blob: 6828738340f3f2f808493e77a49846dd825c90db
| 1 | /* |
| 2 | * RAW dvb teletext demuxer |
| 3 | * Copyright (c) 2016 Marton Balnt <cus@passwd.hu> |
| 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/dvbtxt.h" |
| 23 | |
| 24 | #include "avformat.h" |
| 25 | #include "rawdec.h" |
| 26 | |
| 27 | static int dvbtxt_probe(AVProbeData *p) |
| 28 | { |
| 29 | const uint8_t *end = p->buf + p->buf_size; |
| 30 | const uint8_t *buf; |
| 31 | |
| 32 | /* The purpose of this is demuxer is to detect DVB teletext streams in |
| 33 | * mpegts, so we reject invalid buffer sizes */ |
| 34 | if ((p->buf_size + 45) % 184 != 0) |
| 35 | return 0; |
| 36 | |
| 37 | if (!ff_data_identifier_is_teletext(p->buf[0])) |
| 38 | return 0; |
| 39 | |
| 40 | for (buf = p->buf + 1; buf < end; buf += 46) { |
| 41 | if (!ff_data_unit_id_is_teletext(buf[0]) && buf[0] != 0xff) |
| 42 | return 0; |
| 43 | if (buf[1] != 0x2c) // data_unit_length |
| 44 | return 0; |
| 45 | } |
| 46 | |
| 47 | return AVPROBE_SCORE_MAX / 2; |
| 48 | } |
| 49 | |
| 50 | FF_DEF_RAWSUB_DEMUXER(dvbtxt, "dvbtxt", dvbtxt_probe, NULL, AV_CODEC_ID_DVB_TELETEXT, 0) |
| 51 |