/* ----------------------------------------------------------------------
* Copyright (C) 2010-2012 ARM Limited. All rights reserved.
*
* $Date: 17. January 2013
* $Revision: V1.4.0 b
*
* Project: CMSIS DSP Library
*
* Title: math_helper.c
*
* Description: Definition of all helper functions required.
*
* Target Processor: Cortex-M4/Cortex-M3
*
* 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 standard header files
* -------------------------------------------------------------------- */
#include<math.h>
/* ----------------------------------------------------------------------
* Include project header files
* -------------------------------------------------------------------- */
#include "math_helper.h"
/**
* @brief Caluclation of SNR
* @param[in] pRef Pointer to the reference buffer
* @param[in] pTest Pointer to the test buffer
* @param[in] buffSize total number of samples
* @return SNR
* The function Caluclates signal to noise ratio for the reference output
* and test output
*/
float arm_snr_f32(float *pRef, float *pTest, uint32_t buffSize)
{
float EnergySignal = 0.0, EnergyError = 0.0;
uint32_t i;
float SNR;
int temp;
int *test;
for (i = 0; i < buffSize; i++)
{
/* Checking for a NAN value in pRef array */
test = (int *)(&pRef[i]);
temp = *test;
if (temp == 0x7FC00000)
{
return(0);
}
/* Checking for a NAN value in pTest array */
test = (int *)(&pTest[i]);
temp = *test;
if (temp == 0x7FC00000)
{
return(0);
}
EnergySignal += pRef[i] * pRef[i];
EnergyError += (pRef[i] - pTest[i]) * (pRef[i] - pTest[i]);
}
/* Checking for a NAN value in EnergyError */
test = (int *)(&EnergyError);
temp = *test;
if (temp == 0x7FC00000)
{
return(0);
}
SNR = 10 * log10 (EnergySignal / EnergyError);
return (SNR);
}
/**
* @brief Provide guard bits for Input buffer
* @param[in,out] input_buf Pointer to input buffer
* @param[in] blockSize block Size
* @param[in] guard_bits guard bits
* @return none
* The function Provides the guard bits for the buffer
* to avoid overflow
*/
void arm_provide_guard_bits_q15 (q15_t * input_buf, uint32_t blockSize,
uint32_t guard_bits)
{
uint32_t i;
for (i = 0; i < blockSize; i++)
{
input_buf[i] = input_buf[i] >> guard_bits;
}
}
/**
* @brief Converts float to fixed in q12.20 format
* @param[in] pIn pointer to input buffer
* @param[out] pOut pointer to outputbuffer
* @param[in] numSamples number of samples in the input buffer
* @return none
* The function converts floating point values to fixed point(q12.20) values
*/
void arm_float_to_q12_20(float *pIn, q31_t * pOut, uint32_t numSamples)
{
uint32_t i;
for (i = 0; i < numSamples; i++)
{
/* 1048576.0f corresponds to pow(2, 20) */
pOut[i] = (q31_t) (pIn[i] * 1048576.0f);
pOut[i] += pIn[i] > 0 ? 0.5 : -0.5;
if (pIn[i] == (float) 1.0)
{
pOut[i] = 0x000FFFFF;
}
}
}
/**
* @brief Compare MATLAB Reference Output and ARM Test output
* @param[in] pIn Pointer to Ref buffer
* @param[in] pOut Pointer to Test buffer
* @param[in] numSamples number of samples in the buffer
* @return maximum difference
*/
uint32_t arm_compare_fixed_q15(q15_t *pIn, q15_t *pOut, uint32_t numSamples)
{
uint32_t i;
int32_t diff, diffCrnt = 0;
uint32_t maxDiff = 0;
for (i = 0; i < numSamples; i++)
{
diff = pIn[i] - pOut[i];
diffCrnt = (diff > 0) ? diff : -diff;
if (diffCrnt > maxDiff)
{
maxDiff = diffCrnt;
}
}
return(maxDiff);
}
/**
* @brief Compare MATLAB Reference Output and ARM Test output
* @param[in] pIn Pointer to Ref buffer
* @param[in] pOut Pointer to Test buffer
* @param[in] numSamples number of samples in the buffer
* @return maximum difference
*/
uint32_t arm_compare_fixed_q31(q31_t *pIn, q31_t * pOut, uint32_t numSamples)
{
uint32_t i;
int32_t diff, diffCrnt = 0;
uint32_t maxDiff = 0;
for (i = 0; i < numSamples; i++)
{
diff = pIn[i] - pOut[i];
diffCrnt = (diff > 0) ? diff : -diff;
if (diffCrnt > maxDiff)
{
maxDiff = diffCrnt;
}
}
return(maxDiff);
}
/**
* @brief Provide guard bits for Input buffer
* @param[in,out] input_buf Pointer to input buffer
* @param[in] blockSize block Size
* @param[in] guard_bits guard bits
* @return none
* The function Provides the guard bits for the buffer
* to avoid overflow
*/
void arm_provide_guard_bits_q31 (q31_t * input_buf,
uint32_t blockSize,
uint32_t guard_bits)
{
uint32_t i;
for (i = 0; i < blockSize; i++)
{
input_buf[i] = input_buf[i] >> guard_bits;
}
}
/**
* @brief Provide guard bits for Input buffer
* @param[in,out] input_buf Pointer to input buffer
* @param[in] blockSize block Size
* @param[in] guard_bits guard bits
* @return none
* The function Provides the guard bits for the buffer
* to avoid overflow
*/
void arm_provide_guard_bits_q7 (q7_t * input_buf,
uint32_t blockSize,
uint32_t guard_bits)
{
uint32_t i;
for (i = 0; i < blockSize; i++)
{
input_buf[i] = input_buf[i] >> guard_bits;
}
}
/**
* @brief Caluclates number of guard bits
* @param[in] num_adds number of additions
* @return guard bits
* The function Caluclates the number of guard bits
* depending on the numtaps
*/
uint32_t arm_calc_guard_bits (uint32_t num_adds)
{
uint32_t i = 1, j = 0;
if (num_adds == 1)
{
return (0);
}
while (i < num_adds)
{
i = i * 2;
j++;
}
return (j);
}
/**
* @brief Apply guard bits to buffer
* @param[in,out] pIn pointer to input buffer
* @param[in] numSamples number of samples in the input buffer
* @param[in] guard_bits guard bits
* @return none
*/
void arm_apply_guard_bits (float32_t *pIn,
uint32_t numSamples,
uint32_t guard_bits)
{
uint32_t i;
for (i = 0; i < numSamples; i++)
{
pIn[i] = pIn[i] * arm_calc_2pow(guard_bits);
}
}
/**
* @brief Calculates pow(2, numShifts)
* @param[in] numShifts number of shifts
* @return pow(2, numShifts)
*/
uint32_t arm_calc_2pow(uint32_t numShifts)
{
uint32_t i, val = 1;
for (i = 0; i < numShifts; i++)
{
val = val * 2;
}
return(val);
}
/**
* @brief Converts float to fixed q14
* @param[in] pIn pointer to input buffer
* @param[out] pOut pointer to output buffer
* @param[in] numSamples number of samples in the buffer
* @return none
* The function converts floating point values to fixed point values
*/
void arm_float_to_q14 (float *pIn, q15_t *pOut, uint32_t numSamples)
{
uint32_t i;
for (i = 0; i < numSamples; i++)
{
/* 16384.0f corresponds to pow(2, 14) */
pOut[i] = (q15_t) (pIn[i] * 16384.0f);
pOut[i] += pIn[i] > 0 ? 0.5 : -0.5;
if (pIn[i] == (float) 2.0)
{
pOut[i] = 0x7FFF;
}
}
}
/**
* @brief Converts float to fixed q30 format
* @param[in] pIn pointer to input buffer
* @param[out] pOut pointer to output buffer
* @param[in] numSamples number of samples in the buffer
* @return none
* The function converts floating point values to fixed point values
*/
void arm_float_to_q30 (float *pIn, q31_t * pOut, uint32_t numSamples)
{
uint32_t i;
for (i = 0; i < numSamples; i++)
{
/* 1073741824.0f corresponds to pow(2, 30) */
pOut[i] = (q31_t) (pIn[i] * 1073741824.0f);
pOut[i] += pIn[i] > 0 ? 0.5 : -0.5;
if (pIn[i] == (float) 2.0)
{
pOut[i] = 0x7FFFFFFF;
}
}
}
/**
* @brief Converts float to fixed q30 format
* @param[in] pIn pointer to input buffer
* @param[out] pOut pointer to output buffer
* @param[in] numSamples number of samples in the buffer
* @return none
* The function converts floating point values to fixed point values
*/
void arm_float_to_q29 (float *pIn, q31_t *pOut, uint32_t numSamples)
{
uint32_t i;
for (i = 0; i < numSamples; i++)
{
/* 1073741824.0f corresponds to pow(2, 30) */
pOut[i] = (q31_t) (pIn[i] * 536870912.0f);
pOut[i] += pIn[i] > 0 ? 0.5 : -0.5;
if (pIn[i] == (float) 4.0)
{
pOut[i] = 0x7FFFFFFF;
}
}
}
/**
* @brief Converts float to fixed q28 format
* @param[in] pIn pointer to input buffer
* @param[out] pOut pointer to output buffer
* @param[in] numSamples number of samples in the buffer
* @return none
* The function converts floating point values to fixed point values
*/
void arm_float_to_q28 (float *pIn, q31_t *pOut, uint32_t numSamples)
{
uint32_t i;
for (i = 0; i < numSamples; i++)
{
/* 268435456.0f corresponds to pow(2, 28) */
pOut[i] = (q31_t) (pIn[i] * 268435456.0f);
pOut[i] += pIn[i] > 0 ? 0.5 : -0.5;
if (pIn[i] == (float) 8.0)
{
pOut[i] = 0x7FFFFFFF;
}
}
}
/*
Conflicting with the new clip functions in CMSIS-DSP and not used
in the examples.
*/
#if 0
/**
* @brief Clip the float values to +/- 1
* @param[in,out] pIn input buffer
* @param[in] numSamples number of samples in the buffer
* @return none
* The function converts floating point values to fixed point values
*/
void arm_clip_f32 (float *pIn, uint32_t numSamples)
{
uint32_t i;
for (i = 0; i < numSamples; i++)
{
if (pIn[i] > 1.0f)
{
pIn[i] = 1.0;
}
else if ( pIn[i] < -1.0f)
{
pIn[i] = -1.0;
}
}
}
#endif