/* ----------------------------------------------------------------------
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* Copyright (C) 2010-2012 ARM Limited. All rights reserved.
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*
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* $Date: 17. January 2013
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* $Revision: V1.4.0 b
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*
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* Project: CMSIS DSP Library
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*
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* Title: math_helper.c
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*
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* Description: Definition of all helper functions required.
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*
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* Target Processor: Cortex-M4/Cortex-M3
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* - Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* - Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* - Neither the name of ARM LIMITED nor the names of its contributors
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* may be used to endorse or promote products derived from this
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* software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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* -------------------------------------------------------------------- */
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/* ----------------------------------------------------------------------
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* Include standard header files
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* -------------------------------------------------------------------- */
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#include<math.h>
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/* ----------------------------------------------------------------------
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* Include project header files
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* -------------------------------------------------------------------- */
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#include "math_helper.h"
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/**
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* @brief Caluclation of SNR
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* @param[in] pRef Pointer to the reference buffer
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* @param[in] pTest Pointer to the test buffer
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* @param[in] buffSize total number of samples
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* @return SNR
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* The function Caluclates signal to noise ratio for the reference output
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* and test output
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*/
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float arm_snr_f32(float *pRef, float *pTest, uint32_t buffSize)
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{
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float EnergySignal = 0.0, EnergyError = 0.0;
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uint32_t i;
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float SNR;
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int temp;
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int *test;
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for (i = 0; i < buffSize; i++)
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{
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/* Checking for a NAN value in pRef array */
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test = (int *)(&pRef[i]);
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temp = *test;
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if (temp == 0x7FC00000)
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{
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return(0);
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}
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/* Checking for a NAN value in pTest array */
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test = (int *)(&pTest[i]);
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temp = *test;
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if (temp == 0x7FC00000)
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{
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return(0);
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}
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EnergySignal += pRef[i] * pRef[i];
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EnergyError += (pRef[i] - pTest[i]) * (pRef[i] - pTest[i]);
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}
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/* Checking for a NAN value in EnergyError */
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test = (int *)(&EnergyError);
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temp = *test;
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if (temp == 0x7FC00000)
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{
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return(0);
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}
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SNR = 10 * log10 (EnergySignal / EnergyError);
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return (SNR);
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}
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/**
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* @brief Provide guard bits for Input buffer
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* @param[in,out] input_buf Pointer to input buffer
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* @param[in] blockSize block Size
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* @param[in] guard_bits guard bits
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* @return none
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* The function Provides the guard bits for the buffer
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* to avoid overflow
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*/
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void arm_provide_guard_bits_q15 (q15_t * input_buf, uint32_t blockSize,
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uint32_t guard_bits)
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{
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uint32_t i;
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for (i = 0; i < blockSize; i++)
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{
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input_buf[i] = input_buf[i] >> guard_bits;
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}
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}
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/**
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* @brief Converts float to fixed in q12.20 format
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* @param[in] pIn pointer to input buffer
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* @param[out] pOut pointer to outputbuffer
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* @param[in] numSamples number of samples in the input buffer
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* @return none
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* The function converts floating point values to fixed point(q12.20) values
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*/
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void arm_float_to_q12_20(float *pIn, q31_t * pOut, uint32_t numSamples)
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{
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uint32_t i;
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for (i = 0; i < numSamples; i++)
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{
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/* 1048576.0f corresponds to pow(2, 20) */
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pOut[i] = (q31_t) (pIn[i] * 1048576.0f);
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pOut[i] += pIn[i] > 0 ? 0.5 : -0.5;
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if (pIn[i] == (float) 1.0)
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{
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pOut[i] = 0x000FFFFF;
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}
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}
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}
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/**
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* @brief Compare MATLAB Reference Output and ARM Test output
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* @param[in] pIn Pointer to Ref buffer
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* @param[in] pOut Pointer to Test buffer
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* @param[in] numSamples number of samples in the buffer
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* @return maximum difference
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*/
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uint32_t arm_compare_fixed_q15(q15_t *pIn, q15_t *pOut, uint32_t numSamples)
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{
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uint32_t i;
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int32_t diff, diffCrnt = 0;
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uint32_t maxDiff = 0;
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for (i = 0; i < numSamples; i++)
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{
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diff = pIn[i] - pOut[i];
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diffCrnt = (diff > 0) ? diff : -diff;
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if (diffCrnt > maxDiff)
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{
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maxDiff = diffCrnt;
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}
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}
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return(maxDiff);
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}
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/**
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* @brief Compare MATLAB Reference Output and ARM Test output
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* @param[in] pIn Pointer to Ref buffer
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* @param[in] pOut Pointer to Test buffer
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* @param[in] numSamples number of samples in the buffer
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* @return maximum difference
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*/
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uint32_t arm_compare_fixed_q31(q31_t *pIn, q31_t * pOut, uint32_t numSamples)
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{
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uint32_t i;
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int32_t diff, diffCrnt = 0;
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uint32_t maxDiff = 0;
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for (i = 0; i < numSamples; i++)
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{
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diff = pIn[i] - pOut[i];
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diffCrnt = (diff > 0) ? diff : -diff;
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if (diffCrnt > maxDiff)
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{
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maxDiff = diffCrnt;
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}
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}
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return(maxDiff);
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}
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/**
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* @brief Provide guard bits for Input buffer
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* @param[in,out] input_buf Pointer to input buffer
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* @param[in] blockSize block Size
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* @param[in] guard_bits guard bits
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* @return none
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* The function Provides the guard bits for the buffer
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* to avoid overflow
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*/
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void arm_provide_guard_bits_q31 (q31_t * input_buf,
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uint32_t blockSize,
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uint32_t guard_bits)
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{
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uint32_t i;
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for (i = 0; i < blockSize; i++)
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{
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input_buf[i] = input_buf[i] >> guard_bits;
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}
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}
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/**
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* @brief Provide guard bits for Input buffer
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* @param[in,out] input_buf Pointer to input buffer
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* @param[in] blockSize block Size
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* @param[in] guard_bits guard bits
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* @return none
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* The function Provides the guard bits for the buffer
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* to avoid overflow
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*/
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void arm_provide_guard_bits_q7 (q7_t * input_buf,
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uint32_t blockSize,
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uint32_t guard_bits)
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{
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uint32_t i;
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for (i = 0; i < blockSize; i++)
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{
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input_buf[i] = input_buf[i] >> guard_bits;
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}
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}
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/**
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* @brief Caluclates number of guard bits
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* @param[in] num_adds number of additions
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* @return guard bits
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* The function Caluclates the number of guard bits
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* depending on the numtaps
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*/
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uint32_t arm_calc_guard_bits (uint32_t num_adds)
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{
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uint32_t i = 1, j = 0;
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if (num_adds == 1)
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{
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return (0);
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}
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while (i < num_adds)
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{
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i = i * 2;
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j++;
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}
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return (j);
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}
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/**
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* @brief Apply guard bits to buffer
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* @param[in,out] pIn pointer to input buffer
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* @param[in] numSamples number of samples in the input buffer
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* @param[in] guard_bits guard bits
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* @return none
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*/
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void arm_apply_guard_bits (float32_t *pIn,
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uint32_t numSamples,
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uint32_t guard_bits)
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{
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uint32_t i;
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for (i = 0; i < numSamples; i++)
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{
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pIn[i] = pIn[i] * arm_calc_2pow(guard_bits);
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}
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}
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/**
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* @brief Calculates pow(2, numShifts)
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* @param[in] numShifts number of shifts
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* @return pow(2, numShifts)
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*/
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uint32_t arm_calc_2pow(uint32_t numShifts)
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{
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uint32_t i, val = 1;
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for (i = 0; i < numShifts; i++)
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{
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val = val * 2;
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}
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return(val);
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}
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/**
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* @brief Converts float to fixed q14
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* @param[in] pIn pointer to input buffer
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* @param[out] pOut pointer to output buffer
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* @param[in] numSamples number of samples in the buffer
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* @return none
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* The function converts floating point values to fixed point values
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*/
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void arm_float_to_q14 (float *pIn, q15_t *pOut, uint32_t numSamples)
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{
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uint32_t i;
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for (i = 0; i < numSamples; i++)
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{
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/* 16384.0f corresponds to pow(2, 14) */
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pOut[i] = (q15_t) (pIn[i] * 16384.0f);
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pOut[i] += pIn[i] > 0 ? 0.5 : -0.5;
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if (pIn[i] == (float) 2.0)
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{
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pOut[i] = 0x7FFF;
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}
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}
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}
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/**
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* @brief Converts float to fixed q30 format
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* @param[in] pIn pointer to input buffer
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* @param[out] pOut pointer to output buffer
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* @param[in] numSamples number of samples in the buffer
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* @return none
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* The function converts floating point values to fixed point values
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*/
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void arm_float_to_q30 (float *pIn, q31_t * pOut, uint32_t numSamples)
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{
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uint32_t i;
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for (i = 0; i < numSamples; i++)
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{
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/* 1073741824.0f corresponds to pow(2, 30) */
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pOut[i] = (q31_t) (pIn[i] * 1073741824.0f);
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pOut[i] += pIn[i] > 0 ? 0.5 : -0.5;
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if (pIn[i] == (float) 2.0)
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{
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pOut[i] = 0x7FFFFFFF;
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}
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}
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}
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/**
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* @brief Converts float to fixed q30 format
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* @param[in] pIn pointer to input buffer
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* @param[out] pOut pointer to output buffer
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* @param[in] numSamples number of samples in the buffer
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* @return none
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* The function converts floating point values to fixed point values
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*/
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void arm_float_to_q29 (float *pIn, q31_t *pOut, uint32_t numSamples)
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{
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uint32_t i;
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for (i = 0; i < numSamples; i++)
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{
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/* 1073741824.0f corresponds to pow(2, 30) */
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pOut[i] = (q31_t) (pIn[i] * 536870912.0f);
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pOut[i] += pIn[i] > 0 ? 0.5 : -0.5;
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if (pIn[i] == (float) 4.0)
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{
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pOut[i] = 0x7FFFFFFF;
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}
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}
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}
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/**
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* @brief Converts float to fixed q28 format
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* @param[in] pIn pointer to input buffer
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* @param[out] pOut pointer to output buffer
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* @param[in] numSamples number of samples in the buffer
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* @return none
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* The function converts floating point values to fixed point values
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*/
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void arm_float_to_q28 (float *pIn, q31_t *pOut, uint32_t numSamples)
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{
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uint32_t i;
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for (i = 0; i < numSamples; i++)
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{
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/* 268435456.0f corresponds to pow(2, 28) */
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pOut[i] = (q31_t) (pIn[i] * 268435456.0f);
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pOut[i] += pIn[i] > 0 ? 0.5 : -0.5;
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if (pIn[i] == (float) 8.0)
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{
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pOut[i] = 0x7FFFFFFF;
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}
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}
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}
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/**
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* @brief Clip the float values to +/- 1
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* @param[in,out] pIn input buffer
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* @param[in] numSamples number of samples in the buffer
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* @return none
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* The function converts floating point values to fixed point values
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*/
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void arm_clip_f32 (float *pIn, uint32_t numSamples)
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{
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uint32_t i;
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for (i = 0; i < numSamples; i++)
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{
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if (pIn[i] > 1.0f)
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{
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pIn[i] = 1.0;
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}
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else if ( pIn[i] < -1.0f)
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{
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pIn[i] = -1.0;
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}
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}
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}
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