mirror of https://github.com/FFmpeg/FFmpeg.git
Signed-off-by: Marton Balint <cus@passwd.hu>pull/178/head
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/*
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* DVB teletext common functions. |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#ifndef AVCODEC_DVBTXT_H |
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#define AVCODEC_DVBTXT_H |
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#include "libavutil/attributes.h" |
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/* Returns true if data identifier matches a teletext stream according to EN
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* 301 775 section 4.4.2 */ |
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static av_always_inline int ff_data_identifier_is_teletext(int data_identifier) |
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{ |
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return (data_identifier >= 0x10 && data_identifier <= 0x1F || |
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data_identifier >= 0x99 && data_identifier <= 0x9B); |
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} |
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/* Returns true if data unit id matches EBU teletext data according to
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* EN 301 775 section 4.4.2 */ |
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static av_always_inline int ff_data_unit_id_is_teletext(int data_unit_id) |
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{ |
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return (data_unit_id == 0x02 || data_unit_id == 0x03); |
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} |
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#endif /* AVCODEC_DVBTXT_H */ |
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/*
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* RAW dvb teletext demuxer |
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* Copyright (c) 2016 Marton Balnt <cus@passwd.hu> |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#include "libavcodec/dvbtxt.h" |
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#include "avformat.h" |
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#include "rawdec.h" |
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static int dvbtxt_probe(AVProbeData *p) |
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{ |
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const uint8_t *end = p->buf + p->buf_size; |
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const uint8_t *buf; |
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/* The purpose of this is demuxer is to detect DVB teletext streams in
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* mpegts, so we reject invalid buffer sizes */ |
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if ((p->buf_size + 45) % 184 != 0) |
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return 0; |
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if (!ff_data_identifier_is_teletext(p->buf[0])) |
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return 0; |
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for (buf = p->buf + 1; buf < end; buf += 46) { |
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if (!ff_data_unit_id_is_teletext(buf[0]) && buf[0] != 0xff) |
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return 0; |
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if (buf[1] != 0x2c) // data_unit_length
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return 0; |
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} |
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return AVPROBE_SCORE_MAX / 2; |
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} |
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FF_DEF_RAWSUB_DEMUXER(dvbtxt, "dvbtxt", dvbtxt_probe, NULL, AV_CODEC_ID_DVB_TELETEXT, 0) |
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