ilbc_common.java

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       int in2_idx,
       float coef,      /* (i) interpolation weights */
       int length)      /* (i) length of all vectors */
   {
       int i;
       float invcoef;

       invcoef = (float)1.0f - coef;
       for (i = 0; i < length; i++) {
           out[i] = coef * in1[i] + invcoef * in2[i + in2_idx];
	   //	   System.out.println("out["+i+"] devient " + out[i] + ", par " +
	   //			      coef + " * " + in1[i] + " + " + invcoef + " * " + in2[i + in2_idx]);
       }
   }

   /*----------------------------------------------------------------*
    *  lpc bandwidth expansion
    *---------------------------------------------------------------*/

    public static void bwexpand(
		 float out[],      /* (o) the bandwidth expanded lpc
                              coefficients */
		 int out_idx,
		 float in[],      /* (i) the lpc coefficients before bandwidth
                              expansion */
		 float coef,     /* (i) the bandwidth expansion factor */
		 int length)      /* (i) the length of lpc coefficient vectors */
    {
	int i;
	float  chirp;

	chirp = coef;

	out[out_idx] = in[0];
	for (i = 1; i < length; i++) {
	    out[i + out_idx] = chirp * in[i];
	    chirp *= coef;
	}
    }

    public static void getCBvec(
		  float cbvec[],  /* (o) Constructed codebook vector */
		  float mem[],    /* (i) Codebook buffer */
		  int mem_idx,
		  int index,      /* (i) Codebook index */
		  int lMem,       /* (i) Length of codebook buffer */
		  int cbveclen)   /* (i) Codebook vector length */
    {
	int j, k, n, memInd, sFilt;
	float [] tmpbuf = new float[ilbc_constants.CB_MEML];
	int base_size;
	int ilow, ihigh;
	float alfa, alfa1;

       /* Determine size of codebook sections */

       base_size=lMem-cbveclen+1;

       if (cbveclen==ilbc_constants.SUBL) {
           base_size+=cbveclen/2;
       }

       /* No filter -> First codebook section */

       if (index<lMem-cbveclen+1) {

           /* first non-interpolated vectors */

           k=index+cbveclen;
           /* get vector */
	   System.arraycopy(mem, mem_idx + lMem - k, cbvec, 0, cbveclen);
	   //           memcpy(cbvec, mem+lMem-k, cbveclen*sizeof(float));

       } else if (index < base_size) {

           k=2*(index-(lMem-cbveclen+1))+cbveclen;

           ihigh=k/2;
           ilow=ihigh-5;

           /* Copy first noninterpolated part */

	   System.arraycopy(mem, mem_idx + lMem - k / 2, cbvec, 0, ilow);
	   //           memcpy(cbvec, mem+lMem-k/2, ilow*sizeof(float));

           /* interpolation */

           alfa1=(float)0.2;
           alfa=0.0f;
           for (j=ilow; j<ihigh; j++) {
               cbvec[j]=((float)1.0f-alfa)*mem[mem_idx + lMem-k/2+j]+
                   alfa*mem[mem_idx + lMem-k+j];
               alfa+=alfa1;
           }

           /* Copy second noninterpolated part */

	   System.arraycopy(mem, mem_idx+lMem-k+ihigh, cbvec, ihigh, (cbveclen-ihigh));
//            memcpy(cbvec+ihigh, mem+lMem-k+ihigh,
//                (cbveclen-ihigh)*sizeof(float));

       }

       /* Higher codebook section based on filtering */

       else {

           /* first non-interpolated vectors */

           if (index-base_size<lMem-cbveclen+1) {
               float [] tempbuff2 = new float[ilbc_constants.CB_MEML+ilbc_constants.CB_FILTERLEN+1];
//                float *pos;
//                float *pp, *pp1;
	       int pos, pp, pp1;

	       for (int li = 0; li < ilbc_constants.CB_HALFFILTERLEN; li++)
		   tempbuff2[li] = 0.0f;
//                memset(tempbuff2, 0,
//                    CB_HALFFILTERLEN*sizeof(float));
	       System.arraycopy(mem, mem_idx, tempbuff2, ilbc_constants.CB_HALFFILTERLEN, lMem);
//                memcpy(&tempbuff2[CB_HALFFILTERLEN], mem,
//                    lMem*sizeof(float));
	       for (int li = 0; li < ilbc_constants.CB_HALFFILTERLEN + 1; li++)
		   tempbuff2[lMem + ilbc_constants.CB_HALFFILTERLEN + li] = 0.0f;
//                memset(&tempbuff2[lMem+CB_HALFFILTERLEN], 0,
//                    (CB_HALFFILTERLEN+1)*sizeof(float));

               k=index-base_size+cbveclen;
               sFilt=lMem-k;
               memInd=sFilt+1-ilbc_constants.CB_HALFFILTERLEN;

               /* do filtering */
	       //               pos=cbvec;
	       pos = 0;
	       for (int li = 0; li < cbveclen; li++)
		   cbvec[li] = 0;
//                memset(pos, 0, cbveclen*sizeof(float));
               for (n=0; n<cbveclen; n++) {
		   pp = memInd + n + ilbc_constants.CB_HALFFILTERLEN;
//                    pp=&tempbuff2[memInd+n+CB_HALFFILTERLEN];
		   pp1 = ilbc_constants.CB_FILTERLEN - 1;
//                    pp1=&cbfiltersTbl[CB_FILTERLEN-1];
                   for (j=0; j < ilbc_constants.CB_FILTERLEN; j++) {
//                        (*pos)+=(*pp++)*(*pp1--);
		       cbvec[pos] += tempbuff2[pp] * ilbc_constants.cbfiltersTbl[pp1];
		       pp++;
		       pp1--;
                   }
                   pos++;
               }
           }

           /* interpolated vectors */

           else {
               float [] tempbuff2 = new float[ilbc_constants.CB_MEML+ilbc_constants.CB_FILTERLEN+1];

//                float *pos;
//                float *pp, *pp1;
	       int pos, pp, pp1;
               int i;

	       for (int li = 0; li < ilbc_constants.CB_HALFFILTERLEN; li++)
		   tempbuff2[li] = 0.0f;
//                memset(tempbuff2, 0,
//                    CB_HALFFILTERLEN*sizeof(float));
	       System.arraycopy(mem, mem_idx, tempbuff2, ilbc_constants.CB_HALFFILTERLEN, lMem);
//                memcpy(&tempbuff2[CB_HALFFILTERLEN], mem,
//                    lMem*sizeof(float));
	       for (int li = 0; li < ilbc_constants.CB_HALFFILTERLEN; li++)
		   tempbuff2[lMem+ilbc_constants.CB_HALFFILTERLEN+li] = 0.0f;
//                memset(&tempbuff2[lMem+CB_HALFFILTERLEN], 0,
//                    (CB_HALFFILTERLEN+1)*sizeof(float));

               k=2*(index-base_size-
		    (lMem-cbveclen+1))+cbveclen;
               sFilt=lMem-k;
               memInd=sFilt+1 - ilbc_constants.CB_HALFFILTERLEN;

               /* do filtering */
	       //               pos=&tmpbuf[sFilt];
	       pos = sFilt;
	       //               memset(pos, 0, k*sizeof(float));
	       for (int li = 0; li < k; li++)
		   tmpbuf[pos+li] = 0.0f;

               for (i=0; i<k; i++) {
		   pp = memInd + i + ilbc_constants.CB_HALFFILTERLEN;
//                    pp=&tempbuff2[memInd+i+CB_HALFFILTERLEN];
		   pp1 = ilbc_constants.CB_FILTERLEN-1;
//                    pp1=&cbfiltersTbl[CB_FILTERLEN-1];
                   for (j=0; j < ilbc_constants.CB_FILTERLEN; j++) {
		       //                       (*pos)+=(*pp++)*(*pp1--);
		       tmpbuf[pos] += tempbuff2[pp] * ilbc_constants.cbfiltersTbl[pp1];
		       pp++;
		       pp1--;
                   }
                   pos++;
               }

               ihigh = k / 2;
               ilow=ihigh-5;

               /* Copy first noninterpolated part */

	       System.arraycopy(tmpbuf, lMem - k / 2, cbvec, 0, ilow);
//                memcpy(cbvec, tmpbuf+lMem-k/2,
//                    ilow*sizeof(float));

               /* interpolation */

               alfa1=(float)0.2;
               alfa=0.0f;
               for (j=ilow; j<ihigh; j++) {
                   cbvec[j]=((float)1.0f-alfa)*
                       tmpbuf[lMem-k/2+j]+alfa*tmpbuf[lMem-k+j];
                   alfa+=alfa1;
               }

               /* Copy second noninterpolated part */

	       System.arraycopy(tmpbuf, lMem-k+ihigh, cbvec, ihigh, cbveclen - ihigh);
//                memcpy(cbvec+ihigh, tmpbuf+lMem-k+ihigh,
//                    (cbveclen-ihigh)*sizeof(float));
           }
       }
   }



    public static float gainquant(/* (o) quantized gain value */
		    float in,       /* (i) gain value */
		    float maxIn,/* (i) maximum of gain value */
		    int cblen,      /* (i) number of quantization indices */
		    int index[],      /* (o) quantization index */
		    int index_idx)
    {
	int i, tindex;
	float minmeasure,measure, cb[], scale;

	/* ensure a lower bound on the scaling factor */

	scale = maxIn;

	if (scale < 0.1) {
	    scale = (float)0.1;
	}

	/* select the quantization table */

	if (cblen == 8) {
	    cb = ilbc_constants.gain_sq3Tbl;
	} else if (cblen == 16) {
	    cb = ilbc_constants.gain_sq4Tbl;
	} else  {
	    cb = ilbc_constants.gain_sq5Tbl;
	}

	/* select the best index in the quantization table */

	minmeasure=10000000.0f;
	tindex=0;
	for (i=0; i<cblen; i++) {
	    measure = (in - scale*cb[i])*(in-scale*cb[i]);

	    if (measure<minmeasure) {
		tindex=i;
		minmeasure=measure;
	    }
	}
	index[index_idx] = tindex;

	/* return the quantized value */

	return scale*cb[tindex];
    }

    /*----------------------------------------------------------------*
     *  decoder for quantized gains in the gain-shape coding of
     *  residual
     *---------------------------------------------------------------*/

    public static float gaindequant(  /* (o) quantized gain value */
		      int index,      /* (i) quantization index */
		      float maxIn,/* (i) maximum of unquantized gain */
		      int cblen)       /* (i) number of quantization indices */
    {
	float scale;

	/* obtain correct scale factor */

	scale=(float)(float)Math.abs(maxIn);

	if (scale < 0.1) {
	    scale=(float)0.1;
	}

	/* select the quantization table and return the decoded value */

	if (cblen==8) {
	    return scale*ilbc_constants.gain_sq3Tbl[index];
	} else if (cblen==16) {
	    return scale*ilbc_constants.gain_sq4Tbl[index];
	}
	else if (cblen==32) {
	    return scale*ilbc_constants.gain_sq5Tbl[index];
	}

	return 0.0f;
    }


    public static void iCBConstruct(
		     float decvector[],   /* (o) Decoded vector */
		     int decvector_idx,
		     int index[],         /* (i) Codebook indices */
		     int index_idx,
		     int gain_index[],/* (i) Gain quantization indices */
		     int gain_index_idx,
		     float mem[],         /* (i) Buffer for codevector construction */
		     int mem_idx,
		     int lMem,           /* (i) Length of buffer */
		     int veclen,         /* (i) Length of vector */
		     int nStages         /* (i) Number of codebook stages */
   ){
       int j,k;

       float [] gain = new float[ilbc_constants.CB_NSTAGES];
       float [] cbvec = new float[ilbc_constants.SUBL];

       /* gain de-quantization */

       gain[0] = gaindequant(gain_index[gain_index_idx + 0], 1.0f, 32);
       if (nStages > 1) {
           gain[1] = gaindequant(gain_index[gain_index_idx + 1],
               (float)(float)Math.abs(gain[0]), 16);
       }
       if (nStages > 2) {
           gain[2] = gaindequant(gain_index[gain_index_idx + 2],
               (float)(float)Math.abs(gain[1]), 8);
       }

       /* codebook vector construction and construction of
       total vector */

       getCBvec(cbvec, mem, mem_idx, index[index_idx + 0], lMem, veclen);
       for (j=0;j<veclen;j++){
           decvector[decvector_idx + j] = gain[0]*cbvec[j];
       }
       if (nStages > 1) {
           for (k=1; k<nStages; k++) {
               getCBvec(cbvec, mem, mem_idx, index[index_idx + k], lMem, veclen);
               for (j=0;j<veclen;j++) {
                   decvector[decvector_idx + j] += gain[k]*cbvec[j];
               }
           }
       }
   }



}