rlm@23: #include <stdio.h>
rlm@23: #include <stdlib.h>
rlm@23: #include <math.h>
rlm@23: #include <assert.h>
rlm@23: #include <string.h>
rlm@23: #include "SndfileWavUtil.h"
rlm@23: 
rlm@23: const  int Taps = 9;
rlm@23: const  int Points = 8;
rlm@23: const  int log_Points = 3;
rlm@23: static int newest;
rlm@23: static short int x[Taps] = {0,0,0,0,0,0,0,0,0};
rlm@23: static short int fir(short int);
rlm@23: 
rlm@23: // foreward declaration. This is defined in DFT.cpp
rlm@23: int DFT(int dir,int m,double *x1,double *y1);
rlm@23: 
rlm@23: // lifted from the bluespec code
rlm@23: static double h[Taps] =  {-0.0124,
rlm@23: 			  0.0,
rlm@23: 			  -0.0133,
rlm@23: 			  0.0,
rlm@23: 			  0.8181,
rlm@23: 			  0.0,
rlm@23: 			  -0.0133,
rlm@23: 			  0.0,
rlm@23: 			  -0.0124};
rlm@23: 
rlm@23: int
rlm@23: main (int argc, char * argv [])
rlm@23: {
rlm@23:   const char* inputWavFileName;
rlm@23:   const char* outputWavFileName;
rlm@23: 
rlm@23:   FILE *inputPcmFile;
rlm@23:   FILE *firPcmFile;
rlm@23:   FILE *outputPcmFile;
rlm@23: 
rlm@23:   short int sample;
rlm@23:   short int samples[Points];
rlm@23: 
rlm@23:   inputWavFileName = argv[1];
rlm@23:   outputWavFileName = argv[2];
rlm@23: 
rlm@23:   // Convert input wav to pcm
rlm@23:   generate_pcm(inputWavFileName, "input.pcm");
rlm@23: 
rlm@23:   inputPcmFile  = fopen("input.pcm", "r");
rlm@23:   firPcmFile    = fopen("fir.pcm", "w");
rlm@23: 
rlm@23:   assert(inputPcmFile);
rlm@23:   assert(firPcmFile);
rlm@23: 
rlm@23:   newest = 0;
rlm@23:   memset(x, 0, sizeof(x));
rlm@23: 
rlm@23:   while(fread(&sample, 2, 1, inputPcmFile)) {
rlm@23:     sample = fir(sample);
rlm@23:     assert(fwrite(&sample,2,1,firPcmFile));
rlm@23:   }
rlm@23: 
rlm@23:   fclose(inputPcmFile);
rlm@23:   fclose(firPcmFile);
rlm@23: 
rlm@23:   firPcmFile    = fopen("fir.pcm", "r");
rlm@23:   outputPcmFile = fopen("output.pcm", "w");
rlm@23: 
rlm@23:   assert(firPcmFile);
rlm@23:   assert(outputPcmFile);
rlm@23: 
rlm@23:   // we will do an Points point fft, and then undo it
rlm@23:   while(true) {
rlm@23: 
rlm@23:     int read = fread(samples, 2,Points,firPcmFile);
rlm@23: 
rlm@23:     if(read == 0)
rlm@23:       break;
rlm@23: 
rlm@23:     // pad out the 
rlm@23:     if(read<Points){
rlm@23:       for(int i = read; i < Points; i++)
rlm@23: 	samples[i] = 0;
rlm@23:     }
rlm@23: 
rlm@23:     double dsamples[Points];
rlm@23:     double dimag[Points];
rlm@23: 
rlm@23:     // This shift is performed in the HW
rlm@23:     for(int i = 0; i < Points; i++){
rlm@23:       dsamples[i] = (double)(samples[i]>>log_Points);
rlm@23:       dimag[i] = 0.0;
rlm@23:     }
rlm@23: 
rlm@23:     DFT(1,Points,dsamples,dimag);
rlm@23:     DFT(-1,Points,dsamples,dimag);
rlm@23: 
rlm@23:     for(int i = 0; i < Points; i++){
rlm@23:       samples[i] = (int)dsamples[i];
rlm@23:     }
rlm@23: 
rlm@23:     if(read < Points){
rlm@23:       assert(fwrite(samples,2,read,outputPcmFile)==read);
rlm@23:       break;
rlm@23:     } else {
rlm@23:       assert(fwrite(samples,2,Points,outputPcmFile)==Points);
rlm@23:     }
rlm@23:   }
rlm@23: 
rlm@23:   fclose(firPcmFile);
rlm@23:   fclose(outputPcmFile);
rlm@23: 
rlm@23:   generate_wav("output.pcm", inputWavFileName, outputWavFileName);
rlm@23: 
rlm@23: }
rlm@23: 
rlm@23: short int
rlm@23: fir(short int sample)
rlm@23: {
rlm@23: 
rlm@23:   x[newest] = sample; 
rlm@23:   double y = 0;
rlm@23: 
rlm@23:   for (int k = 0; k < Taps; k++) { 
rlm@23: 
rlm@23:     short int bits = x[(newest+k)%Taps];
rlm@23:     double x = (double)bits;
rlm@23:     y += h[k] * x; 
rlm@23: 
rlm@23:   }
rlm@23: 
rlm@23:   newest = (newest == 0) ? (Taps-1) : (newest-1);
rlm@23: 
rlm@23:   short int rv = ((short int)y)&0x0000FFFF;
rlm@23:   return rv;
rlm@23: }
rlm@23: