header.cpp

264的播放器

/*!
 *************************************************************************************
 * \file header.c
 *
 * \brief
 *    H.26L Slice headers
 *
 *************************************************************************************
 */

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

#include "global.h"
#include "elements.h"
#include "defines.h"
#include "fmo.h"
#include "vlc.h"
#include "mbuffer.h"
#include "header.h"

extern int UsedBits;
extern pic_parameter_set_rbsp_t *active_pps;
extern seq_parameter_set_rbsp_t *active_sps;

static void ref_pic_list_reordering();
static void pred_weight_table();


/*!
 ************************************************************************
 * \brief
 *    calculate Ceil(Log2(uiVal))
 ************************************************************************
 */
unsigned CeilLog2( unsigned uiVal)
{
  unsigned uiTmp = uiVal;
  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 (img->frame_num != img->pre_frame_num && img->frame_num != (img->pre_frame_num + 1) % img->MaxFrameNum) 
  {
    if (active_sps->gaps_in_frame_num_value_allowed_flag == 0)
    {
      /* Advanced Error Concealment would be called here to combat unintentional loss of pictures. */
      error("An unintentional loss of pictures occurs! Exit\n", 100);
    }
    fill_frame_num_gap(img);
  }

  if (active_sps->frame_mbs_only_flag)
  {
    img->field_pic_flag=0;
  }
  else
  {
    // field_pic_flag   u(1)
    img->field_pic_flag = u_1("SH: field_pic_flag", currStream);//0
  }

  if (img->idr_flag)
  {
    img->idr_pic_id = ue_v("SH: idr_pic_id", currStream);
  }

  // POC200301
  if (img->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( img->pic_order_present_flag  ==  1 )
      img->delta_pic_order_cnt_bottom = se_v("SH: delta_pic_order_cnt_bottom", currStream);
    else
      img->delta_pic_order_cnt_bottom = 0;  
  }
  if( img->pic_order_cnt_type == 1 && !img->delta_pic_order_always_zero_flag ) 
  {
    img->delta_pic_order_cnt[ 0 ] = se_v("SH: delta_pic_order_cnt[0]", currStream);
    if( img->pic_order_present_flag  ==  1)
      img->delta_pic_order_cnt[ 1 ] = se_v("SH: delta_pic_order_cnt[1]", currStream);
  }else
  {
    if (img->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 = u_1 ("SH: redundant_pic_cnt", currStream);
  }

  img->num_ref_idx_l0_active = active_pps->num_ref_idx_l0_active_minus1 + 1;

  if(img->type==P_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);
    }
  }
  
  ref_pic_list_reordering();

  img->apply_weights = ((img->weighted_pred_flag && (currSlice->picture_type == P_SLICE) ));

  if ((active_pps->weighted_pred_flag&&(img->type==P_SLICE)))
  {
    pred_weight_table();
  }

  if (img->nal_reference_idc)
    dec_ref_pic_marking(currStream);

  val = se_v("SH: slice_qp_delta", currStream);
  currSlice->qp = img->qp = 26 + active_pps->pic_init_qp_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);

    img->slice_group_change_cycle = u_v (len, "SH: slice_group_change_cycle", currStream);
  }
  img->PicHeightInMbs = img->FrameHeightInMbs / ( 1);
  img->PicSizeInMbs   = img->PicWidthInMbs * img->PicHeightInMbs;
  img->FrameSizeInMbs = img->PicWidthInMbs * img->FrameHeightInMbs;

  //calculate pocs  POC200301
  decoding_poc(img);

  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)
  {
    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++;
      } 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,  chroma_weight_flag_l0;
  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; i<img->num_ref_idx_l0_active; i++)
  {
    luma_weight_flag_l0 = u_1("SH: luma_weight_flag_l0", currStream);