enhancer.cxx

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           odata[i]=C*surround[i]; 
           err=psseq[i]-odata[i]; 
           errs+=err*err; 
       } 
        
       /* if constraint violated by first try, add constraint */  
        
       if( errs > alpha0 * w00){ 
           if( w00 < 1) { 
               w00=1; 
           } 
           denom = (w11*w00-w10*w10)/(w00*w00); 
            
           if( denom > 0.0001){ /* eliminates numerical problems  
                                   for if smooth */ 
               A = (float)sqrt( (alpha0- alpha0*alpha0/4)/denom); 
               B = -alpha0/2 - A * w10/w00; 
               B = B+1; 
           } 
           else{ /* essentially no difference between cycles;  
                    smoothing not needed */ 
               A= 0.0; 
               B= 1.0; 
           } 
            
           /* create smoothed sequence */ 
    
           psseq=sseq+hl*ENH_BLOCKL; 
           for(i=0;i<ENH_BLOCKL;i++) { 
               odata[i]=A*surround[i]+B*psseq[i]; 
           } 
       } 
   } 
    
   /*----------------------------------------------------------------* 
    * get the pitch-synchronous sample sequence 
    *---------------------------------------------------------------*/ 
    
   void getsseq( 
       float *sseq,    /* (o) the pitch-synchronous sequence */ 
       float *idata,       /* (i) original data */ 
       int idatal,         /* (i) dimension of data */ 
       int centerStartPos, /* (i) where current block starts */ 
       float *period,      /* (i) rough-pitch-period array */ 
       float *plocs,       /* (i) where periods of period array  
                                  are taken */ 
       int periodl,    /* (i) dimension period array */ 
       int hl              /* (i)( 2*hl+1 is the number of sequences */ 
   ){ 
       int i,centerEndPos,q; 
       float blockStartPos[2*ENH_HL+1]; 
     
       int lagBlock[2*ENH_HL+1]; 
       float plocs2[ENH_PLOCSL];  
       float *psseq; 
    
       centerEndPos=centerStartPos+ENH_BLOCKL-1; 
        
       /* present */ 
    
       NearestNeighbor(lagBlock+hl,plocs, 
           (float)0.5*(centerStartPos+centerEndPos),periodl); 
        
       blockStartPos[hl]=(float)centerStartPos; 
       psseq=sseq+ENH_BLOCKL*hl; 
       memcpy(psseq, idata+centerStartPos, ENH_BLOCKL*sizeof(float)); 
        
       /* past */ 
    
       for(q=hl-1;q>=0;q--) { 
           blockStartPos[q]=blockStartPos[q+1]-period[lagBlock[q+1]]; 
           NearestNeighbor(lagBlock+q,plocs, 
               blockStartPos[q]+ENH_BLOCKL_HALF-period[lagBlock[q+1]], 
               periodl); 
                                
            
           if(blockStartPos[q]-ENH_OVERHANG>=0) { 
               refiner(sseq+q*ENH_BLOCKL,blockStartPos+q,idata,idatal, 
                   centerStartPos,blockStartPos[q], 
                   period[lagBlock[q+1]]); 
           } else { 
    
               psseq=sseq+q*ENH_BLOCKL; 
               memset(psseq, 0, ENH_BLOCKL*sizeof(float)); 
           } 
       } 
        
       /* future */ 
    
       for(i=0;i<periodl;i++) { 
           plocs2[i]=plocs[i]-period[i]; 
       } 
       for(q=hl+1;q<=2*hl;q++) {  
           NearestNeighbor(lagBlock+q,plocs2, 
               blockStartPos[q-1]+ENH_BLOCKL_HALF,periodl); 
    
           blockStartPos[q]=blockStartPos[q-1]+period[lagBlock[q]]; 
           if( blockStartPos[q]+ENH_BLOCKL+ENH_OVERHANG<idatal) { 
    
               refiner(sseq+ENH_BLOCKL*q,blockStartPos+q,idata,idatal, 
                   centerStartPos,blockStartPos[q],period[lagBlock[q]]); 
                
           } 
           else { 
               psseq=sseq+q*ENH_BLOCKL; 
     
               memset(psseq, 0, ENH_BLOCKL*sizeof(float)); 
           } 
       } 
   } 
    
   /*----------------------------------------------------------------* 
    * perform enhancement on idata+centerStartPos through  
    * idata+centerStartPos+ENH_BLOCKL-1 
    *---------------------------------------------------------------*/ 
    
   void enhancer( 
       float *odata,       /* (o) smoothed block, dimension blockl */ 
       float *idata,       /* (i) data buffer used for enhancing */ 
       int idatal,         /* (i) dimension idata */ 
       int centerStartPos, /* (i) first sample current block  
                                  within idata */ 
       float alpha0,       /* (i) max correction-energy-fraction  
                                 (in [0,1]) */ 
       float *period,      /* (i) pitch period array */ 
       float *plocs,       /* (i) locations where period array  
                                  values valid */ 
       int periodl         /* (i) dimension of period and plocs */ 
   ){ 
       float sseq[(2*ENH_HL+1)*ENH_BLOCKL]; 
    
       /* get said second sequence of segments */ 
    
       getsseq(sseq,idata,idatal,centerStartPos,period, 
           plocs,periodl,ENH_HL); 
    
       /* compute the smoothed output from said second sequence */ 
    
       smath(odata,sseq,ENH_HL,alpha0); 
    
   } 
    
   /*----------------------------------------------------------------* 
    * cross correlation 
    *---------------------------------------------------------------*/ 
    
   float xCorrCoef(  
       float *target,      /* (i) first array */ 
       float *regressor,   /* (i) second array */ 
       int subl        /* (i) dimension arrays */ 
   ){ 
       int i; 
       float ftmp1, ftmp2; 
            
       ftmp1 = 0.0; 
       ftmp2 = 0.0; 
       for (i=0; i<subl; i++) { 
           ftmp1 += target[i]*regressor[i]; 
           ftmp2 += regressor[i]*regressor[i];  
     
       } 
        
       if (ftmp1 > 0.0) { 
           return (float)(ftmp1*ftmp1/ftmp2); 
       } 
       else { 
           return (float)0.0; 
       } 
   } 
    
   /*----------------------------------------------------------------* 
    * interface for enhancer 
    *---------------------------------------------------------------*/ 
    
   int enhancerInterface( 
       float *out,                     /* (o) enhanced signal */ 
       float *in,                      /* (i) unenhanced signal */ 
       iLBC_Dec_Inst_t *iLBCdec_inst   /* (i) buffers etc */ 
   ){ 
       float *enh_buf, *enh_period; 
       int iblock, isample; 
       int lag, ilag, i; 
       float cc, maxcc; 
       float ftmp1, ftmp2, gain; 
       float *inPtr, *enh_bufPtr1, *enh_bufPtr2; 
    
       float lpState[6], downsampled[(ENH_NBLOCKS*ENH_BLOCKL+120)/2]; 
       int inLen=ENH_NBLOCKS*ENH_BLOCKL+120; 
       int start; 
    
       enh_buf=iLBCdec_inst->enh_buf; 
       enh_period=iLBCdec_inst->enh_period; 
        
        
       memmove(enh_buf, &enh_buf[ENH_NBLOCKS*ENH_BLOCKL],  
           (ENH_NBLOCKS_EXTRA*ENH_BLOCKL)*sizeof(float)); 
                                                                
       memcpy(&enh_buf[ENH_NBLOCKS_EXTRA*ENH_BLOCKL], in,  
           (ENH_NBLOCKS*ENH_BLOCKL)*sizeof(float)); 
    
       if (iLBCdec_inst->prev_enh_pl==1) { 
           /* PLC was performed on the previous packet */ 
    
           lag = 20; 
           maxcc = xCorrCoef(in, in+lag, ENH_BLOCKL); 
           for (ilag=21; ilag<120; ilag++) { 
               cc = xCorrCoef(in, in+ilag, ENH_BLOCKL); 
                
               if (cc > maxcc) { 
                   maxcc = cc; 
                   lag = ilag; 
               } 
           } 
     
    
           ftmp1 = 0.0; 
           ftmp2 = 0.0; 
           for (i=0; i<ENH_BLOCKL; i++) { 
               ftmp1 += in[i]*in[i+lag]; 
               ftmp2 += in[i+lag]*in[i+lag]; 
           } 
            
           if (ftmp1 > 0.0) { 
               gain=(float)(ftmp1/ftmp2); 
           } 
           else { 
               gain=(float)0.0; 
           } 
           if (gain>1.0) { 
               gain=1.0; 
           } else if (gain<-1.0) { 
               gain=-1.0; 
           } 
    
           inPtr=&in[lag-1]; 
            
           enh_bufPtr1=&enh_buf[ENH_NBLOCKS_EXTRA*ENH_BLOCKL-1]; 
            
           if (lag>ENH_BLOCKL) { 
               start=ENH_BLOCKL; 
           } else { 
               start=lag; 
           } 
    
           for (isample = start; isample>0; isample--) { 
               *enh_bufPtr1-- = gain*(*inPtr--); 
           } 
            
           enh_bufPtr2=&enh_buf[ENH_NBLOCKS_EXTRA*ENH_BLOCKL-1]; 
           for (isample = (ENH_BLOCKL-1-lag); isample>=0; isample--) { 
               *enh_bufPtr1-- = gain*(*enh_bufPtr2--); 
           } 
    
       } 
    
       memmove(enh_period, &enh_period[ENH_NBLOCKS],  
           ENH_NBLOCKS_EXTRA*sizeof(float)); 
    
    
       /* Set state information to the 6 samples right before  
          the samples to be downsampled. */ 
    
       memcpy(lpState, enh_buf+ENH_NBLOCKS_EXTRA*ENH_BLOCKL-126,  
           6*sizeof(float)); 
    
       /* Down sample a factor 2 to save computations */ 
    
     
       DownSample(enh_buf+ENH_NBLOCKS_EXTRA*ENH_BLOCKL-120, 
                   lpFilt_coefsTbl, inLen, 
                   lpState, downsampled); 
    
       /* Estimate the pitch in the down sampled domain. */ 
       for(iblock = 0; iblock<ENH_NBLOCKS; iblock++){ 
            
           lag = 10; 
           maxcc = xCorrCoef(downsampled+60+iblock* 
               ENH_BLOCKL_HALF, downsampled+60+iblock* 
               ENH_BLOCKL_HALF-lag, ENH_BLOCKL_HALF); 
           for (ilag=11; ilag<60; ilag++) { 
               cc = xCorrCoef(downsampled+60+iblock* 
                   ENH_BLOCKL_HALF, downsampled+60+iblock* 
                   ENH_BLOCKL_HALF-ilag, ENH_BLOCKL_HALF); 
                
               if (cc > maxcc) { 
                   maxcc = cc; 
                   lag = ilag; 
               } 
           } 
    
           /* Store the estimated lag in the non-downsampled domain */ 
           enh_period[iblock+ENH_NBLOCKS_EXTRA] = (float)lag*2; 
       }    
    
       for(iblock = 0; iblock<2; iblock++){ 
            
           enhancer(out+iblock*ENH_BLOCKL, enh_buf,  
               ENH_BUFL, (5+iblock)*ENH_BLOCKL+40, 
               ENH_ALPHA0, enh_period, enh_plocsTbl,  
                   ENH_NBLOCKS_TOT); 
            
       } 
       return (lag*2); 
   }