libavformat/vvcdec.c

   1 /*
   2  * RAW H.266 / VVC video demuxer
   3  * Copyright (c) 2020 Nuo Mi <nuomi2021@gmail.com>
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "libavcodec/vvc.h"
  23
  24 #include "avformat.h"
  25 #include "rawdec.h"
  26
  27 static int check_temporal_id(uint8_t nuh_temporal_id_plus1, int type)
  28 {
  29     if (nuh_temporal_id_plus1 == 0)
  30         return 0;
  31
  32     if (nuh_temporal_id_plus1 != 1) {
  33         if (type >= VVC_IDR_W_RADL && type <= VVC_RSV_IRAP_11
  34                 || type == VVC_DCI_NUT || type == VVC_OPI_NUT
  35                 || type == VVC_VPS_NUT || type == VVC_SPS_NUT
  36                 || type == VVC_EOS_NUT || type == VVC_EOB_NUT)
  37             return 0;
  38     }
  39
  40     return 1;
  41 }
  42
  43 static int vvc_probe(const AVProbeData *p)
  44 {
  45     uint32_t code = -1;
  46     int sps = 0, pps = 0, irap = 0;
  47     int i;
  48
  49     for (i = 0; i < p->buf_size - 1; i++) {
  50         code = (code << 8) + p->buf[i];
  51         if ((code & 0xffffff00) == 0x100) {
  52             uint8_t nal2 = p->buf[i + 1];
  53             int type = (nal2 & 0xF8) >> 3;
  54
  55             if (code & 0x80) // forbidden_zero_bit
  56                 return 0;
  57
  58             if (!check_temporal_id(nal2 & 0x7, type))
  59                 return 0;
  60
  61             switch (type) {
  62             case VVC_SPS_NUT:       sps++;  break;
  63             case VVC_PPS_NUT:       pps++;  break;
  64             case VVC_IDR_N_LP:
  65             case VVC_IDR_W_RADL:
  66             case VVC_CRA_NUT:
  67             case VVC_GDR_NUT:       irap++; break;
  68             }
  69         }
  70     }
  71
  72     if (sps && pps && irap)
  73         return AVPROBE_SCORE_EXTENSION + 1; // 1 more than .mpg
  74     return 0;
  75 }
  76
  77 FF_DEF_RAWVIDEO_DEMUXER(vvc, "raw H.266/VVC video", vvc_probe, "h266,266,vvc", AV_CODEC_ID_VVC)