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FFmpeg/libavformat/supenc.c
Andreas Rheinhardt 1fc5d327e4 avformat/(mpeg|mpegts|mxf|sup)enc: Use const uint8_t* to access pkt data
The packets muxers receive are not guaranteed to be writable,
so they must not be modified. Ergo only access the packet's data
via a const uint8_t*.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-07-04 14:56:43 +02:00

97 lines
2.7 KiB
C

/*
* SUP muxer
* Copyright (c) 2014 Petri Hintukainen <phintuka@users.sourceforge.net>
*
* 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 "internal.h"
#include "libavutil/intreadwrite.h"
#define SUP_PGS_MAGIC 0x5047 /* "PG", big endian */
static int sup_write_packet(AVFormatContext *s, AVPacket *pkt)
{
const uint8_t *data = pkt->data;
size_t size = pkt->size;
uint32_t pts = 0, dts = 0;
if (pkt->pts != AV_NOPTS_VALUE) {
pts = pkt->pts;
}
if (pkt->dts != AV_NOPTS_VALUE) {
dts = pkt->dts;
}
/*
Split frame to segments.
mkvmerge stores multiple segments in one frame.
*/
while (size > 2) {
size_t len = AV_RB16(data + 1) + 3;
if (len > size) {
av_log(s, AV_LOG_ERROR, "Not enough data, skipping %"SIZE_SPECIFIER" bytes\n",
size);
return AVERROR_INVALIDDATA;
}
/* header */
avio_wb16(s->pb, SUP_PGS_MAGIC);
avio_wb32(s->pb, pts);
avio_wb32(s->pb, dts);
avio_write(s->pb, data, len);
data += len;
size -= len;
}
if (size > 0) {
av_log(s, AV_LOG_ERROR, "Skipping %"SIZE_SPECIFIER" bytes after last segment in frame\n",
size);
return AVERROR_INVALIDDATA;
}
return 0;
}
static int sup_write_header(AVFormatContext *s)
{
if (s->nb_streams != 1) {
av_log(s, AV_LOG_ERROR, "%s files have exactly one stream\n",
s->oformat->name);
return AVERROR(EINVAL);
}
avpriv_set_pts_info(s->streams[0], 32, 1, 90000);
return 0;
}
const AVOutputFormat ff_sup_muxer = {
.name = "sup",
.long_name = NULL_IF_CONFIG_SMALL("raw HDMV Presentation Graphic Stream subtitles"),
.extensions = "sup",
.mime_type = "application/x-pgs",
.subtitle_codec = AV_CODEC_ID_HDMV_PGS_SUBTITLE,
.write_header = sup_write_header,
.write_packet = sup_write_packet,
.flags = AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT,
};