ref: d3161c5c72ae6adac078e969c12f364e06473a73
dir: /amr-wb/p_med_ol.c/
/*------------------------------------------------------------------------*
* P_MED_OL.C *
*------------------------------------------------------------------------*
* Compute the open loop pitch lag. *
*------------------------------------------------------------------------*/
#include "typedef.h"
#include "basic_op.h"
#include "acelp.h"
#include "oper_32b.h"
#include "count.h"
#include "math_op.h"
#include "p_med_ol.tab"
Word16 Pitch_med_ol( /* output: open loop pitch lag */
Word16 wsp[], /* input : signal used to compute the open loop pitch */
/* wsp[-pit_max] to wsp[-1] should be known */
Word16 L_min, /* input : minimum pitch lag */
Word16 L_max, /* input : maximum pitch lag */
Word16 L_frame, /* input : length of frame to compute pitch */
Word16 L_0, /* input : old_ open-loop pitch */
Word16 * gain, /* output: normalize correlation of hp_wsp for the Lag */
Word16 * hp_wsp_mem, /* i:o : memory of the hypass filter for hp_wsp[] (lg=9) */
Word16 * old_hp_wsp, /* i:o : hypass wsp[] */
Word16 wght_flg /* input : is weighting function used */
)
{
Word16 i, j, Tm;
Word16 hi, lo;
Word16 *ww, *we, *hp_wsp;
Word16 exp_R0, exp_R1, exp_R2;
Word32 max, R0, R1, R2;
ww = &corrweight[198];
move16();
we = &corrweight[98 + L_max - L_0];
move16();
max = MIN_32; move32();
Tm = 0; move16();
for (i = L_max; i > L_min; i--)
{
/* Compute the correlation */
R0 = 0; move32();
for (j = 0; j < L_frame; j++)
R0 = L_mac(R0, wsp[j], wsp[j - i]);
/* Weighting of the correlation function. */
L_Extract(R0, &hi, &lo);
R0 = Mpy_32_16(hi, lo, *ww);
ww--;
test();
test();
if ((L_0 > 0) && (wght_flg > 0))
{
/* Weight the neighbourhood of the old lag. */
L_Extract(R0, &hi, &lo);
R0 = Mpy_32_16(hi, lo, *we);
we--;
move16();
}
test();
if (L_sub(R0, max) >= 0)
{
max = R0;
move32();
Tm = i;
move16();
}
}
/* Hypass the wsp[] vector */
hp_wsp = old_hp_wsp + L_max; move16();
Hp_wsp(wsp, hp_wsp, L_frame, hp_wsp_mem);
/* Compute normalize correlation at delay Tm */
R0 = 0; move32();
R1 = 1L; move32();
R2 = 1L; move32();
for (j = 0; j < L_frame; j++)
{
R0 = L_mac(R0, hp_wsp[j], hp_wsp[j - Tm]);
R1 = L_mac(R1, hp_wsp[j - Tm], hp_wsp[j - Tm]);
R2 = L_mac(R2, hp_wsp[j], hp_wsp[j]);
}
/* gain = R0/ sqrt(R1*R2) */
exp_R0 = norm_l(R0);
R0 = L_shl(R0, exp_R0);
exp_R1 = norm_l(R1);
R1 = L_shl(R1, exp_R1);
exp_R2 = norm_l(R2);
R2 = L_shl(R2, exp_R2);
R1 = L_mult(roundL(R1), roundL(R2));
i = norm_l(R1);
R1 = L_shl(R1, i);
exp_R1 = add(exp_R1, exp_R2);
exp_R1 = add(exp_R1, i);
exp_R1 = sub(62, exp_R1);
Isqrt_n(&R1, &exp_R1);
R0 = L_mult(roundL(R0), roundL(R1));
exp_R0 = sub(31, exp_R0);
exp_R0 = add(exp_R0, exp_R1);
*gain = roundL(L_shl(R0, exp_R0));
move16();
/* Shitf hp_wsp[] for next frame */
for (i = 0; i < L_max; i++)
{
old_hp_wsp[i] = old_hp_wsp[i + L_frame];
move16();
}
return (Tm);
}
/*____________________________________________________________________
|
|
| FUNCTION NAME median5
|
| Returns the median of the set {X[-2], X[-1],..., X[2]},
| whose elements are 16-bit integers.
|
| INPUT
| X[-2:2] 16-bit integers.
|
| RETURN VALUE
| The median of {X[-2], X[-1],..., X[2]}.
|_____________________________________________________________________
*/
Word16 median5(Word16 x[])
{
Word16 x1, x2, x3, x4, x5;
Word16 tmp;
x1 = x[-2]; move16();
x2 = x[-1]; move16();
x3 = x[0]; move16();
x4 = x[1]; move16();
x5 = x[2]; move16();
test();test();test();test();test();test();test();test();test();
if (sub(x2, x1) < 0)
{
tmp = x1;
x1 = x2;
x2 = tmp; move16();move16();move16();
}
if (sub(x3, x1) < 0)
{
tmp = x1;
x1 = x3;
x3 = tmp; move16();move16();move16();
}
if (sub(x4, x1) < 0)
{
tmp = x1;
x1 = x4;
x4 = tmp; move16();move16();move16();
}
if (sub(x5, x1) < 0)
{
x5 = x1; move16();
}
if (sub(x3, x2) < 0)
{
tmp = x2;
x2 = x3;
x3 = tmp; move16();move16();move16();
}
if (sub(x4, x2) < 0)
{
tmp = x2;
x2 = x4;
x4 = tmp; move16();move16();move16();
}
if (sub(x5, x2) < 0)
{
x5 = x2; move16();
}
if (sub(x4, x3) < 0)
{
x3 = x4; move16();
}
if (sub(x5, x3) < 0)
{
x3 = x5; move16();
}
return (x3);
}
/*____________________________________________________________________
|
|
| FUNCTION NAME med_olag
|
|
|_____________________________________________________________________
*/
Word16 Med_olag( /* output : median of 5 previous open-loop lags */
Word16 prev_ol_lag, /* input : previous open-loop lag */
Word16 old_ol_lag[5]
)
{
Word16 i;
/* Use median of 5 previous open-loop lags as old lag */
for (i = 4; i > 0; i--)
{
old_ol_lag[i] = old_ol_lag[i - 1]; move16();
}
old_ol_lag[0] = prev_ol_lag; move16();
i = median5(&old_ol_lag[2]);
return i;
}