Diff: src/Common/Source/math_helper.c

Revision:

0:1014af42efd9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Common/Source/math_helper.c	Thu Mar 10 15:07:50 2011 +0000
@@ -0,0 +1,419 @@
+/* ----------------------------------------------------------------------
+* 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;
+
+  for (i = 0; i < buffSize; i++)
+    {
+      EnergySignal += pRef[i] * pRef[i];
+      EnergyError += (pRef[i] - pTest[i]) * (pRef[i] - pTest[i]); 
+    }
+	
+
+  SNR = 10 * log10 (EnergySignal / EnergyError);
+
+  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;
+	  }
+	       
+    }
+}
+
+
+
+