/*
  * VC-1 demuxer
  * Copyright (c) 2015 Carl Eugen Hoyos
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include "avformat.h"
 #include "rawdec.h"
 #include "libavutil/intreadwrite.h"
 #include "libavcodec/vc1_common.h"
 
 static int vc1_probe(AVProbeData *p)
 {
     int seq = 0, entry = 0, frame = 0, i;
 
     for (i = 0; i < p->buf_size + 5; i++) {
         uint32_t code = AV_RB32(p->buf + i);
         if ((code & 0xffffffe0) == 0x100) {
             int type = code & 0x11f;
             i += 4;
             switch (type) {
             case VC1_CODE_SEQHDR: {
                 int profile, level, chromaformat;
                 profile = (p->buf[i] & 0xc0) >> 6;
                 if (profile != PROFILE_ADVANCED) {
                     seq = 0;
                     continue;
                 }
                 level = (p->buf[i] & 0x38) >> 3;
                 if (level >= 5) {
                     seq = 0;
                     continue;
                 }
                 chromaformat = (p->buf[i] & 0x6) >> 1;
                 if (chromaformat != 1) {
                     seq = 0;
                     continue;
                 }
                 seq++;
                 i += 6;
                 break;
             }
             case VC1_CODE_ENTRYPOINT:
                 if (!seq)
                     continue;
                 entry++;
                 i += 2;
                 break;
             case VC1_CODE_FRAME:
             case VC1_CODE_FIELD:
             case VC1_CODE_SLICE:
                 if (seq && entry)
                     frame++;
                 break;
             }
         }
     }
 
     if (frame > 1)
         return AVPROBE_SCORE_EXTENSION / 2 + 1;
     if (frame == 1)
         return AVPROBE_SCORE_EXTENSION / 4;
     return 0;
 }
 
 FF_DEF_RAWVIDEO_DEMUXER2(vc1, "raw VC-1", vc1_probe, "vc1", AV_CODEC_ID_VC1, AVFMT_GENERIC_INDEX|AVFMT_NOTIMESTAMPS)