ztscan_dec.cpp

《Visual C++小波变换技术与工程实践》靳济芳编著的光盘程序。

  /* scan each coefficients in the spatial layer */  
  k = 1<<n;

//Modified by Sarnoff for error resilience, 3/5/99
 if(mzte_codec.m_usErrResiDisable){ //no error resi case
  for(h=0;h<ac_h;h+=k)
    for(w=ac_w;w<ac_w2;w+=k)
    {
      /* LH */
      decodeSQBlocks(h,w,n);

      /* HL */
      h += ac_h;
      w -= ac_w;
      decodeSQBlocks(h,w,n);

      /* HH */
      w += ac_w;
      decodeSQBlocks(h,w,n);

      /* Set h back to where it started. w is already there */
      h -= ac_h;
    }
 }
 else{ //error resi case
  while (1)  /* ph, 11/17/98 - removed: for(h=0;h<ac_h;h+=k) */
  {
    /***** ph, 11/17/98 - check for error *****/
    if (LTU>TU_max)
    {
      /* error */
      return;
    }

    /* check that current TU and this function are ok */
    get_TU_location(LTU);
    
    /* if color or band_height (spatial layer) are mismatched then leave */
    if (TU_color!=color || band_height!=ac_h)
      return;
    
    /* color and spatial layer are correct test row. Set row of TU */
    h = start_h;

    /*******************************************/

    for(w=ac_w;w<ac_w2;w+=k)
    {
      /* LH */
      decodeSQBlocks_ErrResi(h,w,n,color);
      if(n>0 && n<5) /* ph, 11/17/98 */
		if (found_segment_error(color)==1)
		{
		  /* found error */
		}
 
      /* HL */
      h += ac_h;
      w -= ac_w;
      decodeSQBlocks_ErrResi(h,w,n,color);
      if(n>0 && n<5) /* ph, 11/17/98 */
		if (found_segment_error(color)==1)
		{
		  /* found error */
		}

      /* HH */
      w += ac_w;
      decodeSQBlocks_ErrResi(h,w,n,color);
      if(n>0 && n<5) /* ph, 11/17/98 */
		if (found_segment_error(color)==1)
		{
		  /* found error */
		}


      /* Set h back to where it started. w is already there */
      h -= ac_h;  /* ph, 11/19/98 - removed not needed */
    }

    check_end_of_packet(); /* ph, 11/17/98 */
    ++LTU;
  }
 }
//End modified by Sarnoff for error resilience, 3/5/99

}


     
/*******************************************************
  The following single quant routines are for tree
  depth scan order.
*******************************************************/
/********************************************************
  Function Name
  -------------
  Void wavelet_higher_bands_decode_SQ_tree()

  Arguments
  ---------
  None.

  Description
  -----------
  Control program for decoding AC information for single quant mode.
  All colors decoded. 

  Functions Called
  ----------------
  cachb_decode_SQ_tree()
  mzte_ac_decoder_init()
  mzte_ac_model_init()
  mzte_ac_model_done()
  mzte_ac_decoder_done()

  Return Value
  ------------
  None.

********************************************************/ 
Void CVTCDecoder::wavelet_higher_bands_decode_SQ_tree()
{
  noteDetail("Decoding AC band (wavelet_higher_bands_decode_SQ)....");
  
//Modified by Sarnoff for error resilience, 3/5/99
 if(mzte_codec.m_usErrResiDisable){
  /* init arithmetic coder */
  mzte_ac_decoder_init(&acd);
  
  for (color=0; color<mzte_codec.m_iColors; color++) 
  {  
	    probModelInitSQ(color);  // hjlee 0901
  
  }

//  cachb_decode_SQ();  // hjlee 0901
  cachb_decode_SQ_tree();

  for (color=0; color<mzte_codec.m_iColors; color++) 
    /* close arithmetic coder */
    probModelFreeSQ(color);

  mzte_ac_decoder_done(&acd);
 }
 else{ //error resi case
  /* init arithmetic coder */
  init_arith_decoder_model(color);
  cachb_decode_SQ_tree();
  close_arith_decoder_model(color);
 }
//End modified by Sarnoff for error resilience, 3/5/99

  noteDetail("Completed decoding AC band.");
}



/********************************************************
  Function Name
  -------------
  static Void cachb_decode_SQ()

  Arguments
  ---------
  None.

  Description
  -----------
  Decode AC information for one color component. 
  Single quant mode, tree-depth scan

  Functions Called
  ----------------
  decode_pixel_SQ()

  Return Value
  ------------
  None.

********************************************************/ 

Void CVTCDecoder::cachb_decode_SQ_tree()
{
//Modified by Sarnoff for error resilience, 3/5/99
 if(mzte_codec.m_usErrResiDisable){  //no error resi case
  Int h,w,dc_h,dc_w,dc_h2,dc_w2;

  dc_h=mzte_codec.m_iDCHeight;
  dc_w=mzte_codec.m_iDCWidth;
  dc_h2=dc_h<<1;
  dc_w2=dc_w<<1;

  for(h=0;h<dc_h;h++)
    for(w=0;w<dc_w;w++)  // 1127    
      for (color=0; color<mzte_codec.m_iColors; color++) 
      {  	
	SNR_IMAGE *snr_image;
	int tw,sw,sh,n; // 1127
	
	snr_image=&(mzte_codec.m_SPlayer[color].SNRlayer.snr_image);
 
	height=mzte_codec.m_SPlayer[color].height;
	width=mzte_codec.m_SPlayer[color].width;

	setProbModelsSQ(color);  // hjlee 0901


	coeffinfo=mzte_codec.m_SPlayer[color].coeffinfo;

	/* LH */
	n = 0;
	for (tw=mzte_codec.m_iDCWidth; tw < width; tw<<=1)
	{
	  sh = h << n;
	  sw = (w+dc_w) << n;
	  decodeSQBlocks(sh,sw,n);
	  n++;
	}
	/* HL */
	n = 0;
	for (tw=mzte_codec.m_iDCWidth; tw < width; tw<<=1)
	{
	  sh = (h+dc_h) << n;
	  sw = w << n;
	  decodeSQBlocks(sh,sw,n);
	  n++;
	}
	/* HH */
	n = 0;
	for (tw=mzte_codec.m_iDCWidth; tw < width; tw<<=1)
	{
	  sh = (h+dc_h) << n;
	  sw = (w+dc_w) << n;
	  decodeSQBlocks(sh,sw,n);
	  n++;
	}

      }
 }
 else{ //error resilience case
  Int dc_h,dc_w;
  Int tw,sw,sh,n;

  dc_h=mzte_codec.m_iDCHeight;
  dc_w=mzte_codec.m_iDCWidth;

  /* rewrote for error resilience, bbc, 11/9/98 */
  while(LTU<=TU_max){
    get_TU_location(LTU);
    height=mzte_codec.m_SPlayer[TU_color].height;
    width=mzte_codec.m_SPlayer[TU_color].width;
	
    setProbModelsSQ(TU_color);
    coeffinfo=mzte_codec.m_SPlayer[TU_color].coeffinfo;
    color=TU_color;

    /* decoding one TU */
    n = 0;
    for (tw=mzte_codec.m_iDCWidth; tw < width; tw<<=1){
      sh = start_h << n;
      sw = start_w << n;
      decodeSQBlocks_ErrResi(sh,sw,n,TU_color);
      if(n>0 && n<5)
		found_segment_error(TU_color);
      n++;
    }

    check_end_of_packet();  /* error resilience code, bbc, 11/9/98 */
    LTU++;
  }    
 }
//End modified by Sarnoff for error resilience, 3/5/99
}



/********************************************************
  Function Name
  -------------
  static Void decode_pixel_SQ(Int h,Int w)

  Arguments
  ---------
  Int h,Int w - position of a pixel in height and width
  
  Description
  -----------
  Decoding the type and/or value of a coefficient, a
  recursive function.

  Functions Called
  ----------------
  mag_sign_decode_SQ()
  mzte_ac_decode_symbol()
  decode_pixel_SQ()

  Return Value
  ------------
  None.

********************************************************/ 
// hjlee 0901
Void CVTCDecoder::decode_pixel_SQ(Int h,Int w)
{

  UChar zt_type;
  Int l;

  if(coeffinfo[h][w].type == ZTR_D)
    return;


  l=xy2wvtDecompLev(w,h);


  /* decode leave coefficients, value only */  
  if(IS_STATE_LEAF(coeffinfo[h][w].state)){ /* zero value. no sign */
   


      /* Map leaf code word to type 0->ZTR, 1->VZTR */
      coeffinfo[h][w].type = 
	mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_LINIT]) ? VZTR : ZTR;
      if (coeffinfo[h][w].type==VZTR)


	mag_sign_decode_SQ(h,w);

      else
	coeffinfo[h][w].quantized_value = 0;  
      
      return;
  }
  
  
  /* decode zero tree symbols */

    coeffinfo[h][w].type=zt_type=


    mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_INIT]);

   
  /* code magnitude and sign */
  switch(zt_type){
    case IZ :
      break;
    case VZTR:
      mag_sign_decode_SQ(h,w);
    case ZTR:
      mark_ZTR_D(h,w);  /* necessary for checking purpose bandwise scan */
      return;
    case VAL:
      mag_sign_decode_SQ(h,w);
      break;
    default: 
      errorHandler("Invalid zerotree symbol in single quant decode");
  }

#if 0
  UChar zt_type;
  Int h, w, k;
  Int dcc[4]; /* Don't Code Children */
  Int nSib; /* number siblings */
  Int l;

  l=xy2wvtDecompLev(w0,h0);

  nSib = (h0<(mzte_codec.m_iDCHeight<<1) && w0<(mzte_codec.m_iDCWidth<<1)) ? 1 : 4;

  /********************* CODE SIBLINGS *****************************/
  for (k=0; k<nSib; ++k)
  {
    h = h0 + (k/2);
    w = w0 + (k%2);

    /* decode leave coefficients, value only */
    if(IS_STATE_LEAF(coeffinfo[h][w].state)){ /* zero value. no sign */
#ifdef _SHAPE_
      if(coeffinfo[h][w].mask==1)
      {
#endif      

	/* Map leaf code word to type 0->ZTR, 1->VZTR */
	coeffinfo[h][w].type = 
	  mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_LINIT]) ? VZTR : ZTR;
	if (coeffinfo[h][w].type==VZTR)


	  mag_sign_decode_SQ(h,w);
	else
	  coeffinfo[h][w].quantized_value = 0;

#ifdef _SHAPE_
      }
      else 
	coeffinfo[h][w].quantized_value = 0;
#endif      
      
      continue;
    }
    
    
    /* decode zero tree symbols */
#ifdef _SHAPE_
    if(coeffinfo[h][w].mask==1)
#endif
      coeffinfo[h][w].type=zt_type=

      mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_INIT]);
#ifdef _SHAPE_
    else
      coeffinfo[h][w].type=zt_type = IZ;
#endif

    /* code magnitude and sign */
    switch(zt_type){
      case IZ :
	dcc[k]=0;
	break;
      case VZTR:
	mag_sign_decode_SQ(h,w);
      case ZTR:
	dcc[k]=1;
	break;
      case VAL:
	dcc[k]=0;
	mag_sign_decode_SQ(h,w);
	break;
      default: 
	errorHandler("Invalid zerotree symbol in single quant decode");
    }
  }
  

  /********************* CODE CHILDREN *****************************/
   if (!IS_STATE_LEAF(coeffinfo[h0][w0].state)) 
  {
    Int i, j;

    for (k=0; k<nSib; ++k)
    {
      if (dcc[k]==0)
      {
	h = h0 + (k/2);
	w = w0 + (k%2);  

	/* scan children */
	i=h<<1; j=w<<1;
	decode_pixel_SQ_tree(i,j);
      }
    }
  }

#endif

}


     
/********************************************************
  Function Name
  -------------
  static Void  mag_sign_decode_SQ(Int h,Int w)

  Arguments
  ---------
  Int h,Int w - position of a pixel

  Description
  -----------
  Decode the value of a coefficient.

  Functions Called
  ----------------
  mzte_ac_decode_symbol()

  Return Value
  ------------
  None.

********************************************************/ 



Void  CVTCDecoder::mag_sign_decode_SQ(Int h,Int w)
{
  Int value,v_sign;
  Int l;
    
  l=xy2wvtDecompLev(w,h);


  value=bitplane_decode(l,WVTDECOMP_NUMBITPLANES(color,l))+1;
  v_sign=mzte_ac_decode_symbol(&acd,acm_sign[l]);
  coeffinfo[h][w].quantized_value=(v_sign==0) ? value : -value;

}


/*********************************************************************/
/******************************  AC  *********************************/
/**************************  Multi quant  ****************************/
/*********************************************************************/


Int CVTCDecoder::bitplane_res_decode(Int l,Int max_bplane)
{
  register Int i,val=0,k=0;

  for(i=max_bplane-1;i>=0;i--,k++)
    val+=mzte_ac_decode_symbol(&acd,&acm_bpres[l][k])<<i;

  return val;
}

/********************************************************
  Function Name
  -------------
  Void wavelet_higher_bands_decode_MQ(Int scanDirection)

  Arguments
  ---------
  Int scanDirection - 0 <=> tree, 1 <=> band
  
  Description
  -----------
  Control program for decoding AC information for one 
  color component. Multi quant mode.

  Functions Called
  ----------------
  cachb_decode_MQ_band()
  mzte_ac_decoder_init()