ilbc_encode.cxx

MiniSip Client with DomainKeys Authentication, Sip, Audio communications, Echo Cancel

//A.3 iLBC_encode.c 
    
   /****************************************************************** 
    
       iLBC Speech Coder ANSI-C Source Code 
    
       iLBC_encode.c  
    
       Copyright (c) 2001, 
       Global IP Sound AB. 
       All rights reserved. 
    
   ******************************************************************/ 
    
   #include <math.h> 
   #include <string.h>
    
#include"iLBC_define.h"
#include"LPCencode.h"
#include"FrameClassify.h"
#include"StateSearchW.h"
#include"StateConstructW.h"
#include"helpfun.h"
#include"constants.h"
#include"packing.h"
#include"iCBSearch.h"
#include"iCBConstruct.h"
#include"hpInput.h"
#include"anaFilter.h"
#include"syntFilter.h"
    
   /*----------------------------------------------------------------* 
    *  Initiation of encoder instance. 
    *---------------------------------------------------------------*/ 
    
   short initEncode(                   /* (o) Number of bytes encoded */ 
       iLBC_Enc_Inst_t *iLBCenc_inst   /* (i/o) Encoder instance */ 
   ){ 
       memset((*iLBCenc_inst).anaMem, 0,  
           LPC_FILTERORDER*sizeof(float)); 
       memcpy((*iLBCenc_inst).lsfold, lsfmeanTbl, 
           LPC_FILTERORDER*sizeof(float)); 
       memcpy((*iLBCenc_inst).lsfdeqold, lsfmeanTbl, 
           LPC_FILTERORDER*sizeof(float)); 
       memset((*iLBCenc_inst).lpc_buffer, 0,  
           (LPC_LOOKBACK+BLOCKL_MAX)*sizeof(float)); 
       memset((*iLBCenc_inst).hpimem, 0, 4*sizeof(float)); 
    
       return (NO_OF_BYTES); 
   } 
    
   /*----------------------------------------------------------------* 
    *  main encoder function  
     
   Andersen et. al.  Experimental - Expires March 20th, 2003        46 
    
                     Internet Low Bit Rate Codec       September 2002 
    
    *---------------------------------------------------------------*/ 
    
   void iLBC_encode( 
       unsigned char *bytes,           /* (o) encoded data bits iLBC */ 
       float *block,                   /* (o) speech vector to encode */ 
       iLBC_Enc_Inst_t *iLBCenc_inst   /* (i/o) the general encoder  
                                              state */ 
   ){ 
        
       float data[BLOCKL_MAX]; 
       float residual[BLOCKL_MAX], reverseResidual[BLOCKL_MAX]; 
    
       int start, idxForMax, idxVec[STATE_LEN]; 
       float reverseDecresidual[BLOCKL_MAX], mem[CB_MEML]; 
       int n, k, meml_gotten, Nfor, Nback, i, pos; 
       int gain_index[CB_NSTAGES*NASUB_MAX], extra_gain_index[CB_NSTAGES]; 
       int cb_index[CB_NSTAGES*NASUB_MAX],extra_cb_index[CB_NSTAGES]; 
       int lsf_i[LSF_NSPLIT*LPC_N_MAX]; 
       unsigned char *pbytes; 
       int diff, start_pos, state_first; 
       float en1, en2; 
       int index, ulp, firstpart; 
       int subcount, subframe; 
       float weightState[LPC_FILTERORDER]; 
       float syntdenum[NSUB_MAX*(LPC_FILTERORDER+1)];  
       float weightdenum[NSUB_MAX*(LPC_FILTERORDER+1)];  
       float decresidual[BLOCKL_MAX]; 
    
       /* high pass filtering of input signal if such is not done  
              prior to calling this function */ 
    
       /*hpInput(block, BLOCKL, data, (*iLBCenc_inst).hpimem);*/ 
    
       /* otherwise simply copy */ 
    
       memcpy(data,block,BLOCKL*sizeof(float)); 
            
       /* LPC of hp filtered input data */ 
    
       LPCencode(syntdenum, weightdenum, lsf_i, data, 
           iLBCenc_inst); 
    
       /* inverse filter to get residual */ 
    
       for (n=0; n<NSUB; n++ ) { 
           anaFilter(&data[n*SUBL], &syntdenum[n*(LPC_FILTERORDER+1)],  
               SUBL, &residual[n*SUBL], (*iLBCenc_inst).anaMem); 
       } 
    
       /* find state location */ 
    
       start = FrameClassify(residual); 
        
     
       /* check if state should be in first or last part of the  
       two subframes */ 
    
       diff = STATE_LEN - STATE_SHORT_LEN; 
       en1 = 0; 
       index = (start-1)*SUBL; 
       for (i = 0; i < STATE_SHORT_LEN; i++) { 
           en1 += residual[index+i]*residual[index+i]; 
       } 
       en2 = 0; 
       index = (start-1)*SUBL+diff; 
       for (i = 0; i < STATE_SHORT_LEN; i++) { 
           en2 += residual[index+i]*residual[index+i]; 
       } 
        
        
       if (en1 > en2) { 
           state_first = 1; 
           start_pos = (start-1)*SUBL; 
       } else { 
           state_first = 0; 
           start_pos = (start-1)*SUBL + diff; 
       } 
    
       /* scalar quantization of state */ 
    
       StateSearchW(&residual[start_pos],  
           &syntdenum[(start-1)*(LPC_FILTERORDER+1)],  
           &weightdenum[(start-1)*(LPC_FILTERORDER+1)], &idxForMax,  
           idxVec, STATE_SHORT_LEN, state_first); 
    
       StateConstructW(idxForMax, idxVec,  
           &syntdenum[(start-1)*(LPC_FILTERORDER+1)],  
           &decresidual[start_pos], STATE_SHORT_LEN); 
    
       /* predictive quantization in state */ 
        
       if (state_first) { /* put adaptive part in the end */ 
            
           /* setup memory */ 
    
           memset(mem, 0, (CB_MEML-STATE_SHORT_LEN)*sizeof(float)); 
           memcpy(mem+CB_MEML-STATE_SHORT_LEN, decresidual+start_pos,  
                          STATE_SHORT_LEN*sizeof(float)); 
           memset(weightState, 0, LPC_FILTERORDER*sizeof(float)); 
    
           /* encode subframes */ 
    
           iCBSearch(extra_cb_index, extra_gain_index,  
               &residual[start_pos+STATE_SHORT_LEN],  
               mem+CB_MEML-stMemLTbl, 
               stMemLTbl, diff, CB_NSTAGES,  
               &weightdenum[start*(LPC_FILTERORDER+1)], weightState, 0); 
     
    
           /* construct decoded vector */ 
    
           iCBConstruct(&decresidual[start_pos+STATE_SHORT_LEN], 
               extra_cb_index, extra_gain_index, mem+CB_MEML-stMemLTbl,  
               stMemLTbl, diff, CB_NSTAGES); 
        
       }  
       else { /* put adaptive part in the beginning */ 
            
           /* create reversed vectors for prediction */ 
    
           for(k=0; k<diff; k++ ){ 
               reverseResidual[k] = residual[(start+1)*SUBL -1 
                   -(k+STATE_SHORT_LEN)]; 
           } 
            
           /* setup memory */ 
    
           meml_gotten = STATE_SHORT_LEN; 
           for( k=0; k<meml_gotten; k++){  
               mem[CB_MEML-1-k] = decresidual[start_pos + k]; 
           }  
           memset(mem, 0, (CB_MEML-k)*sizeof(float)); 
           memset(weightState, 0, LPC_FILTERORDER*sizeof(float)); 
            
           /* encode subframes */ 
    
           iCBSearch(extra_cb_index, extra_gain_index,  
               reverseResidual, mem+CB_MEML-stMemLTbl, stMemLTbl, diff,  
               CB_NSTAGES, &weightdenum[(start-1)*(LPC_FILTERORDER+1)],  
               weightState, 0); 
    
           /* construct decoded vector */ 
    
           iCBConstruct(reverseDecresidual, extra_cb_index,  
               extra_gain_index, mem+CB_MEML-stMemLTbl, stMemLTbl, diff,  
               CB_NSTAGES); 
            
           /* get decoded residual from reversed vector */ 
    
           for( k=0; k<diff; k++ ){ 
               decresidual[start_pos-1-k] = reverseDecresidual[k]; 
           } 
       } 
    
       /* counter for predicted subframes */ 
    
       subcount=0; 
    
       /* forward prediction of subframes */ 
    
       Nfor = NSUB-start-1; 
     
    
        
       if( Nfor > 0 ){ 
            
           /* setup memory */ 
    
           memset(mem, 0, (CB_MEML-STATE_LEN)*sizeof(float)); 
           memcpy(mem+CB_MEML-STATE_LEN, decresidual+(start-1)*SUBL,  
               STATE_LEN*sizeof(float)); 
           memset(weightState, 0, LPC_FILTERORDER*sizeof(float));