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#include "ref.h"
void ref_fir_interpolate_f32(
const arm_fir_interpolate_instance_f32 * S,
float32_t * pSrc,
float32_t * pDst,
uint32_t blockSize)
{
float32_t *pState = S->pState; /* State pointer */
float32_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */
float32_t *pStateCurnt; /* Points to the current sample of the state */
float32_t *ptr1, *ptr2; /* Temporary pointers for state and coefficient buffers */
float32_t sum; /* Accumulator */
uint32_t i, blkCnt; /* Loop counters */
uint16_t phaseLen = S->phaseLength, tapCnt; /* Length of each polyphase filter component */
/* S->pState buffer contains previous frame (phaseLen - 1) samples */
/* pStateCurnt points to the location where the new input data should be written */
pStateCurnt = S->pState + phaseLen - 1;
/* Total number of intput samples */
blkCnt = blockSize;
/* Loop over the blockSize. */
while (blkCnt > 0U)
{
/* Copy new input sample into the state buffer */
*pStateCurnt++ = *pSrc++;
/* Loop over the Interpolation factor. */
i = S->L;
while (i > 0U)
{
/* Set accumulator to zero */
sum = 0.0f;
/* Initialize state pointer */
ptr1 = pState;
/* Initialize coefficient pointer */
ptr2 = pCoeffs + i - 1;
/* Loop over the polyPhase length */
tapCnt = phaseLen;
while (tapCnt > 0U)
{
/* Perform the multiply-accumulate */
sum += *ptr1++ * *ptr2;
/* Increment the coefficient pointer by interpolation factor times. */
ptr2 += S->L;
/* Decrement the loop counter */
tapCnt--;
}
/* The result is in the accumulator, store in the destination buffer. */
*pDst++ = sum;
/* Decrement the loop counter */
i--;
}
/* Advance the state pointer by 1
* to process the next group of interpolation factor number samples */
pState = pState + 1;
/* Decrement the loop counter */
blkCnt--;
}
/* Processing is complete.
** Now copy the last phaseLen - 1 samples to the start of the state buffer.
** This prepares the state buffer for the next function call. */
/* Points to the start of the state buffer */
pStateCurnt = S->pState;
tapCnt = phaseLen - 1U;
while (tapCnt > 0U)
{
*pStateCurnt++ = *pState++;
/* Decrement the loop counter */
tapCnt--;
}
}
void ref_fir_interpolate_q31(
const arm_fir_interpolate_instance_q31 * S,
q31_t * pSrc,
q31_t * pDst,
uint32_t blockSize)
{
q31_t *pState = S->pState; /* State pointer */
q31_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */
q31_t *pStateCurnt; /* Points to the current sample of the state */
q31_t *ptr1, *ptr2; /* Temporary pointers for state and coefficient buffers */
/* Run the below code for Cortex-M0 */
q63_t sum; /* Accumulator */
q31_t x0, c0; /* Temporary variables to hold state and coefficient values */
uint32_t i, blkCnt; /* Loop counters */
uint16_t phaseLen = S->phaseLength, tapCnt; /* Length of each polyphase filter component */
/* S->pState buffer contains previous frame (phaseLen - 1) samples */
/* pStateCurnt points to the location where the new input data should be written */
pStateCurnt = S->pState + (q31_t)phaseLen - 1;
/* Total number of intput samples */
blkCnt = blockSize;
/* Loop over the blockSize. */
while (blkCnt > 0U)
{
/* Copy new input sample into the state buffer */
*pStateCurnt++ = *pSrc++;
/* Loop over the Interpolation factor. */
i = S->L;
while (i > 0U)
{
/* Set accumulator to zero */
sum = 0;
/* Initialize state pointer */
ptr1 = pState;
/* Initialize coefficient pointer */
ptr2 = pCoeffs + i - 1;
tapCnt = phaseLen;
while (tapCnt > 0U)
{
/* Read the coefficient */
c0 = *(ptr2);
/* Increment the coefficient pointer by interpolation factor times. */
ptr2 += S->L;
/* Read the input sample */
x0 = *ptr1++;
/* Perform the multiply-accumulate */
sum += (q63_t) x0 *c0;
/* Decrement the loop counter */
tapCnt--;
}
/* The result is in the accumulator, store in the destination buffer. */
*pDst++ = (q31_t)(sum >> 31);
/* Decrement the loop counter */
i--;
}
/* Advance the state pointer by 1
* to process the next group of interpolation factor number samples */
pState = pState + 1;
/* Decrement the loop counter */
blkCnt--;
}
/* Processing is complete.
** Now copy the last phaseLen - 1 samples to the satrt of the state buffer.
** This prepares the state buffer for the next function call. */
/* Points to the start of the state buffer */
pStateCurnt = S->pState;
tapCnt = phaseLen - 1U;
/* copy data */
while (tapCnt > 0U)
{
*pStateCurnt++ = *pState++;
/* Decrement the loop counter */
tapCnt--;
}
}
void ref_fir_interpolate_q15(
const arm_fir_interpolate_instance_q15 * S,
q15_t * pSrc,
q15_t * pDst,
uint32_t blockSize)
{
q15_t *pState = S->pState; /* State pointer */
q15_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */
q15_t *pStateCurnt; /* Points to the current sample of the state */
q15_t *ptr1, *ptr2; /* Temporary pointers for state and coefficient buffers */
q63_t sum; /* Accumulator */
q15_t x0, c0; /* Temporary variables to hold state and coefficient values */
uint32_t i, blkCnt, tapCnt; /* Loop counters */
uint16_t phaseLen = S->phaseLength; /* Length of each polyphase filter component */
/* S->pState buffer contains previous frame (phaseLen - 1) samples */
/* pStateCurnt points to the location where the new input data should be written */
pStateCurnt = S->pState + phaseLen - 1;
/* Total number of intput samples */
blkCnt = blockSize;
/* Loop over the blockSize. */
while (blkCnt > 0U)
{
/* Copy new input sample into the state buffer */
*pStateCurnt++ = *pSrc++;
/* Loop over the Interpolation factor. */
i = S->L;
while (i > 0U)
{
/* Set accumulator to zero */
sum = 0;
/* Initialize state pointer */
ptr1 = pState;
/* Initialize coefficient pointer */
ptr2 = pCoeffs + i - 1;
/* Loop over the polyPhase length */
tapCnt = (uint32_t)phaseLen;
while (tapCnt > 0U)
{
/* Read the coefficient */
c0 = *ptr2;
/* Increment the coefficient pointer by interpolation factor times. */
ptr2 += S->L;
/* Read the input sample */
x0 = *ptr1++;
/* Perform the multiply-accumulate */
sum += (q31_t) x0 * c0;
/* Decrement the loop counter */
tapCnt--;
}
/* Store the result after converting to 1.15 format in the destination buffer */
*pDst++ = ref_sat_q15(sum >> 15);
/* Decrement the loop counter */
i--;
}
/* Advance the state pointer by 1
* to process the next group of interpolation factor number samples */
pState = pState + 1;
/* Decrement the loop counter */
blkCnt--;
}
/* Processing is complete.
** Now copy the last phaseLen - 1 samples to the start of the state buffer.
** This prepares the state buffer for the next function call. */
/* Points to the start of the state buffer */
pStateCurnt = S->pState;
i = (uint32_t) phaseLen - 1U;
while (i > 0U)
{
*pStateCurnt++ = *pState++;
/* Decrement the loop counter */
i--;
}
}
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