header.c

H.264编码解码器源码(c语言).zip

/*!
 *************************************************************************************
 * \file header.c
 *
 * \brief
 *    H.26L Slice and Sequence headers
 *
 * \author
 *    Main contributors (see contributors.h for copyright, address and affiliation details)
 *      - Stephan Wenger                  <[e-mail]>
 *************************************************************************************
 */

#include <math.h>
#include <assert.h>
#include <string.h>
#include <stdlib.h>

#include "elements.h"
#include "header.h"
#include "rtp.h"
#include "mbuffer.h"
#include "defines.h"
#include "vlc.h"
#include "parset.h"

// A little trick to avoid those horrible #if TRACE all over the source code
#if TRACE
#define SYMTRACESTRING(s) strncpy(sym->tracestring,s,TRACESTRING_SIZE)
#else
#define SYMTRACESTRING(s) // do nothing
#endif

static int ref_pic_list_reordering();
static int dec_ref_pic_marking();
static int pred_weight_table();

/*!
 ********************************************************************************************
 * \brief 
 *    Write a slice header
 ********************************************************************************************
*/
int SliceHeader()
{
  int dP_nr = assignSE2partition[input->partition_mode][SE_HEADER];
  DataPartition *partition = &((img->currentSlice)->partArr[dP_nr]);
  int len = 0;
  unsigned int field_pic_flag = 0, bottom_field_flag = 0;    // POC200301

  len  = ue_v("SH: first_mb_in_slice", img->current_mb_nr,   partition);

  len += ue_v("SH: slice_type",        get_picture_type (),   partition);

  // Note: Encoder supports only one pic/seq parameter set, hence value is
  // hard coded to zero
  len += ue_v("SH: pic_parameter_set_id" , 0 ,partition);

  // frame_num
  assert (img->frame_num < 1<<(LOG2_MAX_FRAME_NUM_MINUS4+4));  // check that it fits
  len += u_v (LOG2_MAX_FRAME_NUM_MINUS4 + 4,"SH: frame_num", img->frame_num, partition);

  if (input->InterlaceCodingOption != FRAME_CODING) // same condition as for sps->frame_mbs_only_flag!
  {
    // field_pic_flag    u(1)
    field_pic_flag = (img->structure ==TOP_FIELD || img->structure ==BOTTOM_FIELD)?1:0;
    assert( field_pic_flag == img->fld_flag );
    len += u_1("SH: field_pic_flag", field_pic_flag, partition);

    if (field_pic_flag)
    {
      //bottom_field_flag     u(1)
      bottom_field_flag = (img->structure == BOTTOM_FIELD)?1:0;
      len += u_1("SH: bottom_field_flag" , bottom_field_flag ,partition);
    }
  }

  if (img->currentPicture->idr_flag)
  {
    // idr_pic_id
    // hard coded to zero because we don't have proper IDR handling at the moment
    len += ue_v ("SH: idr_pic_id", 0, partition);
  }

  // POC200301
  if (img->pic_order_cnt_type == 0)
  {
    if (input->InterlaceCodingOption == FRAME_CODING) // same condition as for sps->frame_mbs_only_flag!
    {
      img->pic_order_cnt_lsb = (img->toppoc & ~((((unsigned int)(-1)) << (LOG2_MAX_PIC_ORDER_CNT_LSB_MINUS4+4))) );
    }
    else
    {
      if (!field_pic_flag || img->structure == TOP_FIELD)
        img->pic_order_cnt_lsb = (img->toppoc & ~((((unsigned int)(-1)) << (LOG2_MAX_PIC_ORDER_CNT_LSB_MINUS4+4))) );
      else if ( img->structure == BOTTOM_FIELD )
        img->pic_order_cnt_lsb = (img->bottompoc & ~((((unsigned int)(-1)) << (LOG2_MAX_PIC_ORDER_CNT_LSB_MINUS4+4))) );
    }

    len += u_v (LOG2_MAX_PIC_ORDER_CNT_LSB_MINUS4+4, "SH: pic_order_cnt_lsb", img->pic_order_cnt_lsb, partition);
    if (img->pic_order_present_flag && !field_pic_flag)  // img->fld_flag
    {
      len += se_v ("SH: delta_pic_order_cnt_bottom", img->delta_pic_order_cnt_bottom, partition);
    }
  }
  if (img->pic_order_cnt_type == 1 && !img->delta_pic_order_always_zero_flag)
  {
    len += se_v ("SH: delta_pic_order_cnt[0]", img->delta_pic_order_cnt[0], partition);

    if (img->pic_order_present_flag && !field_pic_flag)  // img->fld_flag
    {
      len += se_v ("SH: delta_pic_order_cnt[1]", img->delta_pic_order_cnt[1], partition);
    }
  }

  // ist there any sense in the following assignments ???
  toprefpoc[0]=toprefpoc[0];
  bottomrefpoc[0]=bottomrefpoc[0];
  
  // redundant slice info redundant_pic_cnt is missing here
  if (input->redundant_slice_flag)
  {
    len += se_v ("SH: redundant_pic_cnt", img->redundant_pic_cnt, partition);
  }

  // Direct Mode Type selection for B pictures
	if (img->type==B_SLICE)
  {
    len +=  u_1 ("SH: direct_spatial_mv_pred_flag", input->direct_type, partition);
  }

//  if ((img->type == P_SLICE) || (img->type == B_SLICE) || (img->type == BS_IMG) || (img->type==SP_SLICE))
	  if ((img->type == P_SLICE) || (img->type == B_SLICE) || (img->type==SP_SLICE))
  {
    // num_ref_idx_active_override_flag here always 1
    len +=  u_1 ("SH: num_ref_idx_active_override_flag", 1, partition);
    
    if (1) // if (num_ref_idx_active_override_flag)
    {
      len += ue_v ("SH: num_ref_idx_l0_active_minus1", img->num_ref_idx_l0_active-1, partition);
		  if (img->type==B_SLICE)
      {
        len += ue_v ("SH: num_ref_idx_l1_active_minus1", img->num_ref_idx_l1_active-1, partition);
      }
    }

  }
  len += ref_pic_list_reordering();

  if (((img->type == P_SLICE || img->type == SP_SLICE) && input->WeightedPrediction) || 
		 ((img->type == B_SLICE) && input->WeightedBiprediction == 1))
  {
    len += pred_weight_table();
  }

  if (img->nal_reference_idc)
    len += dec_ref_pic_marking();

  if(input->symbol_mode==CABAC && img->type!=I_SLICE /*&& img->type!=SI_IMG*/)
  {
    len += ue_v("SH: cabac_init_idc", img->model_number, partition);
  }

  // we transmit zero in the pps, so here the real QP
  len += se_v("SH: slice_qp_delta", (img->qp - 26), partition);

  if (img->type==SP_SLICE /*|| img->type==SI_SLICE*/)
  {
    if (img->type==SP_SLICE) // Switch Flag only for SP pictures
    {
      len += u_1 ("SH: sp_for_switch_flag", 0, partition);   // 1 for switching SP, 0 for normal SP
    }
    len += se_v ("SH: slice_qs_delta", (img->qpsp - 26), partition );
  }

  if (input->LFSendParameters)
  {
    len += ue_v("SH: disable_deblocking_filter_idc",input->LFDisableIdc, partition);  // Turn loop filter on/off on slice basis 

    if (input->LFDisableIdc!=1)
    {
      len += se_v ("SH: slice_alpha_c0_offset_div2", input->LFAlphaC0Offset / 2, partition);

      len += se_v ("SH: slice_beta_offset_div2", input->LFBetaOffset / 2, partition);
    }
  }

  // !KS: all fmo map types are currently mapped to type 6 so 
  //      no slice_group_change_cycle is transmitted

  return len;
}

/*!
 ********************************************************************************************
 * \brief 
 *    writes the ref_pic_list_reordering syntax
 *    based on content of according fields in img structure
 *
 * \return
 *    number of bits used 
 ********************************************************************************************
*/
static int ref_pic_list_reordering()
{
  int dP_nr = assignSE2partition[input->partition_mode][SE_HEADER];
  DataPartition *partition = &((img->currentSlice)->partArr[dP_nr]);
  Slice *currSlice = img->currentSlice;

  int i, len=0;

  if ((img->type!=I_SLICE) /*&&(img->type!=SI_IMG)*/ )
  {
    len += u_1 ("SH: ref_pic_list_reordering_flag_l0", currSlice->ref_pic_list_reordering_flag_l0, partition);
    if (currSlice->ref_pic_list_reordering_flag_l0)
    {
      i=0;
      do
      {
        len += ue_v ("SH: remapping_of_pic_num_idc", currSlice->remapping_of_pic_nums_idc_l0[i], partition);
        if (currSlice->remapping_of_pic_nums_idc_l0[i]==0 ||
            currSlice->remapping_of_pic_nums_idc_l0[i]==1)
        {
          len += ue_v ("SH: abs_diff_pic_num_minus1_l0", currSlice->abs_diff_pic_num_minus1_l0[i], partition);
        }
        else
        {
          if (currSlice->remapping_of_pic_nums_idc_l0[i]==2)
          {
            len += ue_v ("SH: long_term_pic_idx_l0", currSlice->long_term_pic_idx_l0[i], partition);
          }
        }
        i++;
      } while (currSlice->remapping_of_pic_nums_idc_l0[i] != 3);
    }
  }

  if (img->type==B_SLICE)
  {
    len += u_1 ("SH: ref_pic_list_reordering_flag_l1", currSlice->ref_pic_list_reordering_flag_l1, partition);
    if (currSlice->ref_pic_list_reordering_flag_l1)
    {
      i=0;
      do
      {
        len += ue_v ("SH: remapping_of_pic_num_idc", currSlice->remapping_of_pic_nums_idc_l1[i], partition);
        if (currSlice->remapping_of_pic_nums_idc_l1[i]==0 ||
            currSlice->remapping_of_pic_nums_idc_l1[i]==1)
        {
          len += ue_v ("SH: abs_diff_pic_num_minus1_l1", currSlice->abs_diff_pic_num_minus1_l1[i], partition);
        }
        else
        {
          if (currSlice->remapping_of_pic_nums_idc_l1[i]==2)
          {
            len += ue_v ("SH: long_term_pic_idx_l1", currSlice->long_term_pic_idx_l1[i], partition);
          }
        }
        i++;
      } while (currSlice->remapping_of_pic_nums_idc_l1[i] != 3);
    }
  }