cabac.c

the newest JM software by h.264 JVT official reference model.

    if (act_sym==0) // 4x4 Intra
    {
      biari_encode_symbol(eep_dp, 0, ctx->mb_type_contexts[0] + act_ctx );
    }
    else if( act_sym == 25 ) // PCM-MODE
    {
      biari_encode_symbol(eep_dp, 1, ctx->mb_type_contexts[0] + act_ctx );
      biari_encode_symbol_final(eep_dp, 1);
    }
    else // 16x16 Intra
    {
      biari_encode_symbol(eep_dp, 1, ctx->mb_type_contexts[0] + act_ctx );

      biari_encode_symbol_final(eep_dp, 0);

      mode_sym = act_sym-1; // Values in the range of 0...23
      act_ctx  = 4;
      act_sym  = mode_sym/12;
      biari_encode_symbol(eep_dp, (signed short) act_sym, ctx->mb_type_contexts[0] + act_ctx ); // coding of AC/no AC
      mode_sym = mode_sym % 12;
      act_sym  = mode_sym / 4; // coding of cbp: 0,1,2
      act_ctx  = 5;
      if (act_sym==0)
      {
        biari_encode_symbol(eep_dp, 0, ctx->mb_type_contexts[0] + act_ctx );
      }
      else
      {
        biari_encode_symbol(eep_dp, 1, ctx->mb_type_contexts[0] + act_ctx );
        act_ctx=6;
        biari_encode_symbol(eep_dp, (signed short) (act_sym!=1), ctx->mb_type_contexts[0] + act_ctx );
      }
      mode_sym = mode_sym & 0x03; // coding of I pred-mode: 0,1,2,3
      act_sym  = mode_sym >> 1;
      act_ctx  = 7;
      biari_encode_symbol(eep_dp, (signed short) act_sym, ctx->mb_type_contexts[0] + act_ctx );
      act_ctx  = 8;
      act_sym  = mode_sym & 0x01;
      biari_encode_symbol(eep_dp, (signed short) act_sym, ctx->mb_type_contexts[0] + act_ctx );
    }
  }
  else // INTER
  {

    if (bframe)
    {
      if (currMB->mb_available_up == NULL)
        b = 0;
      else
        b = ((currMB->mb_available_up->mb_type != 0) ? 1 : 0 );

      if (currMB->mb_available_left == NULL)
        a = 0;
      else
        a = ((currMB->mb_available_left->mb_type != 0) ? 1 : 0 );
      act_ctx = a + b;
      se->context = act_ctx; // store context
    }
    act_sym = curr_mb_type;

    if (act_sym>=(mode16x16=(bframe?24:7)))
    {
      mode_sym = act_sym-mode16x16;
      act_sym  = mode16x16; // 16x16 mode info
    }

    if (!bframe)
    {
      switch (act_sym)
      {
      case 0:
        break;
      case 1:
        biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[1][4]);
        biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[1][5]);
        biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[1][6]);
        break;
      case 2:
        biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[1][4]);
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[1][5]);
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[1][7]);
        break;
      case 3:
        biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[1][4]);
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[1][5]);
        biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[1][7]);
        break;
      case 4:
      case 5:
        biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[1][4]);
        biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[1][5]);
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[1][6]);
        break;
      case 6:
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[1][4]);
        biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[1][7]);
        break;
      case 7:
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[1][4]);
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[1][7]);
        break;
      default:
        printf ("Unsupported MB-MODE in writeMB_typeInfo_CABAC!\n");
        exit (1);
      }
    }
    else //===== B-FRAMES =====
    {
      if (act_sym==0)
      {
        biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[2][act_ctx]);
      }
      else if (act_sym<=2)
      {
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][act_ctx]);
        biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[2][4]);
        csym = (act_sym-1 != 0);
        biari_encode_symbol (eep_dp, csym, &ctx->mb_type_contexts[2][6]);
      }
      else if (act_sym<=10)
      {
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][act_ctx]);
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][4]);
        biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[2][5]);
        csym=(((act_sym-3)>>2)&0x01) != 0;
        biari_encode_symbol (eep_dp, csym, &ctx->mb_type_contexts[2][6]);
        csym=(((act_sym-3)>>1)&0x01) != 0;
        biari_encode_symbol (eep_dp, csym, &ctx->mb_type_contexts[2][6]);
        csym=((act_sym-3)&0x01) != 0;
        biari_encode_symbol (eep_dp, csym, &ctx->mb_type_contexts[2][6]);
      }
      else if (act_sym==11 || act_sym==22)
      {
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][act_ctx]);
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][4]);
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][5]);
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][6]);
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][6]);
        csym = (act_sym != 11);
        biari_encode_symbol (eep_dp, csym, &ctx->mb_type_contexts[2][6]);
      }
      else
      {
        if (act_sym > 22) act_sym--;
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][act_ctx]);
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][4]);
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][5]);
        csym=(((act_sym-12)>>3)&0x01) != 0;
        biari_encode_symbol (eep_dp, csym, &ctx->mb_type_contexts[2][6]);
        csym=(((act_sym-12)>>2)&0x01) != 0;
        biari_encode_symbol (eep_dp, csym, &ctx->mb_type_contexts[2][6]);
        csym=(((act_sym-12)>>1)&0x01) != 0;
        biari_encode_symbol (eep_dp, csym, &ctx->mb_type_contexts[2][6]);
        csym=((act_sym-12)&0x01) != 0;
        biari_encode_symbol (eep_dp, csym, &ctx->mb_type_contexts[2][6]);
        if (act_sym >=22) act_sym++;
      }
    }

    if(act_sym==mode16x16) // additional info for 16x16 Intra-mode
    {
      if( mode_sym==24 )
      {
        biari_encode_symbol_final(eep_dp, 1 );
        dp->bitstream->write_flag = 1;
        se->len = (arienco_bits_written(eep_dp) - curr_len);
        CABAC_TRACE;
        return;
      }
      biari_encode_symbol_final(eep_dp, 0 );

      act_ctx = 8;
      act_sym = mode_sym/12;
      biari_encode_symbol(eep_dp, (signed short) act_sym, ctx->mb_type_contexts[1] + act_ctx ); // coding of AC/no AC
      mode_sym = mode_sym % 12;

      act_sym = mode_sym / 4; // coding of cbp: 0,1,2
      act_ctx = 9;
      if (act_sym==0)
      {
        biari_encode_symbol(eep_dp, 0, ctx->mb_type_contexts[1] + act_ctx );
      }
      else
      {
        biari_encode_symbol(eep_dp, 1, ctx->mb_type_contexts[1] + act_ctx );
        biari_encode_symbol(eep_dp, (signed short) (act_sym!=1), ctx->mb_type_contexts[1] + act_ctx );
      }

      mode_sym = mode_sym % 4; // coding of I pred-mode: 0,1,2,3
      act_ctx  = 10;
      act_sym  = mode_sym/2;
      biari_encode_symbol(eep_dp, (signed short) act_sym, ctx->mb_type_contexts[1] + act_ctx );
      act_sym  = mode_sym%2;
      biari_encode_symbol(eep_dp, (signed short) act_sym, ctx->mb_type_contexts[1] + act_ctx );
    }
  }
  dp->bitstream->write_flag = 1;
  se->len = (arienco_bits_written(eep_dp) - curr_len);
  CABAC_TRACE;
}


/*!
 ***************************************************************************
 * \brief
 *    This function is used to arithmetically encode the 8x8 block
 *    type info
 ***************************************************************************
 */
void writeB8_typeInfo_CABAC(SyntaxElement *se, DataPartition *dp)
{
  EncodingEnvironmentPtr eep_dp = &(dp->ee_cabac);
  int curr_len = arienco_bits_written(eep_dp);
  int act_ctx;
  int act_sym;
  signed short csym;
  int bframe=(img->type==B_SLICE);

  BiContextType (*b8_type_contexts)[9] = (img->currentSlice)->mot_ctx->b8_type_contexts;

  act_sym = se->value1;
  act_ctx = 0;

  if (!bframe)
  {
    switch (act_sym)
    {
    case 0:
      biari_encode_symbol (eep_dp, 1, &b8_type_contexts[0][1]);
      break;
    case 1:
      biari_encode_symbol (eep_dp, 0, &b8_type_contexts[0][1]);
      biari_encode_symbol (eep_dp, 0, &b8_type_contexts[0][3]);
      break;
    case 2:
      biari_encode_symbol (eep_dp, 0, &b8_type_contexts[0][1]);
      biari_encode_symbol (eep_dp, 1, &b8_type_contexts[0][3]);
      biari_encode_symbol (eep_dp, 1, &b8_type_contexts[0][4]);
      break;
    case 3:
      biari_encode_symbol (eep_dp, 0, &b8_type_contexts[0][1]);
      biari_encode_symbol (eep_dp, 1, &b8_type_contexts[0][3]);
      biari_encode_symbol (eep_dp, 0, &b8_type_contexts[0][4]);
      break;
    }
  }
  else //===== B-FRAME =====
  {
    if (act_sym==0)
    {
      biari_encode_symbol (eep_dp, 0, &b8_type_contexts[1][0]);
      dp->bitstream->write_flag = 1;
      se->len = (arienco_bits_written(eep_dp) - curr_len);
      CABAC_TRACE;
      return;
    }
    else
    {
      biari_encode_symbol (eep_dp, 1, &b8_type_contexts[1][0]);
      act_sym--;
    }

    if (act_sym < 2)
    {
      biari_encode_symbol (eep_dp, 0, &b8_type_contexts[1][1]);
      biari_encode_symbol (eep_dp, (signed short) (act_sym!=0), &b8_type_contexts[1][3]);
    }
    else if (act_sym < 6)
    {
      biari_encode_symbol (eep_dp, 1, &b8_type_contexts[1][1]);
      biari_encode_symbol (eep_dp, 0, &b8_type_contexts[1][2]);
      csym=(((act_sym - 2) >> 1) & 0x01) != 0;
      biari_encode_symbol (eep_dp, csym, &b8_type_contexts[1][3]);
      csym=((act_sym - 2) & 0x01) != 0;
      biari_encode_symbol (eep_dp, csym, &b8_type_contexts[1][3]);
    }
    else
    {
      biari_encode_symbol (eep_dp, 1, &b8_type_contexts[1][1]);
      biari_encode_symbol (eep_dp, 1, &b8_type_contexts[1][2]);
      csym=(((act_sym - 6)>> 2) & 0x01);
      if (csym)
      {
        biari_encode_symbol (eep_dp, 1, &b8_type_contexts[1][3]);
        csym=((act_sym - 6) & 0x01) != 0;
        biari_encode_symbol (eep_dp, csym, &b8_type_contexts[1][3]);
      }
      else
      {
        biari_encode_symbol (eep_dp, 0, &b8_type_contexts[1][3]);
        csym=(((act_sym - 6) >> 1) & 0x01) != 0;
        biari_encode_symbol (eep_dp, csym, &b8_type_contexts[1][3]);
        csym=((act_sym - 6) & 0x01) != 0;
        biari_encode_symbol (eep_dp, csym, &b8_type_contexts[1][3]);
      }
    }
  }

  dp->bitstream->write_flag = 1;
  se->len = (arienco_bits_written(eep_dp) - curr_len);
  CABAC_TRACE;
}

/*!
 ****************************************************************************
 * \brief
 *    This function is used to arithmetically encode a pair of
 *    intra prediction modes of a given MB.
 ****************************************************************************
 */
void writeIntraPredMode_CABAC(SyntaxElement *se, DataPartition *dp)
{
  EncodingEnvironmentPtr eep_dp = &(dp->ee_cabac);
  int curr_len = arienco_bits_written(eep_dp);
  BiContextType *ipr_contexts = (img->currentSlice)->tex_ctx->ipr_contexts;

  // use_most_probable_mode
  if (se->value1 == -1)
    biari_encode_symbol(eep_dp, 1, ipr_contexts);
  else
  {
    biari_encode_symbol(eep_dp, 0, ipr_contexts);

    // remaining_mode_selector
    biari_encode_symbol(eep_dp,(signed short)( se->value1 & 0x1    ), ipr_contexts+1);
    biari_encode_symbol(eep_dp,(signed short)((se->value1 & 0x2)>>1), ipr_contexts+1);
    biari_encode_symbol(eep_dp,(signed short)((se->value1 & 0x4)>>2), ipr_contexts+1);
  }

  dp->bitstream->write_flag = 1;
  se->len = (arienco_bits_written(eep_dp) - curr_len);
  CABAC_TRACE;
}

/*!
 ****************************************************************************
 * \brief
 *    This function is used to arithmetically encode the reference
 *    parameter of a given MB.
 ****************************************************************************
 */
void writeRefFrame_CABAC(SyntaxElement *se, DataPartition *dp)
{
  EncodingEnvironmentPtr eep_dp = &(dp->ee_cabac);
  int curr_len = arienco_bits_written(eep_dp);
  int   mb_nr = img->current_mb_nr;
  MotionInfoContexts  *ctx    = img->currentSlice->mot_ctx;
  Macroblock          *currMB = &img->mb_data[mb_nr];
  int                 addctx  = 0;

  int   a, b;
  int   act_ctx;
  int   act_sym;
  char** refframe_array = enc_picture->motion.ref_idx[se->value2];

  int bslice = (img->type==B_SLICE);

  int   b8a, b8b;

  PixelPos block_a, block_b;
  int *mb_size = img->mb_size[IS_LUMA];

  get4x4Neighbour(currMB, (img->subblock_x << 2) - 1, (img->subblock_y << 2)    , mb_size, &block_a);
  get4x4Neighbour(currMB, (img->subblock_x << 2),     (img->subblock_y << 2) - 1, mb_size, &block_b);

  if (!block_b.available)
    b=0;
  else 
  {
    b8b=((block_b.x >> 1) & 0x01)+2*((block_b.y >> 1) & 0x01);
    // if (IS_DIRECT(&img->mb_data[block_b.mb_addr]) || (img->mb_data[block_b.mb_addr].b8mode[b8b]==0 && bslice))
    if ((IS_DIRECT(&img->mb_data[block_b.mb_addr]) && !giRDOpt_B8OnlyFlag) || (img->mb_data[block_b.mb_addr].b8mode[b8b]==0 && bslice))
      b=0;
    else
    {
      if (img->MbaffFrameFlag && (currMB->mb_field == 0) && (img->mb_data[block_b.mb_addr].mb_field == 1))
        b = (refframe_array[block_b.pos_y][block_b.pos_x] > 1 ? 1 : 0);
      else
        b = (refframe_array[block_b.pos_y][block_b.pos_x] > 0 ? 1 : 0);
    }
  }

  if (!block_a.available)
    a=0;
  else 
  {
    b8a=((block_a.x >> 1) & 0x01)+2*((block_a.y >> 1) & 0x01);
    // if (IS_DIRECT(&img->mb_data[block_a.mb_addr]) || (img->mb_data[block_a.mb_addr].b8mode[b8a]==0 && bslice))
    if ((IS_DIRECT(&img->mb_data[block_a.mb_addr]) && !giRDOpt_B8OnlyFlag) || (img->mb_data[block_a.mb_addr].b8mode[b8a]==0 && bslice))
      a=0;
    else
    {
      if (img->MbaffFrameFlag && (currMB->mb_field == 0) && (img->mb_data[block_a.mb_addr].mb_field == 1))
        a = (refframe_array[block_a.pos_y][block_a.pos_x] > 1 ? 1 : 0);
      else
        a = (refframe_array[block_a.pos_y][block_a.pos_x] > 0 ? 1 : 0);
    }
  }

  act_ctx     = a + 2*b;
  se->context = act_ctx; // store context
  act_sym     = se->value1;

  if (act_sym==0)
  {
    biari_encode_symbol(eep_dp, 0, ctx->ref_no_contexts[addctx] + act_ctx );
  }
  else
  {
    biari_encode_symbol(eep_dp, 1, ctx->ref_no_contexts[addctx] + act_ctx);
    act_sym--;