bl_mcu_sdk/examples/dsp/BasicMathFunctions_part2/scale.c

#include "ref.h"

void ref_scale_f32(float32_t *pSrc, float32_t scale, float32_t *pDst,
                   uint32_t blockSize)
{
    uint32_t i;

    for (i = 0; i < blockSize; i++) {
        pDst[i] = pSrc[i] * scale;
    }
}

void ref_scale_q31(q31_t *pSrc, q31_t scaleFract, int8_t shift, q31_t *pDst,
                   uint32_t blockSize)
{
    uint32_t i;
    int8_t kShift = shift + 1; /* Shift to apply after scaling */
    int8_t sign = (kShift & 0x80);
    q63_t temp;

    for (i = 0; i < blockSize; i++) {
        temp = ((q63_t)pSrc[i] * scaleFract) >> 32;
        if (sign)
            pDst[i] = temp >> -kShift;
        else
            pDst[i] = ref_sat_q31((q63_t)temp << kShift);
    }
}

void ref_scale_q15(q15_t *pSrc, q15_t scaleFract, int8_t shift, q15_t *pDst,
                   uint32_t blockSize)
{
    uint32_t i;
    int8_t kShift = 15 - shift; /* Shift to apply after scaling */

    for (i = 0; i < blockSize; i++) {
        pDst[i] = ref_sat_q15(((q31_t)pSrc[i] * scaleFract) >> kShift);
    }
}

void ref_scale_q7(q7_t *pSrc, q7_t scaleFract, int8_t shift, q7_t *pDst,
                  uint32_t blockSize)
{
    uint32_t i;
    int8_t kShift = 7 - shift; /* Shift to apply after scaling */

    for (i = 0; i < blockSize; i++) {
        pDst[i] = ref_sat_q7(((q15_t)pSrc[i] * scaleFract) >> kShift);
    }
}