cabac.c

h.264/avc 视频编码程序,实现分数像素匹配功能,非原创.

  if( enco_ctx == NULL )
    return;

  for (j=0; j<3; j++)
  {
    if (enco_ctx->mb_type_contexts[j] != NULL)
      free(enco_ctx->mb_type_contexts[j] );
  }

  for (j=0; j<2; j++)
  {
    if (enco_ctx->b8_type_contexts[j] != NULL)
      free(enco_ctx->b8_type_contexts[j]);

    if (enco_ctx->mv_res_contexts[j]  != NULL)
      free(enco_ctx->mv_res_contexts [j]);

    if (enco_ctx->ref_no_contexts[j]  != NULL)
      free(enco_ctx->ref_no_contexts [j]);
  }

  if (enco_ctx->delta_qp_inter_contexts != NULL)
    free(enco_ctx->delta_qp_inter_contexts);

  if (enco_ctx->delta_qp_intra_contexts != NULL)
    free(enco_ctx->delta_qp_intra_contexts);

  free( enco_ctx );

  return;
}

/*!
 ************************************************************************
 * \brief
 *    Frees the memory of the contexts models
 *    used for arithmetic encoding of the texture info.
 ************************************************************************
 */
void delete_contexts_TextureInfo(TextureInfoContexts *enco_ctx)
{

  int j,k;

  if( enco_ctx == NULL )
    return;

  for (j=0; j < 6; j++)
  {
    if (enco_ctx->ipr_contexts[j] != NULL)
      free(enco_ctx->ipr_contexts[j]);
  }

  for (k=0; k<2; k++)
    for (j=0; j<3; j++)
    {
      if (enco_ctx->cbp_contexts[k][j] != NULL)
        free(enco_ctx->cbp_contexts[k][j]);
    }

  for (j=0; j < 4*NUM_TRANS_TYPE; j++)
  {
    if (enco_ctx->level_context[j] != NULL)
      free(enco_ctx->level_context[j]);
  }

  for (j=0; j < 2*NUM_TRANS_TYPE; j++)
  {
    if (enco_ctx->run_context[j] != NULL)
      free(enco_ctx->run_context[j]);
  }
      
  for (j=0; j < NUM_TRANS_TYPE; j++)
  {
    if (enco_ctx->coeff_count_context[j] != NULL)
      free(enco_ctx->coeff_count_context[j]);
  }
  free( enco_ctx );

  return;

}


/*!
 **************************************************************************
 * \brief
 *    generates arithmetic code and passes the code to the buffer
 **************************************************************************
 */
int writeSyntaxElement_CABAC(SyntaxElement *se, DataPartition *this_dataPart)
{
  int curr_len;
  EncodingEnvironmentPtr eep_dp = &(this_dataPart->ee_cabac);

  curr_len = arienco_bits_written(eep_dp);

  // perform the actual coding by calling the appropriate method
  se->writing(se, eep_dp);

  if(se->type != SE_HEADER)
    this_dataPart->bitstream->write_flag = 1;

  return (se->len = (arienco_bits_written(eep_dp) - curr_len));
}


/*!
 ***************************************************************************
 * \brief
 *    This function is used to arithmetically encode the macroblock
 *    type info of a given MB.
 ***************************************************************************
 */
void writeMB_typeInfo2Buffer_CABAC(SyntaxElement *se, EncodingEnvironmentPtr eep_dp)
{
  int a, b;
  int act_ctx;
  int act_sym;
  int csym;
  int bframe   = (img->type==B_IMG);
  int mode_sym = 0;
  int mode16x16;

  MotionInfoContexts *ctx         = (img->currentSlice)->mot_ctx;
  Macroblock         *currMB      = &img->mb_data[img->current_mb_nr];
  int                curr_mb_type = se->value1;

  if(img->type == INTRA_IMG)  // INTRA-frame
  {
    if (currMB->mb_available[0][1] == NULL)
      b = 0;
    else 
      b = (( (currMB->mb_available[0][1])->mb_type != I4MB) ? 1 : 0 );
    if (currMB->mb_available[1][0] == NULL)
      a = 0;
    else 
      a = (( (currMB->mb_available[1][0])->mb_type != I4MB) ? 1 : 0 );

    act_ctx     = a + b;
    act_sym     = curr_mb_type;
    se->context = act_ctx; // store context

    if (act_sym==0) // 4x4 Intra
    {
      biari_encode_symbol(eep_dp, 0, ctx->mb_type_contexts[0] + act_ctx );
    }
    else // 16x16 Intra
    {
      biari_encode_symbol(eep_dp, 1, ctx->mb_type_contexts[0] + act_ctx );
      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, (unsigned char) 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;
        if (act_sym==1)
        {
          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 );
        }
      }
      mode_sym = mode_sym % 4; // coding of I pred-mode: 0,1,2,3
      act_sym  = mode_sym/2;
      act_ctx  = 7;
      biari_encode_symbol(eep_dp, (unsigned char) act_sym, ctx->mb_type_contexts[0] + act_ctx );
      act_ctx  = 8;
      act_sym  = mode_sym%2;
      biari_encode_symbol(eep_dp, (unsigned char) act_sym, ctx->mb_type_contexts[0] + act_ctx );
    }
  }
  else // INTER
  {
    if (currMB->mb_available[0][1] == NULL)
      b = 0;
    else
      b = (( (currMB->mb_available[0][1])->mb_type != 0) ? 1 : 0 );
    if (currMB->mb_available[1][0] == NULL)
      a = 0;
    else
      a = (( (currMB->mb_available[1][0])->mb_type != 0) ? 1 : 0 );

    act_sym = curr_mb_type;

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


    act_ctx = a + b;
    se->context = act_ctx; // store context

    if (!bframe)
    {
      switch (act_sym)
      {
      case 0:
        biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[1][act_ctx]);
        break;
      case 1:
        biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[1][act_ctx]);
        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, 1, &ctx->mb_type_contexts[1][act_ctx]);
        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, 1, &ctx->mb_type_contexts[1][act_ctx]);
        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, 1, &ctx->mb_type_contexts[1][act_ctx]);
        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][act_ctx]);
        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][act_ctx]);
        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_typeInfo2Buffer_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;
        if (csym) biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][6]);
        else      biari_encode_symbol (eep_dp, 0, &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);
        if (csym) biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][6]);
        else      biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[2][6]);
        csym=(((act_sym-3)>>1)&0x01);
        if (csym) biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][6]);
        else      biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[2][6]);
        csym=((act_sym-3)&0x01);
        if (csym) biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][6]);
        else      biari_encode_symbol (eep_dp, 0, &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]);
        if (act_sym==11)  biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[2][6]);
        else              biari_encode_symbol (eep_dp, 1, &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);
        if (csym) biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][6]);
        else      biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[2][6]);
        csym=(((act_sym-12)>>2)&0x01);
        if (csym) biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][6]);
        else      biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[2][6]);
        csym=(((act_sym-12)>>1)&0x01);
        if (csym) biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][6]);
        else      biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[2][6]);
        csym=((act_sym-12)&0x01);
        if (csym) biari_encode_symbol (eep_dp, 1, &ctx->mb_type_contexts[2][6]);
        else      biari_encode_symbol (eep_dp, 0, &ctx->mb_type_contexts[2][6]);
        if (act_sym >=22) act_sym++;
      }
    }

    if(act_sym==mode16x16) // additional info for 16x16 Intra-mode
    {
      act_ctx = 8;
      act_sym = mode_sym/12;
      biari_encode_symbol(eep_dp, (unsigned char) 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 );
        if (act_sym==1)
        {
          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 );
        }
      }

      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, (unsigned char) act_sym, ctx->mb_type_contexts[1] + act_ctx );
      act_sym  = mode_sym%2;
      biari_encode_symbol(eep_dp, (unsigned char) act_sym, ctx->mb_type_contexts[1] + act_ctx );
    }
  }
}


/*!
 ***************************************************************************
 * \brief
 *    This function is used to arithmetically encode the 8x8 block
 *    type info
 ***************************************************************************
 */
void writeB8_typeInfo2Buffer_CABAC(SyntaxElement *se, EncodingEnvironmentPtr eep_dp)
{
  int act_ctx;
  int act_sym, csym;
  int bframe=(img->type==B_IMG);

  MotionInfoContexts *ctx    = (img->currentSlice)->mot_ctx;

  act_sym = se->value1;
  act_ctx = 0;

  if (!bframe)
  {
    switch (act_sym)
    {
    case 0:
      biari_encode_symbol (eep_dp, 1, &ctx->b8_type_contexts[0][1]);
      break;
    case 1:
      biari_encode_symbol (eep_dp, 0, &ctx->b8_type_contexts[0][1]);
      biari_encode_symbol (eep_dp, 0, &ctx->b8_type_contexts[0][2]);
      biari_encode_symbol (eep_dp, 0, &ctx->b8_type_contexts[0][3]);
      break;
    case 2:
      biari_encode_symbol (eep_dp, 0, &ctx->b8_type_contexts[0][1]);
      biari_encode_symbol (eep_dp, 0, &ctx->b8_type_contexts[0][2]);
      biari_encode_symbol (eep_dp, 1, &ctx->b8_type_contexts[0][3]);
      biari_encode_symbol (eep_dp, 1, &ctx->b8_type_contexts[0][4]);
      break;
    case 3:
      biari_encode_symbol (eep_dp, 0, &ctx->b8_type_contexts[0][1]);
      biari_encode_symbol (eep_dp, 0, &ctx->b8_type_contexts[0][2]);
      biari_encode_symbol (eep_dp, 1, &ctx->b8_type_contexts[0][3]);
      biari_encode_symbol (eep_dp, 0, &ctx->b8_type_contexts[0][4]);
      break;
    case 4:
      biari_encode_symbol (eep_dp, 0, &ctx->b8_type_contexts[0][1]);
      biari_encode_symbol (eep_dp, 1, &ctx->b8_type_contexts[0][2]);