Rexperiment.c was added accidentally.

git-svn-id: https://svn.xiph.org/trunk/postfish@6599 0101bb08-14d6-0310-b084-bc0e0c8e3800

rexperiment.c

-/*
- *
- *  postfish
- *    
- *      Copyright (C) 2002-2004 Monty and Xiph.Org
- *
- *  Postfish is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2, or (at your option)
- *  any later version.
- *   
- *  Postfish is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *   
- *  You should have received a copy of the GNU General Public License
- *  along with Postfish; see the file COPYING.  If not, write to the
- *  Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- * 
- */
-
-/* arbitrary reconstruction filter.  Postfish uses this for declipping.
-
-   Many thanks to Johnathan Richard Shewchuk and his excellent paper
-   'An Introduction to the Conjugate Gradient Method Without the
-   Agonizing Pain' for the additional understanding needed to make the
-   n^3 -> n^2 log n jump possible. Google for it, you'll find it. */
-
-#include <string.h>
-#include "smallft.h"
-
-static void drft_forward_transpose(drft_lookup *fft, double *x){
-  int i;
-  
-  for(i=1;i<fft->n-1;i++)x[i]*=.5;
-  drft_backward(fft,x);
-}
-
-static void drft_backward_transpose(drft_lookup *fft, double *x){
-  int i;
-  
-  drft_forward(fft,x);
-  for(i=1;i<fft->n-1;i++)x[i]*=2.;
-}
-
-#include "postfish.h"
-#include "test.h"
-
-static void sliding_bark_average(double *f,double *w, int n){
-  int lo=0,hi=0,i;
-  double acc=0.;
-
-  {
-    double bark=toBark(0);
-    int newhi=rint(fromBark(bark+.5)*n/44100.)+5;
-    acc+=fabs(f[0]);
-    for(hi=1;hi<newhi;hi++)acc+=hypot(f[(hi<<1)-1],f[hi<<1]);
-    w[0]=acc/hi;
-  }
-
-  for(i=1;i<n/2;i++){
-    double bark=toBark(44100.*i/n);
-    int newlo=rint(fromBark(bark-.5)*n/44100.)-5;
-    int newhi=rint(fromBark(bark+.5)*n/44100.)+5;
-    if(newhi>n/2)newhi=n/2;
-
-    for(;hi<newhi;hi++)
-      acc+=hypot(f[(hi<<1)-1],f[hi<<1]);
-    for(;lo<newlo;lo++)
-      if(lo==0)
-        acc-=fabs(f[0]);
-      else
-        acc-=hypot(f[(lo<<1)-1],f[lo<<1]);
-
-    w[(i<<1)-1]=w[i<<1]=acc/(hi-lo);
-  }
-  w[n-1]=w[n-2];
-}
-
-void _analysis(char *base,int i,double *v,int n,int bark,int dB){
-  int j;
-  FILE *of;
-  char buffer[80];
-
-  sprintf(buffer,"%s_%d.m",base,i);
-  of=fopen(buffer,"w");
-  
-  if(!of)perror("failed to open data dump file");
-  
-  for(j=0;j<n;j++){
-    if(bark){
-      float b=toBark((4000.f*j/n)+.25);
-      fprintf(of,"%f ",b);
-    }else
-      fprintf(of,"%f ",(double)j);
-    
-    if(dB){
-      if(j==0||j==n-1)
-        fprintf(of,"%f\n",todB(v[j]));
-      else{
-        fprintf(of,"%f\n",todB(hypot(v[j],v[j+1])));
-        j++;
-      }
-    }else{
-      fprintf(of,"%f\n",v[j]);
-    }
-  }
-  fclose(of);
-}
-
-static double inner_product(double *a, double *b, int n){
-  int i;
-  double acc=0.;
-  for(i=0;i<n;i++)acc+=a[i]*b[i];
-  return acc;
-}
-
-static void compute_AtAx(drft_lookup *fft,
-			 double *x,double *w,int *flag,int mask,int n,
-			 double *out){
-  int i;
-
-  if(mask){
-    for(i=0;i<n;i++)
-      if(!flag[i])
-	out[i]=0;
-      else
-	out[i]=x[i];
-  }else
-    for(i=0;i<n;i++)
-      if(flag[i])
-	out[i]=0;
-      else
-	out[i]=x[i];
-  
-  drft_forward(fft,out);
-  for(i=0;i<n;i++)out[i]*=w[i];
-  drft_backward(fft,out);
-
-  for(i=0;i<n;i++)
-    if(!flag[i])out[i]=0;
-  
-}
-
-static void compute_Atb_minus_AtAx(drft_lookup *fft,
-				   double *x,double *w,double *Atb,int *flag,
-				   int n,double *out){
-  int i;
-  compute_AtAx(fft,x,w,flag,1,n,out);
-  for(i=0;i<n;i++)out[i]=Atb[i]-out[i];
-}
-
-void reconstruct(drft_lookup *fft,
-		 double *x, double *w, int *flag, double e,int max,int n){
-  int i,j;
-  double Atb[n];
-  double r[n];
-  double d[n];
-  double q[n];
-  double phi_new,phi_old,phi_0;
-  double alpha,beta;
-
-  /* compute initial Atb */
-  compute_AtAx(fft,x,w,flag,0,n,Atb);
-  for(j=0;j<n;j++)Atb[j]= -Atb[j];
-
-  compute_Atb_minus_AtAx(fft,x,w,Atb,flag,n,r);
-  memcpy(d,r,sizeof(d));
-  phi_0=phi_new=inner_product(r,r,n);
-
-  for(i=0;i<max && phi_new>e*e*phi_0;i++){
-    compute_AtAx(fft,d,w,flag,1,n,q);
-    alpha=phi_new/inner_product(d,q,n);
-    for(j=0;j<n;j++)x[j]+=alpha*d[j];
-
-    _analysis("x",i,x,512,0,0);
-    {
-      double freq[n];
-      memcpy(freq,x,sizeof(freq));
-      drft_forward(fft,freq);
-      _analysis("f",i,freq,512,1,1);
-    }
-
-    if((i & 0x3f)==0x3f)
-      compute_Atb_minus_AtAx(fft,x,w,Atb,flag,n,r);
-    else
-      for(j=0;j<n;j++)r[j]-=alpha*q[j];
-    
-    phi_old=phi_new;
-    phi_new=inner_product(r,r,n);
-    beta=phi_new/phi_old;
-    for(j=0;j<n;j++) d[j]=r[j]+beta*d[j];
-  }
-}
-
-void precondition(drft_lookup *fft,double *x, 
-		  double *w, int *flag, int n,double *out){
-  int i;
-  memcpy(out,x,sizeof(*x)*n);
-  for(i=0;i<n;i++)
-    if(!flag[i])out[i]=0;
-  drft_backward_transpose(fft,out);
-  for(i=0;i<n;i++)out[i]/=w[i]*n;  
-  drft_backward(fft,out);
-  for(i=0;i<n;i++)out[i]/=n;  
-  for(i=0;i<n;i++)
-    if(!flag[i])out[i]=0;
-}
-
-void reconstruct2(drft_lookup *fft,
-		 double *x, double *w, int *flag, double e,int max,int n){
-  int i,j;
-  double Atb[n];
-  double r[n];
-  double s[n];
-  double d[n];
-  double q[n];
-  double phi_new,phi_old,phi_0;
-  double alpha,beta;
-
-  /* compute initial Atb */
-  compute_AtAx(fft,x,w,flag,0,n,Atb);
-  for(j=0;j<n;j++)Atb[j]= -Atb[j];
-
-  compute_Atb_minus_AtAx(fft,x,w,Atb,flag,n,r);
-  precondition(fft,r,w,flag,n,d);
-  phi_0=phi_new=inner_product(r,d,n);
-
-  for(i=0;i<max && phi_new>e*e*phi_0;i++){
-    compute_AtAx(fft,d,w,flag,1,n,q);
-    alpha=phi_new/inner_product(d,q,n);
-    for(j=0;j<n;j++)x[j]+=alpha*d[j];
-
-    _analysis("x1",i,x,512,0,0);
-    {
-      double freq[n];
-      memcpy(freq,x,sizeof(freq));
-      drft_forward(fft,freq);
-      _analysis("f1",i,freq,512,1,1);
-    }
-
-    if((i & 0x3f)==0x3f)
-      compute_Atb_minus_AtAx(fft,x,w,Atb,flag,n,r);
-    else
-      for(j=0;j<n;j++)r[j]-=alpha*q[j];
-    
-    precondition(fft,r,w,flag,n,s);
-    phi_old=phi_new;
-    phi_new=inner_product(r,s,n);
-    beta=phi_new/phi_old;
-    for(j=0;j<n;j++) d[j]=s[j]+beta*d[j];
-  }
-}
-
-int main(){
-  int i,j,k;
-  drft_lookup fft;
-  int blocksize=512;
-  double window[512];
-  double work[512];
-  double freq[blocksize];
-  double w[blocksize];
-  int flag[512];
-
-  drft_init(&fft,512);
-  for(i=0;i<blocksize;i++) window[i]=sin( (double)i/blocksize*M_PIl);
-  for(i=0;i<blocksize;i++) window[i]*=window[i];
-  for(i=0;i<blocksize;i++) window[i]=sin(window[i]*M_PIl*.5);
-
-  memcpy(work,testdata[0],sizeof(work));
-
-  for(i=0;i<blocksize;i++){
-    flag[i]=0;
-    if(work[i]>=.2 || work[i]<=-.2)flag[i]=1;
-  }
-
-  for(i=0;i<512;i++)work[i]*=window[i];
-
-  for(i=0;i<512;i++)_analysis("pcm",i,work,512,0,0);
-  memcpy(freq,work,sizeof(work));
-  drft_forward(&fft,freq);
-  for(i=0;i<512;i++)_analysis("freq",i,freq,512,1,1);
-
-  sliding_bark_average(freq,w,blocksize);
-  _analysis("w",0,w,512,1,1);
-
-  for(i=0;i<512;i++)w[i]= 1./(w[i]*w[i]);
-
-  reconstruct2(&fft,work,w,flag,0,blocksize,blocksize);
-
-}
-
-