github.com/cnotch/ipchub@v1.1.0/av/codec/hevc/const.go (about)

     1  // Copyright (c) 2019,CAOHONGJU All rights reserved.
     2  // Use of this source code is governed by a MIT-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package hevc
     6  
     7  /**
     8   * Table 7-1 – NAL unit type codes and NAL unit type classes in
     9   * T-REC-H.265-201802
    10   */
    11  const (
    12  	NalTrailN    = 0
    13  	NalTrailR    = 1
    14  	NalTsaN      = 2
    15  	NalTsaR      = 3
    16  	NalStsaN     = 4
    17  	NalStsaR     = 5
    18  	NalRadlN     = 6
    19  	NalRadlR     = 7
    20  	NalRaslN     = 8
    21  	NalRaslR     = 9
    22  	NalVclN10    = 10
    23  	NalVclR11    = 11
    24  	NalVclN12    = 12
    25  	NalVclR13    = 13
    26  	NalVclN14    = 14
    27  	NalVclR15    = 15
    28  	NalBlaWLp    = 16
    29  	NalBlaWRadl  = 17
    30  	NalBlaNLp    = 18
    31  	NalIdrWRadl  = 19
    32  	NalIdrNLp    = 20
    33  	NalCraNut    = 21
    34  	NalIrapVcl22 = 22
    35  	NalIrapVcl23 = 23
    36  	NalRsvVcl24  = 24
    37  	NalRsvVcl25  = 25
    38  	NalRsvVcl26  = 26
    39  	NalRsvVcl27  = 27
    40  	NalRsvVcl28  = 28
    41  	NalRsvVcl29  = 29
    42  	NalRsvVcl30  = 30
    43  	NalRsvVcl31  = 31
    44  	NalVps       = 32
    45  	NalSps       = 33
    46  	NalPps       = 34
    47  	NalAud       = 35
    48  	NalEosNut    = 36
    49  	NalEobNut    = 37
    50  	NalFdNut     = 38
    51  	NalSeiPrefix = 39
    52  	NalSeiSuffix = 40
    53  	NalRsvNvcl41 = 41
    54  	NalRsvNvcl42 = 42
    55  	NalRsvNvcl43 = 43
    56  	NalRsvNvcl44 = 44
    57  	NalRsvNvcl45 = 45
    58  	NalRsvNvcl46 = 46
    59  	NalRsvNvcl47 = 47
    60  	NalUnspec48  = 48
    61  	NalUnspec49  = 49
    62  	NalUnspec50  = 50
    63  	NalUnspec51  = 51
    64  	NalUnspec52  = 52
    65  	NalUnspec53  = 53
    66  	NalUnspec54  = 54
    67  	NalUnspec55  = 55
    68  	NalUnspec56  = 56
    69  	NalUnspec57  = 57
    70  	NalUnspec58  = 58
    71  	NalUnspec59  = 59
    72  	NalUnspec60  = 60
    73  	NalUnspec61  = 61
    74  	NalUnspec62  = 62
    75  	NalUnspec63  = 63
    76  
    77  	// RTP 中扩展
    78  	NalStapInRtp = 48
    79  	NalFuInRtp = 49
    80  )
    81  
    82  // HEVC(h265) 的图像片类型
    83  const (
    84  	SliceB = 0
    85  	SliceP = 1
    86  	SliceI = 2
    87  )
    88  
    89  /** ffmpeg 中帧统计代码
    90  static int hevc_probe(char* pbuf, int buf_size)
    91  {
    92      unsigned int code = -1;
    93      int vps = 0, sps = 0, pps = 0, irap = 0;
    94      int i;
    95  
    96      for (i = 0; i < buf_size - 1; i++) {
    97          code = (code << 8) + pbuf[i];
    98          if ((code & 0xffffff00) == 0x100) {
    99              char nal2 = pbuf[i + 1];
   100              int type = (code & 0x7E) >> 1;
   101  
   102              if (code & 0x81) // forbidden and reserved zero bits
   103                  return 0;
   104  
   105              if (nal2 & 0xf8) // reserved zero
   106                  return 0;
   107  
   108              switch (type) {
   109                  case NalVPS:        vps++;  break;
   110                  case NalSPS:        sps++;  break;
   111                  case NalPPS:        pps++;  break;
   112                  case NalBLA_N_LP:
   113                  case NalBLA_W_LP:
   114                  case NalBLA_W_RADL:
   115                  case NalCRA_NUT:
   116                  case NalIDR_N_LP:
   117                  case NalIDR_W_RADL: irap++; break;
   118              }
   119          }
   120      }
   121  
   122      return 0;
   123  }
   124  **/
   125  
   126  const (
   127  	// 7.4.3.1: vps_max_layers_minus1 is in [0, 62].
   128  	HEVC_MAX_LAYERS = 63
   129  	// 7.4.3.1: vps_max_sub_layers_minus1 is in [0, 6].
   130  	HEVC_MAX_SUB_LAYERS = 7
   131  	// 7.4.3.1: vps_num_layer_sets_minus1 is in [0, 1023].
   132  	HEVC_MAX_LAYER_SETS = 1024
   133  
   134  	// 7.4.2.1: vps_video_parameter_set_id is u(4).
   135  	HEVC_MAX_VPS_COUNT = 16
   136  	// 7.4.3.2.1: sps_seq_parameter_set_id is in [0, 15].
   137  	HEVC_MAX_SPS_COUNT = 16
   138  	// 7.4.3.3.1: pps_pic_parameter_set_id is in [0, 63].
   139  	HEVC_MAX_PPS_COUNT = 64
   140  
   141  	// A.4.2: MaxDpbSize is bounded above by 16.
   142  	HEVC_MAX_DPB_SIZE = 16
   143  	// 7.4.3.1: vps_max_dec_pic_buffering_minus1[i] is in [0, MaxDpbSize - 1].
   144  	HEVC_MAX_REFS = HEVC_MAX_DPB_SIZE
   145  
   146  	// 7.4.3.2.1: num_short_term_ref_pic_sets is in [0, 64].
   147  	HEVC_MAX_SHORT_TERM_REF_PIC_SETS = 64
   148  	// 7.4.3.2.1: num_long_term_ref_pics_sps is in [0, 32].
   149  	HEVC_MAX_LONG_TERM_REF_PICS = 32
   150  
   151  	// A.3: all profiles require that CtbLog2SizeY is in [4, 6].
   152  	HEVC_MIN_LOG2_CTB_SIZE = 4
   153  	HEVC_MAX_LOG2_CTB_SIZE = 6
   154  
   155  	// E.3.2: cpb_cnt_minus1[i] is in [0, 31].
   156  	HEVC_MAX_CPB_CNT = 32
   157  
   158  	// A.4.1: in table A.6 the highest level allows a MaxLumaPs of 35 651 584.
   159  	HEVC_MAX_LUMA_PS = 35651584
   160  	// A.4.1: pic_width_in_luma_samples and pic_height_in_luma_samples are
   161  	// constrained to be not greater than sqrt(MaxLumaPs * 8).  Hence height/
   162  	// width are bounded above by sqrt(8 * 35651584) = 16888.2 samples.
   163  	HEVC_MAX_WIDTH  = 16888
   164  	HEVC_MAX_HEIGHT = 16888
   165  
   166  	// A.4.1: table A.6 allows at most 22 tile rows for any level.
   167  	HEVC_MAX_TILE_ROWS = 22
   168  	// A.4.1: table A.6 allows at most 20 tile columns for any level.
   169  	HEVC_MAX_TILE_COLUMNS = 20
   170  
   171  	// A.4.2: table A.6 allows at most 600 slice segments for any level.
   172  	HEVC_MAX_SLICE_SEGMENTS = 600
   173  
   174  	// 7.4.7.1: in the worst case (tiles_enabled_flag and
   175  	// entropy_coding_sync_enabled_flag are both set), entry points can be
   176  	// placed at the beginning of every Ctb row in every tile, giving an
   177  	// upper bound of (num_tile_columns_minus1 + 1) * PicHeightInCtbsY - 1.
   178  	// Only a stream with very high resolution and perverse parameters could
   179  	// get near that, though, so set a lower limit here with the maximum
   180  	// possible value for 4K video (at most 135 16x16 Ctb rows).
   181  	HEVC_MAX_ENTRY_POINT_OFFSETS = HEVC_MAX_TILE_COLUMNS * 135
   182  )