b_frame.c

包含了从MPEG4的视频解码到H.264的视频编码部分的源代码

/*
***********************************************************************
* COPYRIGHT AND WARRANTY INFORMATION
*
* Copyright 2001, International Telecommunications Union, Geneva
*
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*
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* use of these programs.
*
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*
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* hereunder are free of infringement of any third-party patents.
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/*!
 *************************************************************************************
 * \file b_frame.c
 *
 * \brief
 *    B picture decoding
 *
 * \author
 *    Main contributors (see contributors.h for copyright, address and affiliation details)
 *    - Byeong-Moon Jeon                <[e-mail]>
 *    - Yoon-Seong Soh                  <[e-mail]>
 *    - Thomas Wedi                     <[e-mail]>
 *************************************************************************************
 */

#include <stdlib.h>
#include <math.h>
#include <string.h>

#include "global.h"
#include "mbuffer.h"
#include "b_frame.h"

/*!
 ************************************************************************
 * \brief
 *    Copy decoded P frame to temporary image array
 ************************************************************************
 */
void copy_Pframe(struct img_par *img)
{
  int i,j;

  /*
   * the mmin, mmax macros are taken out, because it makes no sense due to limited range of data type
   */
  
  for(i=0;i<img->height;i++)
    for(j=0;j<img->width;j++)
    {
      imgY_prev[i][j] = imgY[i][j];
    }
  for(i=0;i<img->height_cr;i++)
    for(j=0;j<img->width_cr;j++)
    {
      imgUV_prev[0][i][j] = imgUV[0][i][j];
    }
  for(i=0;i<img->height_cr;i++)
    for(j=0;j<img->width_cr;j++)
    {
      imgUV_prev[1][i][j] = imgUV[1][i][j];
    }
}




/*!
 ************************************************************************
 * \brief
 *    init macroblock B frames
 ************************************************************************
 */
void init_macroblock_Bframe(struct img_par *img)
{
  int i,j,k;
  int img_block_y;
  int j2 = img->block_y; 
  Macroblock *currMB = &img->mb_data[img->map_mb_nr];//GB current_mb_nr];

  if (img->mb_frame_field_flag)
    j2 = img->block_y/2 - 2*(img->current_mb_nr%2);

  // reset vectors and pred. modes
  for (i=0;i<BLOCK_SIZE;i++)
  {
    for(j=0;j<BLOCK_SIZE;j++)
    {
      img->fw_mv_frm[img->block_x+i+4][img->block_y+j][0]=img->fw_mv_frm[img->block_x+i+4][img->block_y+j][1]=0;
      img->bw_mv_frm[img->block_x+i+4][img->block_y+j][0]=img->bw_mv_frm[img->block_x+i+4][img->block_y+j][1]=0;
      img->dfMV [img->block_x+i+4][img->block_y+j][0]=img->dfMV[img->block_x+i+4][img->block_y+j][1]=0;
      img->dbMV [img->block_x+i+4][img->block_y+j][0]=img->dbMV[img->block_x+i+4][img->block_y+j][1]=0;
      img->ipredmode[img->block_x+i+1][img->block_y+j+1] = DC_PRED;
      if (img->mb_frame_field_flag)
      {
        img->dfMV_top[img->block_x+i+4][img->block_y+j][0]=img->dfMV_top[img->block_x+i+4][img->block_y+j][1]=0;
        img->dbMV_top[img->block_x+i+4][img->block_y+j][0]=img->dbMV_top[img->block_x+i+4][img->block_y+j][1]=0;
        
        img->dfMV_bot[img->block_x+i+4][img->block_y+j][0]=img->dfMV_bot[img->block_x+i+4][img->block_y+j][1]=0;
        img->dbMV_bot[img->block_x+i+4][img->block_y+j][0]=img->dbMV_bot[img->block_x+i+4][img->block_y+j][1]=0;
      }
      if (img->current_mb_nr%2==0 && img->mb_frame_field_flag)
      {
        img->ipredmode_top[img->block_x+i+1][j2+j+1] = DC_PRED;
        img->fw_mv_top[img->block_x+i+4][j2+j][0]=img->fw_mv_top[img->block_x+i+4][j2+j][1]=0;
        img->bw_mv_top[img->block_x+i+4][j2+j][0]=img->bw_mv_top[img->block_x+i+4][j2+j][1]=0;
      }
      else if (img->mb_frame_field_flag)
      {
        img->ipredmode_bot[img->block_x+i+1][j2+j+1] = DC_PRED;
        img->fw_mv_bot[img->block_x+i+4][j2+j][0]=img->fw_mv_bot[img->block_x+i+4][j2+j][1]=0;
        img->bw_mv_bot[img->block_x+i+4][j2+j][0]=img->bw_mv_bot[img->block_x+i+4][j2+j][1]=0;
      }
      else
      {
        img->fw_mv[img->block_x+i+4][img->block_y+j][0]=img->fw_mv[img->block_x+i+4][img->block_y+j][1]=0;
        img->bw_mv[img->block_x+i+4][img->block_y+j][0]=img->bw_mv[img->block_x+i+4][img->block_y+j][1]=0;
      }
    }
  }

  // Set the reference frame information for motion vector prediction
  if (IS_INTRA (currMB) || IS_DIRECT (currMB))
  {
    if (img->structure != FRAME || img->mb_frame_field_flag == 0)
    {
      for (j=0; j<4; j++)
        for (i=0; i<4; i++)
        {
          img->fw_refFrArr[img->block_y+j][img->block_x+i] = -1;
          img->bw_refFrArr[img->block_y+j][img->block_x+i] = -1;
        }
    }
    else 
    {
      if (img->current_mb_nr%2==0)
      {
        img_block_y   = img->block_y/2;
        for (j=0; j<4; j++)
          for (i=0; i<4; i++)
          {
            img->fw_refFrArr_top[img_block_y+j][img->block_x+i] = -1;
            img->fw_refFrArr_frm[img->block_y+j][img->block_x+i] = -1;
            img->bw_refFrArr_top[img_block_y+j][img->block_x+i] = -1;
            img->bw_refFrArr_frm[img->block_y+j][img->block_x+i] = -1;
          }
      }
      else
      {
        img_block_y   = (img->block_y-4)/2;
        for (j=0; j<4; j++)
          for (i=0; i<4; i++)
          {
            img->fw_refFrArr_bot[img_block_y+j][img->block_x+i] = -1;
            img->fw_refFrArr_frm[img->block_y+j][img->block_x+i] = -1;
            img->bw_refFrArr_bot[img_block_y+j][img->block_x+i] = -1;
            img->bw_refFrArr_frm[img->block_y+j][img->block_x+i] = -1;
          }
      }
    }
  }
  else
  {
    for(j=0;j<4;j++)
      for(i=0;i<4;i++)
      {
        k=2*(j/2)+(i/2);
        if(img->structure != FRAME)
        {
          img->fw_refFrArr[img->block_y+j][img->block_x+i] = ((currMB->b8pdir[k]==0||currMB->b8pdir[k]==2)&&currMB->b8mode[k]!=0?2:-1);
          img->bw_refFrArr[img->block_y+j][img->block_x+i] = ((currMB->b8pdir[k]==1||currMB->b8pdir[k]==2)&&currMB->b8mode[k]!=0?0:-1);
        }
        else if (img->mb_frame_field_flag)
        {
          if (img->current_mb_nr%2==0)
          {
            img_block_y   = img->block_y/2;
            img->fw_refFrArr_top[img_block_y+j][img->block_x+i] = ((currMB->b8pdir[k]==0||currMB->b8pdir[k]==2)&&currMB->b8mode[k]!=0?0:-1);
            img->bw_refFrArr_top[img_block_y+j][img->block_x+i] = ((currMB->b8pdir[k]==1||currMB->b8pdir[k]==2)&&currMB->b8mode[k]!=0?0:-1);
            img->fw_refFrArr_frm[img->block_y+j][img->block_x+i] = ((currMB->b8pdir[k]==0||currMB->b8pdir[k]==2)&&currMB->b8mode[k]!=0?0:-1);
            img->bw_refFrArr_frm[img->block_y+j][img->block_x+i] = ((currMB->b8pdir[k]==1||currMB->b8pdir[k]==2)&&currMB->b8mode[k]!=0?0:-1);
          }
          else
          {
            img_block_y   = (img->block_y-4)/2;
            img->fw_refFrArr_bot[img_block_y+j][img->block_x+i] = ((currMB->b8pdir[k]==0||currMB->b8pdir[k]==2)&&currMB->b8mode[k]!=0?0:-1);
            img->bw_refFrArr_bot[img_block_y+j][img->block_x+i] = ((currMB->b8pdir[k]==1||currMB->b8pdir[k]==2)&&currMB->b8mode[k]!=0?0:-1);
            img->fw_refFrArr_frm[img->block_y+j][img->block_x+i] = ((currMB->b8pdir[k]==0||currMB->b8pdir[k]==2)&&currMB->b8mode[k]!=0?0:-1);
            img->bw_refFrArr_frm[img->block_y+j][img->block_x+i] = ((currMB->b8pdir[k]==1||currMB->b8pdir[k]==2)&&currMB->b8mode[k]!=0?0:-1);
          }
        }
        else
        {
          img->fw_refFrArr[img->block_y+j][img->block_x+i] = ((currMB->b8pdir[k]==0||currMB->b8pdir[k]==2)&&currMB->b8mode[k]!=0?0:-1);
          img->bw_refFrArr[img->block_y+j][img->block_x+i] = ((currMB->b8pdir[k]==1||currMB->b8pdir[k]==2)&&currMB->b8mode[k]!=0?0:-1);
        }
      }
  }
}