intra8x8_pred.c

H.264基于baseline解码器的C++实现源码

/*!
 ***********************************************************************
 * \brief
 *    makes and returns 8x8 horizontal up prediction mode
 *
 * \return
 *    DECODING_OK   decoding of intraprediction mode was sucessfull            \n
 *
 ***********************************************************************
 */
static inline int intra8x8_hor_up_pred(ImageParameters *img,  //!< image parameters 
                                       Macroblock *currMB,    //!< current macroblock
                                       ColorPlane pl,         //!< current image plane
                                       int ioff,              //!< pixel offset X within MB
                                       int joff)              //!< pixel offset Y within MB
{
  int i;
  imgpel PredPel[25];  // array of predictor pels
  imgpel **imgY = (pl) ? dec_picture->imgUV[pl - 1] : dec_picture->imgY; // For MB level frame/field coding tools -- set default to imgY

  PixelPos pix_a[8];
  PixelPos pix_b, pix_c, pix_d;

  int block_available_up;
  int block_available_left;
  int block_available_up_left;
  int block_available_up_right;
  int jpos0 = joff    , jpos1 = joff + 1, jpos2 = joff + 2, jpos3 = joff + 3;
  int jpos4 = joff + 4, jpos5 = joff + 5, jpos6 = joff + 6, jpos7 = joff + 7;
  int ipos0 = ioff    , ipos1 = ioff + 1, ipos2 = ioff + 2, ipos3 = ioff + 3;
  int ipos4 = ioff + 4, ipos5 = ioff + 5, ipos6 = ioff + 6, ipos7 = ioff + 7;
  imgpel *pred_pels, **mpr = img->mb_pred[pl];
  int *mb_size = img->mb_size[IS_LUMA];

  for (i=0;i<8;i++)
  {
    getNeighbour(currMB, ioff - 1, joff + i, mb_size, &pix_a[i]);
  }

  getNeighbour(currMB, ioff    , joff - 1, mb_size, &pix_b);
  getNeighbour(currMB, ioff + 8, joff - 1, mb_size, &pix_c);
  getNeighbour(currMB, ioff - 1, joff - 1, mb_size, &pix_d);

  pix_c.available = pix_c.available &&!(ioff == 8 && joff == 8);

  if (active_pps->constrained_intra_pred_flag)
  {
    for (i=0, block_available_left=1; i<8;i++)
      block_available_left  &= pix_a[i].available ? img->intra_block[pix_a[i].mb_addr]: 0;
    block_available_up       = pix_b.available ? img->intra_block [pix_b.mb_addr] : 0;
    block_available_up_right = pix_c.available ? img->intra_block [pix_c.mb_addr] : 0;
    block_available_up_left  = pix_d.available ? img->intra_block [pix_d.mb_addr] : 0;
  }
  else
  {
    block_available_left     = pix_a[0].available;
    block_available_up       = pix_b.available;
    block_available_up_right = pix_c.available;
    block_available_up_left  = pix_d.available;
  }

  if (!block_available_left)
    printf ("warning: Intra_8x8_Horizontal_Up prediction mode not allowed at mb %d\n", (int) img->current_mb_nr);

  // form predictor pels
  if (block_available_up)
  {
    pred_pels = &imgY[pix_b.pos_y][pix_b.pos_x];
    P_A = pred_pels[0];
    P_B = pred_pels[1];
    P_C = pred_pels[2];
    P_D = pred_pels[3];
    P_E = pred_pels[4];
    P_F = pred_pels[5];
    P_G = pred_pels[6];
    P_H = pred_pels[7];
  }
  else
  {
    P_A = P_B = P_C = P_D = P_E = P_F = P_G = P_H = (imgpel) img->dc_pred_value_comp[pl];
  }

  if (block_available_up_right)
  {
    pred_pels = &imgY[pix_c.pos_y][pix_c.pos_x];
    P_I = pred_pels[0];
    P_J = pred_pels[1];
    P_K = pred_pels[2];
    P_L = pred_pels[3];
    P_M = pred_pels[4];
    P_N = pred_pels[5];
    P_O = pred_pels[6];
    P_P = pred_pels[7];

  }
  else
  {
    P_I = P_J = P_K = P_L = P_M = P_N = P_O = P_P = P_H;
  }

  if (block_available_left)
  {
    P_Q = imgY[pix_a[0].pos_y][pix_a[0].pos_x];
    P_R = imgY[pix_a[1].pos_y][pix_a[1].pos_x];
    P_S = imgY[pix_a[2].pos_y][pix_a[2].pos_x];
    P_T = imgY[pix_a[3].pos_y][pix_a[3].pos_x];
    P_U = imgY[pix_a[4].pos_y][pix_a[4].pos_x];
    P_V = imgY[pix_a[5].pos_y][pix_a[5].pos_x];
    P_W = imgY[pix_a[6].pos_y][pix_a[6].pos_x];
    P_X = imgY[pix_a[7].pos_y][pix_a[7].pos_x];
  }
  else
  {
    P_Q = P_R = P_S = P_T = P_U = P_V = P_W = P_X = (imgpel) img->dc_pred_value_comp[pl];
  }

  if (block_available_up_left)
  {
    P_Z = imgY[pix_d.pos_y][pix_d.pos_x];
  }
  else
  {
    P_Z = (imgpel) img->dc_pred_value_comp[pl];
  }

  LowPassForIntra8x8Pred(&(P_Z), block_available_up_left, block_available_up, block_available_left);

  mpr[jpos0][ipos0] = (imgpel) ((P_Q + P_R + 1) >> 1);
  mpr[jpos1][ipos0] =
    mpr[jpos0][ipos2] = (imgpel) ((P_R + P_S + 1) >> 1);
  mpr[jpos2][ipos0] =
    mpr[jpos1][ipos2] =
    mpr[jpos0][ipos4] = (imgpel) ((P_S + P_T + 1) >> 1);
  mpr[jpos3][ipos0] =
    mpr[jpos2][ipos2] =
    mpr[jpos1][ipos4] =
    mpr[jpos0][ipos6] = (imgpel) ((P_T + P_U + 1) >> 1);
  mpr[jpos4][ipos0] =
    mpr[jpos3][ipos2] =
    mpr[jpos2][ipos4] =
    mpr[jpos1][ipos6] = (imgpel) ((P_U + P_V + 1) >> 1);
  mpr[jpos5][ipos0] =
    mpr[jpos4][ipos2] =
    mpr[jpos3][ipos4] =
    mpr[jpos2][ipos6] = (imgpel) ((P_V + P_W + 1) >> 1);
  mpr[jpos6][ipos0] =
    mpr[jpos5][ipos2] =
    mpr[jpos4][ipos4] =
    mpr[jpos3][ipos6] = (imgpel) ((P_W + P_X + 1) >> 1);
  mpr[jpos4][ipos6] =
    mpr[jpos4][ipos7] =
    mpr[jpos5][ipos4] =
    mpr[jpos5][ipos5] =
    mpr[jpos5][ipos6] =
    mpr[jpos5][ipos7] =
    mpr[jpos6][ipos2] =
    mpr[jpos6][ipos3] =
    mpr[jpos6][ipos4] =
    mpr[jpos6][ipos5] =
    mpr[jpos6][ipos6] =
    mpr[jpos6][ipos7] =
    mpr[jpos7][ipos0] =
    mpr[jpos7][ipos1] =
    mpr[jpos7][ipos2] =
    mpr[jpos7][ipos3] =
    mpr[jpos7][ipos4] =
    mpr[jpos7][ipos5] =
    mpr[jpos7][ipos6] =
    mpr[jpos7][ipos7] = (imgpel) P_X;
  mpr[jpos6][ipos1] =
    mpr[jpos5][ipos3] =
    mpr[jpos4][ipos5] =
    mpr[jpos3][ipos7] = (imgpel) ((P_W + 3*P_X + 2) >> 2);
  mpr[jpos5][ipos1] =
    mpr[jpos4][ipos3] =
    mpr[jpos3][ipos5] =
    mpr[jpos2][ipos7] = (imgpel) ((P_X + P_V + 2*P_W + 2) >> 2);
  mpr[jpos4][ipos1] =
    mpr[jpos3][ipos3] =
    mpr[jpos2][ipos5] =
    mpr[jpos1][ipos7] = (imgpel) ((P_W + P_U + 2*P_V + 2) >> 2);
  mpr[jpos3][ipos1] =
    mpr[jpos2][ipos3] =
    mpr[jpos1][ipos5] =
    mpr[jpos0][ipos7] = (imgpel) ((P_V + P_T + 2*P_U + 2) >> 2);
  mpr[jpos2][ipos1] =
    mpr[jpos1][ipos3] =
    mpr[jpos0][ipos5] = (imgpel) ((P_U + P_S + 2*P_T + 2) >> 2);
  mpr[jpos1][ipos1] =
    mpr[jpos0][ipos3] = (imgpel) ((P_T + P_R + 2*P_S + 2) >> 2);
  mpr[jpos0][ipos1] = (imgpel) ((P_S + P_Q + 2*P_R + 2) >> 2);

  return DECODING_OK;
}

/*!
 ***********************************************************************
 * \brief
 *    makes and returns 8x8 horizontal down prediction mode
 *
 * \return
 *    DECODING_OK   decoding of intraprediction mode was sucessfull            \n
 *
 ***********************************************************************
 */
static inline int intra8x8_hor_down_pred(ImageParameters *img,  //!< image parameters 
                                         Macroblock *currMB,    //!< current macroblock
                                         ColorPlane pl,         //!< current image plane
                                         int ioff,              //!< pixel offset X within MB
                                         int joff)              //!< pixel offset Y within MB
{
  int i;
  imgpel PredPel[25];  // array of predictor pels
  imgpel **imgY = (pl) ? dec_picture->imgUV[pl - 1] : dec_picture->imgY; // For MB level frame/field coding tools -- set default to imgY

  PixelPos pix_a[8];
  PixelPos pix_b, pix_c, pix_d;

  int block_available_up;
  int block_available_left;
  int block_available_up_left;
  int block_available_up_right;
  int jpos0 = joff    , jpos1 = joff + 1, jpos2 = joff + 2, jpos3 = joff + 3;
  int jpos4 = joff + 4, jpos5 = joff + 5, jpos6 = joff + 6, jpos7 = joff + 7;
  int ipos0 = ioff    , ipos1 = ioff + 1, ipos2 = ioff + 2, ipos3 = ioff + 3;
  int ipos4 = ioff + 4, ipos5 = ioff + 5, ipos6 = ioff + 6, ipos7 = ioff + 7;
  imgpel *pred_pels, **mpr = img->mb_pred[pl];
  int *mb_size = img->mb_size[IS_LUMA];

  for (i=0;i<8;i++)
  {
    getNeighbour(currMB, ioff - 1, joff + i, mb_size, &pix_a[i]);
  }

  getNeighbour(currMB, ioff    , joff - 1, mb_size, &pix_b);
  getNeighbour(currMB, ioff + 8, joff - 1, mb_size, &pix_c);
  getNeighbour(currMB, ioff - 1, joff - 1, mb_size, &pix_d);

  pix_c.available = pix_c.available &&!(ioff == 8 && joff == 8);

  if (active_pps->constrained_intra_pred_flag)
  {
    for (i=0, block_available_left=1; i<8;i++)
      block_available_left  &= pix_a[i].available ? img->intra_block[pix_a[i].mb_addr]: 0;
    block_available_up       = pix_b.available ? img->intra_block [pix_b.mb_addr] : 0;
    block_available_up_right = pix_c.available ? img->intra_block [pix_c.mb_addr] : 0;
    block_available_up_left  = pix_d.available ? img->intra_block [pix_d.mb_addr] : 0;
  }
  else
  {
    block_available_left     = pix_a[0].available;
    block_available_up       = pix_b.available;
    block_available_up_right = pix_c.available;
    block_available_up_left  = pix_d.available;
  }

  if ((!block_available_up)||(!block_available_left)||(!block_available_up_left))
    printf ("warning: Intra_8x8_Horizontal_Down prediction mode not allowed at mb %d\n", (int) img->current_mb_nr);

  // form predictor pels
  if (block_available_up)
  {
    pred_pels = &imgY[pix_b.pos_y][pix_b.pos_x];
    P_A = pred_pels[0];
    P_B = pred_pels[1];
    P_C = pred_pels[2];
    P_D = pred_pels[3];
    P_E = pred_pels[4];
    P_F = pred_pels[5];
    P_G = pred_pels[6];
    P_H = pred_pels[7];
  }
  else
  {
    P_A = P_B = P_C = P_D = P_E = P_F = P_G = P_H = (imgpel) img->dc_pred_value_comp[pl];
  }

  if (block_available_up_right)
  {
    pred_pels = &imgY[pix_c.pos_y][pix_c.pos_x];
    P_I = pred_pels[0];
    P_J = pred_pels[1];
    P_K = pred_pels[2];
    P_L = pred_pels[3];
    P_M = pred_pels[4];
    P_N = pred_pels[5];
    P_O = pred_pels[6];
    P_P = pred_pels[7];

  }
  else
  {
    P_I = P_J = P_K = P_L = P_M = P_N = P_O = P_P = P_H;
  }

  if (block_available_left)
  {
    P_Q = imgY[pix_a[0].pos_y][pix_a[0].pos_x];
    P_R = imgY[pix_a[1].pos_y][pix_a[1].pos_x];
    P_S = imgY[pix_a[2].pos_y][pix_a[2].pos_x];
    P_T = imgY[pix_a[3].pos_y][pix_a[3].pos_x];
    P_U = imgY[pix_a[4].pos_y][pix_a[4].pos_x];
    P_V = imgY[pix_a[5].pos_y][pix_a[5].pos_x];
    P_W = imgY[pix_a[6].pos_y][pix_a[6].pos_x];
    P_X = imgY[pix_a[7].pos_y][pix_a[7].pos_x];
  }
  else
  {
    P_Q = P_R = P_S = P_T = P_U = P_V = P_W = P_X = (imgpel) img->dc_pred_value_comp[pl];
  }

  if (block_available_up_left)
  {
    P_Z = imgY[pix_d.pos_y][pix_d.pos_x];
  }
  else
  {
    P_Z = (imgpel) img->dc_pred_value_comp[pl];
  }

  LowPassForIntra8x8Pred(&(P_Z), block_available_up_left, block_available_up, block_available_left);

  mpr[jpos0][ipos0] =
    mpr[jpos1][ipos2] =
    mpr[jpos2][ipos4] =
    mpr[jpos3][ipos6] = (imgpel) ((P_Q + P_Z + 1) >> 1);
  mpr[jpos1][ipos0] =
    mpr[jpos2][ipos2] =
    mpr[jpos3][ipos4] =
    mpr[jpos4][ipos6] = (imgpel) ((P_R + P_Q + 1) >> 1);
  mpr[jpos2][ipos0] =
    mpr[jpos3][ipos2] =
    mpr[jpos4][ipos4] =
    mpr[jpos5][ipos6] = (imgpel) ((P_S + P_R + 1) >> 1);
  mpr[jpos3][ipos0] =
    mpr[jpos4][ipos2] =
    mpr[jpos5][ipos4] =
    mpr[jpos6][ipos6] = (imgpel) ((P_T + P_S + 1) >> 1);
  mpr[jpos4][ipos0] =
    mpr[jpos5][ipos2] =
    mpr[jpos6][ipos4] =
    mpr[jpos7][ipos6] = (imgpel) ((P_U + P_T + 1) >> 1);
  mpr[jpos5][ipos0] =
    mpr[jpos6][ipos2] =
    mpr[jpos7][ipos4] = (imgpel) ((P_V + P_U + 1) >> 1);
  mpr[jpos6][ipos0] =
    mpr[jpos7][ipos2] = (imgpel) ((P_W + P_V + 1) >> 1);
  mpr[jpos7][ipos0] = (imgpel) ((P_X + P_W + 1) >> 1);
  mpr[jpos0][ipos1] =
    mpr[jpos1][ipos3] =
    mpr[jpos2][ipos5] =
    mpr[jpos3][ipos7] = (imgpel) ((P_Q + P_A + 2*P_Z + 2) >> 2);
  mpr[jpos1][ipos1] =
    mpr[jpos2][ipos3] =
    mpr[jpos3][ipos5] =
    mpr[jpos4][ipos7] = (imgpel) ((P_Z + P_R + 2*P_Q + 2) >> 2);
  mpr[jpos2][ipos1] =
    mpr[jpos3][ipos3] =
    mpr[jpos4][ipos5] =
    mpr[jpos5][ipos7] = (imgpel) ((P_Q + P_S + 2*P_R + 2) >> 2);
  mpr[jpos3][ipos1] =
    mpr[jpos4][ipos3] =
    mpr[jpos5][ipos5] =
    mpr[jpos6][ipos7] = (imgpel) ((P_R + P_T + 2*P_S + 2) >> 2);
  mpr[jpos4][ipos1] =
    mpr[jpos5][ipos3] =
    mpr[jpos6][ipos5] =
    mpr[jpos7][ipos7] = (imgpel) ((P_S + P_U + 2*P_T + 2) >> 2);
  mpr[jpos5][ipos1] =
    mpr[jpos6][ipos3] =
    mpr[jpos7][ipos5] = (imgpel) ((P_T + P_V + 2*P_U + 2) >> 2);
  mpr[jpos6][ipos1] =
    mpr[jpos7][ipos3] = (imgpel) ((P_U + P_W + 2*P_V + 2) >> 2);
  mpr[jpos7][ipos1] = (imgpel) ((P_V + P_X + 2*P_W + 2) >> 2);
  mpr[jpos0][ipos2] =
    mpr[jpos1][ipos4] =
    mpr[jpos2][ipos6] = (imgpel) ((P_Z + P_B + 2*P_A + 2) >> 2);
  mpr[jpos0][ipos3] =
    mpr[jpos1][ipos5] =
    mpr[jpos2][ipos7] = (imgpel) ((P_A + P_C + 2*P_B + 2) >> 2);
  mpr[jpos0][ipos4] =
    mpr[jpos1][ipos6] = (imgpel) ((P_B + P_D + 2*P_C + 2) >> 2);
  mpr[jpos0][ipos5] =
    mpr[jpos1][ipos7] = (imgpel) ((P_C + P_E + 2*P_D + 2) >> 2);
  mpr[jpos0][ipos6] = (imgpel) ((P_D + P_F + 2*P_E + 2) >> 2);
  mpr[jpos0][ipos7] = (imgpel) ((P_E + P_G + 2*P_F + 2) >> 2);

  return DECODING_OK;
}

/*!
 ************************************************************************
 * \brief
 *    Make intra 8x8 prediction according to all 9 prediction modes.
 *    The routine uses left and upper neighbouring points from
 *    previous coded blocks to do this (if available). Notice that
 *    inaccessible neighbouring points are signalled with a negative
 *    value in the predmode array .
 *
 *  \par Input:
 *     Starting point of current 8x8 block image position
 *
 ************************************************************************
 */
int intrapred8x8(ImageParameters *img,  //!< image parameters
                 Macroblock *currMB,    //!< Current Macroblock
                 ColorPlane pl,         //!< Current color plane
                 int b8)                //!< block position

{  
  //imgpel **imgY = (pl) ? dec_picture->imgUV[pl - 1] : dec_picture->imgY; // For MB level frame/field coding tools -- set default to imgY

  int img_block_x = (img->mb_x << 2) + ((b8 & 0x01) << 1);
  int img_block_y = (img->mb_y << 2) + ((b8  >>  1) << 1);
  int ioff = (b8 & 0x01) << 3;
  int joff = (b8 >> 1  ) << 3;

  byte predmode = img->ipredmode[img_block_y][img_block_x];
  ipmode_DPCM = predmode;  //For residual DPCM

  switch (predmode)
  {
  case DC_PRED:
    return (intra8x8_dc_pred(img, currMB, pl, ioff, joff));
    break;
  case VERT_PRED:
    return (intra8x8_vert_pred(img, currMB, pl, ioff, joff));
    break;
  case HOR_PRED:
    return (intra8x8_hor_pred(img, currMB, pl, ioff, joff));
    break;
  case DIAG_DOWN_RIGHT_PRED:
    return (intra8x8_diag_down_right_pred(img, currMB, pl, ioff, joff));
    break;
  case DIAG_DOWN_LEFT_PRED:
    return (intra8x8_diag_down_left_pred(img, currMB, pl, ioff, joff));
    break;
  case VERT_RIGHT_PRED:
    return (intra8x8_vert_right_pred(img, currMB, pl, ioff, joff));
    break;
  case VERT_LEFT_PRED:
    return (intra8x8_vert_left_pred(img, currMB, pl, ioff, joff));
    break;
  case HOR_UP_PRED:
    return (intra8x8_hor_up_pred(img, currMB, pl, ioff, joff));
    break;
  case HOR_DOWN_PRED:  
    return (intra8x8_hor_down_pred(img, currMB, pl, ioff, joff));
  default:
    printf("Error: illegal intra_8x8 prediction mode: %d\n", (int) predmode);
    return SEARCH_SYNC;
    break;
  }

  return DECODING_OK;
}