ffmpeg/libavformat/mpl2dec.c
wm4 060c6c4647 avformat/mpl2dec: handle files with CRLF linebreaks correctly
Skip the "\r" as normal text. Otherwise it will be the first character
of the string passed to sscanf(), which then fill fail to match the
timestamps.

Signed-off-by: Clément Bœsch <u@pkh.me>
2013-09-03 20:38:40 +02:00

147 lines
3.9 KiB
C

/*
* 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
* MPL2 subtitles format demuxer
*/
#include "avformat.h"
#include "internal.h"
#include "subtitles.h"
typedef struct {
FFDemuxSubtitlesQueue q;
} MPL2Context;
static int mpl2_probe(AVProbeData *p)
{
int i;
char c;
int64_t start, end;
const unsigned char *ptr = p->buf;
const unsigned char *ptr_end = ptr + p->buf_size;
for (i = 0; i < 2; i++) {
if (sscanf(ptr, "[%"SCNd64"][%"SCNd64"]%c", &start, &end, &c) != 3 &&
sscanf(ptr, "[%"SCNd64"][]%c", &start, &c) != 2)
return 0;
ptr += strcspn(ptr, "\n") + 1;
if (ptr >= ptr_end)
return 0;
}
return AVPROBE_SCORE_MAX;
}
static int read_ts(char **line, int64_t *pts_start, int *duration)
{
char c;
int len;
int64_t end;
if (sscanf(*line, "[%"SCNd64"][]%c%n",
pts_start, &c, &len) >= 2) {
*duration = -1;
*line += len - 1;
return 0;
}
if (sscanf(*line, "[%"SCNd64"][%"SCNd64"]%c%n",
pts_start, &end, &c, &len) >= 3) {
*duration = end - *pts_start;
*line += len - 1;
return 0;
}
return -1;
}
static int mpl2_read_header(AVFormatContext *s)
{
MPL2Context *mpl2 = s->priv_data;
AVStream *st = avformat_new_stream(s, NULL);
int res = 0;
if (!st)
return AVERROR(ENOMEM);
avpriv_set_pts_info(st, 64, 1, 10);
st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
st->codec->codec_id = AV_CODEC_ID_MPL2;
while (!url_feof(s->pb)) {
char line[4096];
char *p = line;
const int64_t pos = avio_tell(s->pb);
int len = ff_get_line(s->pb, line, sizeof(line));
int64_t pts_start;
int duration;
if (!len)
break;
line[strcspn(line, "\r\n")] = 0;
if (!read_ts(&p, &pts_start, &duration)) {
AVPacket *sub;
sub = ff_subtitles_queue_insert(&mpl2->q, p, strlen(p), 0);
if (!sub)
return AVERROR(ENOMEM);
sub->pos = pos;
sub->pts = pts_start;
sub->duration = duration;
}
}
ff_subtitles_queue_finalize(&mpl2->q);
return res;
}
static int mpl2_read_packet(AVFormatContext *s, AVPacket *pkt)
{
MPL2Context *mpl2 = s->priv_data;
return ff_subtitles_queue_read_packet(&mpl2->q, pkt);
}
static int mpl2_read_seek(AVFormatContext *s, int stream_index,
int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
{
MPL2Context *mpl2 = s->priv_data;
return ff_subtitles_queue_seek(&mpl2->q, s, stream_index,
min_ts, ts, max_ts, flags);
}
static int mpl2_read_close(AVFormatContext *s)
{
MPL2Context *mpl2 = s->priv_data;
ff_subtitles_queue_clean(&mpl2->q);
return 0;
}
AVInputFormat ff_mpl2_demuxer = {
.name = "mpl2",
.long_name = NULL_IF_CONFIG_SMALL("MPL2 subtitles"),
.priv_data_size = sizeof(MPL2Context),
.read_probe = mpl2_probe,
.read_header = mpl2_read_header,
.read_packet = mpl2_read_packet,
.read_seek2 = mpl2_read_seek,
.read_close = mpl2_read_close,
.extensions = "txt,mpl2",
};