* Evaluate the LPC filter coefficients from the reflection coefficients.
* Does the inverse of the eq() function.
*/
-static void do_voice(const int *a1, int *a2)
+static void do_voice(const int *refl, int *coefs)
{
int buffer[10];
int *b1 = buffer;
- int *b2 = a2;
+ int *b2 = coefs;
int x, y;
for (x=0; x < 10; x++) {
- b1[x] = a1[x] << 4;
+ b1[x] = refl[x] << 4;
for (y=0; y < x; y++)
- b1[y] = ((a1[x] * b2[x-y-1]) >> 12) + b2[y];
+ b1[y] = ((refl[x] * b2[x-y-1]) >> 12) + b2[y];
FFSWAP(int *, b1, b2);
}
for (x=0; x < 10; x++)
- a2[x] >>= 4;
+ coefs[x] >>= 4;
}
/* rotate block */
* @return 1 if one of the reflection coefficients is of magnitude greater than
* 4095, 0 if not.
*/
-static int eq(const int16_t *in, int *target)
+static int eq(const int16_t *coefs, int *refl)
{
int retval = 0;
int b, c, i;
int *bp2 = buffer2;
for (i=0; i < 10; i++)
- buffer2[i] = in[i];
+ buffer2[i] = coefs[i];
- u = target[9] = bp2[9];
+ u = refl[9] = bp2[9];
if (u + 0x1000 > 0x1fff)
return 0; /* We're screwed, might as well go out with a bang. :P */
b++;
for (u=0; u<=c; u++)
- bp1[u] = ((bp2[u] - ((target[c+1] * bp2[c-u]) >> 12)) * (0x1000000 / b)) >> 12;
+ bp1[u] = ((bp2[u] - ((refl[c+1] * bp2[c-u]) >> 12)) * (0x1000000 / b)) >> 12;
- target[c] = u = bp1[c];
+ refl[c] = u = bp1[c];
if ((u + 0x1000) > 0x1fff)
retval = 1;