/*
*****************************************************************************
*
*      GSM AMR-NB speech codec   R98   Version 7.6.0   December 12, 2001
*                                R99   Version 3.3.0                
*                                REL-4 Version 4.1.0                
*
*****************************************************************************
*
*      File             : p_ol_wgh.c
*      Purpose          : Compute the open loop pitch lag with weighting      
*
*************************************************************************/
/*
********************************************************************************
*                         MODULE INCLUDE FILE AND VERSION ID
********************************************************************************
*/
#include "namespace.h"
#include "p_ol_wgh.h"

/*
*****************************************************************************
*                         INCLUDE FILES
*****************************************************************************
*/
#include "typedef.h"
#include "basic_op.h"
#include "oper_32b.h"
#include "no_count.h"
#include "cnst.h"
#include "corrwght.tab"
#include "gmed_n.h"
#include "inv_sqrt.h"
#include "vad.h"
#include "calc_cor.h"
#include "hp_max.h"
                      
/*
*****************************************************************************
*                         LOCAL VARIABLES AND TABLES
*****************************************************************************
*/
/*************************************************************************
 *
 *  FUNCTION:  Lag_max
 *
 *  PURPOSE: Find the lag that has maximum correlation of scal_sig[] in a
 *           given delay range.
 *
 *  DESCRIPTION:
 *      The correlation is given by
 *           cor[t] = <scal_sig[n],scal_sig[n-t]>,  t=lag_min,...,lag_max
 *      The functions outputs the maximum correlation after normalization
 *      and the corresponding lag.
 *
 *************************************************************************/
static Word16 Lag_max ( /* o : lag found                               */
    vadState *vadSt,    /* i/o : VAD state struct                      */
    Word32 corr[],      /* i   : correlation vector.                   */
    Word16 scal_sig[],  /* i : scaled signal.                          */
    Word16 L_frame,     /* i : length of frame to compute pitch        */
    Word16 lag_max,     /* i : maximum lag                             */
    Word16 lag_min,     /* i : minimum lag                             */
    Word16 old_lag,     /* i : old open-loop lag                       */
    Word16 *cor_max,    /* o : normalized correlation of selected lag  */
    Word16 wght_flg,    /* i : is weighting function used              */ 
    Word16 *gain_flg,   /* o : open-loop flag                          */
    Flag dtx            /* i   : dtx flag; use dtx=1, do not use dtx=0 */
    )
{
    Word16 i, j;
    Word16 *p, *p1;
    Word32 max, t0;
    Word16 t0_h, t0_l;
    Word16 p_max;
    const Word16 *ww, *we;
    Word32 t1;
    
    ww = &corrweight[250];                                 move16 ();
    we = &corrweight[123 + lag_max - old_lag];             move16 ();

    max = MIN_32;                                          move32 ();
    p_max = lag_max;                                       move16 ();

    for (i = lag_max; i >= lag_min; i--)
    {
       t0 = corr[-i];                                      move32 ();   
       
       /* Weighting of the correlation function.   */
       L_Extract (corr[-i], &t0_h, &t0_l);
       t0 = Mpy_32_16 (t0_h, t0_l, *ww);
       ww--;                                               move16();
       test ();
       if (wght_flg > 0) {
          /* Weight the neighbourhood of the old lag. */
          L_Extract (t0, &t0_h, &t0_l);
          t0 = Mpy_32_16 (t0_h, t0_l, *we);
          we--;                                            move16();
       }
       
       test (); 
       if (L_sub (t0, max) >= 0)
       {
          max = t0;                                        move32 (); 
          p_max = i;                                       move16 (); 
       }
    }
    
    p  = &scal_sig[0];                                     move16 (); 
    p1 = &scal_sig[-p_max];                                move16 (); 
    t0 = 0;                                                move32 (); 
    t1 = 0;                                                move32 (); 
    
    for (j = 0; j < L_frame; j++, p++, p1++)
    {
       t0 = L_mac (t0, *p, *p1);               
       t1 = L_mac (t1, *p1, *p1);
    }

    if (dtx)
    {  /* no test() call since this if is only in simulation env */
	if (vadSt->use_vad2) {
		/* Save max correlation */
		vadSt->u.v2.L_Rmax = L_add(vadSt->u.v2.L_Rmax, t0);
		/* Save max energy */
		vadSt->u.v2.L_R0 =   L_add(vadSt->u.v2.L_R0, t1);
	} else {
		/* update and detect tone */
		vad_tone_detection_update (&vadSt->u.v1, 0);
		vad_tone_detection (&vadSt->u.v1, t0, t1);
	}
    }

    /* gain flag is set according to the open_loop gain */
    /* is t2/t1 > 0.4 ? */    
    *gain_flg = round(L_msu(t0, round(t1), 13107));        move16(); 
    
    *cor_max = 0;                                          move16 ();

    return (p_max);
}

/*
*****************************************************************************
*                         PUBLIC PROGRAM CODE
*****************************************************************************
*/

/*************************************************************************
*
*  Function:   p_ol_wgh_reset
*  Purpose:    Initializes state memory to zero
*
**************************************************************************
*/
void p_ol_wgh_reset (pitchOLWghtState *st)
{
   /* Reset pitch search states */
   st->old_T0_med = 40;
   st->ada_w = 0;
   st->wght_flg = 0; 
}
 
/*************************************************************************
*
*  Function:   p_ol_wgh
*  Purpose:    open-loop pitch search with weighting
*
**************************************************************************
*/
Word16 Pitch_ol_wgh (     /* o   : open loop pitch lag                            */
    pitchOLWghtState *st, /* i/o : State struct                                   */
    vadState *vadSt,      /* i/o : VAD state struct                               */
    Word16 signal[],      /* i   : signal used to compute the open loop pitch     */
                          /*       signal[-pit_max] to signal[-1] should be known */
    Word16 pit_min,       /* i   : minimum pitch lag                              */
    Word16 pit_max,       /* i   : maximum pitch lag                              */
    Word16 L_frame,       /* i   : length of frame to compute pitch               */
    Word16 old_lags[],    /* i   : history with old stored Cl lags                */
    Word16 ol_gain_flg[], /* i   : OL gain flag                                   */
    Word16 idx,           /* i   : index                                          */
    Flag dtx              /* i   : dtx flag; use dtx=1, do not use dtx=0          */
    )
{
    Word16 i;
    Word16 max1;
    Word16 p_max1;
    Word32 t0;
    Word16 corr_hp_max;
    Word32 corr[PIT_MAX+1], *corr_ptr;    

    /* Scaled signal */
    Word16 scaled_signal[PIT_MAX + L_FRAME];
    Word16 *scal_sig;

    scal_sig = &scaled_signal[pit_max];                          move16 (); 

    t0 = 0L;                                                     move32 (); 
    for (i = -pit_max; i < L_frame; i++)
    {
        t0 = L_mac (t0, signal[i], signal[i]);
    }
    /*--------------------------------------------------------*
     * Scaling of input signal.                               *
     *                                                        *
     *   if Overflow        -> scal_sig[i] = signal[i]>>2     *
     *   else if t0 < 1^22  -> scal_sig[i] = signal[i]<<2     *
     *   else               -> scal_sig[i] = signal[i]        *
     *--------------------------------------------------------*/

    /*--------------------------------------------------------*
     *  Verification for risk of overflow.                    *
     *--------------------------------------------------------*/

    test (); test (); 
    if (L_sub (t0, MAX_32) == 0L)               /* Test for overflow */
    {
        for (i = -pit_max; i < L_frame; i++)
        {
            scal_sig[i] = shr (signal[i], 3);   move16 (); 
        }
    }
    else if (L_sub (t0, (Word32) 1048576L) < (Word32) 0)
    {
        for (i = -pit_max; i < L_frame; i++)
        {
            scal_sig[i] = shl (signal[i], 3);   move16 (); 
        }
    }
    else
    {
        for (i = -pit_max; i < L_frame; i++)
        {
            scal_sig[i] = signal[i];            move16 (); 
        }
    }

    /* calculate all coreelations of scal_sig, from pit_min to pit_max */
    corr_ptr = &corr[pit_max];                  move32 ();
    comp_corr (scal_sig, L_frame, pit_max, pit_min, corr_ptr); 

    p_max1 = Lag_max (vadSt, corr_ptr, scal_sig, L_frame, pit_max, pit_min,
                      st->old_T0_med, &max1, st->wght_flg, &ol_gain_flg[idx],
                      dtx);
    move16 ();

    test (); move16 ();
    if (ol_gain_flg[idx] > 0)
    {
       /* Calculate 5-point median of previous lags */
       for (i = 4; i > 0; i--) /* Shift buffer */
       {
          old_lags[i] = old_lags[i-1];              move16 ();
       }
       old_lags[0] = p_max1;                        move16 (); 
       st->old_T0_med = gmed_n (old_lags, 5);       move16 ();
       st->ada_w = 32767;                           move16 (); /* Q15 = 1.0 */
    }	
    else
    {        
       st->old_T0_med = p_max1;                     move16 ();
       st->ada_w = mult(st->ada_w, 29491);      /* = ada_w = ada_w * 0.9 */
    }
    
    test ();
    if (sub(st->ada_w, 9830) < 0)  /* ada_w - 0.3 */
    { 
       st->wght_flg = 0;                            move16 ();
    } 
    else
    {
       st->wght_flg = 1;                            move16 ();
    }

    if (dtx && !vadSt->use_vad2)
    {  /* no test() call since this if is only in simulation env */
       test ();
       if (sub(idx, 1) == 0)
       {
          /* calculate max high-passed filtered correlation of all lags */
          hp_max (corr_ptr, scal_sig, L_frame, pit_max, pit_min, &corr_hp_max); 
          
          /* update complex background detector */
          vad_complex_detection_update(&vadSt->u.v1, corr_hp_max);
       }
    }

    return (p_max1);
}