/* * RAW dvb teletext demuxer * Copyright (c) 2016 Marton Balnt <cus@passwd.hu> * * 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 "libavcodec/dvbtxt.h" #include "avformat.h" #include "rawdec.h" static int dvbtxt_probe(const AVProbeData *p) { const uint8_t *end = p->buf + p->buf_size; const uint8_t *buf; /* The purpose of this is demuxer is to detect DVB teletext streams in * mpegts, so we reject invalid buffer sizes */ if ((p->buf_size + 45) % 184 != 0) return 0; if (!ff_data_identifier_is_teletext(p->buf[0])) return 0; for (buf = p->buf + 1; buf < end; buf += 46) { if (!ff_data_unit_id_is_teletext(buf[0]) && buf[0] != 0xff) return 0; if (buf[1] != 0x2c) // data_unit_length return 0; } return AVPROBE_SCORE_MAX / 2; } FF_DEF_RAWSUB_DEMUXER(dvbtxt, "dvbtxt", dvbtxt_probe, NULL, AV_CODEC_ID_DVB_TELETEXT, 0)