{
        //! Next is Display Order
        if (order_read == 0)
        {
          if (isdigit((int)(*(input->ExplicitPyramidFormat+i))))
          {
            sscanf(input->ExplicitPyramidFormat+i,"%d",&display_no);
            gop_structure[coded_frame].display_no = display_no;
            order_read = 1;
            if (display_no<0 || display_no>=input->jumpd)
            {
              snprintf(errortext, ET_SIZE, "Invalid Frame Order value. Frame position needs to be in [0,%d] range.",input->jumpd-1);
              error (errortext, 400);          
            }
            for (k=0;k<coded_frame;k++)
            {
              if (gop_structure[k].display_no == display_no)
              {
                snprintf(errortext, ET_SIZE, "Frame Order value %d in frame %d already used for enhancement frame %d.",display_no,coded_frame,k);
                error (errortext, 400);          
              }
            }
          }
          else
          {
            snprintf(errortext, ET_SIZE, "Slice Type needs to be followed by Display Order. Please check configuration file.");
            error (errortext, 400);
          }
        }
        else if (order_read == 1)
        { 
          if (stored_read == 0 && !(isdigit((int)(*(input->ExplicitPyramidFormat+i)))))
          {
            switch (input->ExplicitPyramidFormat[i])
            {
            case 'E':
            case 'e':
              gop_structure[coded_frame].reference_idc = NALU_PRIORITY_DISPOSABLE;
              break;
            case 'R':
            case 'r':
              gop_structure[coded_frame].reference_idc= NALU_PRIORITY_HIGH;
              break;
            default:
              snprintf(errortext, ET_SIZE, "Reference_IDC invalid in ExplicitPyramidFormat param. Please check configuration file.");
              error (errortext, 400);
              break;
            }
            stored_read = 1;          
          }
          else if (stored_read == 1 && qp_read == 0)
          {
            if (isdigit((int)(*(input->ExplicitPyramidFormat+i))))
            {
              sscanf(input->ExplicitPyramidFormat+i,"%d",&qp);
              gop_structure[coded_frame].slice_qp= qp;
                qp_read = 1;
                if (qp<0 || qp>51)
                {
                  snprintf(errortext, ET_SIZE, "Invalid QP value. Please check configuration file.");
                  error (errortext, 400);          
                }
            }
            else
            {
              snprintf(errortext, ET_SIZE, "Reference_IDC needs to be followed by QP. Please check configuration file.");
              error (errortext, 400);
            }
          }
          else if (stored_read == 1 && qp_read == 1 && !(isdigit((int)(*(input->ExplicitPyramidFormat+i)))) && (i < nLength - 2))
          {
            stored_read =0;
            qp_read=0;
            order_read=0;
            slice_read=0;
            i--;
            coded_frame ++;
            if (coded_frame >= input->jumpd )
            {
              snprintf(errortext, ET_SIZE, "Total number of frames in Enhancement GOP need to be fewer or equal to FrameSkip parameter.");
              error (errortext, 400);
            }
            
          }
        }
        
      }      
    }
  }
  else
  {
    snprintf(errortext, ET_SIZE, "ExplicitPyramidFormat is empty. Please check configuration file.");
    error (errortext, 400);
  }

  input->successive_Bframe = coded_frame + 1;
}


/*!
************************************************************************
* \brief
*    Encode Enhancement Layer. 
************************************************************************
*/
void encode_enhancement_layer()
{
    if ((input->successive_Bframe != 0) && (IMG_NUMBER > 0)) // B-frame(s) to encode
    {
      img->type = B_SLICE;            // set image type to B-frame
      
      if (input->NumFramesInELSubSeq == 0) 
        img->layer = 0;
      else 
        img->layer = 1;
      
      if (input->StoredBPictures == 0 && input->PyramidCoding==0)
      {
        img->frame_num++;                 //increment frame_num once for B-frames
        img->frame_num %= (1 << (log2_max_frame_num_minus4 + 4));
      }
      img->nal_reference_idc = 0;     

      //if (input->PyramidCoding == 3 || input->PyramidCoding == 1)
      if (input->PyramidCoding)
      {
        for(img->b_frame_to_code=1; img->b_frame_to_code<=input->successive_Bframe; img->b_frame_to_code++)
        {
          
          img->nal_reference_idc = 0;     

          img->type = gop_structure[img->b_frame_to_code - 1].slice_type;

          if (gop_structure[img->b_frame_to_code - 1].reference_idc== NALU_PRIORITY_HIGH )            
          {
            img->nal_reference_idc = 1;
            img->frame_num++;                 //increment frame_num for each stored B slice
            img->frame_num %= (1 << (log2_max_frame_num_minus4 + 4));
          } 

          img->b_interval =
            ((double) (input->jumpd + 1) / (input->successive_Bframe + 1.0) );

          if (input->PyramidCoding == 3)
            img->b_interval = 1.0;
          
          img->toppoc = 2*((IMG_NUMBER-1)*(input->jumpd + 1) + (int) (img->b_interval * (double)(1 + gop_structure[img->b_frame_to_code - 1].display_no)));      

          if (img->b_frame_to_code == 1)
            img->delta_pic_order_cnt[0] = img->toppoc - 2*(start_tr_in_this_IGOP  + (IMG_NUMBER)*((input->jumpd+1)));
          else
            img->delta_pic_order_cnt[0] = img->toppoc - 2*(start_tr_in_this_IGOP  + (IMG_NUMBER-1)*((input->jumpd+1)) + (int) (2.0 *img->b_interval * (double) (1+ gop_structure[img->b_frame_to_code - 2].display_no)));

          if ((input->PicInterlace==FRAME_CODING)&&(input->MbInterlace==FRAME_CODING))
            img->bottompoc = img->toppoc;     //progressive
          else 
            img->bottompoc = img->toppoc+1;
          
          img->framepoc = min (img->toppoc, img->bottompoc);
          
          img->delta_pic_order_cnt[1]= 0;   // POC200301
          
          encode_one_frame();  // encode one B-frame
          if (input->ReportFrameStats)
            report_frame_statistic();
        }
        img->b_frame_to_code = 0;
      }
      else 
      {      
        for(img->b_frame_to_code=1; img->b_frame_to_code<=input->successive_Bframe; img->b_frame_to_code++)
        {
          
          img->nal_reference_idc = 0;     
          if (input->StoredBPictures == 1 )
            
          {
            img->nal_reference_idc = 1;
            img->frame_num++;                 //increment frame_num once for B-frames
            img->frame_num %= (1 << (log2_max_frame_num_minus4 + 4));
          }

          img->b_interval =
            ((double) (input->jumpd + 1) / (input->successive_Bframe + 1.0) );

          if (input->PyramidCoding == 3)
            img->b_interval = 1.0;
          
          img->toppoc = 2*((IMG_NUMBER-1)*(input->jumpd+1) + (int) (img->b_interval * (double)img->b_frame_to_code));      


          if ((input->PicInterlace==FRAME_CODING)&&(input->MbInterlace==FRAME_CODING))
            img->bottompoc = img->toppoc;     //progressive
          else 
            img->bottompoc = img->toppoc+1;
          
          img->framepoc = min (img->toppoc, img->bottompoc);
          
          //the following is sent in the slice header
          if (!input->StoredBPictures)
          {
            img->delta_pic_order_cnt[0]= 2*(img->b_frame_to_code-1);
          }
          else
          {
            img->delta_pic_order_cnt[0]= -2;
          }
          
          img->delta_pic_order_cnt[1]= 0;   // POC200301
          
          encode_one_frame();  // encode one B-frame
          if (input->ReportFrameStats)
            report_frame_statistic();
        }
      }
    }
    img->b_frame_to_code = 0;
}


void poc_based_ref_management(int current_pic_num)
{
  unsigned i, pic_num = 0;

  int min_poc=INT_MAX;
  DecRefPicMarking_t *tmp_drpm,*tmp_drpm2;

  if (img->dec_ref_pic_marking_buffer!=NULL)
    return;

  if ((dpb.ref_frames_in_buffer+dpb.ltref_frames_in_buffer)==0)
    return;

  for (i=0; i<dpb.used_size;i++)
  {
    if (dpb.fs[i]->is_reference  && (!(dpb.fs[i]->is_long_term)) && dpb.fs[i]->poc < min_poc)
    {
      min_poc = dpb.fs[i]->frame->poc ;
      pic_num =  dpb.fs[i]->frame->pic_num;
    }
  }
  
  tmp_drpm=(DecRefPicMarking_t*)calloc (1,sizeof (DecRefPicMarking_t));
  tmp_drpm->Next=NULL;
  
  tmp_drpm->memory_management_control_operation = 0;
  
  tmp_drpm2=(DecRefPicMarking_t*)calloc (1,sizeof (DecRefPicMarking_t));
  tmp_drpm2->Next=tmp_drpm;
  
  tmp_drpm2->memory_management_control_operation = 1;
  tmp_drpm2->difference_of_pic_nums_minus1 = current_pic_num - pic_num - 1;
  img->dec_ref_pic_marking_buffer = tmp_drpm2;

}