vol_ti_ivol.c

来自「DSP体系结构实现与应用源代码」· C语言 代码 · 共 89 行

/*
 *  Copyright 2003 by Texas Instruments Incorporated.
 *  All rights reserved. Property of Texas Instruments Incorporated.
 *  Restricted rights to use, duplicate or disclose this code are
 *  granted through contract.
 *  
 */
/* "@(#) ReferenceFrameworks 2.20.00.08 07-18-03 (swat-f02)" */
/*
 *  ======== vol_ti_ivol.c ========
 *  VOL Module - TI implementation of a VOL algorithm
 *
 *  This file contains the implementation of the IVOL abstract interface. 
 */

#include <std.h>
#include <string.h>
#include <xdas.h>
#include <intrindefs.h>

#include "ivol.h"
#include "vol_ti_priv.h"

/* data procesing part - scale buffer by gainPercentage */
static Void scale(XDAS_Int16 *buf, Int nWords, Int gainPercentage);

/*
 *  ======== VOL_TI_amplify ========
 */
Void VOL_TI_amplify(IVOL_Handle handle, XDAS_Int16 *in, XDAS_Int16 *out)
{
    VOL_TI_Obj *vol = (VOL_TI_Obj *)handle;
    
    /* Use memcpy to copy input buffer into scaling buffer */
    memcpy((void *)(vol->scaleBuf),(void *)in,(Uns)((vol->frameLen) * sizeof(XDAS_Int16)));

    /* we process the scaling buffer */      
    scale(vol->scaleBuf, vol->frameLen, vol->gainPercentage);
    
    /* done with processing the scaling buffer, now copy it to out */
    memcpy((void *)(out),(void *)(vol->scaleBuf), (Uns)((vol->frameLen) * sizeof(XDAS_Int16)));
}

/*
 *  ======== VOL_TI_control ========
 */
Int VOL_TI_control(IVOL_Handle handle, IVOL_Cmd cmd, IVOL_Status *status)
{
    VOL_TI_Obj *vol = (VOL_TI_Obj *)handle;

    switch (cmd) {
        case IVOL_GETSTATUS:
            status->gainPercentage = vol->gainPercentage;
            break;
        case IVOL_SETSTATUS:
            vol->gainPercentage = status->gainPercentage;
            break;
        default:
            return IALG_EFAIL;
    }

    return ((Int )IALG_EOK);
}

/*
 *  ======== scale ========
 */
static Void scale(XDAS_Int16 *buf, Int nWords, Int gainPercentage)
{
    XDAS_Int16 i;
    XDAS_Int16 gain[26] = {	0, 2058,  2309,  2591,  2907,  3261,
    						3659,  4106,  4607,  5169,  5799,
    						6507,  7301,  8192,  9192,  10313,
    						11572, 12983, 14568, 16345, 18340,
    						20577, 23088, 25905, 29066, 32613
    					   };
    XDAS_Int32 temp;
    
    for (i = 0; i < nWords; i++)
    {
        //buf[i] = _rnd(_lsshl((_lsmpy((XDAS_Int32)buf[i], gain[gainPercentage])), 2));
        temp = _lsmpy(buf[i], gain[gainPercentage]);
        buf[i] = _rnd(_lsshl(temp, 2));
    }
    
    
}