recon.c

H.263的压缩算法

static void recho (unsigned char *s, int *d, int lx, int lx2, 
                   int addflag, int c, int xa, int xb, int ya, int yb)
{
  int *dp, *om;
  unsigned char *sp;
  int i, j;

  sp = s;
  dp = d;
  om = &OM[c][ya][0];

  if (!addflag)
  {
    for (j = ya; j < yb; j++)
    {
      for (i = xa; i < xb; i++)
      {
        dp[i] = (((unsigned int) (sp[i] + sp[i + 1] + 1 - rtype)) >> 1) * om[i];
      }
      sp += lx2;
      dp += lx;
      om += 8;
    }
  } else
  {
    for (j = ya; j < yb; j++)
    {
      for (i = xa; i < xb; i++)
      {
        dp[i] += (((unsigned int) (sp[i] + sp[i + 1] + 1 - rtype)) >> 1) * OM[c][j][i];
      }
      sp += lx2;
      dp += lx;
      om += 8;
    }
  }
}

static void recv (unsigned char *s, unsigned char *d, 
                  int lx, int lx2, int h)
{
  unsigned char *dp, *sp, *sp2;
  int j;

  sp = s;
  sp2 = s + lx2;
  dp = d;
  for (j = 0; j < h; j++)
  {
    dp[0] = (unsigned int) (sp[0] + sp2[0] + 1 - rtype) >> 1;
    dp[1] = (unsigned int) (sp[1] + sp2[1] + 1 - rtype) >> 1;
    dp[2] = (unsigned int) (sp[2] + sp2[2] + 1 - rtype) >> 1;
    dp[3] = (unsigned int) (sp[3] + sp2[3] + 1 - rtype) >> 1;
    dp[4] = (unsigned int) (sp[4] + sp2[4] + 1 - rtype) >> 1;
    dp[5] = (unsigned int) (sp[5] + sp2[5] + 1 - rtype) >> 1;
    dp[6] = (unsigned int) (sp[6] + sp2[6] + 1 - rtype) >> 1;
    dp[7] = (unsigned int) (sp[7] + sp2[7] + 1 - rtype) >> 1;
    dp[8] = (unsigned int) (sp[8] + sp2[8] + 1 - rtype) >> 1;
    dp[9] = (unsigned int) (sp[9] + sp2[9] + 1 - rtype) >> 1;
    dp[10] = (unsigned int) (sp[10] + sp2[10] + 1 - rtype) >> 1;
    dp[11] = (unsigned int) (sp[11] + sp2[11] + 1 - rtype) >> 1;
    dp[12] = (unsigned int) (sp[12] + sp2[12] + 1 - rtype) >> 1;
    dp[13] = (unsigned int) (sp[13] + sp2[13] + 1 - rtype) >> 1;
    dp[14] = (unsigned int) (sp[14] + sp2[14] + 1 - rtype) >> 1;
    dp[15] = (unsigned int) (sp[15] + sp2[15] + 1 - rtype) >> 1;
    sp += lx2;
    sp2 += lx2;
    dp += lx;
  }
}

static void recvc (unsigned char *s, unsigned char *d, 
                   int lx, int lx2, int h)
{
  unsigned char *dp, *sp, *sp2;
  int j;

  sp = s;
  sp2 = s + lx2;
  dp = d;

  for (j = 0; j < h; j++)
  {
    dp[0] = (unsigned int) (sp[0] + sp2[0] + 1 - rtype) >> 1;
    dp[1] = (unsigned int) (sp[1] + sp2[1] + 1 - rtype) >> 1;
    dp[2] = (unsigned int) (sp[2] + sp2[2] + 1 - rtype) >> 1;
    dp[3] = (unsigned int) (sp[3] + sp2[3] + 1 - rtype) >> 1;
    dp[4] = (unsigned int) (sp[4] + sp2[4] + 1 - rtype) >> 1;
    dp[5] = (unsigned int) (sp[5] + sp2[5] + 1 - rtype) >> 1;
    dp[6] = (unsigned int) (sp[6] + sp2[6] + 1 - rtype) >> 1;
    dp[7] = (unsigned int) (sp[7] + sp2[7] + 1 - rtype) >> 1;
    sp += lx2;
    sp2 += lx2;
    dp += lx;
  }
}

static void recvo (unsigned char *s, int *d, int lx, int lx2, 
                   int addflag, int c, int xa, int xb, int ya, 
                   int yb)
{
  int *dp, *om;
  unsigned char *sp, *sp2;
  int i, j;

  sp = s;
  sp2 = s + lx2;
  dp = d;
  om = &OM[c][ya][0];

  if (!addflag)
  {
    for (j = ya; j < yb; j++)
    {
      for (i = xa; i < xb; i++)
      {
        dp[i] = (((unsigned int) (sp[i] + sp2[i] + 1 - rtype)) >> 1) * om[i];
      }
      sp += lx2;
      sp2 += lx2;
      dp += lx;
      om += 8;
    }
  } else
  {
    for (j = ya; j < yb; j++)
    {
      for (i = xa; i < xb; i++)
      {
        dp[i] += (((unsigned int) (sp[i] + sp2[i] + 1 - rtype)) >> 1) * om[i];
      }
      sp += lx2;
      sp2 += lx2;
      dp += lx;
      om += 8;
    }
  }
}

static void rec4 (unsigned char *s, unsigned char *d, 
                  int lx, int lx2, int h)
{
  unsigned char *dp, *sp, *sp2;
  int j;
  unsigned int s1, s2, s3, s4;

  sp = s;
  sp2 = s + lx2;
  dp = d;
  for (j = 0; j < h; j++)
  {
    s1 = sp[0];
    s3 = sp2[0];
    dp[0] = (unsigned int) (s1 + (s2 = sp[1]) + s3 + (s4 = sp2[1]) + 2 - rtype) >> 2;
    dp[1] = (unsigned int) (s2 + (s1 = sp[2]) + s4 + (s3 = sp2[2]) + 2 - rtype) >> 2;
    dp[2] = (unsigned int) (s1 + (s2 = sp[3]) + s3 + (s4 = sp2[3]) + 2 - rtype) >> 2;
    dp[3] = (unsigned int) (s2 + (s1 = sp[4]) + s4 + (s3 = sp2[4]) + 2 - rtype) >> 2;
    dp[4] = (unsigned int) (s1 + (s2 = sp[5]) + s3 + (s4 = sp2[5]) + 2 - rtype) >> 2;
    dp[5] = (unsigned int) (s2 + (s1 = sp[6]) + s4 + (s3 = sp2[6]) + 2 - rtype) >> 2;
    dp[6] = (unsigned int) (s1 + (s2 = sp[7]) + s3 + (s4 = sp2[7]) + 2 - rtype) >> 2;
    dp[7] = (unsigned int) (s2 + (s1 = sp[8]) + s4 + (s3 = sp2[8]) + 2 - rtype) >> 2;
    dp[8] = (unsigned int) (s1 + (s2 = sp[9]) + s3 + (s4 = sp2[9]) + 2 - rtype) >> 2;
    dp[9] = (unsigned int) (s2 + (s1 = sp[10]) + s4 + (s3 = sp2[10]) + 2 - rtype) >> 2;
    dp[10] = (unsigned int) (s1 + (s2 = sp[11]) + s3 + (s4 = sp2[11]) + 2 - rtype) >> 2;
    dp[11] = (unsigned int) (s2 + (s1 = sp[12]) + s4 + (s3 = sp2[12]) + 2 - rtype) >> 2;
    dp[12] = (unsigned int) (s1 + (s2 = sp[13]) + s3 + (s4 = sp2[13]) + 2 - rtype) >> 2;
    dp[13] = (unsigned int) (s2 + (s1 = sp[14]) + s4 + (s3 = sp2[14]) + 2 - rtype) >> 2;
    dp[14] = (unsigned int) (s1 + (s2 = sp[15]) + s3 + (s4 = sp2[15]) + 2 - rtype) >> 2;
    dp[15] = (unsigned int) (s2 + sp[16] + s4 + sp2[16] + 2 - rtype) >> 2;
    sp += lx2;
    sp2 += lx2;
    dp += lx;
  }
}

static void rec4c (unsigned char *s, unsigned char *d, 
                   int lx, int lx2, int h)
{
  unsigned char *dp, *sp, *sp2;
  int j;
  unsigned int s1, s2, s3, s4;

  sp = s;
  sp2 = s + lx2;
  dp = d;
  for (j = 0; j < h; j++)
  {
    s1 = sp[0];
    s3 = sp2[0];
    dp[0] = (unsigned int) (s1 + (s2 = sp[1]) + s3 + (s4 = sp2[1]) + 2 - rtype) >> 2;
    dp[1] = (unsigned int) (s2 + (s1 = sp[2]) + s4 + (s3 = sp2[2]) + 2 - rtype) >> 2;
    dp[2] = (unsigned int) (s1 + (s2 = sp[3]) + s3 + (s4 = sp2[3]) + 2 - rtype) >> 2;
    dp[3] = (unsigned int) (s2 + (s1 = sp[4]) + s4 + (s3 = sp2[4]) + 2 - rtype) >> 2;
    dp[4] = (unsigned int) (s1 + (s2 = sp[5]) + s3 + (s4 = sp2[5]) + 2 - rtype) >> 2;
    dp[5] = (unsigned int) (s2 + (s1 = sp[6]) + s4 + (s3 = sp2[6]) + 2 - rtype) >> 2;
    dp[6] = (unsigned int) (s1 + (s2 = sp[7]) + s3 + (s4 = sp2[7]) + 2 - rtype) >> 2;
    dp[7] = (unsigned int) (s2 + sp[8] + s4 + sp2[8] + 2 - rtype) >> 2;
    sp += lx2;
    sp2 += lx2;
    dp += lx;
  }
}

static void rec4o (unsigned char *s, int *d, int lx, int lx2, 
                   int addflag, int c, int xa, int xb, int ya, 
                   int yb)
{
  int *dp, *om;
  unsigned char *sp, *sp2;
  int i, j;

  sp = s;
  sp2 = s + lx2;
  dp = d;
  om = &OM[c][ya][0];

  if (!addflag)
  {
    for (j = ya; j < yb; j++)
    {
      for (i = xa; i < xb; i++)
      {
        dp[i] = (((unsigned int) (sp[i] + sp2[i] + sp[i + 1] + sp2[i + 1] + 2 - rtype)) >> 2) * om[i];
      }
      sp += lx2;
      sp2 += lx2;
      dp += lx;
      om += 8;
    }
  } else
  {
    for (j = ya; j < yb; j++)
    {
      for (i = xa; i < xb; i++)
      {
        dp[i] += (((unsigned int) (sp[i] + sp2[i] + sp[i + 1] + sp2[i + 1] + 2 - rtype)) >> 2) * om[i];
      }
      sp += lx2;
      sp2 += lx2;
      dp += lx;
      om += 8;
    }
  }
}

static void recon_comp_obmc (unsigned char *src, unsigned char *dst, 
                             int lx, int lx2, int comp, int w, int h, 
                             int x, int y, int newgob)
{
  int j, k;
  int xmb, ymb;
  int c8, t8, l8, r8;
  int ti8, li8, ri8;
  int xit, xib, xir, xil;
  int yit, yib, yir, yil;
  int vect, vecb, vecr, vecl;
  int nx[5], ny[5], xint[5], yint[5], xh[5], yh[5];
  int p[64], *pd;
  unsigned char *d, *s[5];

  xmb = (x >> 4) + 1;
  ymb = (y >> 4) + 1;

  c8 = (modemap[ymb][xmb] == MODE_INTER4V ? 1 : 0);
  c8 = (modemap[ymb][xmb] == MODE_INTER4V_Q ? 1 : c8);

  t8 = (modemap[ymb - 1][xmb] == MODE_INTER4V ? 1 : 0);
  t8 = (modemap[ymb - 1][xmb] == MODE_INTER4V_Q ? 1 : t8);
  ti8 = (modemap[ymb - 1][xmb] == MODE_INTRA ? 1 : 0);
  ti8 = (modemap[ymb - 1][xmb] == MODE_INTRA_Q ? 1 : ti8);

  l8 = (modemap[ymb][xmb - 1] == MODE_INTER4V ? 1 : 0);
  l8 = (modemap[ymb][xmb - 1] == MODE_INTER4V_Q ? 1 : l8);
  li8 = (modemap[ymb][xmb - 1] == MODE_INTRA ? 1 : 0);
  li8 = (modemap[ymb][xmb - 1] == MODE_INTRA_Q ? 1 : li8);

  r8 = (modemap[ymb][xmb + 1] == MODE_INTER4V ? 1 : 0);
  r8 = (modemap[ymb][xmb + 1] == MODE_INTER4V_Q ? 1 : r8);
  ri8 = (modemap[ymb][xmb + 1] == MODE_INTRA ? 1 : 0);
  ri8 = (modemap[ymb][xmb + 1] == MODE_INTRA_Q ? 1 : ri8);

  if (pb_frame)
  {
    ti8 = li8 = ri8 = 0;
  }
  switch (comp + 1)
  {

    case 1:
      vect = (ti8 ? (c8 ? 1 : 0) : (t8 ? 3 : 0));
      yit = (ti8 ? ymb : ymb - 1);
      xit = xmb;

      vecb = (c8 ? 3 : 0);
      yib = ymb;
      xib = xmb;

      vecl = (li8 ? (c8 ? 1 : 0) : (l8 ? 2 : 0));
      yil = ymb;
      xil = (li8 ? xmb : xmb - 1);

      vecr = (c8 ? 2 : 0);
      yir = ymb;
      xir = xmb;

      /* edge handling */
      if (ymb == 1 || newgob)
      {
        yit = ymb;
        vect = (c8 ? 1 : 0);
      }
      if (xmb == 1)
      {
        xil = xmb;
        vecl = (c8 ? 1 : 0);
      }
      break;

    case 2:
      vect = (ti8 ? (c8 ? 2 : 0) : (t8 ? 4 : 0));
      yit = (ti8 ? ymb : ymb - 1);
      xit = xmb;

      vecb = (c8 ? 4 : 0);
      yib = ymb;
      xib = xmb;
      vecl = (c8 ? 1 : 0);
      yil = ymb;
      xil = xmb;

      vecr = (ri8 ? (c8 ? 2 : 0) : (r8 ? 1 : 0));
      yir = ymb;
      xir = (ri8 ? xmb : xmb + 1);

      /* edge handling */
      if (ymb == 1 || newgob)
      {
        yit = ymb;
        vect = (c8 ? 2 : 0);
      }
      if (xmb == mb_width)
      {
        xir = xmb;
        vecr = (c8 ? 2 : 0);
      }
      break;

    case 3:
      vect = (c8 ? 1 : 0);
      yit = ymb;
      xit = xmb;
      vecb = (c8 ? 3 : 0);
      yib = ymb;
      xib = xmb;

      vecl = (li8 ? (c8 ? 3 : 0) : (l8 ? 4 : 0));
      yil = ymb;
      xil = (li8 ? xmb : xmb - 1);

      vecr = (c8 ? 4 : 0);
      yir = ymb;
      xir = xmb;

      /* edge handling */
      if (xmb == 1)
      {
        xil = xmb;
        vecl = (c8 ? 3 : 0);
      }
      break;

    case 4:
      vect = (c8 ? 2 : 0);
      yit = ymb;
      xit = xmb;
      vecb = (c8 ? 4 : 0);
      yib = ymb;
      xib = xmb;
      vecl = (c8 ? 3 : 0);
      yil = ymb;
      xil = xmb;

      vecr = (ri8 ? (c8 ? 4 : 0) : (r8 ? 3 : 0));
      yir = ymb;
      xir = (ri8 ? xmb : xmb + 1);

      /* edge handling */
      if (xmb == mb_width)
      {
        xir = xmb;
        vecr = (c8 ? 4 : 0);
      }
      break;

    default:
      fprintf (stderr, "Illegal block number in recon_comp_obmc (recon.c)\n");
      exit (1);
      break;
  }

  nx[0] = MV[0][c8 ? comp + 1 : 0][ymb][xmb];
  ny[0] = MV[1][c8 ? comp + 1 : 0][ymb][xmb];

  nx[1] = MV[0][vect][yit][xit];
  ny[1] = MV[1][vect][yit][xit];
  nx[2] = MV[0][vecb][yib][xib];
  ny[2] = MV[1][vecb][yib][xib];
  nx[3] = MV[0][vecr][yir][xir];
  ny[3] = MV[1][vecr][yir][xir];
  nx[4] = MV[0][vecl][yil][xil];
  ny[4] = MV[1][vecl][yil][xil];

  for (k = 0; k < 5; k++)
  {
    xint[k] = nx[k] >> 1;
    xh[k] = nx[k] & 1;
    yint[k] = ny[k] >> 1;
    yh[k] = ny[k] & 1;
    s[k] = src + lx2 * (y + yint[k]) + x + xint[k];
  }

  d = dst + lx * y + x;

  if (!xh[0] && !yh[0])
    reco (s[0], &p[0], 8, lx2, 0, 0, 0, 8, 0, 8);
  else if (!xh[0] && yh[0])
    recvo (s[0], &p[0], 8, lx2, 0, 0, 0, 8, 0, 8);
  else if (xh[0] && !yh[0])
    recho (s[0], &p[0], 8, lx2, 0, 0, 0, 8, 0, 8);
  else                          /* if (xh[] && yh[]) */
    rec4o (s[0], &p[0], 8, lx2, 0, 0, 0, 8, 0, 8);

  if (!xh[1] && !yh[1])
    reco (s[1], &p[0], 8, lx2, 1, 1, 0, 8, 0, 4);
  else if (!xh[1] && yh[1])
    recvo (s[1], &p[0], 8, lx2, 1, 1, 0, 8, 0, 4);
  else if (xh[1] && !yh[1])
    recho (s[1], &p[0], 8, lx2, 1, 1, 0, 8, 0, 4);
  else                          /* if (xh[] && yh[]) */
    rec4o (s[1], &p[0], 8, lx2, 1, 1, 0, 8, 0, 4);

  if (!xh[2] && !yh[2])
    reco (s[2] + (lx2 << 2), &p[32], 8, lx2, 1, 2, 0, 8, 4, 8);
  else if (!xh[2] && yh[2])
    recvo (s[2] + (lx2 << 2), &p[32], 8, lx2, 1, 2, 0, 8, 4, 8);
  else if (xh[2] && !yh[2])
    recho (s[2] + (lx2 << 2), &p[32], 8, lx2, 1, 2, 0, 8, 4, 8);
  else                          /* if (xh[] && yh[]) */
    rec4o (s[2] + (lx2 << 2), &p[32], 8, lx2, 1, 2, 0, 8, 4, 8);

  if (!xh[3] && !yh[3])
    reco (s[3], &p[0], 8, lx2, 1, 3, 4, 8, 0, 8);
  else if (!xh[3] && yh[3])
    recvo (s[3], &p[0], 8, lx2, 1, 3, 4, 8, 0, 8);
  else if (xh[3] && !yh[3])
    recho (s[3], &p[0], 8, lx2, 1, 3, 4, 8, 0, 8);
  else                          /* if (xh[] && yh[]) */
    rec4o (s[3], &p[0], 8, lx2, 1, 3, 4, 8, 0, 8);

  if (!xh[4] && !yh[4])
    reco (s[4], &p[0], 8, lx2, 1, 4, 0, 4, 0, 8);
  else if (!xh[4] && yh[4])
    recvo (s[4], &p[0], 8, lx2, 1, 4, 0, 4, 0, 8);
  else if (xh[4] && !yh[4])
    recho (s[4], &p[0], 8, lx2, 1, 4, 0, 4, 0, 8);
  else                          /* if (xh[] && yh[]) */
    rec4o (s[4], &p[0], 8, lx2, 1, 4, 0, 4, 0, 8);

  pd = &p[0];
  for (j = 0; j < 8; j++)
  {
    d[0] = (pd[0] + 4) >> 3;
    d[1] = (pd[1] + 4) >> 3;
    d[2] = (pd[2] + 4) >> 3;
    d[3] = (pd[3] + 4) >> 3;
    d[4] = (pd[4] + 4) >> 3;
    d[5] = (pd[5] + 4) >> 3;
    d[6] = (pd[6] + 4) >> 3;
    d[7] = (pd[7] + 4) >> 3;
    d += lx;
    pd += 8;
  }

}