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preemp.c
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C/C++ Source or Header
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2000-05-18
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755b
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36 lines
/********************************************************************
*
* PREEMP Version 48
*
********************************************************************
*
* Preemphasize speech with ( 1 - .9375z**-1 ) [old preemphasis]
* cascaded with ( 1 + .2z**-1 ) / ( 1 + .5z**-1 ) [6 db/oct ramp]
*
* Inputs:
* NSAMP - Number of samples to filter
* INBUF - Input speech buffer
* COEF - Preemphasis coeficient
* Output:
* PEBUF - Preemphasized speech buffer (can be equal to INBUF)
* Z - Filter state
*/
preemp( inbuf, pebuf, nsamp, coef, z )
int nsamp;
float *inbuf, *pebuf, coef, *z;
{
int i;
float temp=0.0;
for(i=1; i<=nsamp; i++) {
temp = inbuf[i] - *z + coef**(z+1);
*(z+1) = *z;
*z = inbuf[i];
pebuf[i] = temp;
}
}