ref: 444f41c6fcdf4142c6bca1c6c76df2e4603a24a8
dir: /amr-wb/weight_a.c/
/*-------------------------------------------------------------------*
* WB_VAD.C *
*-------------------------------------------------------------------*
* Weighting of LPC coefficients. *
* ap[i] = a[i] * (gamma ** i) *
*-------------------------------------------------------------------*/
#include "typedef.h"
#include "acelp.h"
#include "basic_op.h"
#include "count.h"
void Weight_a(
Word16 a[], /* (i) Q12 : a[m+1] LPC coefficients */
Word16 ap[], /* (o) Q12 : Spectral expanded LPC coefficients */
Word16 gamma, /* (i) Q15 : Spectral expansion factor. */
Word16 m /* (i) : LPC order. */
)
{
Word16 i, fac;
ap[0] = a[0]; move16();
fac = gamma; move16();
for (i = 1; i < m; i++)
{
ap[i] = roundL(L_mult(a[i], fac)); move16();
fac = roundL(L_mult(fac, gamma));
}
ap[m] = roundL(L_mult(a[m], fac)); move16();
return;
}