*    the complementary field of the picture indicated by picNumX
 ************************************************************************
 */
static void unmark_long_term_field_for_reference_by_frame_idx(PictureStructure structure, int long_term_frame_idx, int mark_current, unsigned curr_frame_num, int curr_pic_num)
{
  unsigned i;
  int MaxFrameNum = 1 << (log2_max_frame_num_minus4 + 4);

  assert(structure!=FRAME);
  if (curr_pic_num<0)
    curr_pic_num+=(2*MaxFrameNum);

  for(i=0; i<dpb.ltref_frames_in_buffer; i++)
  {
    if (dpb.fs_ltref[i]->long_term_frame_idx == long_term_frame_idx)
    {
      if (structure == TOP_FIELD)
      {
        if ((dpb.fs_ltref[i]->is_long_term == 3))
        {
          unmark_for_long_term_reference(dpb.fs_ltref[i]);
        }
        else
        {
          if ((dpb.fs_ltref[i]->is_long_term == 1))
          {
            unmark_for_long_term_reference(dpb.fs_ltref[i]);
          }
          else
          {
            if (mark_current)
            {
              if (dpb.last_picture)
              {
                if ( ( dpb.last_picture != dpb.fs_ltref[i] )|| dpb.last_picture->frame_num != curr_frame_num)
                  unmark_for_long_term_reference(dpb.fs_ltref[i]);
              }
              else
              {
                unmark_for_long_term_reference(dpb.fs_ltref[i]);
              }
            }
            else
            {
              if ((dpb.fs_ltref[i]->frame_num) != (unsigned)(curr_pic_num/2))
              {
                unmark_for_long_term_reference(dpb.fs_ltref[i]);
              }
            }
          }
        }
      }
      if (structure == BOTTOM_FIELD)
      {
        if ((dpb.fs_ltref[i]->is_long_term == 3))
        {
          unmark_for_long_term_reference(dpb.fs_ltref[i]);
        }
        else
        {
          if ((dpb.fs_ltref[i]->is_long_term == 2))
          {
            unmark_for_long_term_reference(dpb.fs_ltref[i]);
          }
          else
          {
            if (mark_current)
            {
              if (dpb.last_picture)
              {
                if ( ( dpb.last_picture != dpb.fs_ltref[i] )|| dpb.last_picture->frame_num != curr_frame_num)
                  unmark_for_long_term_reference(dpb.fs_ltref[i]);
              }
              else
              {
                unmark_for_long_term_reference(dpb.fs_ltref[i]);
              }
            }
            else
            {
              if ((dpb.fs_ltref[i]->frame_num) != (unsigned)(curr_pic_num/2))
              {
                unmark_for_long_term_reference(dpb.fs_ltref[i]);
              }
            }
          }
        }
      }
    }
  }
}


/*!
 ************************************************************************
 * \brief
 *    mark a picture as long-term reference
 ************************************************************************
 */
static void mark_pic_long_term(StorablePicture* p, int long_term_frame_idx, int picNumX)
{
  unsigned i;
  int add_top, add_bottom;

  if (p->structure == FRAME)
  {
    for (i=0; i<dpb.ref_frames_in_buffer; i++)
    {
      if (dpb.fs_ref[i]->is_reference == 3)
      {
        if ((!dpb.fs_ref[i]->frame->is_long_term)&&(dpb.fs_ref[i]->frame->pic_num == picNumX))
        {
          dpb.fs_ref[i]->long_term_frame_idx = dpb.fs_ref[i]->frame->long_term_frame_idx
                                             = long_term_frame_idx;
          dpb.fs_ref[i]->frame->long_term_pic_num = long_term_frame_idx;
          dpb.fs_ref[i]->frame->is_long_term = 1;

          if (dpb.fs_ref[i]->top_field && dpb.fs_ref[i]->bottom_field)
          {
            dpb.fs_ref[i]->top_field->long_term_frame_idx = dpb.fs_ref[i]->bottom_field->long_term_frame_idx
                                                          = long_term_frame_idx;
            dpb.fs_ref[i]->top_field->long_term_pic_num = long_term_frame_idx;
            dpb.fs_ref[i]->bottom_field->long_term_pic_num = long_term_frame_idx;

            dpb.fs_ref[i]->top_field->is_long_term = dpb.fs_ref[i]->bottom_field->is_long_term
                                                   = 1;

          }
          dpb.fs_ref[i]->is_long_term = 3;
          return;
        }
      }
    }
    printf ("Warning: reference frame for long term marking not found\n");
  }
  else
  {
    if (p->structure == 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 & 1)
      {
        if ((!dpb.fs_ref[i]->top_field->is_long_term)&&(dpb.fs_ref[i]->top_field->pic_num == picNumX))
        {
          if ((dpb.fs_ref[i]->is_long_term) && (dpb.fs_ref[i]->long_term_frame_idx != long_term_frame_idx))
          {
              printf ("Warning: assigning long_term_frame_idx different from other field\n");
          }

          dpb.fs_ref[i]->long_term_frame_idx = dpb.fs_ref[i]->top_field->long_term_frame_idx 
                                             = long_term_frame_idx;
          dpb.fs_ref[i]->top_field->long_term_pic_num = 2 * long_term_frame_idx + add_top;
          dpb.fs_ref[i]->top_field->is_long_term = 1;
          dpb.fs_ref[i]->is_long_term |= 1;
          if (dpb.fs_ref[i]->is_long_term == 3)
          {
            dpb.fs_ref[i]->frame->is_long_term = 1;
            dpb.fs_ref[i]->frame->long_term_frame_idx = dpb.fs_ref[i]->frame->long_term_pic_num = long_term_frame_idx;
          }
          return;
        }
      }
      if (dpb.fs_ref[i]->is_reference & 2)
      {
        if ((!dpb.fs_ref[i]->bottom_field->is_long_term)&&(dpb.fs_ref[i]->bottom_field->pic_num == picNumX))
        {
          if ((dpb.fs_ref[i]->is_long_term) && (dpb.fs_ref[i]->long_term_frame_idx != long_term_frame_idx))
          {
              printf ("Warning: assigning long_term_frame_idx different from other field\n");
          }

          dpb.fs_ref[i]->long_term_frame_idx = dpb.fs_ref[i]->bottom_field->long_term_frame_idx 
                                             = long_term_frame_idx;
          dpb.fs_ref[i]->bottom_field->long_term_pic_num = 2 * long_term_frame_idx + add_top;
          dpb.fs_ref[i]->bottom_field->is_long_term = 1;
          dpb.fs_ref[i]->is_long_term |= 2;
          if (dpb.fs_ref[i]->is_long_term == 3)
          {
            dpb.fs_ref[i]->frame->is_long_term = 1;
            dpb.fs_ref[i]->frame->long_term_frame_idx = dpb.fs_ref[i]->frame->long_term_pic_num = long_term_frame_idx;
          }
          return;
        }
      }
    }
    printf ("Warning: reference field for long term marking not found\n");
  }
}


/*!
 ************************************************************************
 * \brief
 *    Assign a long term frame index to a short term picture
 ************************************************************************
 */
static void mm_assign_long_term_frame_idx(StorablePicture* p, int difference_of_pic_nums_minus1, int long_term_frame_idx)
{
  int picNumX;

  picNumX = get_pic_num_x(p, difference_of_pic_nums_minus1);

  // remove frames/fields with same long_term_frame_idx
  if (p->structure == FRAME)
  {
    unmark_long_term_frame_for_reference_by_frame_idx(long_term_frame_idx);
  }
  else
  {
    unsigned i;
    PictureStructure structure = FRAME;

    for (i=0; i<dpb.ref_frames_in_buffer; i++)
    {
      if (dpb.fs_ref[i]->is_reference & 1)
      {
        if (dpb.fs_ref[i]->top_field->pic_num == picNumX)
        {
          structure = TOP_FIELD;
          break;
        }
      }
      if (dpb.fs_ref[i]->is_reference & 2)
      {
        if (dpb.fs_ref[i]->bottom_field->pic_num == picNumX)
        {
          structure = BOTTOM_FIELD;
          break;
        }
      }
    }
    if (structure==FRAME)
    {
      error ("field for long term marking not found",200);
    }
    
    unmark_long_term_field_for_reference_by_frame_idx(structure, long_term_frame_idx, 0, 0, picNumX);
  }

  mark_pic_long_term(p, long_term_frame_idx, picNumX);
}

/*!
 ************************************************************************
 * \brief
 *    Set new max long_term_frame_idx
 ************************************************************************
 */
void mm_update_max_long_term_frame_idx(int max_long_term_frame_idx_plus1)
{
  unsigned i;

  dpb.max_long_term_pic_idx = max_long_term_frame_idx_plus1 - 1;

  // check for invalid frames
  for (i=0; i<dpb.ltref_frames_in_buffer; i++)
  {
    if (dpb.fs_ltref[i]->long_term_frame_idx > dpb.max_long_term_pic_idx)
    {
      unmark_for_long_term_reference(dpb.fs_ltref[i]);
    }
  }
}


/*!
 ************************************************************************
 * \brief
 *    Mark all long term reference pictures unused for reference
 ************************************************************************
 */
static void mm_unmark_all_long_term_for_reference (void)
{
  mm_update_max_long_term_frame_idx(0);
}

/*!
 ************************************************************************
 * \brief
 *    Mark all short term reference pictures unused for reference
 ************************************************************************
 */
static void mm_unmark_all_short_term_for_reference (void)
{
  unsigned int i;
  for (i=0; i<dpb.ref_frames_in_buffer; i++)
  {
    unmark_for_reference(dpb.fs_ref[i]);
  }
  update_ref_list();
}


/*!
 ************************************************************************
 * \brief
 *    Mark the current picture used for long term reference
 ************************************************************************
 */
static void mm_mark_current_picture_long_term(StorablePicture *p, int long_term_frame_idx)
{
  // remove long term pictures with same long_term_frame_idx
  if (p->structure == FRAME)
  {
    unmark_long_term_frame_for_reference_by_frame_idx(long_term_frame_idx);
  }
  else
  {
    unmark_long_term_field_for_reference_by_frame_idx(p->structure, long_term_frame_idx, 1, p->pic_num, 0);
  }

  p->is_long_term = 1;
  p->long_term_frame_idx = long_term_frame_idx;
}


/*!
 ************************************************************************
 * \brief
 *    Perform Adaptive memory control decoded reference picture marking process
 ************************************************************************
 */
static void adaptive_memory_management(StorablePicture* p)
{
  DecRefPicMarking_t *tmp_drpm;

  img->last_has_mmco_5 = 0;

  assert (!img->currentPicture->idr_flag);
  assert (img->adaptive_ref_pic_buffering_flag);

  while (img->dec_ref_pic_marking_buffer)
  {
    tmp_drpm = img->dec_ref_pic_marking_buffer;
    switch (tmp_drpm->memory_management_control_operation)
    {
      case 0:
        if (tmp_drpm->Next != NULL)
        {
          error ("memory_management_control_operation = 0 not last operation in buffer", 500);
        }
        break;
      case 1:
        mm_unmark_short_term_for_reference(p, tmp_drpm->difference_of_pic_nums_minus1);
        update_ref_list();
        break;
      case 2:
        mm_unmark_long_term_for_reference(p, tmp_drpm->long_term_pic_num);
        update_ltref_list();
        break;
      case 3:
        mm_assign_long_term_frame_idx(p, tmp_drpm->difference_of_pic_nums_minus1, tmp_drpm->long_term_frame_idx);
        update_ref_list();
        update_ltref_list();
        break;
      case 4:
        mm_update_max_long_term_frame_idx (tmp_drpm->max_long_term_frame_idx_plus1);
        update_ltref_list();
        break;
      case 5:
        mm_unmark_all_short_term_for_reference();
        mm_unmark_all_long_term_for_reference();
       img->last_has_mmco_5 = 1;
        break;
      case 6:
        mm_mark_current_picture_long_term(p, tmp_drpm->long_term_frame_idx);
        check_num_ref();
        break;
      default:
        error ("invalid memory_management_control_operation in buffer", 500);
    }
    img->dec_ref_pic_marking_buffer = tmp_drpm->Next;
    free (tmp_drpm);
  }
  if ( img->last_has_mmco_5 )
  {
    p->pic_num = p->frame_num = 0;
    
    switch (p->structure)
    {
    case TOP_FIELD:
      {
        p->poc = p->top_poc = img->toppoc =0;
        break;
      }
    case BOTTOM_FIELD:
      {
        p->poc = p->bottom_poc = img->bottompoc = 0;
        break;
      }
    case FRAME:
      {
        p->top_poc    -= p->poc;
        p->bottom_poc -= p->poc;

        img->toppoc = p->top_poc;
        img->bottompoc = p->bottom_poc;

        p->poc = min (p->top_poc, p->bottom_poc);
        img->framepoc = p->poc;
        break;
      }
    }
    img->ThisPOC = p->poc;
    flush_dpb();
  }
}


/*!
 ************************************************************************
 * \brief
 *    Store a picture in DPB. This includes cheking for space in DPB and 
 *    flushing frames.
 *    If we received a frame, we need to check for a new store, if we
 *    got a field, check if it's the second field of an already allocated
 *    store.
 *
 * \param p
 *    Picture to be stored
 *
 ************************************************************************
 */
void store_picture_in_dpb(StorablePicture* p)
{
  unsigned i;
  int poc, pos;
  // diagnostics
  //printf ("Storing (%s) non-ref pic with frame_num #%d\n", (p->type == FRAME)?"FRAME":(p->type == TOP_FIELD)?"TOP_FIELD":"BOTTOM_FIELD", p->pic_num);
  // if frame, check for new store, 
  assert (p!=NULL);

  p->used_for_reference = (img->nal_reference_idc != 0);
  
  img->last_has_mmco_5=0;
  img->last_pic_bottom_field = (img->structure == BOTTOM_FIELD);

  if (img->currentPicture->idr_flag)
    idr_memory_management(p);
  else
  {
    // adaptive memory management
    if (p->used_for_reference && (img->adaptive_ref_pic_buffering_flag))
      adaptive_memory_management(p);
  }

  if ((p->structure==TOP_FIELD)||(p->structure==BOTTOM_FIELD))
  {
    // check for frame store with same pic_number
    if (dpb.last_picture)
    {
      if ((int)dpb.last_picture->frame_num == p->pic_num)
      {
        if (((p->structure==TOP_FIELD)&&(dpb.last_picture->is_used==2))||((p->structure==BOTTOM_FIELD)&&(dpb.last_picture->is_used==1)))
        {
          if ((p->us