cpdr.c

CP detector (CPD) only reports the onset and removal of a tone. The analysis of timing (if required)

/*-------------------------------------------------------------------------*
*                                                                         *
*   THIS IS AN UNPUBLISHED WORK CONTAINING CONFIDENTIAL AND PROPRIETARY   *
*   INFORMATION.  IF PUBLICATION OCCURS, THE FOLLOWING NOTICE APPLIES:    *
*      "COPYRIGHT 2001 MIKET DSP SOLUTIONS, ALL RIGHTS RESERVED"          *
*                                                                         *
*-------------------------------------------------------------------------*/
#if ! defined (_dsp)
#include <stdlib.h> // abs()
#endif

#include "stddefs.h"
#include "cpdi.h"

/*--------------------- local defs ----------------------------------------*/

/*--------------------- public vars ---------------------------------------*/
/*--------------------- local vars ----------------------------------------*/
/*--------------------- local functions -----------------------------------*/
/*-------------------------------------------------------------------------*/
void 					cpd_get_lohi
/*-------------------------------------------------------------------------*/
(
CPD_tDb *pDb, 
CPD_tSc *pSc
)
{
    const ICPD_tCfg *pCfg = pDb->pCfg;

    pSc->sLoIdx = pSc->sMaxIdx;
    pSc->Lo.sEn = pSc->sMaxEn;
    pSc->sHiIdx = pSc->sNextIdx;
    pSc->Hi.sEn = pSc->sNextEn;

    if ((pSc->sMaxEn - pSc->sNextEn) < (pCfg->sTwistThr<<1)) 
    {
        /* that's most probably not a single frequency */
        if (pSc->sMaxIdx > pSc->sNextIdx)
        {
            pSc->sLoIdx = pSc->sNextIdx;
		    pSc->Lo.sEn = pSc->sNextEn;
            pSc->sHiIdx = pSc->sMaxIdx;
		    pSc->Hi.sEn = pSc->sMaxEn;
        }
        pSc->sTestFailed = CPD_MASK_DUAL;
    }
    else
    {
        pSc->sTestFailed = 0;
    }
}

/*-------------------------------------------------------------------------*/
void 					cpd_test
/*-------------------------------------------------------------------------*/
(
CPD_tDb *pDb,
CPD_tSc *pSc
)
{
    const ICPD_tCfg *pCfg = pDb->pCfg;
    S32 ac2;
    S16 sTestFailed = pSc->sTestFailed;
    
    ac2  = pSc->aOut[pSc->sMaxIdx].slEn;
    ac2 += pSc->aOut[pSc->sNextIdx].slEn;
    pSc->sSumEn = cpd_en2log(ac2, CPD_EN_PG);

    /* test that frame energy is high enough. */
    if (pSc->sMaxEn < pCfg->sMinEnThr)
        sTestFailed |= CPD_MASK_MAX_EN;

    /* test leading edge */
    {
        S16 sEn = pDb->v.asSumEn[CPD_EN_SZ-2];
        if (sEn < pDb->v.asSumEn[CPD_EN_SZ-1])
            sEn = pDb->v.asSumEn[CPD_EN_SZ-1];
        
        if ((pSc->sSumEn - sEn) < pCfg->sNoiseThr)
            sTestFailed |= CPD_MASK_RS_EDGE;
    }

    /* test falling edge */
    if ((pDb->v.sAvrEn - pSc->sSumEn) < pCfg->sNoiseThr)
        sTestFailed |= CPD_MASK_FL_EDGE;

    /* test that frame energy is reasonably stable */
    if (abs(pDb->Stts.sLoEn - pSc->Lo.sEn) > pCfg->sStableThr)
        sTestFailed |= CPD_MASK_LO_STABLE;

    if (abs(pDb->Stts.sHiEn - pSc->Hi.sEn) > pCfg->sStableThr)
        sTestFailed |= CPD_MASK_HI_STABLE;


    /* test that the spectrum is clean:
       the highest of two dominant freqs shall be 
       much higher than the rest freqs */
    {
        S16 sDltEn = pSc->sMaxEn - pSc->sRestEn;
        
        if (sDltEn < pCfg->sCleanThr)
            sTestFailed |= CPD_MASK_CLEAN;

        if (sDltEn < (pCfg->sCleanThr>>1))
            sTestFailed |= CPD_MASK_CLEAN_MB;
    }

    /* test if the tone is single:
       the highest freq shall be much higher than the next freq */
    {
        S16 sDltEn = pSc->sMaxEn - pSc->sNextEn;
        
        if (sDltEn < pCfg->sCleanThr)
            sTestFailed |= CPD_MASK_SINGLE;

        if (sDltEn < (pCfg->sCleanThr>>1))
            sTestFailed |= CPD_MASK_SINGLE_MB;

        if (sDltEn > pCfg->sTwistThr) 
            sTestFailed |= CPD_MASK_TWIST;
    }

    /* test that "Lo" freq is in range */
    {
		if ((pSc->Lo.sEn - pSc->Lo.sDist) < pCfg->sMaxFreqDevThr)
            sTestFailed |= CPD_MASK_LO_OK;
    }

    /* test that "Hi" freq is in range */
    {
		if ((pSc->Hi.sEn - pSc->Hi.sDist) < pCfg->sMaxFreqDevThr)
            sTestFailed |= CPD_MASK_HI_OK;
    }

    pSc->sDigit = (1<<(pSc->sLoIdx)); 
    if (pSc->sTestFailed & CPD_MASK_DUAL)
    {
        pSc->sDigit |= (1<<(pSc->sHiIdx)); 
    }

    /* test that the digit is the same */
    if (pDb->v.sDigit != pSc->sDigit)
        sTestFailed |=  CPD_MASK_SAME_DGT;
    
	pSc->sTestFailed = sTestFailed;
}