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Diffstat (limited to 'DSP_Lib/Source/FilteringFunctions/arm_fir_interpolate_f32.c')
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diff --git a/DSP_Lib/Source/FilteringFunctions/arm_fir_interpolate_f32.c b/DSP_Lib/Source/FilteringFunctions/arm_fir_interpolate_f32.c deleted file mode 100644 index 5ad249e..0000000 --- a/DSP_Lib/Source/FilteringFunctions/arm_fir_interpolate_f32.c +++ /dev/null @@ -1,581 +0,0 @@ -/* ---------------------------------------------------------------------- -* Copyright (C) 2010-2014 ARM Limited. All rights reserved. -* -* $Date: 19. March 2015 -* $Revision: V.1.4.5 -* -* Project: CMSIS DSP Library -* Title: arm_fir_interpolate_f32.c -* -* Description: FIR interpolation for floating-point sequences. -* -* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 -* -* Redistribution and use in source and binary forms, with or without -* modification, are permitted provided that the following conditions -* are met: -* - Redistributions of source code must retain the above copyright -* notice, this list of conditions and the following disclaimer. -* - Redistributions in binary form must reproduce the above copyright -* notice, this list of conditions and the following disclaimer in -* the documentation and/or other materials provided with the -* distribution. -* - Neither the name of ARM LIMITED nor the names of its contributors -* may be used to endorse or promote products derived from this -* software without specific prior written permission. -* -* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS -* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE -* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, -* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, -* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; -* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER -* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT -* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN -* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE -* POSSIBILITY OF SUCH DAMAGE. -* -------------------------------------------------------------------- */ - -#include "arm_math.h" - -/** - * @defgroup FIR_Interpolate Finite Impulse Response (FIR) Interpolator - * - * These functions combine an upsampler (zero stuffer) and an FIR filter. - * They are used in multirate systems for increasing the sample rate of a signal without introducing high frequency images. - * Conceptually, the functions are equivalent to the block diagram below: - * \image html FIRInterpolator.gif "Components included in the FIR Interpolator functions" - * After upsampling by a factor of <code>L</code>, the signal should be filtered by a lowpass filter with a normalized - * cutoff frequency of <code>1/L</code> in order to eliminate high frequency copies of the spectrum. - * The user of the function is responsible for providing the filter coefficients. - * - * The FIR interpolator functions provided in the CMSIS DSP Library combine the upsampler and FIR filter in an efficient manner. - * The upsampler inserts <code>L-1</code> zeros between each sample. - * Instead of multiplying by these zero values, the FIR filter is designed to skip them. - * This leads to an efficient implementation without any wasted effort. - * The functions operate on blocks of input and output data. - * <code>pSrc</code> points to an array of <code>blockSize</code> input values and - * <code>pDst</code> points to an array of <code>blockSize*L</code> output values. - * - * The library provides separate functions for Q15, Q31, and floating-point data types. - * - * \par Algorithm: - * The functions use a polyphase filter structure: - * <pre> - * y[n] = b[0] * x[n] + b[L] * x[n-1] + ... + b[L*(phaseLength-1)] * x[n-phaseLength+1] - * y[n+1] = b[1] * x[n] + b[L+1] * x[n-1] + ... + b[L*(phaseLength-1)+1] * x[n-phaseLength+1] - * ... - * y[n+(L-1)] = b[L-1] * x[n] + b[2*L-1] * x[n-1] + ....+ b[L*(phaseLength-1)+(L-1)] * x[n-phaseLength+1] - * </pre> - * This approach is more efficient than straightforward upsample-then-filter algorithms. - * With this method the computation is reduced by a factor of <code>1/L</code> when compared to using a standard FIR filter. - * \par - * <code>pCoeffs</code> points to a coefficient array of size <code>numTaps</code>. - * <code>numTaps</code> must be a multiple of the interpolation factor <code>L</code> and this is checked by the - * initialization functions. - * Internally, the function divides the FIR filter's impulse response into shorter filters of length - * <code>phaseLength=numTaps/L</code>. - * Coefficients are stored in time reversed order. - * \par - * <pre> - * {b[numTaps-1], b[numTaps-2], b[N-2], ..., b[1], b[0]} - * </pre> - * \par - * <code>pState</code> points to a state array of size <code>blockSize + phaseLength - 1</code>. - * Samples in the state buffer are stored in the order: - * \par - * <pre> - * {x[n-phaseLength+1], x[n-phaseLength], x[n-phaseLength-1], x[n-phaseLength-2]....x[0], x[1], ..., x[blockSize-1]} - * </pre> - * The state variables are updated after each block of data is processed, the coefficients are untouched. - * - * \par Instance Structure - * The coefficients and state variables for a filter are stored together in an instance data structure. - * A separate instance structure must be defined for each filter. - * Coefficient arrays may be shared among several instances while state variable array should be allocated separately. - * There are separate instance structure declarations for each of the 3 supported data types. - * - * \par Initialization Functions - * There is also an associated initialization function for each data type. - * The initialization function performs the following operations: - * - Sets the values of the internal structure fields. - * - Zeros out the values in the state buffer. - * - Checks to make sure that the length of the filter is a multiple of the interpolation factor. - * To do this manually without calling the init function, assign the follow subfields of the instance structure: - * L (interpolation factor), pCoeffs, phaseLength (numTaps / L), pState. Also set all of the values in pState to zero. - * - * \par - * Use of the initialization function is optional. - * However, if the initialization function is used, then the instance structure cannot be placed into a const data section. - * To place an instance structure into a const data section, the instance structure must be manually initialized. - * The code below statically initializes each of the 3 different data type filter instance structures - * <pre> - * arm_fir_interpolate_instance_f32 S = {L, phaseLength, pCoeffs, pState}; - * arm_fir_interpolate_instance_q31 S = {L, phaseLength, pCoeffs, pState}; - * arm_fir_interpolate_instance_q15 S = {L, phaseLength, pCoeffs, pState}; - * </pre> - * where <code>L</code> is the interpolation factor; <code>phaseLength=numTaps/L</code> is the - * length of each of the shorter FIR filters used internally, - * <code>pCoeffs</code> is the address of the coefficient buffer; - * <code>pState</code> is the address of the state buffer. - * Be sure to set the values in the state buffer to zeros when doing static initialization. - * - * \par Fixed-Point Behavior - * Care must be taken when using the fixed-point versions of the FIR interpolate filter functions. - * In particular, the overflow and saturation behavior of the accumulator used in each function must be considered. - * Refer to the function specific documentation below for usage guidelines. - */ - -/** - * @addtogroup FIR_Interpolate - * @{ - */ - -/** - * @brief Processing function for the floating-point FIR interpolator. - * @param[in] *S points to an instance of the floating-point FIR interpolator structure. - * @param[in] *pSrc points to the block of input data. - * @param[out] *pDst points to the block of output data. - * @param[in] blockSize number of input samples to process per call. - * @return none. - */ -#ifndef ARM_MATH_CM0_FAMILY - - /* Run the below code for Cortex-M4 and Cortex-M3 */ - -void arm_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 sum0; /* Accumulators */ - float32_t x0, c0; /* Temporary variables to hold state and coefficient values */ - uint32_t i, blkCnt, j; /* Loop counters */ - uint16_t phaseLen = S->phaseLength, tapCnt; /* Length of each polyphase filter component */ - float32_t acc0, acc1, acc2, acc3; - float32_t x1, x2, x3; - uint32_t blkCntN4; - float32_t c1, c2, c3; - - /* 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 - 1u); - - /* Initialise blkCnt */ - blkCnt = blockSize / 4; - blkCntN4 = blockSize - (4 * blkCnt); - - /* Samples loop unrolled by 4 */ - while(blkCnt > 0u) - { - /* Copy new input sample into the state buffer */ - *pStateCurnt++ = *pSrc++; - *pStateCurnt++ = *pSrc++; - *pStateCurnt++ = *pSrc++; - *pStateCurnt++ = *pSrc++; - - /* Address modifier index of coefficient buffer */ - j = 1u; - - /* Loop over the Interpolation factor. */ - i = (S->L); - - while(i > 0u) - { - /* Set accumulator to zero */ - acc0 = 0.0f; - acc1 = 0.0f; - acc2 = 0.0f; - acc3 = 0.0f; - - /* Initialize state pointer */ - ptr1 = pState; - - /* Initialize coefficient pointer */ - ptr2 = pCoeffs + (S->L - j); - - /* Loop over the polyPhase length. Unroll by a factor of 4. - ** Repeat until we've computed numTaps-(4*S->L) coefficients. */ - tapCnt = phaseLen >> 2u; - - x0 = *(ptr1++); - x1 = *(ptr1++); - x2 = *(ptr1++); - - while(tapCnt > 0u) - { - - /* Read the input sample */ - x3 = *(ptr1++); - - /* Read the coefficient */ - c0 = *(ptr2); - - /* Perform the multiply-accumulate */ - acc0 += x0 * c0; - acc1 += x1 * c0; - acc2 += x2 * c0; - acc3 += x3 * c0; - - /* Read the coefficient */ - c1 = *(ptr2 + S->L); - - /* Read the input sample */ - x0 = *(ptr1++); - - /* Perform the multiply-accumulate */ - acc0 += x1 * c1; - acc1 += x2 * c1; - acc2 += x3 * c1; - acc3 += x0 * c1; - - /* Read the coefficient */ - c2 = *(ptr2 + S->L * 2); - - /* Read the input sample */ - x1 = *(ptr1++); - - /* Perform the multiply-accumulate */ - acc0 += x2 * c2; - acc1 += x3 * c2; - acc2 += x0 * c2; - acc3 += x1 * c2; - - /* Read the coefficient */ - c3 = *(ptr2 + S->L * 3); - - /* Read the input sample */ - x2 = *(ptr1++); - - /* Perform the multiply-accumulate */ - acc0 += x3 * c3; - acc1 += x0 * c3; - acc2 += x1 * c3; - acc3 += x2 * c3; - - - /* Upsampling is done by stuffing L-1 zeros between each sample. - * So instead of multiplying zeros with coefficients, - * Increment the coefficient pointer by interpolation factor times. */ - ptr2 += 4 * S->L; - - /* Decrement the loop counter */ - tapCnt--; - } - - /* If the polyPhase length is not a multiple of 4, compute the remaining filter taps */ - tapCnt = phaseLen % 0x4u; - - while(tapCnt > 0u) - { - - /* Read the input sample */ - x3 = *(ptr1++); - - /* Read the coefficient */ - c0 = *(ptr2); - - /* Perform the multiply-accumulate */ - acc0 += x0 * c0; - acc1 += x1 * c0; - acc2 += x2 * c0; - acc3 += x3 * c0; - - /* Increment the coefficient pointer by interpolation factor times. */ - ptr2 += S->L; - - /* update states for next sample processing */ - x0 = x1; - x1 = x2; - x2 = x3; - - /* Decrement the loop counter */ - tapCnt--; - } - - /* The result is in the accumulator, store in the destination buffer. */ - *pDst = acc0; - *(pDst + S->L) = acc1; - *(pDst + 2 * S->L) = acc2; - *(pDst + 3 * S->L) = acc3; - - pDst++; - - /* Increment the address modifier index of coefficient buffer */ - j++; - - /* Decrement the loop counter */ - i--; - } - - /* Advance the state pointer by 1 - * to process the next group of interpolation factor number samples */ - pState = pState + 4; - - pDst += S->L * 3; - - /* Decrement the loop counter */ - blkCnt--; - } - - /* If the blockSize is not a multiple of 4, compute any remaining output samples here. - ** No loop unrolling is used. */ - - while(blkCntN4 > 0u) - { - /* Copy new input sample into the state buffer */ - *pStateCurnt++ = *pSrc++; - - /* Address modifier index of coefficient buffer */ - j = 1u; - - /* Loop over the Interpolation factor. */ - i = S->L; - while(i > 0u) - { - /* Set accumulator to zero */ - sum0 = 0.0f; - - /* Initialize state pointer */ - ptr1 = pState; - - /* Initialize coefficient pointer */ - ptr2 = pCoeffs + (S->L - j); - - /* Loop over the polyPhase length. Unroll by a factor of 4. - ** Repeat until we've computed numTaps-(4*S->L) coefficients. */ - tapCnt = phaseLen >> 2u; - while(tapCnt > 0u) - { - - /* Read the coefficient */ - c0 = *(ptr2); - - /* Upsampling is done by stuffing L-1 zeros between each sample. - * So instead of multiplying zeros with coefficients, - * Increment the coefficient pointer by interpolation factor times. */ - ptr2 += S->L; - - /* Read the input sample */ - x0 = *(ptr1++); - - /* Perform the multiply-accumulate */ - sum0 += x0 * c0; - - /* 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 */ - sum0 += x0 * c0; - - /* 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 */ - sum0 += x0 * c0; - - /* 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 */ - sum0 += x0 * c0; - - /* Decrement the loop counter */ - tapCnt--; - } - - /* If the polyPhase length is not a multiple of 4, compute the remaining filter taps */ - tapCnt = phaseLen % 0x4u; - - while(tapCnt > 0u) - { - /* Perform the multiply-accumulate */ - sum0 += *(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++ = sum0; - - /* Increment the address modifier index of coefficient buffer */ - j++; - - /* 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 */ - blkCntN4--; - } - - /* 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) >> 2u; - - /* copy data */ - while(tapCnt > 0u) - { - *pStateCurnt++ = *pState++; - *pStateCurnt++ = *pState++; - *pStateCurnt++ = *pState++; - *pStateCurnt++ = *pState++; - - /* Decrement the loop counter */ - tapCnt--; - } - - tapCnt = (phaseLen - 1u) % 0x04u; - - /* copy data */ - while(tapCnt > 0u) - { - *pStateCurnt++ = *pState++; - - /* Decrement the loop counter */ - tapCnt--; - } -} - -#else - - /* Run the below code for Cortex-M0 */ - -void arm_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 - 1u); - - /* 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 - 1u); - - /* 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--; - } - -} - -#endif /* #ifndef ARM_MATH_CM0_FAMILY */ - - - - /** - * @} end of FIR_Interpolate group - */ |