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/*
* SubRip subtitle demuxer
* Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org>
*
* 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(AVProbeData *p)
{
unsigned char *ptr = p->buf;
int i, v, num = 0;
if (AV_RB24(ptr) == 0xEFBBBF)
ptr += 3; /* skip UTF-8 BOM */
for (i=0; i<2; i++) {
if ((num == i || num + 1 == i)
&& sscanf(ptr, "%*d:%*2d:%*2d%*1[,.]%*3d --> %*d:%*2d:%*2d%*1[,.]%3d", &v) == 1)
return AVPROBE_SCORE_MAX;
num = atoi(ptr);
ptr += strcspn(ptr, "\n") + 1;
}
return 0;
}
static int64_t get_pts(const char **buf, int *duration,
int32_t *x1, int32_t *y1, int32_t *x2, int32_t *y2)
{
int i;
for (i=0; i<2; i++) {
int hh1, mm1, ss1, ms1;
int hh2, mm2, ss2, ms2;
if (sscanf(*buf, "%d:%2d:%2d%*1[,.]%3d --> %d:%2d:%2d%*1[,.]%3d"
"%*[ ]X1:%u X2:%u Y1:%u Y2:%u",
&hh1, &mm1, &ss1, &ms1,
&hh2, &mm2, &ss2, &ms2,
x1, x2, y1, y2) >= 8) {
int64_t start = (hh1*3600LL + mm1*60LL + ss1) * 1000LL + ms1;
int64_t end = (hh2*3600LL + mm2*60LL + ss2) * 1000LL + ms2;
*duration = end - start;
*buf += strcspn(*buf, "\n") + 1;
return start;
}
*buf += strcspn(*buf, "\n") + 1;
}
return AV_NOPTS_VALUE;
}
static inline int is_eol(char c)
{
return c == '\r' || c == '\n';
}
static void read_chunk(AVIOContext *pb, AVBPrint *buf)
{
char eol_buf[5];
int n = 0, i = 0, nb_eol = 0;
av_bprint_clear(buf);
for (;;) {
char c = avio_r8(pb);
if (!c)
break;
/* ignore all initial line breaks */
if (n == 0 && is_eol(c))
continue;
/* line break buffering: we don't want to add the trailing \r\n */
if (is_eol(c)) {
nb_eol += c == '\n';
if (nb_eol == 2)
break;
eol_buf[i++] = c;
if (i == sizeof(eol_buf) - 1)
break;
continue;
}
/* only one line break followed by data: we flush the line breaks
* buffer */
if (i) {
eol_buf[i] = 0;
av_bprintf(buf, "%s", eol_buf);
i = nb_eol = 0;
}
av_bprint_chars(buf, c, 1);
n++;
}
/* FIXME: remove the following when the lavc SubRip decoder is fixed
* (trailing tags are not correctly flushed, see what happens to FATE when
* you disable this code) */
if (buf->len)
av_bprintf(buf, "\n");
}
static int srt_read_header(AVFormatContext *s)
{
SRTContext *srt = s->priv_data;
AVBPrint buf;
AVStream *st = avformat_new_stream(s, NULL);
int res = 0;
if (!st)
return AVERROR(ENOMEM);
avpriv_set_pts_info(st, 64, 1, 1000);
st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
st->codec->codec_id = AV_CODEC_ID_SUBRIP;
av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
while (!url_feof(s->pb)) {
read_chunk(s->pb, &buf);
if (buf.len) {
int64_t pos = avio_tell(s->pb);
int64_t pts;
int duration;
const char *ptr = buf.str;
int32_t x1 = -1, y1 = -1, x2 = -1, y2 = -1;
AVPacket *sub;
pts = get_pts(&ptr, &duration, &x1, &y1, &x2, &y2);
if (pts != AV_NOPTS_VALUE) {
int len = buf.len - (ptr - buf.str);
sub = ff_subtitles_queue_insert(&srt->q, ptr, len, 0);
if (!sub) {
res = AVERROR(ENOMEM);
goto end;
}
sub->pos = pos;
sub->pts = pts;
sub->duration = duration;
if (x1 != -1) {
uint8_t *p = av_packet_new_side_data(sub, AV_PKT_DATA_SUBTITLE_POSITION, 16);
if (p) {
AV_WL32(p, x1);
AV_WL32(p + 4, y1);
AV_WL32(p + 8, x2);
AV_WL32(p + 12, y2);
}
}
}
}
}
ff_subtitles_queue_finalize(&srt->q);
end:
av_bprint_finalize(&buf, NULL);
return res;
}
static int srt_read_packet(AVFormatContext *s, AVPacket *pkt)
{
SRTContext *srt = s->priv_data;
return ff_subtitles_queue_read_packet(&srt->q, pkt);
}
static int srt_read_seek(AVFormatContext *s, int stream_index,
int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
{
SRTContext *srt = s->priv_data;
return ff_subtitles_queue_seek(&srt->q, s, stream_index,
min_ts, ts, max_ts, flags);
}
static int srt_read_close(AVFormatContext *s)
{
SRTContext *srt = s->priv_data;
ff_subtitles_queue_clean(&srt->q);
return 0;
}
AVInputFormat ff_srt_demuxer = {
.name = "srt",
.long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
.priv_data_size = sizeof(SRTContext),
.read_probe = srt_probe,
.read_header = srt_read_header,
.read_packet = srt_read_packet,
.read_seek2 = srt_read_seek,
.read_close = srt_read_close,
.flags = AVFMT_GENERIC_INDEX,
};
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