JM.rar header.c

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/*! 
 ************************************************************************************* 
 * \file header.c 
 * 
 * \brief 
 *    H.264 Slice headers 
 * 
 ************************************************************************************* 
 */ 
 
#include  
#include  
#include  
#include  
 
#include "global.h" 
#include "elements.h" 
#include "defines.h" 
#include "fmo.h" 
#include "vlc.h" 
#include "mbuffer.h" 
#include "header.h" 
 
#include "ctx_tables.h" 
 
extern StorablePicture *dec_picture; 
 
#if TRACE 
#define SYMTRACESTRING(s) strncpy(sym.tracestring,s,TRACESTRING_SIZE) 
#else 
#define SYMTRACESTRING(s) // to nothing 
#endif 
 
extern int UsedBits; 
 
static void ref_pic_list_reordering(); 
static void pred_weight_table(); 
 
 
/*! 
 ************************************************************************ 
 * \brief 
 *    calculate Ceil(Log2(uiVal)) 
 ************************************************************************ 
 */ 
unsigned CeilLog2( unsigned uiVal) 
{ 
  unsigned uiTmp = uiVal-1; 
  unsigned uiRet = 0; 
 
  while( uiTmp != 0 ) 
  { 
    uiTmp >>= 1; 
    uiRet++; 
  } 
  return uiRet; 
} 
 
 
/*! 
 ************************************************************************ 
 * \brief 
 *    read the first part of the header (only the pic_parameter_set_id) 
 * \return 
 *    Length of the first part of the slice header (in bits) 
 ************************************************************************ 
 */ 
int FirstPartOfSliceHeader() 
{ 
  Slice *currSlice = img->currentSlice; 
  int dP_nr = assignSE2partition[currSlice->dp_mode][SE_HEADER]; 
  DataPartition *partition = &(currSlice->partArr[dP_nr]); 
  Bitstream *currStream = partition->bitstream; 
  int tmp; 
 
  UsedBits= partition->bitstream->frame_bitoffset; // was hardcoded to 31 for previous start-code. This is better. 
 
  // Get first_mb_in_slice 
  currSlice->start_mb_nr = ue_v ("SH: first_mb_in_slice", currStream); 
 
  tmp = ue_v ("SH: slice_type", currStream); 
   
  if (tmp>4) tmp -=5; 
 
  img->type = currSlice->picture_type = (SliceType) tmp; 
 
  currSlice->pic_parameter_set_id = ue_v ("SH: pic_parameter_set_id", currStream); 
   
  return UsedBits; 
} 
 
/*! 
 ************************************************************************ 
 * \brief 
 *    read the scond part of the header (without the pic_parameter_set_id  
 * \return 
 *    Length of the second part of the Slice header in bits 
 ************************************************************************ 
 */ 
int RestOfSliceHeader() 
{ 
  Slice *currSlice = img->currentSlice; 
  int dP_nr = assignSE2partition[currSlice->dp_mode][SE_HEADER]; 
  DataPartition *partition = &(currSlice->partArr[dP_nr]); 
  Bitstream *currStream = partition->bitstream; 
 
  int val, len; 
 
  img->frame_num = u_v (active_sps->log2_max_frame_num_minus4 + 4, "SH: frame_num", currStream); 
 
  /* Tian Dong: frame_num gap processing, if found */ 
  if (img->idr_flag) 
  { 
    img->pre_frame_num = img->frame_num; 
    assert(img->frame_num == 0); 
  } 
 
  if (active_sps->frame_mbs_only_flag) 
  { 
    img->structure = FRAME; 
    img->field_pic_flag=0; 
  } 
  else 
  { 
    // field_pic_flag   u(1) 
    img->field_pic_flag = u_1("SH: field_pic_flag", currStream); 
    if (img->field_pic_flag) 
    { 
      // bottom_field_flag  u(1) 
      img->bottom_field_flag = u_1("SH: bottom_field_flag", currStream); 
 
      img->structure = img->bottom_field_flag ? BOTTOM_FIELD : TOP_FIELD; 
    } 
    else 
    { 
      img->structure = FRAME; 
      img->bottom_field_flag=0; 
    } 
  } 
 
  currSlice->structure = img->structure; 
 
  img->MbaffFrameFlag=(active_sps->mb_adaptive_frame_field_flag && (img->field_pic_flag==0)); 
 
  if (img->structure == FRAME       ) assert (img->field_pic_flag == 0); 
  if (img->structure == TOP_FIELD   ) assert (img->field_pic_flag == 1 && img->bottom_field_flag == 0); 
  if (img->structure == BOTTOM_FIELD) assert (img->field_pic_flag == 1 && img->bottom_field_flag == 1); 
 
  if (img->idr_flag) 
  { 
    img->idr_pic_id = ue_v("SH: idr_pic_id", currStream); 
  } 
 
  if (active_sps->pic_order_cnt_type == 0) 
  { 
    img->pic_order_cnt_lsb = u_v(active_sps->log2_max_pic_order_cnt_lsb_minus4 + 4, "SH: pic_order_cnt_lsb", currStream); 
    if( active_pps->pic_order_present_flag  ==  1 &&  !img->field_pic_flag ) 
      img->delta_pic_order_cnt_bottom = se_v("SH: delta_pic_order_cnt_bottom", currStream); 
    else 
      img->delta_pic_order_cnt_bottom = 0;   
  } 
  if( active_sps->pic_order_cnt_type == 1 && !active_sps->delta_pic_order_always_zero_flag )  
  { 
    img->delta_pic_order_cnt[ 0 ] = se_v("SH: delta_pic_order_cnt[0]", currStream); 
    if( active_pps->pic_order_present_flag  ==  1  &&  !img->field_pic_flag ) 
      img->delta_pic_order_cnt[ 1 ] = se_v("SH: delta_pic_order_cnt[1]", currStream); 
  }else 
  { 
    if (active_sps->pic_order_cnt_type == 1) 
    { 
      img->delta_pic_order_cnt[ 0 ] = 0; 
      img->delta_pic_order_cnt[ 1 ] = 0; 
    } 
  } 
   
  //! redundant_pic_cnt is missing here 
  if (active_pps->redundant_pic_cnt_present_flag) 
  { 
    img->redundant_pic_cnt = ue_v ("SH: redundant_pic_cnt", currStream); 
  } 
 
  if(img->type==B_SLICE) 
  { 
    img->direct_spatial_mv_pred_flag = u_1 ("SH: direct_spatial_mv_pred_flag", currStream); 
  } 
 
  img->num_ref_idx_l0_active = active_pps->num_ref_idx_l0_active_minus1 + 1; 
  img->num_ref_idx_l1_active = active_pps->num_ref_idx_l1_active_minus1 + 1; 
 
  if(img->type==P_SLICE || img->type == SP_SLICE || img->type==B_SLICE) 
  { 
    val = u_1 ("SH: num_ref_idx_override_flag", currStream); 
    if (val) 
    { 
      img->num_ref_idx_l0_active = 1 + ue_v ("SH: num_ref_idx_l0_active_minus1", currStream); 
       
      if(img->type==B_SLICE) 
      { 
        img->num_ref_idx_l1_active = 1 + ue_v ("SH: num_ref_idx_l1_active_minus1", currStream); 
      } 
    } 
  } 
  if (img->type!=B_SLICE) 
  { 
    img->num_ref_idx_l1_active = 0; 
  } 
 
  ref_pic_list_reordering(); 
 
  img->apply_weights = ((active_pps->weighted_pred_flag && (currSlice->picture_type == P_SLICE || currSlice->picture_type == SP_SLICE) ) 
          || ((active_pps->weighted_bipred_idc > 0 ) && (currSlice->picture_type == B_SLICE))); 
 
  if ((active_pps->weighted_pred_flag&&(img->type==P_SLICE|| img->type == SP_SLICE))|| 
      (active_pps->weighted_bipred_idc==1 && (img->type==B_SLICE))) 
  { 
    pred_weight_table(); 
  } 
 
  if (img->nal_reference_idc) 
    dec_ref_pic_marking(currStream); 
 
  if (active_pps->entropy_coding_mode_flag && img->type!=I_SLICE && img->type!=SI_SLICE) 
  { 
    img->model_number = ue_v("SH: cabac_init_idc", currStream); 
  } 
  else  
  { 
    img->model_number = 0; 
  } 
 
  val = se_v("SH: slice_qp_delta", currStream); 
  currSlice->qp = img->qp = 26 + active_pps->pic_init_qp_minus26 + val; 
 
   
  currSlice->slice_qp_delta = val;   
 
  if(img->type==SP_SLICE || img->type == SI_SLICE)  
  { 
    if(img->type==SP_SLICE) 
    { 
      img->sp_switch = u_1 ("SH: sp_for_switch_flag", currStream); 
    } 
    val = se_v("SH: slice_qs_delta", currStream); 
    img->qpsp = 26 + active_pps->pic_init_qs_minus26 + val; 
  } 
 
  if (active_pps->deblocking_filter_control_present_flag) 
  { 
    currSlice->LFDisableIdc = ue_v ("SH: disable_deblocking_filter_idc", currStream); 
 
    if (currSlice->LFDisableIdc!=1) 
    { 
      currSlice->LFAlphaC0Offset = 2 * se_v("SH: slice_alpha_c0_offset_div2", currStream); 
      currSlice->LFBetaOffset = 2 * se_v("SH: slice_beta_offset_div2", currStream); 
    } 
    else 
    { 
      currSlice->LFAlphaC0Offset = currSlice->LFBetaOffset = 0; 
    } 
  } 
  else  
  { 
    currSlice->LFDisableIdc = currSlice->LFAlphaC0Offset = currSlice->LFBetaOffset = 0; 
  } 
 
  if (active_pps->num_slice_groups_minus1>0 && active_pps->slice_group_map_type>=3 && 
      active_pps->slice_group_map_type<=5) 
  { 
    len = (active_sps->pic_height_in_map_units_minus1+1)*(active_sps->pic_width_in_mbs_minus1+1)/  
          (active_pps->slice_group_change_rate_minus1+1); 
    if (((active_sps->pic_height_in_map_units_minus1+1)*(active_sps->pic_width_in_mbs_minus1+1))%  
          (active_pps->slice_group_change_rate_minus1+1)) 
          len +=1; 
 
    len = CeilLog2(len+1); 
 
    img->slice_group_change_cycle = u_v (len, "SH: slice_group_change_cycle", currStream); 
  } 
  img->PicHeightInMbs = img->FrameHeightInMbs / ( 1 + img->field_pic_flag ); 
  img->PicSizeInMbs   = img->PicWidthInMbs * img->PicHeightInMbs; 
  img->FrameSizeInMbs = img->PicWidthInMbs * img->FrameHeightInMbs; 
 
  return UsedBits; 
} 
 
 
/*! 
 ************************************************************************ 
 * \brief 
 *    read the reference picture reordering information 
 ************************************************************************ 
 */ 
static void ref_pic_list_reordering() 
{ 
  Slice *currSlice = img->currentSlice; 
  int dP_nr = assignSE2partition[currSlice->dp_mode][SE_HEADER]; 
  DataPartition *partition = &(currSlice->partArr[dP_nr]); 
  Bitstream *currStream = partition->bitstream; 
  int i, val; 
 
  alloc_ref_pic_list_reordering_buffer(currSlice); 
   
  if (img->type!=I_SLICE && img->type!=SI_SLICE) 
  { 
    val = currSlice->ref_pic_list_reordering_flag_l0 = u_1 ("SH: ref_pic_list_reordering_flag_l0", currStream); 
     
    if (val) 
    { 
      i=0; 
      do 
      { 
        val = currSlice->remapping_of_pic_nums_idc_l0[i] = ue_v("SH: remapping_of_pic_nums_idc_l0", currStream); 
        if (val==0 || val==1) 
        { 
          currSlice->abs_diff_pic_num_minus1_l0[i] = ue_v("SH: abs_diff_pic_num_minus1_l0", currStream); 
        } 
        else 
        { 
          if (val==2) 
          { 
            currSlice->long_term_pic_idx_l0[i] = ue_v("SH: long_term_pic_idx_l0", currStream); 
          } 
        } 
        i++; 
        // assert (i>img->num_ref_idx_l0_active); 
      } while (val != 3); 
    } 
  } 
 
  if (img->type==B_SLICE) 
  { 
    val = currSlice->ref_pic_list_reordering_flag_l1 = u_1 ("SH: ref_pic_list_reordering_flag_l1", currStream); 
     
    if (val) 
    { 
      i=0; 
      do 
      { 
        val = currSlice->remapping_of_pic_nums_idc_l1[i] = ue_v("SH: remapping_of_pic_nums_idc_l1", currStream); 
        if (val==0 || val==1) 
        { 
          currSlice->abs_diff_pic_num_minus1_l1[i] = ue_v("SH: abs_diff_pic_num_minus1_l1", currStream); 
        } 
        else 
        { 
          if (val==2) 
          { 
            currSlice->long_term_pic_idx_l1[i] = ue_v("SH: long_term_pic_idx_l1", currStream); 
          } 
        } 
        i++; 
        // assert (i>img->num_ref_idx_l1_active); 
      } while (val != 3); 
    } 
  } 
} 
 
/*! 
 ************************************************************************ 
 * \brief 
 *    read the weighted prediction tables 
 ************************************************************************ 
 */ 
static void pred_weight_table() 
{ 
  Slice *currSlice = img->currentSlice; 
  int dP_nr = assignSE2partition[currSlice->dp_mode][SE_HEADER]; 
  DataPartition *partition = &(currSlice->partArr[dP_nr]); 
  Bitstream *currStream = partition->bitstream; 
  int luma_weight_flag_l0, luma_weight_flag_l1, chroma_weight_flag_l0, chroma_weight_flag_l1; 
  int i,j; 
 
  img->luma_log2_weight_denom = ue_v ("SH: luma_log2_weight_denom", currStream); 
  img->wp_round_luma = img->luma_log2_weight_denom ? 1<<(img->luma_log2_weight_denom - 1): 0; 
   
  img->chroma_log2_weight_denom = ue_v ("SH: chroma_log2_weight_denom", currStream); 
  img->wp_round_chroma = img->chroma_log2_weight_denom ? 1<<(img->chroma_log2_weight_denom - 1): 0; 
 
  reset_wp_params(img); 
 
  for (i=0; inum_ref_idx_l0_active; i++) 
  { 
    luma_weight_flag_l0 = u_1("SH: luma_weight_flag_l0", currStream); 
     
    if (luma_weight_flag_l0) 
    { 
      img->wp_weight[0][i][0] = se_v ("SH: luma_weight_l0", currStream); 
      img->wp_offset[0][i][0] = se_v ("SH: luma_offset_l0", currStream); 
    } 
    else 
    { 
      img->wp_weight[0][i][0] = 1<luma_log2_weight_denom; 
      img->wp_offset[0][i][0] = 0; 
    } 
     
    chroma_weight_flag_l0 = u_1 ("SH: chroma_weight_flag_l0", currStream); 
     
    for (j=1; j<3; j++) 
    { 
      if (chroma_weight_flag_l0) 
      { 
        img->wp_weight[0][i][j] = se_v("SH: chroma_weight_l0", currStream); 
        img->wp_offset[0][i][j] = se_v("SH: chroma_offset_l0", currStream); 
      } 
      else 
      { 
        img->wp_weight[0][i][j] = 1<chroma_log2_weight_denom; 
        img->wp_offset[0][i][j] = 0; 
      } 
    } 
  } 
  if ((img->type == B_SLICE) && active_pps->weighted_bipred_idc == 1) 
  { 
    for (i=0; inum_ref_idx_l1_active; i++) 
    { 
      luma_weight_flag_l1 = u_1("SH: luma_weight_flag_l1", currStream); 
       
      if (luma_weight_flag_l1) 
      { 
        img->wp_weight[1][i][0] = se_v ("SH: luma_weight_l1", currStream); 
        img->wp_offset[1][i][0] = se_v ("SH: luma_offset_l1", currStream); 
      } 
      else 
      { 
        img->wp_weight[1][i][0] = 1<luma_log2_weight_denom; 
        img->wp_offset[1][i][0] = 0; 
      } 
       
      chroma_weight_flag_l1 = u_1 ("SH: chroma_weight_flag_l1", currStream); 
       
      for (j=1; j<3; j++) 
      { 
        if (chroma_weight_flag_l1) 
        { 
          img->wp_weight[1][i][j] = se_v("SH: chroma_weight_l1", currStream); 
          img->wp_offset[1][i][j] = se_v("SH: chroma_offset_l1", currStream); 
        } 
        else 
        { 
          img->wp_weight[1][i][j] = 1<chroma_log2_weight_denom; 
          img->wp_offset[1][i][j] = 0; 
        } 
      } 
    } 
  }     
} 
 
 
/*! 
 ************************************************************************ 
 * \brief 
 *    read the memory control operations 
 ************************************************************************ 
 */ 
void dec_ref_pic_marking(Bitstream *currStream) 
{ 
  int val; 
 
  DecRefPicMarking_t *tmp_drpm,*tmp_drpm2; 
 
  // free old buffer content 
  while (img->dec_ref_pic_marking_buffer) 
  {  
    tmp_drpm=img->dec_ref_pic_marking_buffer; 
 
    img->dec_ref_pic_marking_buffer=tmp_drpm->Next; 
    free (tmp_drpm); 
  }  
 
  if (img->idr_flag) 
  { 
    img->no_output_of_prior_pics_flag = u_1("SH: no_output_of_prior_pics_flag", currStream); 
    img->long_term_reference_flag = u_1("SH: long_term_reference_flag", currStream); 
  } 
  else 
  { 
    img->adaptive_ref_pic_buffering_flag = u_1("SH: adaptive_ref_pic_buffering_flag", currStream); 
    if (img->adaptive_ref_pic_buffering_flag) 
    { 
      // read Memory Management Control Operation  
      do 
      { 
        tmp_drpm=(DecRefPicMarking_t*)calloc (1,sizeof (DecRefPicMarking_t)); 
        tmp_drpm->Next=NULL; 
         
        val = tmp_drpm->memory_management_control_operation = ue_v("SH: memory_management_control_operation", currStream); 
 
        if ((val==1)||(val==3))  
        { 
          tmp_drpm->difference_of_pic_nums_minus1 = ue_v("SH: difference_of_pic_nums_minus1", currStream); 
        } 
        if (val==2) 
        { 
          tmp_drpm->long_term_pic_num = ue_v("SH: long_term_pic_num", currStream); 
        } 
           
        if ((val==3)||(val==6)) 
        { 
          tmp_drpm->long_term_frame_idx = ue_v("SH: long_term_frame_idx", currStream); 
        } 
        if (val==4) 
        { 
          tmp_drpm->max_long_term_frame_idx_plus1 = ue_v("SH: max_long_term_pic_idx_plus1", currStream); 
        } 
         
        // add command 
        if (img->dec_ref_pic_marking_buffer==NULL)  
        { 
          img->dec_ref_pic_marking_buffer=tmp_drpm; 
        } 
        else 
        { 
          tmp_drpm2=img->dec_ref_pic_marking_buffer; 
          while (tmp_drpm2->Next!=NULL) tmp_drpm2=tmp_drpm2->Next; 
          tmp_drpm2->Next=tmp_drpm; 
        } 
         
      }while (val != 0); 
       
    } 
  } 
} 
 
/*! 
 ************************************************************************ 
 * \brief 
 *    To calculate the poc values 
 *        based upon JVT-F100d2 
 *  POC200301: Until Jan 2003, this function will calculate the correct POC 
 *    values, but the management of POCs in buffered pictures may need more work. 
 * \return 
 *    none 
 ************************************************************************ 
 */ 
void decode_poc(struct img_par *img) 
{ 
  int i; 
  // for POC mode 0: 
  unsigned int        MaxPicOrderCntLsb = (1<<(active_sps->log2_max_pic_order_cnt_lsb_minus4+4)); 
 
  switch ( active_sps->pic_order_cnt_type ) 
  { 
  case 0: // POC MODE 0 
    // 1st 
    if(img->idr_flag) 
    { 
      img->PrevPicOrderCntMsb = 0; 
      img->PrevPicOrderCntLsb = 0; 
    } 
    else 
    { 
      if (img->last_has_mmco_5)  
      { 
        if (img->last_pic_bottom_field) 
        { 
          img->PrevPicOrderCntMsb = 0; 
          img->PrevPicOrderCntLsb = 0; 
        } 
        else 
        { 
          img->PrevPicOrderCntMsb = 0; 
          img->PrevPicOrderCntLsb = img->toppoc; 
        } 
      } 
    } 
    // Calculate the MSBs of current picture 
    if( img->pic_order_cnt_lsb  <  img->PrevPicOrderCntLsb  &&   
      ( img->PrevPicOrderCntLsb - img->pic_order_cnt_lsb )  >=  ( MaxPicOrderCntLsb / 2 ) ) 
      img->PicOrderCntMsb = img->PrevPicOrderCntMsb + MaxPicOrderCntLsb; 
    else if ( img->pic_order_cnt_lsb  >  img->PrevPicOrderCntLsb  && 
      ( img->pic_order_cnt_lsb - img->PrevPicOrderCntLsb )  >  ( MaxPicOrderCntLsb / 2 ) ) 
      img->PicOrderCntMsb = img->PrevPicOrderCntMsb - MaxPicOrderCntLsb; 
    else 
      img->PicOrderCntMsb = img->PrevPicOrderCntMsb; 
     
    // 2nd 
 
    if ((!img->field_pic_flag)||(!img->bottom_field_flag )) 
    { 
      img->ThisPOC= img->toppoc = img->PicOrderCntMsb + img->pic_order_cnt_lsb; 
    } 
 
    if (!img->field_pic_flag) 
    { 
      img->bottompoc = img->toppoc + img->delta_pic_order_cnt_bottom; 
    } 
    else 
    { 
      if( img->bottom_field_flag )  
      { 
        img->ThisPOC= img->bottompoc = img->PicOrderCntMsb + img->pic_order_cnt_lsb; 
      } 
    } 
 
    // last: some post-processing.  
       
//    if (img->newframe == 1) 
    { 
      if (!img->bottom_field_flag) 
      {       
        img->framepoc = img->toppoc; 
      } 
      else 
      { 
        img->framepoc = img->bottompoc; 
      } 
    } 
 
    if ( img->frame_num!=img->PreviousFrameNum) 
      img->PreviousFrameNum=img->frame_num; 
 
    if(!img->disposable_flag) 
    { 
      img->PrevPicOrderCntLsb = img->pic_order_cnt_lsb; 
      img->PrevPicOrderCntMsb = img->PicOrderCntMsb; 
    } 
 
    break; 
 
  case 1: // POC MODE 1 
    // 1st 
    if(img->idr_flag) 
    { 
      img->FrameNumOffset=0;     //  first pix of IDRGOP,  
      img->delta_pic_order_cnt[0]=0;                        //ignore first delta 
      if(img->frame_num)  error("frame_num != 0 in idr pix", -1020); 
    } 
    else  
    { 
      if (img->last_has_mmco_5) 
      { 
        img->PreviousFrameNumOffset = 0; 
        img->PreviousFrameNum = 0; 
      } 
      if (img->frame_numPreviousFrameNum) 
      {             //not first pix of IDRGOP 
        img->FrameNumOffset = img->PreviousFrameNumOffset + img->MaxFrameNum; 
      } 
      else  
      { 
        img->FrameNumOffset = img->PreviousFrameNumOffset; 
      } 
    } 
 
    // 2nd 
    if(active_sps->num_ref_frames_in_pic_order_cnt_cycle)  
      img->AbsFrameNum = img->FrameNumOffset+img->frame_num; 
    else  
      img->AbsFrameNum=0; 
    if(img->disposable_flag && img->AbsFrameNum>0) 
      img->AbsFrameNum--; 
 
    // 3rd 
    img->ExpectedDeltaPerPicOrderCntCycle=0; 
 
    if(active_sps->num_ref_frames_in_pic_order_cnt_cycle) 
    for(i=0;i<(int) active_sps->num_ref_frames_in_pic_order_cnt_cycle;i++) 
      img->ExpectedDeltaPerPicOrderCntCycle += active_sps->offset_for_ref_frame[i]; 
 
    if(img->AbsFrameNum) 
    { 
      img->PicOrderCntCycleCnt = (img->AbsFrameNum-1)/active_sps->num_ref_frames_in_pic_order_cnt_cycle; 
      img->FrameNumInPicOrderCntCycle = (img->AbsFrameNum-1)%active_sps->num_ref_frames_in_pic_order_cnt_cycle; 
      img->ExpectedPicOrderCnt = img->PicOrderCntCycleCnt*img->ExpectedDeltaPerPicOrderCntCycle; 
      for(i=0;i<=(int)img->FrameNumInPicOrderCntCycle;i++) 
        img->ExpectedPicOrderCnt += active_sps->offset_for_ref_frame[i]; 
    } 
    else  
      img->ExpectedPicOrderCnt=0; 
 
    if(img->disposable_flag) 
      img->ExpectedPicOrderCnt += active_sps->offset_for_non_ref_pic; 
 
    if(img->field_pic_flag==0) 
    {           //frame pix 
      img->toppoc = img->ExpectedPicOrderCnt + img->delta_pic_order_cnt[0]; 
      img->bottompoc = img->toppoc + active_sps->offset_for_top_to_bottom_field + img->delta_pic_order_cnt[1]; 
      img->ThisPOC = img->framepoc = (img->toppoc < img->bottompoc)? img->toppoc : img->bottompoc; // POC200301 
    } 
    else if (img->bottom_field_flag==0) 
    {  //top field  
      img->ThisPOC = img->toppoc = img->ExpectedPicOrderCnt + img->delta_pic_order_cnt[0]; 
    }  
    else 
    {  //bottom field 
      img->ThisPOC = img->bottompoc = img->ExpectedPicOrderCnt + active_sps->offset_for_top_to_bottom_field + img->delta_pic_order_cnt[0]; 
    } 
    img->framepoc=img->ThisPOC; 
 
    img->PreviousFrameNum=img->frame_num; 
    img->PreviousFrameNumOffset=img->FrameNumOffset; 
   
    break; 
 
 
  case 2: // POC MODE 2 
    if(img->idr_flag) // IDR picture 
    { 
      img->FrameNumOffset=0;     //  first pix of IDRGOP,  
      img->ThisPOC = img->framepoc = img->toppoc = img->bottompoc = 0; 
      if(img->frame_num)  error("frame_num != 0 in idr pix", -1020); 
    } 
    else 
    { 
      if (img->last_has_mmco_5) 
      { 
        img->PreviousFrameNum = 0; 
        img->PreviousFrameNumOffset = 0; 
      } 
      if (img->frame_numPreviousFrameNum) 
        img->FrameNumOffset = img->PreviousFrameNumOffset + img->MaxFrameNum; 
      else  
        img->FrameNumOffset = img->PreviousFrameNumOffset; 
 
 
      img->AbsFrameNum = img->FrameNumOffset+img->frame_num; 
      if(img->disposable_flag) 
        img->ThisPOC = (2*img->AbsFrameNum - 1); 
      else 
        img->ThisPOC = (2*img->AbsFrameNum); 
 
      if (img->field_pic_flag==0) 
        img->toppoc = img->bottompoc = img->framepoc = img->ThisPOC; 
      else if (img->bottom_field_flag==0) 
         img->toppoc = img->framepoc = img->ThisPOC; 
      else img->bottompoc = img->framepoc = img->ThisPOC; 
    } 
 
    if (!img->disposable_flag) 
      img->PreviousFrameNum=img->frame_num; 
    img->PreviousFrameNumOffset=img->FrameNumOffset; 
    break; 
 
 
  default: 
    //error must occurs 
    assert( 1==0 ); 
    break; 
  } 
} 
 
/*! 
 ************************************************************************ 
 * \brief 
 *    A little helper for the debugging of POC code 
 * \return 
 *    none 
 ************************************************************************ 
 */ 
int dumppoc(struct img_par *img) { 
    printf ("\nPOC locals...\n"); 
    printf ("toppoc                                %d\n", img->toppoc); 
    printf ("bottompoc                             %d\n", img->bottompoc); 
    printf ("frame_num                             %d\n", img->frame_num); 
    printf ("field_pic_flag                        %d\n", img->field_pic_flag); 
    printf ("bottom_field_flag                     %d\n", img->bottom_field_flag); 
    printf ("POC SPS\n"); 
    printf ("log2_max_frame_num_minus4             %d\n", active_sps->log2_max_frame_num_minus4);         // POC200301 
    printf ("log2_max_pic_order_cnt_lsb_minus4     %d\n", active_sps->log2_max_pic_order_cnt_lsb_minus4); 
    printf ("pic_order_cnt_type                    %d\n", active_sps->pic_order_cnt_type); 
    printf ("num_ref_frames_in_pic_order_cnt_cycle %d\n", active_sps->num_ref_frames_in_pic_order_cnt_cycle); 
    printf ("delta_pic_order_always_zero_flag      %d\n", active_sps->delta_pic_order_always_zero_flag); 
    printf ("offset_for_non_ref_pic                %d\n", active_sps->offset_for_non_ref_pic); 
    printf ("offset_for_top_to_bottom_field        %d\n", active_sps->offset_for_top_to_bottom_field); 
    printf ("offset_for_ref_frame[0]               %d\n", active_sps->offset_for_ref_frame[0]); 
    printf ("offset_for_ref_frame[1]               %d\n", active_sps->offset_for_ref_frame[1]); 
    printf ("POC in SLice Header\n"); 
    printf ("pic_order_present_flag                %d\n", active_pps->pic_order_present_flag); 
    printf ("delta_pic_order_cnt[0]                %d\n", img->delta_pic_order_cnt[0]); 
    printf ("delta_pic_order_cnt[1]                %d\n", img->delta_pic_order_cnt[1]); 
    printf ("delta_pic_order_cnt[2]                %d\n", img->delta_pic_order_cnt[2]); 
    printf ("idr_flag                              %d\n", img->idr_flag); 
    printf ("MaxFrameNum                           %d\n", img->MaxFrameNum); 
 
    return 0; 
} 
 
/*! 
 ************************************************************************ 
 * \brief 
 *    return the poc of img as per (8-1) JVT-F100d2 
 *  POC200301 
 ************************************************************************ 
 */ 
int picture_order(struct img_par *img) 
{ 
  if (img->field_pic_flag==0) // is a frame 
    return img->framepoc; 
  else if (img->bottom_field_flag==0) // top field 
    return img->toppoc; 
  else // bottom field 
    return img->bottompoc; 
}