sei.cpp

h264编解码.用C++实现了图像的编解码功能。

  Bitstream* buf;

  buf =(Bitstream *) malloc(sizeof(Bitstream));
  buf->bitstream_length = size;
  buf->streamBuffer = payload;
  buf->frame_bitoffset = 0;

  UsedBits = 0;

  original_idr_flag     = u_1 (    "SEI: original_idr_flag"    , buf);
  original_frame_num    = ue_v(    "SEI: original_frame_num"   , buf);

  // we need to save everything that is probably overwritten in dec_ref_pic_marking()
  old_drpm = img->dec_ref_pic_marking_buffer;
  old_idr_flag = img->idr_flag;

  old_no_output_of_prior_pics_flag = img->no_output_of_prior_pics_flag;
  old_long_term_reference_flag = img->long_term_reference_flag;
  old_adaptive_ref_pic_buffering_flag = img->adaptive_ref_pic_buffering_flag;

  // set new initial values
  img->idr_flag = original_idr_flag;
  img->dec_ref_pic_marking_buffer = NULL;

  dec_ref_pic_marking(buf);

  while (img->dec_ref_pic_marking_buffer)
  {
    tmp_drpm = img->dec_ref_pic_marking_buffer->Next;
    free (tmp_drpm);
  }

  // restore old values in img
  img->dec_ref_pic_marking_buffer = old_drpm;
  img->idr_flag = old_idr_flag;
  img->no_output_of_prior_pics_flag = old_no_output_of_prior_pics_flag;
  img->long_term_reference_flag = old_long_term_reference_flag;
  img->adaptive_ref_pic_buffering_flag = old_adaptive_ref_pic_buffering_flag;
  
   
  free (buf);
}

/*!
 ************************************************************************
 *  \brief
 *     Interpret the Full-frame snapshot SEI message
 *  \param payload
 *     a pointer that point to the sei payload
 *  \param size
 *     the size of the sei message
 *  \param img
 *     the image pointer
 *    
 ************************************************************************
 */
void interpret_full_frame_snapshot_info( byte* payload, int size, ImageParameters *img )
{
  int snapshot_id;

  Bitstream* buf;

  buf =(Bitstream *) malloc(sizeof(Bitstream));
  buf->bitstream_length = size;
  buf->streamBuffer = payload;
  buf->frame_bitoffset = 0;

  UsedBits = 0;

  snapshot_id = ue_v("SEI: snapshot_id", buf);
  free (buf);
}

/*!
 ************************************************************************
 *  \brief
 *     Interpret the Progressive refinement segment end SEI message
 *  \param payload
 *     a pointer that point to the sei payload
 *  \param size
 *     the size of the sei message
 *  \param img
 *     the image pointer
 *    
 ************************************************************************
 */
void interpret_progressive_refinement_end_info( byte* payload, int size, ImageParameters *img )
{
  int progressive_refinement_id;

  Bitstream* buf;

  buf =(Bitstream *) malloc(sizeof(Bitstream));
  buf->bitstream_length = size;
  buf->streamBuffer = payload;
  buf->frame_bitoffset = 0;

  UsedBits = 0;

  progressive_refinement_id   = ue_v("SEI: progressive_refinement_id"  , buf);
  free (buf);
}


/*!
 ************************************************************************
 *  \brief
 *     Interpret the Motion-constrained slice group set SEI message
 *  \param payload
 *     a pointer that point to the sei payload
 *  \param size
 *     the size of the sei message
 *  \param img
 *     the image pointer
 *    
 ************************************************************************
 */
void interpret_motion_constrained_slice_group_set_info( byte* payload, int size, ImageParameters *img )
{
  int num_slice_groups_minus1, slice_group_id, exact_match_flag, pan_scan_rect_flag, pan_scan_rect_id;
  int i;

  Bitstream* buf;

  buf =(Bitstream *) malloc(sizeof(Bitstream));
  buf->bitstream_length = size;
  buf->streamBuffer = payload;
  buf->frame_bitoffset = 0;

  UsedBits = 0;
  
  num_slice_groups_minus1   = ue_v("SEI: num_slice_groups_minus1"  , buf);
  
  for (i=0; i<=num_slice_groups_minus1;i++)
  {
    slice_group_id   = ue_v("SEI: slice_group_id"  , buf);
  }
  
  exact_match_flag   = u_1("SEI: exact_match_flag"  , buf);
  pan_scan_rect_flag = u_1("SEI: pan_scan_rect_flag"  , buf);
  
  if (pan_scan_rect_flag)
  {
    pan_scan_rect_id = ue_v("SEI: pan_scan_rect_id"  , buf);
  }

  free (buf);
}


/*!
 ************************************************************************
 *  \brief
 *     Interpret the Reserved SEI message
 *  \param payload
 *     a pointer that point to the sei payload
 *  \param size
 *     the size of the sei message
 *  \param img
 *     the image pointer
 *    
 ************************************************************************
 */
void interpret_reserved_info( byte* payload, int size, ImageParameters *img )
{
  int offset = 0;
  byte payload_byte;
  assert (size<16);

  while (offset < size)
  {
    payload_byte = payload[offset];
    offset ++;
  }
}


/*!
 ************************************************************************
 *  \brief
 *     Interpret the Buffering period SEI message
 *  \param payload
 *     a pointer that point to the sei payload
 *  \param size
 *     the size of the sei message
 *  \param img
 *     the image pointer
 *    
 ************************************************************************
 */
void interpret_buffering_period_info( byte* payload, int size, ImageParameters *img )
{
  int seq_parameter_set_id, initial_cpb_removal_delay, initial_cpb_removal_delay_offset;
  unsigned int k;

  Bitstream* buf;
  seq_parameter_set_rbsp_t *sps;

  buf =(Bitstream *) malloc(sizeof(Bitstream));
  buf->bitstream_length = size;
  buf->streamBuffer = payload;
  buf->frame_bitoffset = 0;

  UsedBits = 0;

  seq_parameter_set_id   = ue_v("SEI: seq_parameter_set_id"  , buf);

  active_sps = sps = &SeqParSet[seq_parameter_set_id];

  if (sps->vui_seq_parameters.nal_hrd_parameters_present_flag)
  {
    for (k=0; k<sps->vui_seq_parameters.nal_hrd_parameters.cpb_cnt; k++)
    {
      initial_cpb_removal_delay        = u_v(sps->vui_seq_parameters.nal_hrd_parameters.cpb_removal_delay_length_minus1+1,
                                             "SEI: initial_cpb_removal_delay"         , buf);
      initial_cpb_removal_delay_offset = u_v(sps->vui_seq_parameters.nal_hrd_parameters.cpb_removal_delay_length_minus1+1,
                                             "SEI: initial_cpb_removal_delay_offset"  , buf);
    }
  }

  if (sps->vui_seq_parameters.vcl_hrd_parameters_present_flag)
  {
    for (k=0; k<sps->vui_seq_parameters.vcl_hrd_parameters.cpb_cnt; k++)
    {
      initial_cpb_removal_delay        = u_v(sps->vui_seq_parameters.vcl_hrd_parameters.cpb_removal_delay_length_minus1+1,
                                             "SEI: initial_cpb_removal_delay"         , buf);
      initial_cpb_removal_delay_offset = u_v(sps->vui_seq_parameters.vcl_hrd_parameters.cpb_removal_delay_length_minus1+1,
                                             "SEI: initial_cpb_removal_delay_offset"  , buf);
    }
  }

  free (buf);
}


/*!
 ************************************************************************
 *  \brief
 *     Interpret the Picture timing SEI message
 *  \param payload
 *     a pointer that point to the sei payload
 *  \param size
 *     the size of the sei message
 *  \param img
 *     the image pointer
 *    
 ************************************************************************
 */
void interpret_picture_timing_info( byte* payload, int size, ImageParameters *img )
{
  int cpb_removal_delay, dpb_output_delay, picture_structure_present_flag, picture_structure;
  int clock_time_stamp_flag;
  int ct_type, nuit_field_based_flag, counting_type, full_timestamp_flag, discontinuity_flag, cnt_dropped_flag, nframes;
  int seconds_value, minutes_value, hours_value, seconds_flag, minutes_flag, hours_flag;
  int NumClockTs = 0;
  int i;

  Bitstream* buf;

  buf =(Bitstream *) malloc(sizeof(Bitstream));
  buf->bitstream_length = size;
  buf->streamBuffer = payload;
  buf->frame_bitoffset = 0;

  UsedBits = 0;

  assert (NULL!=active_sps);

  if ((active_sps->vui_seq_parameters.nal_hrd_parameters_present_flag)||
      (active_sps->vui_seq_parameters.vcl_hrd_parameters_present_flag))
  {
      cpb_removal_delay = ue_v("SEI: cpb_removal_delay" , buf);
      dpb_output_delay  = ue_v("SEI: dpb_output_delay"  , buf);
  }

  picture_structure_present_flag  = u_1("SEI: picture_structure_present_flag"  , buf);
  if (picture_structure_present_flag)
  {
    picture_structure = u_v(3, "SEI: picture_structure" , buf);
    switch (picture_structure)
    {
    case 0:
    case 1:
    case 2:
      NumClockTs = 1;
      break;
    case 3:
    case 4:
    case 7:
      NumClockTs = 2;
      break;
    case 5:
    case 6:
    case 8:
      NumClockTs = 3;
      break;
    default:
      error("reserved picture_structure used (can't determine NumClockTs)", 500);
    }
    for (i=0; i<NumClockTs; i++)
    {
      clock_time_stamp_flag = u_1("SEI: clock_time_stamp_flag"  , buf);

      if (clock_time_stamp_flag)
      {
        ct_type               = u_v(2, "SEI: ct_type"               , buf);
        nuit_field_based_flag = u_1(   "SEI: nuit_field_based_flag" , buf);
        counting_type         = u_v(5, "SEI: counting_type"         , buf);
        full_timestamp_flag   = u_1(   "SEI: full_timestamp_flag"   , buf);
        discontinuity_flag    = u_1(   "SEI: discontinuity_flag"    , buf);
        cnt_dropped_flag      = u_1(   "SEI: cnt_dropped_flag"      , buf);
        nframes               = u_v(8, "SEI: nframes"               , buf);

        if (full_timestamp_flag)
        {
          seconds_value         = u_v(6, "SEI: seconds_value"   , buf);
          minutes_value         = u_v(6, "SEI: minutes_value"   , buf);
          hours_value           = u_v(5, "SEI: hours_value"     , buf);
        }
        else
        {
          seconds_flag          = u_1(   "SEI: seconds_flag" , buf);
          if (seconds_flag)
          {
            seconds_value         = u_v(6, "SEI: seconds_value"   , buf);
            minutes_flag          = u_1(   "SEI: minutes_flag" , buf);
            if(minutes_flag)
            {
              minutes_value         = u_v(6, "SEI: minutes_value"   , buf);
              hours_flag            = u_1(   "SEI: hours_flag" , buf);
              if(hours_flag)
              {
                hours_value           = u_v(5, "SEI: hours_value"     , buf);
              }
            
            }
          }
        }
      }
    }
  }

  free (buf);
}