225 lines
7.1 KiB
C
225 lines
7.1 KiB
C
/*
|
|
* SubRip subtitle demuxer
|
|
* Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org>
|
|
* Copyright (c) 2015 Clément Bœsch <u pkh me>
|
|
*
|
|
* 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 "subtitles.h"
|
|
#include "libavutil/bprint.h"
|
|
#include "libavutil/intreadwrite.h"
|
|
|
|
typedef struct {
|
|
FFDemuxSubtitlesQueue q;
|
|
} SRTContext;
|
|
|
|
static int srt_probe(const AVProbeData *p)
|
|
{
|
|
int v;
|
|
char buf[64], *pbuf;
|
|
FFTextReader tr;
|
|
|
|
ff_text_init_buf(&tr, p->buf, p->buf_size);
|
|
|
|
while (ff_text_peek_r8(&tr) == '\r' || ff_text_peek_r8(&tr) == '\n')
|
|
ff_text_r8(&tr);
|
|
|
|
/* Check if the first non-empty line is a number. We do not check what the
|
|
* number is because in practice it can be anything.
|
|
* Also, that number can be followed by random garbage, so we can not
|
|
* unfortunately check that we only have a number. */
|
|
if (ff_subtitles_read_line(&tr, buf, sizeof(buf)) < 0 ||
|
|
strtol(buf, &pbuf, 10) < 0 || pbuf == buf)
|
|
return 0;
|
|
|
|
/* Check if the next line matches a SRT timestamp */
|
|
if (ff_subtitles_read_line(&tr, buf, sizeof(buf)) < 0)
|
|
return 0;
|
|
pbuf = buf;
|
|
if (buf[0] == '-')
|
|
pbuf++;
|
|
if (pbuf[0] >= '0' && pbuf[0] <= '9' && strstr(buf, " --> ")
|
|
&& sscanf(buf, "%*d:%*d:%*d%*1[,.]%*d --> %*d:%*d:%*d%*1[,.]%d", &v) == 1)
|
|
return AVPROBE_SCORE_MAX;
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct event_info {
|
|
int32_t x1, x2, y1, y2;
|
|
int duration;
|
|
int64_t pts;
|
|
int64_t pos;
|
|
};
|
|
|
|
static int get_event_info(const char *line, struct event_info *ei)
|
|
{
|
|
int hh1, mm1, ss1, ms1;
|
|
int hh2, mm2, ss2, ms2;
|
|
|
|
ei->x1 = ei->x2 = ei->y1 = ei->y2 = ei->duration = -1;
|
|
ei->pts = AV_NOPTS_VALUE;
|
|
ei->pos = -1;
|
|
if (sscanf(line, "%d:%d:%d%*1[,.]%d --> %d:%d:%d%*1[,.]%d"
|
|
"%*[ ]X1:%"PRId32" X2:%"PRId32" Y1:%"PRId32" Y2:%"PRId32,
|
|
&hh1, &mm1, &ss1, &ms1,
|
|
&hh2, &mm2, &ss2, &ms2,
|
|
&ei->x1, &ei->x2, &ei->y1, &ei->y2) >= 8) {
|
|
const int64_t start = (hh1*3600LL + mm1*60LL + ss1) * 1000LL + ms1;
|
|
const int64_t end = (hh2*3600LL + mm2*60LL + ss2) * 1000LL + ms2;
|
|
ei->duration = end - start;
|
|
ei->pts = start;
|
|
return 0;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
static int add_event(FFDemuxSubtitlesQueue *q, AVBPrint *buf, char *line_cache,
|
|
const struct event_info *ei, int append_cache)
|
|
{
|
|
if (append_cache && line_cache[0])
|
|
av_bprintf(buf, "%s\n", line_cache);
|
|
line_cache[0] = 0;
|
|
|
|
while (buf->len > 0 && buf->str[buf->len - 1] == '\n')
|
|
buf->str[--buf->len] = 0;
|
|
|
|
if (buf->len) {
|
|
AVPacket *sub = ff_subtitles_queue_insert(q, buf->str, buf->len, 0);
|
|
if (!sub)
|
|
return AVERROR(ENOMEM);
|
|
av_bprint_clear(buf);
|
|
sub->pos = ei->pos;
|
|
sub->pts = ei->pts;
|
|
sub->duration = ei->duration;
|
|
if (ei->x1 != -1) {
|
|
uint8_t *p = av_packet_new_side_data(sub, AV_PKT_DATA_SUBTITLE_POSITION, 16);
|
|
if (p) {
|
|
AV_WL32(p, ei->x1);
|
|
AV_WL32(p + 4, ei->y1);
|
|
AV_WL32(p + 8, ei->x2);
|
|
AV_WL32(p + 12, ei->y2);
|
|
}
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int srt_read_header(AVFormatContext *s)
|
|
{
|
|
SRTContext *srt = s->priv_data;
|
|
AVBPrint buf;
|
|
AVStream *st = avformat_new_stream(s, NULL);
|
|
int res = 0;
|
|
char line[4096], line_cache[4096];
|
|
int has_event_info = 0;
|
|
struct event_info ei;
|
|
FFTextReader tr;
|
|
ff_text_init_avio(s, &tr, s->pb);
|
|
|
|
if (!st)
|
|
return AVERROR(ENOMEM);
|
|
avpriv_set_pts_info(st, 64, 1, 1000);
|
|
st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
|
|
st->codecpar->codec_id = AV_CODEC_ID_SUBRIP;
|
|
|
|
av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
|
|
|
|
line_cache[0] = 0;
|
|
|
|
while (!ff_text_eof(&tr)) {
|
|
struct event_info tmp_ei;
|
|
const int64_t pos = ff_text_pos(&tr);
|
|
ptrdiff_t len = ff_subtitles_read_line(&tr, line, sizeof(line));
|
|
|
|
if (len < 0)
|
|
break;
|
|
|
|
if (!len || !line[0])
|
|
continue;
|
|
|
|
if (get_event_info(line, &tmp_ei) < 0) {
|
|
char *pline;
|
|
|
|
if (!has_event_info)
|
|
continue;
|
|
|
|
if (line_cache[0]) {
|
|
/* We got some cache and a new line so we assume the cached
|
|
* line was actually part of the payload */
|
|
av_bprintf(&buf, "%s\n", line_cache);
|
|
line_cache[0] = 0;
|
|
}
|
|
|
|
/* If the line doesn't start with a number, we assume it's part of
|
|
* the payload, otherwise is likely an event number preceding the
|
|
* timing information... but we can't be sure of this yet, so we
|
|
* cache it */
|
|
if (strtol(line, &pline, 10) < 0 || line == pline)
|
|
av_bprintf(&buf, "%s\n", line);
|
|
else
|
|
strcpy(line_cache, line);
|
|
} else {
|
|
if (has_event_info) {
|
|
/* We have the information of previous event, append it to the
|
|
* queue. We insert the cached line if and only if the payload
|
|
* is empty and the cached line is not a standalone number. */
|
|
char *pline = NULL;
|
|
const int standalone_number = strtol(line_cache, &pline, 10) >= 0 && pline && !*pline;
|
|
res = add_event(&srt->q, &buf, line_cache, &ei, !buf.len && !standalone_number);
|
|
if (res < 0)
|
|
goto end;
|
|
} else {
|
|
has_event_info = 1;
|
|
}
|
|
tmp_ei.pos = pos;
|
|
ei = tmp_ei;
|
|
}
|
|
}
|
|
|
|
/* Append the last event. Here we force the cache to be flushed, because a
|
|
* trailing number is more likely to be geniune (for example a copyright
|
|
* date) and not the event index of an inexistant event */
|
|
if (has_event_info) {
|
|
res = add_event(&srt->q, &buf, line_cache, &ei, 1);
|
|
if (res < 0)
|
|
goto end;
|
|
}
|
|
|
|
ff_subtitles_queue_finalize(s, &srt->q);
|
|
|
|
end:
|
|
av_bprint_finalize(&buf, NULL);
|
|
return res;
|
|
}
|
|
|
|
const AVInputFormat ff_srt_demuxer = {
|
|
.name = "srt",
|
|
.long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
|
|
.priv_data_size = sizeof(SRTContext),
|
|
.flags_internal = FF_FMT_INIT_CLEANUP,
|
|
.read_probe = srt_probe,
|
|
.read_header = srt_read_header,
|
|
.read_packet = ff_subtitles_read_packet,
|
|
.read_seek2 = ff_subtitles_read_seek,
|
|
.read_close = ff_subtitles_read_close,
|
|
};
|