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/*
* Copyright (c) 2012 Clément Bœsch
*
* 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
*/
/**
* @file
* MPlayer subtitles format demuxer
*/
#include "avformat.h"
#include "demux.h"
#include "internal.h"
#include "subtitles.h"
#define TSBASE 10000000
typedef struct {
FFDemuxSubtitlesQueue q;
} MPSubContext;
static int mpsub_probe(const AVProbeData *p)
{
const char *ptr = p->buf;
const char *ptr_end = p->buf + p->buf_size;
while (ptr < ptr_end) {
int inc;
if (!memcmp(ptr, "FORMAT=TIME", 11))
return AVPROBE_SCORE_EXTENSION;
if (!memcmp(ptr, "FORMAT=", 7))
return AVPROBE_SCORE_EXTENSION / 3;
inc = ff_subtitles_next_line(ptr);
if (!inc)
break;
ptr += inc;
}
return 0;
}
static int parse_line(const char *line, int64_t *value, int64_t *value2)
{
int vi, p1, p2;
for (vi = 0; vi < 2; vi++) {
long long intval, fracval;
int n = av_sscanf(line, "%lld%n.%lld%n", &intval, &p1, &fracval, &p2);
if (n <= 0 || intval < INT64_MIN / TSBASE || intval > INT64_MAX / TSBASE)
return AVERROR_INVALIDDATA;
intval *= TSBASE;
if (n == 2) {
if (fracval < 0)
return AVERROR_INVALIDDATA;
for (;p2 - p1 < 7 + 1; p1--)
fracval *= 10;
for (;p2 - p1 > 7 + 1; p1++)
fracval /= 10;
if (intval > 0) intval = av_sat_add64(intval, fracval);
else intval = av_sat_sub64(intval, fracval);
line += p2;
} else
line += p1;
*value = intval;
value = value2;
}
return 0;
}
static int mpsub_read_header(AVFormatContext *s)
{
MPSubContext *mpsub = s->priv_data;
AVStream *st;
AVBPrint buf;
AVRational pts_info = (AVRational){ TSBASE, 1 }; // ts based by default
int res = 0;
int64_t current_pts = 0;
int i;
int common_factor = 0;
av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
while (!avio_feof(s->pb)) {
char line[1024];
int64_t start, duration;
int fps, len = ff_get_line(s->pb, line, sizeof(line));
if (!len)
break;
line[strcspn(line, "\r\n")] = 0;
if (sscanf(line, "FORMAT=%d", &fps) == 1 && fps > 3 && fps < 100) {
/* frame based timing */
pts_info = (AVRational){ TSBASE * fps, 1 };
} else if (parse_line(line, &start, &duration) >= 0) {
AVPacket *sub;
const int64_t pos = avio_tell(s->pb);
res = ff_subtitles_read_chunk(s->pb, &buf);
if (res < 0) goto end;
if (buf.len) {
sub = ff_subtitles_queue_insert_bprint(&mpsub->q, &buf, 0);
if (!sub) {
res = AVERROR(ENOMEM);
goto end;
}
if ( current_pts < 0 && start < INT64_MIN - current_pts
|| current_pts > 0 && start > INT64_MAX - current_pts) {
res = AVERROR_INVALIDDATA;
goto end;
}
sub->pts = current_pts + start;
if (duration < 0 || sub->pts > INT64_MAX - duration) {
res = AVERROR_INVALIDDATA;
goto end;
}
sub->duration = duration;
common_factor = av_gcd(duration, common_factor);
common_factor = av_gcd(sub->pts, common_factor);
current_pts = sub->pts + duration;
sub->pos = pos;
}
}
}
if (common_factor > 1) {
common_factor = av_gcd(pts_info.num, common_factor);
for (i = 0; i < mpsub->q.nb_subs; i++) {
mpsub->q.subs[i]->pts /= common_factor;
mpsub->q.subs[i]->duration /= common_factor;
}
pts_info.num /= common_factor;
}
st = avformat_new_stream(s, NULL);
if (!st) {
res = AVERROR(ENOMEM);
goto end;
}
avpriv_set_pts_info(st, 64, pts_info.den, pts_info.num);
st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
st->codecpar->codec_id = AV_CODEC_ID_TEXT;
ff_subtitles_queue_finalize(s, &mpsub->q);
end:
av_bprint_finalize(&buf, NULL);
return res;
}
const FFInputFormat ff_mpsub_demuxer = {
.p.name = "mpsub",
.p.long_name = NULL_IF_CONFIG_SMALL("MPlayer subtitles"),
.p.extensions = "sub",
.priv_data_size = sizeof(MPSubContext),
.flags_internal = FF_FMT_INIT_CLEANUP,
.read_probe = mpsub_probe,
.read_header = mpsub_read_header,
.read_packet = ff_subtitles_read_packet,
.read_seek2 = ff_subtitles_read_seek,
.read_close = ff_subtitles_read_close,
};
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