/* ----------------------------------------------------------------------
* Copyright (C) 2010 ARM Limited. All rights reserved.
*
* $Date: 29. November 2010
* $Revision: V1.0.3
*
* Project: CMSIS DSP Library
*
* Title: math_helper.c
*
* Description: Definition of all helper functions required.
*
* Target Processor: Cortex-M4/Cortex-M3
*
* Version 1.0.3 2010/11/29
* Re-organized the CMSIS folders and updated documentation.
*
* Version 1.0.2 2010/11/11
* Documentation updated.
*
* Version 1.0.1 2010/10/05
* Production release and review comments incorporated.
*
* Version 1.0.0 2010/09/20
* Production release and review comments incorporated.
*
* Version 0.0.7 2010/06/10
* Misra-C changes done
* -------------------------------------------------------------------- */
/* ----------------------------------------------------------------------
* Include standard header files
* -------------------------------------------------------------------- */
#include<math.h>
/* ----------------------------------------------------------------------
* Include project header files
* -------------------------------------------------------------------- */
#include "math_helper.h"
/**
* @brief Caluclation of SNR
* @param float* Pointer to the reference buffer
* @param float* Pointer to the test buffer
* @param uint32_t total number of samples
* @return float 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(100000.0);
}
/* Checking for a NAN value in pTest array */
test = (int *)(&pTest[i]);
temp = *test;
if (temp == 0x7FC00000)
{
return(100000.0);
}
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(100000.0);
}
SNR = 10 * log10f (EnergySignal / EnergyError);
/* Checking for a NAN value in SNR */
test = (int *)(&SNR);
temp = *test;
if (temp == 0x7FC00000)
{
return(100000.0);
}
return (SNR);
}
double arm_snr_f64(double *pRef, double *pTest, uint32_t buffSize)
{
double EnergySignal = 0.0, EnergyError = 0.0;
uint32_t i;
double 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(100000.0);
}
/* Checking for a NAN value in pTest array */
test = (int *)(&pTest[i]);
temp = *test;
if (temp == 0x7FC00000)
{
return(100000.0);
}
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(100000.0);
}
SNR = 10 * log10 (EnergySignal / EnergyError);
/* Checking for a NAN value in SNR */
test = (int *)(&SNR);
temp = *test;
if (temp == 0x7FC00000)
{
return(10000.0);
}
return (SNR);
}
/**
* @brief Provide guard bits for Input buffer
* @param q15_t* Pointer to input buffer
* @param uint32_t blockSize
* @param uint32_t 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 uint32_t number of samples in the 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 q15_t* Pointer to Ref buffer
* @param q15_t* Pointer to Test buffer
* @param uint32_t number of samples in the buffer
* @return none
*/
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 q31_t* Pointer to Ref buffer
* @param q31_t* Pointer to Test buffer
* @param uint32_t number of samples in the buffer
* @return none
*/
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 q31_t* Pointer to input buffer
* @param uint32_t blockSize
* @param uint32_t 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 q31_t* Pointer to input buffer
* @param uint32_t blockSize
* @param uint32_t 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 uint32_t number of additions
* @return none
* 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 Converts Q15 to floating-point
* @param uint32_t number of samples in the buffer
* @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 uint32_t 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 uint32_t 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 uint32_t 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 uint32_t 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 uint32_t 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;
}
}
}
/**
* @brief Clip the float values to +/- 1
* @param pIn input buffer
* @param 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;
}
}
}
