Fix to bug #1229

svn path=/trunk/vorbis/; revision=13657

diff --git a/lib/block.c b/lib/block.c
index 4cb8e52..50ab425 100644 (file)
--- a/lib/block.c
+++ b/lib/block.c
@@ -403,7 +403,7 @@ float **vorbis_analysis_buffer(vorbis_dsp_state *v, int vals){
 
 static void _preextrapolate_helper(vorbis_dsp_state *v){
   int i;
-  int order=32;
+  int order=16;
   float *lpc=alloca(order*sizeof(*lpc));
   float *work=alloca(v->pcm_current*sizeof(*work));
   long j;
@@ -417,7 +417,18 @@ static void _preextrapolate_helper(vorbis_dsp_state *v){
       
       /* prime as above */
       vorbis_lpc_from_data(work,lpc,v->pcm_current-v->centerW,order);
-      
+
+#if 0
+      if(v->vi->channels==2){
+       if(i==0)
+         _analysis_output("predataL",0,work,v->pcm_current-v->centerW,0,0,0);
+       else
+         _analysis_output("predataR",0,work,v->pcm_current-v->centerW,0,0,0);
+      }else{
+       _analysis_output("predata",0,work,v->pcm_current-v->centerW,0,0,0);
+      }
+#endif 
+ 
       /* run the predictor filter */
       vorbis_lpc_predict(lpc,work+v->pcm_current-v->centerW-order,
                         order,

diff --git a/lib/lpc.c b/lib/lpc.c
index 0215cc5..b3c0998 100644 (file)
--- a/lib/lpc.c
+++ b/lib/lpc.c
@@ -62,6 +62,7 @@ float vorbis_lpc_from_data(float *data,float *lpci,int n,int m){
   double *aut=alloca(sizeof(*aut)*(m+1));
   double *lpc=alloca(sizeof(*lpc)*(m));
   double error;
+  double epsilon;
   int i,j;
 
   /* autocorrelation, p+1 lag coefficients */
@@ -74,14 +75,16 @@ float vorbis_lpc_from_data(float *data,float *lpci,int n,int m){
   
   /* Generate lpc coefficients from autocorr values */
 
-  error=aut[0];
-  
+  /* set our noise floor to about -100dB */
+  error=aut[0] * (1. + 1e-10);
+  epsilon=1e-9*aut[0]+1e-10;
+
   for(i=0;i<m;i++){
     double r= -aut[i+1];
 
-    if(error==0){
-      memset(lpci,0,m*sizeof(*lpci));
-      return 0;
+    if(error<epsilon){
+      memset(lpc+i,0,(m-i)*sizeof(*lpc));
+      goto done;
     }
 
     /* Sum up this iteration's reflection coefficient; note that in
@@ -101,9 +104,22 @@ float vorbis_lpc_from_data(float *data,float *lpci,int n,int m){
       lpc[j]+=r*lpc[i-1-j];
       lpc[i-1-j]+=r*tmp;
     }
-    if(i%2)lpc[j]+=lpc[j]*r;
+    if(i&1)lpc[j]+=lpc[j]*r;
+
+    error*=1.-r*r;
 
-    error*=1.f-r*r;
+  }
+
+ done:
+   
+  /* slightly damp the filter */ 
+  {
+    double g = .99;
+    double damp = g;
+    for(j=0;j<m;j++){
+      lpc[j]*=damp;
+      damp*=g;
+    }
   }
 
   for(j=0;j<m;j++)lpci[j]=(float)lpc[j];

diff --git a/lib/mapping0.c b/lib/mapping0.c
index 63afa75..912b754 100644 (file)
--- a/lib/mapping0.c
+++ b/lib/mapping0.c
@@ -280,22 +280,28 @@ static int mapping0_forward(vorbis_block *vb){
                                      next major model upgrade. */
 
 #if 0
-    if(vi->channels==2)
+    if(vi->channels==2){
       if(i==0)
        _analysis_output("pcmL",seq,pcm,n,0,0,total-n/2);
       else
        _analysis_output("pcmR",seq,pcm,n,0,0,total-n/2);
+    }else{
+      _analysis_output("pcm",seq,pcm,n,0,0,total-n/2);
+    }
 #endif
   
     /* window the PCM data */
     _vorbis_apply_window(pcm,b->window,ci->blocksizes,vb->lW,vb->W,vb->nW);
 
 #if 0
-    if(vi->channels==2)
+    if(vi->channels==2){
       if(i==0)
        _analysis_output("windowedL",seq,pcm,n,0,0,total-n/2);
       else
        _analysis_output("windowedR",seq,pcm,n,0,0,total-n/2);
+    }else{
+      _analysis_output("windowed",seq,pcm,n,0,0,total-n/2);
+    }
 #endif
 
     /* transform the PCM data */
@@ -349,6 +355,8 @@ static int mapping0_forward(vorbis_block *vb){
       }else{
        _analysis_output("fftR",seq,logfft,n/2,1,0,0);
       }
+    }else{
+      _analysis_output("fft",seq,logfft,n/2,1,0,0);
     }
 #endif
 
@@ -419,6 +427,8 @@ static int mapping0_forward(vorbis_block *vb){
          _analysis_output("noiseL",seq,noise,n/2,1,0,0);
        else
          _analysis_output("noiseR",seq,noise,n/2,1,0,0);
+      }else{
+       _analysis_output("noise",seq,noise,n/2,1,0,0);
       }
 #endif
 
@@ -438,6 +448,8 @@ static int mapping0_forward(vorbis_block *vb){
          _analysis_output("toneL",seq,tone,n/2,1,0,0);
        else
          _analysis_output("toneR",seq,tone,n/2,1,0,0);
+      }else{
+       _analysis_output("tone",seq,tone,n/2,1,0,0);
       }
 #endif
 
@@ -465,6 +477,8 @@ static int mapping0_forward(vorbis_block *vb){
            _analysis_output("aotuvM1_L",seq,aotuv,psy_look->n,1,1,0);
          else
            _analysis_output("aotuvM1_R",seq,aotuv,psy_look->n,1,1,0);
+       }else{
+         _analysis_output("aotuvM1",seq,aotuv,psy_look->n,1,1,0);
        }
       }
 #endif
@@ -476,6 +490,8 @@ static int mapping0_forward(vorbis_block *vb){
          _analysis_output("mask1L",seq,logmask,n/2,1,0,0);
        else
          _analysis_output("mask1R",seq,logmask,n/2,1,0,0);
+      }else{
+       _analysis_output("mask1",seq,logmask,n/2,1,0,0);
       }
 #endif
 
@@ -508,6 +524,8 @@ static int mapping0_forward(vorbis_block *vb){
            _analysis_output("mask2L",seq,logmask,n/2,1,0,0);
          else
            _analysis_output("mask2R",seq,logmask,n/2,1,0,0);
+       }else{
+         _analysis_output("mask2",seq,logmask,n/2,1,0,0);
        }
 #endif
        
@@ -526,11 +544,14 @@ static int mapping0_forward(vorbis_block *vb){
                           logmdct);
 
 #if 0
-       if(vi->channels==2)
+       if(vi->channels==2){
          if(i==0)
            _analysis_output("mask0L",seq,logmask,n/2,1,0,0);
          else
            _analysis_output("mask0R",seq,logmask,n/2,1,0,0);
+       }else{
+         _analysis_output("mask0",seq,logmask,n/2,1,0,0);
+       }
 #endif
 
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