From 51afd9f4e1f79144d0ff2874c55f55eaba012343 Mon Sep 17 00:00:00 2001 From: Marton Balint Date: Tue, 16 Feb 2016 03:05:10 +0100 Subject: avformat/dvbtxt: add raw demuxer for dvb teletext probing Signed-off-by: Marton Balint --- libavformat/dvbtxt.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 libavformat/dvbtxt.c (limited to 'libavformat/dvbtxt.c') diff --git a/libavformat/dvbtxt.c b/libavformat/dvbtxt.c new file mode 100644 index 0000000000..6828738340 --- /dev/null +++ b/libavformat/dvbtxt.c @@ -0,0 +1,50 @@ +/* + * RAW dvb teletext demuxer + * Copyright (c) 2016 Marton Balnt + * + * 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(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) -- cgit v1.2.3