| /* |
| * 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(const AVProbeData *p) |
| { |
| int seq = 0, entry = 0, invalid = 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; |
| invalid++; |
| continue; |
| } |
| level = (p->buf[i] & 0x38) >> 3; |
| if (level >= 5) { |
| seq = 0; |
| invalid++; |
| continue; |
| } |
| chromaformat = (p->buf[i] & 0x6) >> 1; |
| if (chromaformat != 1) { |
| seq = 0; |
| invalid++; |
| continue; |
| } |
| seq++; |
| i += 6; |
| break; |
| } |
| case VC1_CODE_ENTRYPOINT: |
| if (!seq) { |
| invalid++; |
| 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 && frame >> 1 > invalid) |
| 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) |