header.c

H.264编码解码器源码(c语言).zip

  return len;
}


/*!
 ************************************************************************
 * \brief
 *    write the memory menagement control operations
 ************************************************************************
 */
static int dec_ref_pic_marking()
{
  int dP_nr = assignSE2partition[input->partition_mode][SE_HEADER];
  DataPartition *partition = &((img->currentSlice)->partArr[dP_nr]);

  DecRefPicMarking_t *tmp_drpm;

  int val, len=0;

  if (img->currentPicture->idr_flag)
  {
    len += u_1("SH: no_output_of_prior_pics_flag", img->no_output_of_prior_pics_flag, partition);
    len += u_1("SH: long_term_reference_flag", img->long_term_reference_flag, partition);
  }
  else
  {
    img->adaptive_ref_pic_buffering_flag = (img->dec_ref_pic_marking_buffer!=NULL);

    len += u_1("SH: adaptive_ref_pic_buffering_flag", img->adaptive_ref_pic_buffering_flag, partition);

    if (img->adaptive_ref_pic_buffering_flag)
    {
      tmp_drpm = img->dec_ref_pic_marking_buffer;
      // write Memory Management Control Operation 
      do
      {
        if (tmp_drpm==NULL) error ("Error encoding MMCO commands", 500);
        
        val = tmp_drpm->memory_management_control_operation;
        len += ue_v("SH: memory_management_control_operation", val, partition);

        if ((val==1)||(val==3)) 
        {
          len += 1 + ue_v("SH: difference_of_pic_nums_minus1", tmp_drpm->difference_of_pic_nums_minus1, partition);
        }
        if (val==2)
        {
          len+= ue_v("SH: long_term_pic_num", tmp_drpm->long_term_pic_num, partition);
        }
        if ((val==3)||(val==6))
        {
          len+= ue_v("SH: long_term_frame_idx", tmp_drpm->long_term_frame_idx, partition);
        }
        if (val==4)
        {
          len += ue_v("SH: max_long_term_pic_idx_plus1", tmp_drpm->max_long_term_frame_idx_plus1, partition);
        }
        
        tmp_drpm=tmp_drpm->Next;
        
      } while (val != 0);
      
    }
  }
  return len;
}

/*!
 ************************************************************************
 * \brief
 *    write the memory menagement control operations
 ************************************************************************
 */
static int pred_weight_table()
{
  int dP_nr = assignSE2partition[input->partition_mode][SE_HEADER];
  DataPartition *partition = &((img->currentSlice)->partArr[dP_nr]);

  int len = 0;
  int i,j;

  len += ue_v("SH: luma_log_weight_denom", luma_log_weight_denom, partition);
  
  len += ue_v("SH: chroma_log_weight_denom", chroma_log_weight_denom, partition);

  for (i=0; i< img->num_ref_idx_l0_active; i++)
  {
	  if ( (wp_weight[0][i][0] != 1<<luma_log_weight_denom) || (wp_offset[0][i][0] != 0) )
    {
      len += u_1 ("SH: luma_weight_flag_l0", 1, partition);
      
      len += se_v ("SH: luma_weight_l0", wp_weight[0][i][0], partition);
        
      len += se_v ("SH: luma_offset_l0", wp_offset[0][i][0], partition);
    }
    else
    {
        len += u_1 ("SH: luma_weight_flag_l0", 0, partition);
    }

    if ( (wp_weight[0][i][1] != 1<<chroma_log_weight_denom) || (wp_offset[0][i][1] != 0) || 
		 (wp_weight[0][i][2] != 1<<chroma_log_weight_denom) || (wp_offset[0][i][2] != 0)	)
    {
      len += u_1 ("chroma_weight_flag_l0", 1, partition);
      for (j=1; j<3; j++)
      {
        len += se_v ("chroma_weight_l0", wp_weight[0][i][j] ,partition);
      
        len += se_v ("chroma_offset_l0", wp_offset[0][i][j] ,partition);
      }
    }
    else
    {
      len += u_1 ("chroma_weight_flag_l0", 0, partition);
    }
  }

	if (img->type == B_SLICE)
  {
    for (i=0; i< img->num_ref_idx_l1_active; i++)
    {
      if ( (wp_weight[1][i][0] != 1<<luma_log_weight_denom) || (wp_offset[1][i][0] != 0) )
      {
        len += u_1 ("SH: luma_weight_flag_l1", 1, partition);
        
        len += se_v ("SH: luma_weight_l1", wp_weight[1][i][0], partition);
        
        len += se_v ("SH: luma_offset_l1", wp_offset[1][i][0], partition);
      }
      else
      {
        len += u_1 ("SH: luma_weight_flag_l1", 0, partition);
      }
      
      if ( (wp_weight[1][i][1] != 1<<chroma_log_weight_denom) || (wp_offset[1][i][1] != 0) || 
		  (wp_weight[1][i][2] != 1<<chroma_log_weight_denom) || (wp_offset[1][i][2] != 0) )
      {
        len += u_1 ("chroma_weight_flag_l1", 1, partition);
        for (j=1; j<3; j++)
        {
          len += se_v ("chroma_weight_l1", wp_weight[1][i][j] ,partition);
          
          len += se_v ("chroma_offset_l1", wp_offset[1][i][j] ,partition);
        }
      }
      else
      {
        len += u_1 ("chroma_weight_flag_l1", 0, partition);
      }
    }
  }
  return len;
}
  
/********************************************************************************************
 ********************************************************************************************
 *
 * Local Support Functions
 *
 ********************************************************************************************
 ********************************************************************************************/



// StW Note: This function is a hack.  It would be cleaner if the encoder maintains
// the picture type in the given format.  Note further that I have yet to understand
// why the encoder needs to know whether a picture is predicted from one or more
// reference pictures.

/*!
 ************************************************************************
 * \brief
 *    Selects picture type and codes it to symbol
 ************************************************************************
 */
int get_picture_type()
{

  // set this value to zero for transmission without signaling 
  // that the whole picture has the same slice type
  int same_slicetype_for_whole_frame = 5;

  switch (img->type)
  {
  case I_SLICE:
    return 2 + same_slicetype_for_whole_frame;
    break;
  case P_SLICE:
    return 0 + same_slicetype_for_whole_frame;
    break;
  case B_SLICE:
    return 1 + same_slicetype_for_whole_frame;
    break;
  case SP_SLICE:
    return 3 + same_slicetype_for_whole_frame;
    break;
  default:
    error("Picture Type not supported!",1);
    break;
  }
   
  return 0;
}



/*!
 *****************************************************************************
 *
 * \brief 
 *    int Partition_BC_Header () write the Partition type B, C header
 *
 * \return
 *    Number of bits used by the partition header
 *
 * \para Parameters
 *    PartNo: Partition Number to which the header should be written
 *
 * \para Side effects
 *    Partition header as per VCEG-N72r2 is written into the appropriate 
 *    partition bit buffer
 *
 * \para Limitations/Shortcomings/Tweaks
 *    The current code does not support the change of picture parameters within
 *    one coded sequence, hence there is only one parameter set necessary.  This
 *    is hard coded to zero.
 *
 * \para
 *    Note: this is still the old Partition_BC_Header and not yet compliant with
 *    the spec.
 *   
 * \date
 *    October 24, 2001
 *
 * \author
 *    Stephan Wenger   [e-mail]
 *****************************************************************************/


int Partition_BC_Header(int PartNo)
{
  DataPartition *partition = &((img->currentSlice)->partArr[PartNo]);
  SyntaxElement symbol, *sym = &symbol;

  int len = 0;

  assert (input->of_mode == PAR_OF_RTP);
  assert (PartNo > 0 && PartNo < img->currentSlice->max_part_nr);

  sym->type = SE_HEADER;         // This will be true for all symbols generated here
  sym->mapping = ue_linfo;       // Mapping rule: Simple code number to len/info


  SYMTRACESTRING("RTP-PH: Picture ID");
  sym->value1 = img->currentSlice->picture_id;
  len += writeSyntaxElement_UVLC (sym, partition);

  SYMTRACESTRING("RTP-PH: Slice ID");
  sym->value1 = img->current_slice_nr;
  len += writeSyntaxElement_UVLC (sym, partition);

  return len;
}