 + .5z**-1 ) [6 db/oct ramp] */ 00007 00008 VOID preemp( FLOAT inbuf[], FLOAT pebuf[], INDEX len, FLOAT z[2] ) 00009 { 00010 INDEX i; 00011 00012 for (i = 0; i < len; i++) { 00013 pebuf[i] = inbuf[i] - z[0] + (FLOAT)0.4 * z[1]; 00014 z[1] = z[0]; 00015 z[0] = inbuf[i]; 00016 } 00017 } 00018 00019 /**********************************************************/
1.5.6