floatingpointblockfirtest.c

CHP 4 - Real-Time Digital Signal Processing: Implementations and Applications, Second Edition by Sen

// 
//  Project: Example 4.19: floating-point implementation of block FIR filter - Chapter 4
//  File name: floatingPointFirTest.c   
//
//  Description: This is the test file for the example of floating-point block FIR filter
//               The input data is a white noise.
//               The output data is the filtered white noise.
//               The spectrum of the output data shows the filter response.
//               The spectrum shows it is a bandpass filter.
//
//  For the book "Real Time Digital Signal Processing: 
//                Implementation and Application, 2nd Ed"
//                By Sen M. Kuo, Bob H. Lee, and Wenshun Tian
//                Publisher: John Wiley and Sons, Ltd
//

#include <stdlib.h>
#include <stdio.h>

#include "floatingPointFir.h"

float firCoefFloatingPoint[NUM_TAPS]={
  #include "firCoef.h"
};

float w[NUM_TAPS];
float x[NUM_DATA],  // input data
      y[NUM_DATA];  // output data

void main()
{
  FILE  *fpIn,*fpOut;
  short i,temp[NUM_DATA],
        index;        // delay line index

  fpIn = fopen("..\\data\\input.pcm", "rb");
  fpOut = fopen("..\\data\\output.pcm", "wb");

  if (fpIn == NULL)
  {
    printf("Can't open input file\n");
    exit(0);
  }
    
  // Initialize for filtering process
  for (i=0; i<NUM_TAPS; i++)
  {
    w[i] = 0.0;
  }
  index = 0;

  // Begin filtering the data
  while (fread(temp, sizeof(short), NUM_DATA, fpIn) == NUM_DATA)
  {
    for (i=0; i<NUM_DATA; i++)
    {
      x[i] = (float)temp[i];
    }
    // Filter the data x and save output y
    floatPointBlockFir(x, NUM_DATA, 
                       firCoefFloatingPoint, NUM_TAPS, 
                       y, 
                       w, &index);

    for (i=0; i<NUM_DATA; i++)
    {
      temp[i] = (short)y[i];
    }

    fwrite(temp, sizeof(short), NUM_DATA, fpOut);
  }

  fclose(fpIn);
  fclose(fpOut);
}