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。

  mzte_ac_model_init()
  mzte_ac_model_done()
  mzte_ac_decoder_done()

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

********************************************************/ 
Void CVTCDecoder::wavelet_higher_bands_decode_MQ(Int scanDirection)
{
  noteDetail("Decoding AC band (wavelet_higher_bands_decode_MQ)....");

  /* init arithmetic coder */
  mzte_ac_decoder_init(&acd);
  
  if (scanDirection==0)
    cachb_decode_MQ_tree();
  else
    cachb_decode_MQ_band();

  /* close arithmetic coder */
  mzte_ac_decoder_done(&acd);
}



/**********************************************************************/
/***************       MQ BAND         ********************************/
/**********************************************************************/


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

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

  Description
  -----------
  Decode AC information for one color component. 
  Multiple quant, bandwise scan.

  Functions Called
  ----------------
  clear_ZTR_D();
  codeBlocks();
  decode_pixel_MQ_band()

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

********************************************************/ 
Void CVTCDecoder::cachb_decode_MQ_band()
{
  Int h,w;
  Int ac_h,ac_w,ac_h2,ac_w2;
  Int acH,acW,acH2,acW2;
  Int layer, nCol;
  Int n; /* layer index - for codeBlocks function */
  Int k; /* block jump for the layer */

  /* clear the ZTR_D type from the previous pass */
  for (color=0; color<NCOL; ++color)
  {      
    coeffinfo=mzte_codec.m_SPlayer[color].coeffinfo;
    height=mzte_codec.m_SPlayer[color].height;
    width=mzte_codec.m_SPlayer[color].width;

    clear_ZTR_D(coeffinfo, width, height);
  }
  for (color=0; color<NCOL; ++color)
    probModelInitMQ(color);
 
  acH=mzte_codec.m_iDCHeight;
  acW=mzte_codec.m_iDCWidth;
  acH2=acH<<1;
  acW2=acW<<1;

  /* scan each coefficients in the spatial layer */
  /* assume luma dimensions are >= chroma dimensions */
  layer=0;
  while(acH2<=mzte_codec.m_SPlayer[0].height 
	&& acW2<=mzte_codec.m_SPlayer[0].width)
  {
    nCol = (layer==0) ? 1 : NCOL;
    for (color=0; color < nCol; ++color)
    {      
      SNR_IMAGE *snr_image;

      noteProgress("  Coding Layer %d, Color %d", layer - (color!=0), color);

      ac_h2=acH2;
      ac_w2=acW2;
      ac_h=acH;
      ac_w=acW;

      if (color)
      {
	ac_h2>>=1;
	ac_w2>>=1;
	ac_h>>=1;
	ac_w>>=1;
      }

      snr_image=&(mzte_codec.m_SPlayer[color].SNRlayer.snr_image);

      coeffinfo=mzte_codec.m_SPlayer[color].coeffinfo;
      height=mzte_codec.m_SPlayer[color].height;
      width=mzte_codec.m_SPlayer[color].width;
      setProbModelsMQ(color);
 
      /* Go through bands */
      n = layer - (color>0);
      k = 1<<n;
      for(h=0;h<ac_h;h+=k)
		for(w=ac_w;w<ac_w2;w+=k)
		{
		  /* LH */
		  decodeMQBlocks(h,w,n);
		  
		  /* HL */
		  h += ac_h;
		  w -= ac_w;
		  decodeMQBlocks(h,w,n);
		  
		  /* HH */
		  w += ac_w;
		  decodeMQBlocks(h,w,n);
		  
		  /* Set h back to where it started. w is already there */
		  h -= ac_h;
		}
    }

    /* update ranges */
    acH=acH2;
    acW=acW2;
    acW2<<=1;
    acH2<<=1;

    layer++;
  }
  for (color=0; color<NCOL; ++color)
    probModelFreeMQ(color);

}


/********************************************************
  Function Name
  -------------
  static Void decode_pixel_MQ_band(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, multi quant mode.

  Functions Called
  ----------------
  mzte_ac_decode_symbol()
  mark_ZTR_D()
  mag_sign_decode_MQ()

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

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

//Void CVTCDecoder::decode_pixel_MQ_band(Int h,Int w)
Void CVTCDecoder::decode_pixel_MQ(Int h,Int w) // 1124
{
  Int zt_type;

  /*~~~~~~~~~~~~~~~~~ zerotree descendent ~~~~~~~~~~~~~~~~~~~*/  
  if(coeffinfo[h][w].type==ZTR_D)
    return;

  /*~~~~~~~~~~~~~~ decode zero tree symbol ~~~~~~~~~~~~~~~~~~*/
  if (IS_RESID(w,h,color))
  {
    zt_type=VAL; /* tmp assign. for next switch statement */
  }
  else
  {
    Int czt_type; /* what to put on bitstream */
    Int l;

    l=xy2wvtDecompLev(w,h);  

    zt_type = coeffinfo[h][w].type;
#ifdef _SHAPE_
    if(coeffinfo[h][w].mask==1) /* skip out-node */  
    {
#endif
      switch(coeffinfo[h][w].state)
      {
	case S_INIT:
	  czt_type=mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_INIT]);
	  coeffinfo[h][w].type=zt_type=czt_type;
	  break;
	case S_ZTR:
	  czt_type=mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_ZTR]);
	  coeffinfo[h][w].type=zt_type=czt_type;
	  break;
	case S_ZTR_D:
	  czt_type=mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_ZTR_D]);
	  coeffinfo[h][w].type=zt_type=czt_type;
	  break;
	case S_IZ:
	  czt_type=mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_IZ]);
	  coeffinfo[h][w].type=zt_type = czt_type ? VAL : IZ;
	  break;
	case S_LINIT: 
	  czt_type=mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_LINIT]);
	  coeffinfo[h][w].type=zt_type = czt_type ? VZTR : ZTR;
	  break;
	case S_LZTR:
	  czt_type=mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_LZTR]);
	  coeffinfo[h][w].type=zt_type = czt_type ? VZTR : ZTR;
	  break;
	case S_LZTR_D:
	  czt_type=mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_LZTR_D]);
	  coeffinfo[h][w].type=zt_type = czt_type ? VZTR : ZTR;
	  break;
	default:
	  errorHandler("Invalid state (%d) in multi-quant encoding.", 
		       coeffinfo[h][w].state);
      }
#ifdef _SHAPE_
    }
    else /* treat out-node as isolated zero for decoding purpose */
    {
      switch(coeffinfo[h][w].state)
      {
      case S_INIT:
      case S_ZTR:
      case S_ZTR_D:
      case S_IZ:
	zt_type = coeffinfo[h][w].type = IZ;
	break;
      case S_LINIT: 
      case S_LZTR:
      case S_LZTR_D:
	zt_type = coeffinfo[h][w].type = ZTR;
	break;
      default:
	errorHandler("Invalid state (%d) in multi-quant encoding.", 
		     coeffinfo[h][w].state);
      }
    }
#endif

  }

  /*~~~~~~~~~~~~~~~~ mark ztr_d and encode magnitudes ~~~~~~~~~~~~~~~~~*/
  switch(zt_type)
  {
    case ZTR:
#ifdef _SHAPE_
      if(coeffinfo[h][w].mask!=1)
	return;
#endif
    case ZTR_D:
      mark_ZTR_D(h,w);
    case IZ:
      coeffinfo[h][w].quantized_value=0;
      return;
    case VZTR:
      mark_ZTR_D(h,w);
    case VAL:
#ifdef _SHAPE_
      if(coeffinfo[h][w].mask==1) 
#endif
	mag_sign_decode_MQ(h,w);
      break;
    default:
      errorHandler("Invalid type in multi quant decoding.");     
  }
}



/**********************************************************************/
/***************       MQ TREE         ********************************/
/**********************************************************************/

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

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

  Description
  -----------
  Decode AC information for one color component. 
  Multiple quant, treewise scan.

  Functions Called
  ----------------
  clear_ZTR_D();
  decode_pixel_MQ_tree()

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

********************************************************/ 
Void CVTCDecoder::cachb_decode_MQ_tree()
{
  Int h,w, dc_h, dc_w;
     
  /* clear the ZTR_D type from the previous pass */
  for (color=0; color<NCOL; ++color)
  {      
    coeffinfo=mzte_codec.m_SPlayer[color].coeffinfo;
    height=mzte_codec.m_SPlayer[color].height;
    width=mzte_codec.m_SPlayer[color].width;

    clear_ZTR_D(coeffinfo, width, height);
  }
     
  for (color=0; color<NCOL; ++color)
    probModelInitMQ(color);

  /* ac_h, ac_w init */
  dc_h=mzte_codec.m_iDCHeight;
  dc_w=mzte_codec.m_iDCWidth;

  for (h=0; h<dc_h; ++h)
    for (w=0; w<dc_w; ++w)
    {
      for (color=0; color<NCOL; ++color)
      {      
	SNR_IMAGE *snr_image;
	int tw,sw,sh,n;  // 1124
	
	snr_image=&(mzte_codec.m_SPlayer[color].SNRlayer.snr_image);
	
	coeffinfo=mzte_codec.m_SPlayer[color].coeffinfo;
	height=mzte_codec.m_SPlayer[color].height;
	width=mzte_codec.m_SPlayer[color].width;
      
	setProbModelsMQ(color);

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

#if 0
	decode_pixel_MQ_tree(h,w+dc_w);      /* LH */
	decode_pixel_MQ_tree(h+dc_h,w);      /* HL */
	decode_pixel_MQ_tree(h+dc_h,w+dc_w); /* HH */
#endif


      }
    }


  for (color=0; color<NCOL; ++color)
    probModelFreeMQ(color);

}

#if 0
/********************************************************
  Function Name
  -------------
  static Void decode_pixel_MQ_tree(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, multi quant mode.

  Functions Called
  ----------------
  mzte_ac_decode_symbol()
  mark_ZTR_D()
  mag_sign_decode_MQ()

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

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


Void CVTCDecoder::decode_pixel_MQ_tree(Int h0,Int w0)
{
  Int zt_type, h, w, k;
  Int dcc[4]; /* Don't Code Children */
  Int nSib; /* number siblings */

  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 zero tree symbol */  
    if (IS_RESID(w,h,color))
    {
      zt_type=VAL;
    }
    else
    {
      Int czt_type; /* what to put on bitstream */
      Int l;

      l=xy2wvtDecompLev(w,h);  

      zt_type = coeffinfo[h][w].type;
#ifdef _SHAPE_
      if(coeffinfo[h][w].mask==1) /* skip out-node */  
      {
#endif
	switch(coeffinfo[h][w].state)
	{
	  case S_INIT:
	    czt_type=mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_INIT]);
	    coeffinfo[h][w].type=zt_type=czt_type;
	    break;
	  case S_ZTR:
	    czt_type=mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_ZTR]);
	    coeffinfo[h][w].type=zt_type=czt_type;
	    break;
	  case S_ZTR_D:
	    czt_type=mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_ZTR_D]);
	    coeffinfo[h][w].type=zt_type=czt_type;
	    break;
	  case S_IZ:
	    czt_type=mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_IZ]);
	    coeffinfo[h][w].type=zt_type = czt_type ? VAL : IZ;
	    break;
	  case S_LINIT: 
	    czt_type=mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_LINIT]);
	    coeffinfo[h][w].type=zt_type = czt_type ? VZTR : ZTR;
	    break;
	  case S_LZTR:
	  czt_type=mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_LZTR]);
	  coeffinfo[h][w].type=zt_type = czt_type ? VZTR : ZTR;
	  break;
	  case S_LZTR_D:
	    czt_type=mzte_ac_decode_symbol(&acd,acm_type[l][CONTEXT_LZTR_D]);
	    coeffinfo[h][w].type=zt_type = czt_type ? VZTR : ZTR;
	    break;
	default:
	  errorHandler("Invalid state (%d) in multi-quant encoding.", 
		       coeffinfo[h][w].state);
	}
#ifdef _SHAPE_
      }
      else /* treat out-node as isolated zero for decoding purpose */
      {
	switch(coeffinfo[h][w].state)
	  {
	  case S_INIT:
	  case S_ZTR:
	  case S_ZTR_D:
	  case S_IZ:
	    zt_type = coeffinfo[h][w].type = IZ;
	    break;
	  case S_LINIT: 
	  case S_LZTR:
	  case S_LZTR_D:
	    zt_type = coeffinfo[h][w].type = ZTR;
	    break;
	  default:
	    errorHandler("Invalid state (%d) in multi-quant encoding.", 
			 coeffinfo[h][w].state);
	  }
      }
#endif
      
    }
    /* mark ztr_d and decode magnitudes */
    switch(zt_type)
    {
      case ZTR:
#ifdef _SHAPE_
	if(coeffinfo[h][w].mask==1) { 
#endif
	  dcc[k]=1;
	  mark_ZTR_D(h,w); /* here it's just to zero out descendents */
#ifdef _SHAPE_
	}
	else {
	  dcc[k]=0;
	}
#endif
	coeffinfo[h][w].quantized_value=0;