/************************************************* * libr263: fast H.263 encoder library * * Copyright (C) 1996, Roalt Aalmoes, Twente University * SPA multimedia group * * Based on Telenor TMN 1.6 encoder (Copyright (C) 1995, Telenor R&D) * created by Karl Lillevold  * * Author encoder: Roalt Aalmoes, <aalmoes@huygens.nl> *  * Date: 31-07-96 **************************************************/#include"sim.h"/* Efficient macroblock comparison op. *//* The comparison is between a non-interpolated lowres block of pixel    and a interpolated hires block of pixel. This might be confusing:   Example: compare 3x3 block with 3x3 block, then the 1s of block 1 are   compared with the 2s of block 2.   Block 1:	Block 2:	   1.1.1.	222   ......	222   1.1.1.	222   ......   1.1.1.   You see, for block one (ii), you have 4 times more data!*/
// 返回差值sad//ii為插入半象素后的圖像,curr為當(dāng)前圖像
static  int SAD_HalfPixelMacroblock(unsigned int *ii, unsigned int *curr,int pixels_on_line, int Min_SAD){  int j = 16;  int sad = 0;  while(j--) {    sad += abs(*ii-(*curr++));    ii += 2;    sad += abs(*ii-(*curr++));    ii += 2;    sad += abs(*ii-(*curr++));    ii += 2;    sad += abs(*ii- (*curr++));    ii += 2;    sad += abs(*ii-(*curr++));    ii += 2;    sad += abs(*ii-(*curr++));    ii += 2;    sad += abs(*ii-(*curr++));    ii += 2;    sad += abs(*ii-(*curr++));    ii += 2;    sad += abs(*ii-(*curr++));    ii += 2;    sad += abs(*ii-(*curr++));    ii += 2;    sad += abs(*ii-(*curr++));    ii += 2;    sad += abs(*ii-(*curr++));    ii += 2;    sad += abs(*ii-(*curr++));    ii += 2;    sad += abs(*ii-(*curr++));      ii += 2;    sad += abs(*ii-(*curr++));    ii += 2;    sad += abs(*ii-*curr);    if(sad > Min_SAD)      return INT_MAX;    ii += pixels_on_line*4 - 30;                                 /* Interpolated image, that means two times */				/* We also take only one of the two pixels */				/* This means another two times ... */    curr += pixels_on_line - 15;  } /* end while */  return sad;} /* This implementation contains two mayor algorithms: exhaustive and    logarithmic. The exhaustive algorithm was adapted to be applied on   half-pixel luminance, and the logarithmic algorithm was implemented   by Roalt Aalmoes and is functional equivalent to the one in berkeley's   MPEG encoder. */
// 宏塊運(yùn)動(dòng)估計(jì),得到運(yùn)動(dòng)矢量放入current_MV
// curr當(dāng)前圖像,prev_ipol插入后圖像,seek_dist搜索模式,x_curr當(dāng)前宏塊第一個(gè)值(0,0)在圖像中象素的位置void FullMotionEstimation(unsigned int *curr, unsigned int *prev_ipol, 		     int seek_dist, MotionVector *current_MV, int x_curr, 		     int y_curr)				/*  x_curr and y_curr are whole-pixel values to indicate upperleft (0,0) pixel of this MB in whole frame curr */{  int Min_FRAME;  MotionVector MV_FRAME;  unsigned int *curr_image_MB;  int sxy,xblock,k,yblock,l;  int RightXBorder,LeftXBorder,RightYBorder,LeftYBorder;  int xmax,ymax,sad;  int CenterX, CenterY, origCenterX, origCenterY, newCenterX, newCenterY;  int StepSizeX, StepSizeY;  curr_image_MB = curr + pels*y_curr + x_curr;

  //針對(duì)插入后的圖像操作  /* from now on, all pixel related operations are based on prev_ipol */  /* way: thus resolution is enhanced by 2 for halfpixel search */  CenterX = 2*x_curr;  CenterY = 2*y_curr;  xmax = 2*pels;  ymax = 2*lines;  sxy = mmin(31, seek_dist);  // ?????????????  LeftXBorder = CenterX - sxy;  RightXBorder = CenterX + sxy;  LeftYBorder = CenterY - sxy;  RightYBorder = CenterY + sxy;  if (LeftXBorder<0) LeftXBorder = 0;  if (RightXBorder>xmax-32) RightXBorder = xmax-32;   /* Comparison is still on 16x16 blocks */  if (LeftYBorder<0) LeftYBorder = 0;		        /* but this is interleaved by 1 pixel! */  if (RightYBorder>ymax-32) RightYBorder = ymax-32;   /* e.g. comp. pixno.1 3 5 7 or 2 4 6 8 */  /*but never 1 2 3 4 as this is halfres.*/  Min_FRAME = INT_MAX;  MV_FRAME.x = 0;  MV_FRAME.y = 0;  MV_FRAME.x_half = 0;  MV_FRAME.y_half = 0;     if(search_p_frames == CPARAM_EXHAUSTIVE)  //0  1  
  {    /* This is the spriral search variant of exhaustive seach */    /* First determine zero MV value SAD */    xblock = CenterX; yblock = CenterY;
	//sad差值    sad = SAD_HalfPixelMacroblock(prev_ipol + xblock + yblock*pels*2,curr_image_MB,pels, Min_FRAME) - PREF_NULL_VEC;     /* I assume sad < INT_MAX  */    Min_FRAME = sad;        /* Then do the surrounding MV SADs */    for (l = 1; l <= sxy; l++)
	{      /* For every loop from inside to outside do */      xblock = CenterX - l;      yblock = CenterY - l;      for (k = 0; k < 8*l; k++) 
	  {	      if (xblock>=LeftXBorder && xblock<=RightXBorder && yblock>=LeftYBorder && yblock<=RightYBorder) 
		  {		      /* 16x16 integer pel MV */		      sad = SAD_HalfPixelMacroblock(prev_ipol + xblock + yblock*pels*2,curr_image_MB,pels, Min_FRAME); 			  if (sad < Min_FRAME) 
			  {				MV_FRAME.x = xblock - CenterX;				MV_FRAME.y = yblock - CenterY;				Min_FRAME = sad;			  }		  }			if      (k<2*l) xblock++;			else if (k<4*l) yblock++;			else if (k<6*l) xblock--;			else            yblock--;      }          } /* end for */  } 
  else  /* search_p_frames == 0 */
  {     /* origCenter* is necessary because Center* changes */    origCenterX = CenterX; 
	origCenterY = CenterY;    StepSizeX = ((2*sxy + 1) + 1)/3; /* round(Size of Xinterval / 3), this is maximum size of between twoprobes */     StepSizeY = ((2*sxy + 1) + 1)/3; /* round(Size of Yinterval / 3) */
	//返回兩個(gè)16*16的總差值sad,(是整數(shù)象素還是半象素,如何確定???????)此處為整數(shù)象素    sad = SAD_HalfPixelMacroblock(prev_ipol + CenterX + CenterY*pels*2,curr_image_MB,pels, Min_FRAME) - PREF_NULL_VEC;     /* I assume sad < INT_MAX  */    Min_FRAME = sad; 
    //搜索尋找    while (StepSizeX >= 1 || StepSizeY >= 1)
	{      newCenterX = CenterX;      newCenterY = CenterY;
      /* Do this loop three times */      for(xblock = CenterX - StepSizeX; xblock <= CenterX + StepSizeX &&(StepSizeX != 0); xblock += StepSizeX) 
	  {	       if(xblock < LeftXBorder || xblock > RightXBorder)	         continue;	       /* Do this loop three times */	       for(yblock = CenterY - StepSizeY; yblock <= CenterY + StepSizeY && (StepSizeY != 0); yblock+= StepSizeY)
		   {	           if(yblock < LeftYBorder || yblock > RightYBorder)	              continue;			  /* In fact, the middlest comparison is only required 				 the first time, as the last time it is calculated 				 on the previous while-loop, remember:				 NewCenterZ = zblock */
               //比較	           sad = SAD_HalfPixelMacroblock(prev_ipol + xblock + yblock*pels*2,curr_image_MB,pels, Min_FRAME); 			   if (sad < Min_FRAME)
			   {					MV_FRAME.x = xblock - origCenterX;					MV_FRAME.y = yblock - origCenterY;					Min_FRAME = sad;					newCenterX = xblock; newCenterY = yblock;			   }		   }/* end for yblock */      } /* end for xblock */      if(newCenterX < CenterX) 
	  {	       RightXBorder = LeftXBorder + StepSizeX - 1;      } 
	  else if(newCenterX == CenterX) 
	  {	       LeftXBorder = LeftXBorder + StepSizeX;           RightXBorder = RightXBorder - StepSizeX;      } 
	  else 
	  {	       LeftXBorder = RightXBorder - StepSizeX + 1;      }      if(newCenterY < CenterY)
	  {	       RightYBorder = LeftYBorder + StepSizeY - 1;      }  
	  else if(newCenterY == CenterY) 
	  {			LeftYBorder = LeftYBorder + StepSizeY;			RightYBorder = RightYBorder - StepSizeY;      } 
	  else 
	  {	        LeftYBorder = RightYBorder - StepSizeY + 1;      }      CenterX = newCenterX;      CenterY = newCenterY;      /* Stepsizes are 0 when RightZBorder == LeftZBorder */      StepSizeX = ((RightXBorder - LeftXBorder + 1) + 1)/3;       /* round(Size of Xinterval / 3), this is maximum size of between two	 probes */       StepSizeY = ((RightYBorder - LeftYBorder + 1) + 1)/3;       /* round(Size of Yinterval / 3) */          } /* End while stepsize */  } /* end logarithmic search algorithm */    current_MV->x = MV_FRAME.x / 2;  current_MV->x_half = MV_FRAME.x % 2; /*This might not work for neg. values!*/  current_MV->y = MV_FRAME.y / 2;  current_MV->y_half = MV_FRAME.y % 2; /* This might not work! */  current_MV->min_error = Min_FRAME;  return;}//比較當(dāng)前塊與附近相同大小塊的誤差值int SAD_HalfPixelMacroblock2(unsigned int *ii,unsigned int *curr,int pixels_on_line, int Min_SAD){  int j = 16;  int sad = 0;  while(j--) {    sad += abs(*ii-(*curr));    sad += abs(*(ii + 2)-(*(curr+1)));    sad += abs(*(ii + 4)-(*(curr+2)));    sad += abs(*(ii + 6)-(*(curr+3)));    sad += abs(*(ii + 8)-(*(curr+4)));    sad += abs(*(ii + 10)-(*(curr+5)));    sad += abs(*(ii + 12)-(*(curr+6)));    sad += abs(*(ii + 14)-(*(curr+7)));    sad += abs(*(ii + 16)-(*(curr+8)));    sad += abs(*(ii + 18)-(*(curr+9)));    sad += abs(*(ii + 20)-(*(curr+10)));    sad += abs(*(ii + 22)-(*(curr+11)));    sad += abs(*(ii + 24)-(*(curr+12)));    sad += abs(*(ii + 26)-(*(curr+13)));    sad += abs(*(ii + 28)-(*(curr+14)));    sad += abs(*(ii + 30)-(*(curr+15)));    if(sad > Min_SAD)      return INT_MAX;    ii += pixels_on_line*2*2;                                 /* Interpolated image, that means two times */				/* We also take only one of the two pixels */				/* This means another two times ... */    curr += pixels_on_line;  } /* end while */  return sad;} unsigned int *LoadArea(unsigned int *im, int x, int y, 			int x_size, int y_size, int lx){  unsigned int *res = (unsigned int *)malloc(sizeof(int)*x_size*y_size);  unsigned int *in;  unsigned int *out;  int i = x_size;  int j = y_size;  in = im + (y*lx) + x;  out = res;  while (j--) {    while (i--)      *out++ = *in++;    i = x_size;    in += lx - x_size;  };  return res;}//定位宏塊,從原圖像(x,y)處開(kāi)始,得到一個(gè)宏塊16*16的值void FindMB(int x, int y, unsigned int *image, unsigned int MB[16][16]){  int n;  unsigned int *MB_ptr = &MB[0][0];  unsigned int *image_ptr;  MB_ptr = &MB[0][0];  image_ptr = image + x + y*pels;#ifdef LONGISDOUBLEINT  for(n = 0; n < 16; n++) {    * (unsigned long *) MB_ptr = * (unsigned long *) image_ptr;     MB_ptr += 2; image_ptr += 2;    * (unsigned long *) MB_ptr = * (unsigned long *) image_ptr;     MB_ptr += 2; image_ptr += 2;    * (unsigned long *) MB_ptr = * (unsigned long *) image_ptr;     MB_ptr += 2; image_ptr += 2;    * (unsigned long *) MB_ptr = * (unsigned long *) image_ptr;     MB_ptr += 2; image_ptr += 2;    * (unsigned long *) MB_ptr = * (unsigned long *) image_ptr;     MB_ptr += 2; image_ptr += 2;    * (unsigned long *) MB_ptr = * (unsigned long *) image_ptr;     MB_ptr += 2; image_ptr += 2;    * (unsigned long *) MB_ptr = * (unsigned long *) image_ptr;     MB_ptr += 2; image_ptr += 2;    * (unsigned long *) MB_ptr = * (unsigned long *) image_ptr;     MB_ptr += 2; image_ptr += 2;        image_ptr += pels - 16;  }#else  for (n = 0; n < 16; n++) {    *(unsigned int *) MB_ptr++ = *(unsigned int *) image_ptr++;    *(unsigned int *) MB_ptr++ = *(unsigned int *) image_ptr++;    *(unsigned int *) MB_ptr++ = *(unsigned int *) image_ptr++;    *(unsigned int *) MB_ptr++ = *(unsigned int *) image_ptr++;    *(unsigned int *) MB_ptr++ = *(unsigned int *) image_ptr++;    *(unsigned int *) MB_ptr++ = *(unsigned int *) image_ptr++;    *(unsigned int *) MB_ptr++ = *(unsigned int *) image_ptr++;    *(unsigned int *) MB_ptr++ = *(unsigned int *) image_ptr++;    *(unsigned int *) MB_ptr++ = *(unsigned int *) image_ptr++;    *(unsigned int *) MB_ptr++ = *(unsigned int *) image_ptr++;    *(unsigned int *) MB_ptr++ = *(unsigned int *) image_ptr++;    *(unsigned int *) MB_ptr++ = *(unsigned int *) image_ptr++;    *(unsigned int *) MB_ptr++ = *(unsigned int *) image_ptr++;    *(unsigned int *) MB_ptr++ = *(unsigned int *) image_ptr++;    *(unsigned int *) MB_ptr++ = *(unsigned int *) image_ptr++;    *(unsigned int *) MB_ptr++ = *(unsigned int *) image_ptr++;    image_ptr += pels - 16;  }#endif}