/************************************************* * 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"
// 插入圖像和當(dāng)前圖像x,y處宏塊的差值(宏塊結(jié)構(gòu))
//curr_image當(dāng)前宏塊,prev_image重建圖像,prev_ipol插入圖像,x,y當(dāng)前宏塊象素位置,MV_ptr圖像mv值MB_Structure *Predict_P(unsigned int *curr_image, unsigned int *prev_image,			unsigned int *prev_ipol, int x, int y, 			MotionVector *MV_ptr){  int m,n;  int curr[16][16];  int pred[16][16];  MotionVector *fr0;  int dx, dy;  int xmb, ymb;  MB_Structure *pred_error;  pred_error = (MB_Structure *)malloc(sizeof(MB_Structure));      xmb = x/MB_SIZE;  ymb = y/MB_SIZE;  fr0 = MV_ptr + ymb*mbc + xmb;// mv矢量  /* Find MB in current image */
  //從(x,y)處,開(kāi)始,得到當(dāng)前數(shù)據(jù)宏塊curr[16][16]  FindMB(x, y, curr_image, curr);
  /* Find prediction based on half pel MV */
  // 從插入圖像prev_ipol的相對(duì)位置,取出對(duì)應(yīng)的原始宏塊值,放入pred[16][16]中  FindPred(x, y, fr0, prev_ipol, &pred[0][0]);  /* Do the actual prediction */  if (fr0->Mode == MODE_INTER) 
  {
	 //預(yù)測(cè)差值    for (n = 0; n < MB_SIZE; n++)      for (m = 0; m < MB_SIZE; m++) 	        pred_error->lum[n][m] = (int)(curr[n][m] - pred[n][m]);//差值    dx = 2*fr0->x + fr0->x_half;    dy = 2*fr0->y + fr0->y_half;    dx = ( dx % 4 == 0 ? dx >> 1 : (dx>>1)|1 );    dy = ( dy % 4 == 0 ? dy >> 1 : (dy>>1)|1 );

    DoPredChrom_P(x, y, dx, dy, curr_image, prev_image, pred_error);  }  else    fprintf(stderr,"Illegal Mode in Predict_P (pred.c)\n");  return pred_error;}

//預(yù)測(cè)色度塊   ?????????void DoPredChrom_P(int x_curr, int y_curr, int dx, int dy,		   unsigned int *curr, unsigned int *prev, 		   MB_Structure *pred_error){  int m,n;  int x, y, ofx, ofy, pel, lx;  int xint, yint;  int xh, yh;  lx = pels/2;  x = x_curr>>1;  y = y_curr>>1;  xint = dx>>1;  xh = dx & 1;  yint = dy>>1;  yh = dy & 1;  if (!xh && !yh) {    for (n = 0; n < 8; n++) {      for (m = 0; m < 8; m++) {	ofx = x + xint + m;	ofy = y + yint + n;
	/* prev+vskip does not work directly... */	pel=*(prev+vskip + ofx    + (ofy   )*lx);	pred_error->Cr[n][m] = (int)(*(curr+vskip + x+m + (y+n)*cpels) - pel);	pel=*(prev+uskip + ofx    + (ofy   )*lx);	pred_error->Cb[n][m] = (int)(*(curr + uskip + x+m + (y+n)*cpels) - pel);      }    }  }  else if (!xh && yh) {    for (n = 0; n < 8; n++) {      for (m = 0; m < 8; m++) {	ofx = x + xint + m;	ofy = y + yint + n;	pel=(*(prev+vskip + ofx    + (ofy   )*lx)+	     *(prev+vskip + ofx    + (ofy+yh)*lx) + 1)>>1;	pred_error->Cr[n][m] = 	  (int)(*(curr+vskip + x+m + (y+n)*cpels) - pel);	pel=(*(prev+uskip + ofx    + (ofy   )*lx)+	     *(prev+uskip + ofx    + (ofy+yh)*lx) + 1)>>1;	pred_error->Cb[n][m] = 	  (int)(*( curr+uskip + x+m + (y+n)*cpels) - pel);            }    }  }  else if (xh && !yh) {    for (n = 0; n < 8; n++) {      for (m = 0; m < 8; m++) {	ofx = x + xint + m;	ofy = y + yint + n;	pel=(*(prev+vskip+ofx    + (ofy   )*lx)+	     *(prev+vskip+ofx+xh + (ofy   )*lx) + 1)>>1;	pred_error->Cr[n][m] = 	  (int)(*(curr+vskip + x+m + (y+n)*cpels) - pel);	pel=(*(prev+uskip+ofx    + (ofy   )*lx)+	     *(prev+uskip+ofx+xh + (ofy   )*lx) + 1)>>1;	pred_error->Cb[n][m] = 	  (int)( *( curr+uskip + x+m + (y+n)*cpels) - pel);            }    }  }  else { /* xh && yh */    for (n = 0; n < 8; n++) {      for (m = 0; m < 8; m++) {	ofx = x + xint + m;	ofy = y + yint + n;	pel=(*(prev+vskip+ofx    + (ofy   )*lx)+	     *(prev+vskip+ofx+xh + (ofy   )*lx)+	     *(prev+vskip+ofx    + (ofy+yh)*lx)+	     *(prev+vskip+ofx+xh + (ofy+yh)*lx)+	     2)>>2;	pred_error->Cr[n][m] = 	  (int)(*(curr+vskip + x+m + (y+n)*cpels) - pel);	pel=(*(prev+uskip+ofx    + (ofy   )*lx)+	     *(prev+uskip+ofx+xh + (ofy   )*lx)+	     *(prev+uskip+ofx    + (ofy+yh)*lx)+	     *(prev+uskip+ofx+xh + (ofy+yh)*lx)+	     2)>>2;	pred_error->Cb[n][m] = 	  (int)(*(curr+uskip + x+m + (y+n)*cpels) - pel);            }    }  }  return;}
// 找到運(yùn)動(dòng)矢量對(duì)應(yīng)的插入圖像中的宏塊的值,xy宏塊位置,fr為矢量,prev插入圖像,放入pred[16][16]中void FindPred(int x, int y, MotionVector *fr, unsigned int *prev, int *pred){  int n;  int new_x, new_y;  int *prev_ptr;
  // 新的位置  new_x = 2*(x + fr->x) + fr->x_half;  new_y = 2*(y + fr->y) + fr->y_half;  prev_ptr =  (int *) prev + 2*new_y*pels + new_x;  /* Fill pred. data */  for (n = 0; n < 16; n++) {    /* Interpolated data -> too bad it can't be done in longs... */      *(pred++) = *(prev_ptr);      prev_ptr += 2;       *(pred++) = *(prev_ptr);      prev_ptr += 2;       *(pred++) = *(prev_ptr);      prev_ptr += 2;       *(pred++) = *(prev_ptr);      prev_ptr += 2;       *(pred++) = *(prev_ptr);      prev_ptr += 2;       *(pred++) = *(prev_ptr);      prev_ptr += 2;       *(pred++) = *(prev_ptr);      prev_ptr += 2;       *(pred++) = *(prev_ptr);      prev_ptr += 2;       *(pred++) = *(prev_ptr);      prev_ptr += 2;       *(pred++) = *(prev_ptr);      prev_ptr += 2;       *(pred++) = *(prev_ptr);      prev_ptr += 2;       *(pred++) = *(prev_ptr);      prev_ptr += 2;       *(pred++) = *(prev_ptr);      prev_ptr += 2;       *(pred++) = *(prev_ptr);      prev_ptr += 2;       *(pred++) = *(prev_ptr);      prev_ptr += 2;       *(pred++) = *(prev_ptr);      prev_ptr += pels*4 - 30;  }  return;}//p幀中重建宏塊MB_Structure *MB_Recon_P(unsigned int *prev_image, unsigned int *prev_ipol,			 MB_Structure *diff, int x_curr, int y_curr, 			 MotionVector *MV_ptr){  MB_Structure *recon_data = (MB_Structure *)malloc(sizeof(MB_Structure));  MotionVector *fr0;  int dx, dy;  fr0 = MV_ptr + (y_curr/MB_SIZE)*mbc + (x_curr/MB_SIZE);  if (fr0->Mode == MODE_INTER) {      /* Inter 16x16 */    ReconLumBlock_P(x_curr,y_curr,fr0,prev_ipol,&diff->lum[0][0]);        dx = 2*fr0->x + fr0->x_half;    dy = 2*fr0->y + fr0->y_half;    dx = ( dx % 4 == 0 ? dx >> 1 : (dx>>1)|1 );    dy = ( dy % 4 == 0 ? dy >> 1 : (dy>>1)|1 );    ReconChromBlock_P(x_curr, y_curr, dx, dy, prev_image, diff);  }  memcpy(recon_data, diff, sizeof(MB_Structure));  return recon_data;}

void ReconLumBlock_P(int x, int y, MotionVector *fr, 		     unsigned int *prev, int *data){  int m, n;  int x1, y1;  int *data_ptr = data;  unsigned int *prev_ptr;  x1 = 2*(x + fr->x) + fr->x_half;  y1 = 2*(y + fr->y) + fr->y_half;    prev_ptr = prev + x1 + y1*2*pels;  for (n = 0; n < 16; n++) {    for (m = 0; m < 16; m++) {      *data_ptr++ += (int)(*prev_ptr);      prev_ptr += 2;    }    prev_ptr += 2*2*pels - 32;  }  return;}void ReconChromBlock_P(int x_curr, int y_curr, int dx, int dy,		       unsigned int *prev, MB_Structure *data){  int m,n;  int x, y, ofx, ofy, pel,lx;  int xint, yint;  int xh, yh;  lx = pels/2;  x = x_curr>>1;  y = y_curr>>1;  xint = dx>>1;  xh = dx & 1;  yint = dy>>1;  yh = dy & 1;      if (!xh && !yh) {    for (n = 0; n < 8; n++) {      for (m = 0; m < 8; m++) {	ofx = x + xint + m;	ofy = y + yint + n;	pel=*(prev+vskip+ ofx    + (ofy   )*lx);	data->Cr[n][m] += pel;	pel=*(prev+uskip + ofx    + (ofy   )*lx);	data->Cb[n][m] += pel;      }    }  }  else if (!xh && yh) {    for (n = 0; n < 8; n++) {      for (m = 0; m < 8; m++) {	ofx = x + xint + m;	ofy = y + yint + n;	pel=(*(prev+vskip+ ofx    + (ofy   )*lx)+	     *(prev+vskip+ ofx    + (ofy+yh)*lx) + 1)>>1;	data->Cr[n][m] += pel;	pel=(*(prev+uskip+ofx    + (ofy   )*lx)+	     *(prev+uskip+ofx    + (ofy+yh)*lx) + 1)>>1;	data->Cb[n][m] += pel;            }    }  }  else if (xh && !yh) {    for (n = 0; n < 8; n++) {      for (m = 0; m < 8; m++) {	ofx = x + xint + m;	ofy = y + yint + n;	pel=(*(prev+vskip+ofx    + (ofy   )*lx)+	     *(prev+vskip+ofx+xh + (ofy   )*lx) + 1)>>1;	data->Cr[n][m] += pel;	pel=(*(prev+uskip+ofx    + (ofy   )*lx)+	     *(prev+uskip+ofx+xh + (ofy   )*lx) + 1)>>1;	data->Cb[n][m] += pel;            }    }  }  else { /* xh && yh */    for (n = 0; n < 8; n++) {      for (m = 0; m < 8; m++) {	ofx = x + xint + m;	ofy = y + yint + n;	pel=(*(prev+vskip+ofx    + (ofy   )*lx)+	     *(prev+vskip+ofx+xh + (ofy   )*lx)+	     *(prev+vskip+ofx    + (ofy+yh)*lx)+	     *(prev+vskip+ofx+xh + (ofy+yh)*lx)+	     2)>>2;	data->Cr[n][m] += pel;	pel=(*(prev+uskip+ofx    + (ofy   )*lx)+	     *(prev+uskip+ofx+xh + (ofy   )*lx)+	     *(prev+uskip+ofx    + (ofy+yh)*lx)+	     *(prev+uskip+ofx+xh + (ofy+yh)*lx)+	     2)>>2;	data->Cb[n][m] += pel;            }    }  }  return;}void FindChromBlock_P(int x_curr, int y_curr, int dx, int dy,		      unsigned int *prev, MB_Structure *data){  int m,n;  int x, y, ofx, ofy, pel,lx;  int xint, yint;  int xh, yh;  lx = pels/2;  x = x_curr>>1;  y = y_curr>>1;  xint = dx>>1;  xh = dx & 1;  yint = dy>>1;  yh = dy & 1;      if (!xh && !yh) {    for (n = 0; n < 8; n++) {      for (m = 0; m < 8; m++) {	ofx = x + xint + m;	ofy = y + yint + n;	pel=*(prev+vskip+ofx    + (ofy   )*lx);	data->Cr[n][m] = pel;	pel=*(prev+uskip+ofx    + (ofy   )*lx);	data->Cb[n][m] = pel;      }    }  }  else if (!xh && yh) {    for (n = 0; n < 8; n++) {      for (m = 0; m < 8; m++) {	ofx = x + xint + m;	ofy = y + yint + n;	pel=(*(prev+vskip+ofx    + (ofy   )*lx)+	     *(prev+vskip+ofx    + (ofy+yh)*lx) + 1)>>1;	data->Cr[n][m] = pel;	pel=(*(prev+uskip+ofx    + (ofy   )*lx)+	     *(prev+uskip+ofx    + (ofy+yh)*lx) + 1)>>1;	data->Cb[n][m] = pel;            }    }  }  else if (xh && !yh) {    for (n = 0; n < 8; n++) {      for (m = 0; m < 8; m++) {	ofx = x + xint + m;	ofy = y + yint + n;	pel=(*(prev+vskip+ofx    + (ofy   )*lx)+	     *(prev+vskip+ofx+xh + (ofy   )*lx) + 1)>>1;	data->Cr[n][m] = pel;	pel=(*(prev+uskip+ofx    + (ofy   )*lx)+	     *(prev+uskip+ofx+xh + (ofy   )*lx) + 1)>>1;	data->Cb[n][m] = pel;            }    }  }  else { /* xh && yh */    for (n = 0; n < 8; n++) {      for (m = 0; m < 8; m++) {	ofx = x + xint + m;	ofy = y + yint + n;	pel=(*(prev+vskip+ofx    + (ofy   )*lx)+	     *(prev+vskip+ofx+xh + (ofy   )*lx)+	     *(prev+vskip+ofx    + (ofy+yh)*lx)+	     *(prev+vskip+ofx+xh + (ofy+yh)*lx)+	     2)>>2;	data->Cr[n][m] = pel;	pel=(*(prev+uskip+ofx    + (ofy   )*lx)+	     *(prev+uskip+ofx+xh + (ofy   )*lx)+	     *(prev+uskip+ofx    + (ofy+yh)*lx)+	     *(prev+uskip+ofx+xh + (ofy+yh)*lx)+	     2)>>2;	data->Cb[n][m] = pel;            }    }  }  return;}//curr當(dāng)前圖像,x,y位置的宏塊, min_SAD當(dāng)前mv的誤差差值
//此宏塊的整體方差較小時(shí),A小于(inter誤差 - 500)時(shí),用interint ChooseMode(unsigned int *curr, int x_pos, int y_pos, int min_SAD){  int i,j;  int MB_mean = 0, A = 0;  int y_off;  for (j = 0; j < MB_SIZE; j++)
  {    y_off = (y_pos + j) * pels;    for (i = 0; i < MB_SIZE; i++) 
	{      MB_mean += *(curr + x_pos + i + y_off);    }  }
  MB_mean /= (MB_SIZE*MB_SIZE);  for (j = 0; j < MB_SIZE; j++) 
  {    y_off = (y_pos + j) * pels;    for (i = 0; i < MB_SIZE; i++) 
	{      A += abs( *(curr + x_pos + i + y_off) - MB_mean );    }  }
  //16*16的方差較小時(shí),用intra  if (A < (min_SAD - 500))     return MODE_INTRA;  else    return MODE_INTER;}