}


/*!
************************************************************************
* \brief
*    returns true, if picture is short term reference picture
*
************************************************************************
*/
int is_short_ref(StorablePicture *s)
{
  return ((s->used_for_reference) && (!(s->is_long_term)));
}


/*!
************************************************************************
* \brief
*    returns true, if picture is long term reference picture
*
************************************************************************
*/
int is_long_ref(StorablePicture *s)
{
  return ((s->used_for_reference) && (s->is_long_term));
}


/*!
************************************************************************
* \brief
*    Generates a alternating field list from a given FrameStore list
*
************************************************************************
*/
static void gen_pic_list_from_frame_list(PictureStructure currStrcture, FrameStore **fs_list, int list_idx, StorablePicture **list, int *list_size, int long_term)
{
  int top_idx = 0;
  int bot_idx = 0;

  int (*is_ref)(StorablePicture *s);

  if (long_term)
    is_ref=is_long_ref;
  else
    is_ref=is_short_ref;

  if (currStrcture == TOP_FIELD)
  {
    while ((top_idx<list_idx)||(bot_idx<list_idx))
    {
      for ( ; top_idx<list_idx; top_idx++)
      {
        if(fs_list[top_idx]->is_used & 1)
        {
          if(is_ref(fs_list[top_idx]->top_field))
          {
            // short term ref pic
            list[*list_size] = fs_list[top_idx]->top_field;
            (*list_size)++;
            top_idx++;
            break;
          }
        }
      }
      for ( ; bot_idx<list_idx; bot_idx++)
      {
        if(fs_list[bot_idx]->is_used & 2)
        {
          if(is_ref(fs_list[bot_idx]->bottom_field))
          {
            // short term ref pic
            list[*list_size] = fs_list[bot_idx]->bottom_field;
            (*list_size)++;
            bot_idx++;
            break;
          }
        }
      }
    }
  }
  if (currStrcture == BOTTOM_FIELD)
  {
    while ((top_idx<list_idx)||(bot_idx<list_idx))
    {
      for ( ; bot_idx<list_idx; bot_idx++)
      {
        if(fs_list[bot_idx]->is_used & 2)
        {
          if(is_ref(fs_list[bot_idx]->bottom_field))
          {
            // short term ref pic
            list[*list_size] = fs_list[bot_idx]->bottom_field;
            (*list_size)++;
            bot_idx++;
            break;
          }
        }
      }
      for ( ; top_idx<list_idx; top_idx++)
      {
        if(fs_list[top_idx]->is_used & 1)
        {
          if(is_ref(fs_list[top_idx]->top_field))
          {
            // short term ref pic
            list[*list_size] = fs_list[top_idx]->top_field;
            (*list_size)++;
            top_idx++;
            break;
          }
        }
      }
    }
  }
}


/*!
************************************************************************
* \brief
*    Initialize listX[0] and list 1 depending on current picture type
*
************************************************************************
*/
void init_lists(int currSliceType, PictureStructure currPicStructure)
{
  int add_top = 0, add_bottom = 0;
  unsigned i;
  int j;
  int MaxFrameNum = 1 << (log2_max_frame_num_minus4 + 4);
  int diff;

  int list0idx = 0;
  int list0idx_1 = 0;
  int listltidx = 0;

  FrameStore **fs_list0;
  FrameStore **fs_list1;
  FrameStore **fs_listlt;

  StorablePicture *tmp_s;

  if (currPicStructure == FRAME)  
  {
    for (i=0; i<dpb.ref_frames_in_buffer; i++)
    {
      if (dpb.fs_ref[i]->is_used==3)
      {
        if ((dpb.fs_ref[i]->frame->used_for_reference)&&(!dpb.fs_ref[i]->frame->is_long_term))
        {
          if( dpb.fs_ref[i]->frame_num > img->frame_num )
          {
            dpb.fs_ref[i]->frame_num_wrap = dpb.fs_ref[i]->frame_num - MaxFrameNum;
          }
          else
          {
            dpb.fs_ref[i]->frame_num_wrap = dpb.fs_ref[i]->frame_num;
          }
          dpb.fs_ref[i]->frame->pic_num = dpb.fs_ref[i]->frame_num_wrap;
        }
      }
    }
    // update long_term_pic_num
    for (i=0; i<dpb.ltref_frames_in_buffer; i++)
    {
      if (dpb.fs_ltref[i]->is_used==3)
      {
        if (dpb.fs_ltref[i]->frame->is_long_term)
        {
          dpb.fs_ltref[i]->frame->long_term_pic_num = dpb.fs_ltref[i]->frame->long_term_frame_idx;
        }
      }
    }
  }
  else
  {
    if (currPicStructure == TOP_FIELD)
    {
      add_top    = 1;
      add_bottom = 0;
    }
    else
    {
      add_top    = 0;
      add_bottom = 1;
    }

    for (i=0; i<dpb.ref_frames_in_buffer; i++)
    {
      if (dpb.fs_ref[i]->is_reference)
      {
        if( dpb.fs_ref[i]->frame_num > img->frame_num )
        {
          dpb.fs_ref[i]->frame_num_wrap = dpb.fs_ref[i]->frame_num - MaxFrameNum;
        }
        else
        {
          dpb.fs_ref[i]->frame_num_wrap = dpb.fs_ref[i]->frame_num;
        }
        if (dpb.fs_ref[i]->is_reference & 1)
        {
          dpb.fs_ref[i]->top_field->pic_num = (2 * dpb.fs_ref[i]->frame_num_wrap) + add_top;
        }
        if (dpb.fs_ref[i]->is_reference & 2)
        {
          dpb.fs_ref[i]->bottom_field->pic_num = (2 * dpb.fs_ref[i]->frame_num_wrap) + add_bottom;
        }
      }
    }
    // update long_term_pic_num
    for (i=0; i<dpb.ltref_frames_in_buffer; i++)
    {
      if (dpb.fs_ltref[i]->is_long_term & 1)
      {
        dpb.fs_ltref[i]->top_field->long_term_pic_num = 2 * dpb.fs_ltref[i]->top_field->long_term_frame_idx + add_top;
      }
      if (dpb.fs_ltref[i]->is_long_term & 2)
      {
        dpb.fs_ltref[i]->bottom_field->long_term_pic_num = 2 * dpb.fs_ltref[i]->bottom_field->long_term_frame_idx + add_bottom;
      }
    }
  }



  if ((currSliceType == I_SLICE)||(currSliceType == SI_SLICE))
  {
    listXsize[0] = 0;
    listXsize[1] = 0;
    return;
  }

  if ((currSliceType == P_SLICE)||(currSliceType == SP_SLICE))
  {
    // Calculate FrameNumWrap and PicNum
    if (currPicStructure == FRAME)  
    {
      for (i=0; i<dpb.ref_frames_in_buffer; i++)
      {
        if (dpb.fs_ref[i]->is_used==3)
        {
          if ((dpb.fs_ref[i]->frame->used_for_reference)&&(!dpb.fs_ref[i]->frame->is_long_term))
          {
            listX[0][list0idx++] = dpb.fs_ref[i]->frame;
          }
        }
      }
      // order list 0 by PicNum
      qsort((void *)listX[0], list0idx, sizeof(StorablePicture*), compare_pic_by_pic_num_desc);
      listXsize[0] = list0idx;
      //      printf("listX[0] (PicNum): "); for (i=0; i<list0idx; i++){printf ("%d  ", listX[0][i]->pic_num);} printf("\n");

      // long term handling
      for (i=0; i<dpb.ltref_frames_in_buffer; i++)
      {
        if (dpb.fs_ltref[i]->is_used==3)
        {
          if (dpb.fs_ltref[i]->frame->is_long_term)
          {
            listX[0][list0idx++]=dpb.fs_ltref[i]->frame;
          }
        }
      }
      qsort((void *)&listX[0][listXsize[0]], list0idx-listXsize[0], sizeof(StorablePicture*), compare_pic_by_lt_pic_num_asc);
      listXsize[0] = list0idx;
    }
    else
    {
      fs_list0 = calloc(dpb.size, sizeof (FrameStore*));
      if (NULL==fs_list0) 
        no_mem_exit("init_lists: fs_list0");
      fs_listlt = calloc(dpb.size, sizeof (FrameStore*));
      if (NULL==fs_listlt) 
        no_mem_exit("init_lists: fs_listlt");

      for (i=0; i<dpb.ref_frames_in_buffer; i++)
      {
        if (dpb.fs_ref[i]->is_reference)
        {
          fs_list0[list0idx++] = dpb.fs_ref[i];
        }
      }

      qsort((void *)fs_list0, list0idx, sizeof(FrameStore*), compare_fs_by_frame_num_desc);

      //      printf("fs_list0 (FrameNum): "); for (i=0; i<list0idx; i++){printf ("%d  ", fs_list0[i]->frame_num_wrap);} printf("\n");

      listXsize[0] = 0;
      gen_pic_list_from_frame_list(currPicStructure, fs_list0, list0idx, listX[0], &listXsize[0], 0);

      //      printf("listX[0] (PicNum): "); for (i=0; i<listXsize[0]; i++){printf ("%d  ", listX[0][i]->pic_num);} printf("\n");

      // long term handling
      for (i=0; i<dpb.ltref_frames_in_buffer; i++)
      {
        fs_listlt[listltidx++]=dpb.fs_ltref[i];
      }

      qsort((void *)fs_listlt, listltidx, sizeof(FrameStore*), compare_fs_by_lt_pic_idx_asc);

      gen_pic_list_from_frame_list(currPicStructure, fs_listlt, listltidx, listX[0], &listXsize[0], 1);

      free(fs_list0);
      free(fs_listlt);
    }
    listXsize[1] = 0;
  }
  else
  {
    // B-Slice
    if (currPicStructure == FRAME)  
    {
      for (i=0; i<dpb.ref_frames_in_buffer; i++)
      {
        if (dpb.fs_ref[i]->is_used==3)
        {
          if ((dpb.fs_ref[i]->frame->used_for_reference)&&(!dpb.fs_ref[i]->frame->is_long_term))
          {
            if (img->framepoc > dpb.fs_ref[i]->frame->poc)
            {
              listX[0][list0idx++] = dpb.fs_ref[i]->frame;
            }
          }
        }
      }
      qsort((void *)listX[0], list0idx, sizeof(StorablePicture*), compare_pic_by_poc_desc);
      list0idx_1 = list0idx;
      for (i=0; i<dpb.ref_frames_in_buffer; i++)
      {
        if (dpb.fs_ref[i]->is_used==3)
        {
          if ((dpb.fs_ref[i]->frame->used_for_reference)&&(!dpb.fs_ref[i]->frame->is_long_term))
          {
            if (img->framepoc < dpb.fs_ref[i]->frame->poc)
            {
              listX[0][list0idx++] = dpb.fs_ref[i]->frame;
            }
          }
        }
      }
      qsort((void *)&listX[0][list0idx_1], list0idx-list0idx_1, sizeof(StorablePicture*), compare_pic_by_poc_asc);

      for (j=0; j<list0idx_1; j++)
      {
        listX[1][list0idx-list0idx_1+j]=listX[0][j];
      }
      for (j=list0idx_1; j<list0idx; j++)
      {
        listX[1][j-list0idx_1]=listX[0][j];
      }

      listXsize[0] = listXsize[1] = list0idx;

      //      printf("listX[0] currPoc=%d (Poc): ", img->framepoc); for (i=0; i<listXsize[0]; i++){printf ("%d  ", listX[0][i]->poc);} printf("\n");
      //      printf("listX[1] currPoc=%d (Poc): ", img->framepoc); for (i=0; i<listXsize[1]; i++){printf ("%d  ", listX[1][i]->poc);} printf("\n");

      // long term handling
      for (i=0; i<dpb.ltref_frames_in_buffer; i++)
      {
        if (dpb.fs_ltref[i]->is_used==3)
        {
          if (dpb.fs_ltref[i]->frame->is_long_term)
          {
            listX[0][list0idx]  =dpb.fs_ltref[i]->frame;
            listX[1][list0idx++]=dpb.fs_ltref[i]->frame;
          }
        }
      }
      qsort((void *)&listX[0][listXsize[0]], list0idx-listXsize[0], sizeof(StorablePicture*), compare_pic_by_lt_pic_num_asc);
      qsort((void *)&listX[1][listXsize[0]], list0idx-listXsize[0], sizeof(StorablePicture*), compare_pic_by_lt_pic_num_asc);
      
#ifdef SWITCHED_FILTERS
      if(input->UseHPFilter == HPF_SIFO)
      {
        listXsize[0] = list0idx_1;
        listXsize[1] = listXsize[1] - list0idx_1;
      }
      else
      {
        listXsize[0] = listXsize[1] = list0idx;
      }
#else
      listXsize[0] = listXsize[1] = list0idx;
#endif  // SWITCHED_FILTERS
    }
    else
    {
      fs_list0 = calloc(dpb.size, sizeof (FrameStore*));
      if (NULL==fs_list0) 
        no_mem_exit("init_lists: fs_list0");
      fs_list1 = calloc(dpb.size, sizeof (FrameStore*));
      if (NULL==fs_list1) 
        no_mem_exit("init_lists: fs_list1");
      fs_listlt = calloc(dpb.size, sizeof (FrameStore*));
      if (NULL==fs_listlt) 
        no_mem_exit("init_lists: fs_listlt");

      listXsize[0] = 0;
      listXsize[1] = 1;

      for (i=0; i<dpb.ref_frames_in_buffer; i++)
      {
        if (dpb.fs_ref[i]->is_used)
        {
          if (img->ThisPOC >= dpb.fs_ref[i]->poc)
          {
            fs_list0[list0idx++] = dpb.fs_ref[i];
          }
        }
      }
      qsort((void *)fs_list0, list0idx, sizeof(FrameStore*), compare_fs_by_poc_desc);
      list0idx_1 = list0idx;
      for (i=0; i<dpb.ref_frames_in_buffer; i++)
      {
        if (dpb.fs_ref[i]->is_used)
        {
          if (img->ThisPOC < dpb.fs_ref[i]->poc)
          {
            fs_list0[list0idx++] = dpb.fs_ref[i];
          }
        }
      }
      qsort((void *)&fs_list0[list0idx_1], list0idx-list0idx_1, sizeof(FrameStore*), compare_fs_by_poc_asc);

      for (j=0; j<list0idx_1; j++)
      {
        fs_list1[list0idx-list0idx_1+j]=fs_list0[j];
      }
      for (j=list0idx_1; j<list0idx; j++)
      {
        fs_list1[j-list0idx_1]=fs_list0[j];
      }

      //      printf("fs_list0 currPoc=%d (Poc): ", img->ThisPOC); for (i=0; i<list0idx; i++){printf ("%d  ", fs_list0[i]->poc);} printf("\n");
      //      printf("fs_list1 currPoc=%d (Poc): ", img->ThisPOC); for (i=0; i<list0idx; i++){printf ("%d  ", fs_list1[i]->poc);} printf("\n");

      listXsize[0] = 0;
      listXsize[1] = 0;
      gen_pic_list_from_frame_list(currPicStructure, fs_list0, list0idx, listX[0], &listXsize[0], 0);
      gen_pic_list_from_frame_list(currPicStructure, fs_list1, list0idx, listX[1], &listXsize[1], 0);

      //      printf("listX[0] currPoc=%d (Poc): ", img->framepoc); for (i=0; i<listXsize[0]; i++){printf ("%d  ", listX[0][i]->poc);} printf("\n");
      //      printf("listX[1] currPoc=%d (Poc): ", img->framepoc); for (i=0; i<listXsize[1]; i++){printf ("%d  ", listX[1][i]->poc);} printf("\n");

      // long term handling
      for (i=0; i<dpb.ltref_frames_in_buffer; i++)
      {
        fs_listlt[listltidx++]=dpb.fs_ltref[i];
      }

      qsort((void *)fs_listlt, listltidx, sizeof(FrameStore*), compare_fs_by_lt_pic_idx_asc);

      gen_pic_list_from_frame_list(currPicStructure, fs_listlt, listltidx, listX[0], &listXsize[0], 1);
      gen_pic_list_from_frame_list(currPicStructure, fs_listlt, listltidx, listX[1], &listXsize[1], 1);

      free(fs_list0);
      free(fs_list1);
      free(fs_listlt);
    }
  } 

  if ((listXsize[0] == listXsize[1]) && (listXsize[0] > 1))
  {
    // check if lists are identical, if yes swap first two elements of listX[1]
    diff=0;
    for (j = 0; j< listXsize[0]; j++)
    {
      if (listX[0][j]!=listX[1][j])
        diff=1;
    }
    if (!diff)