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/*
* SSA/ASS demuxer
* Copyright (c) 2008 Michael Niedermayer
* Copyright (c) 2014 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
*/
#include <stdint.h>
#include "avformat.h"
#include "internal.h"
#include "subtitles.h"
#include "libavcodec/internal.h"
#include "libavutil/bprint.h"
typedef struct ASSContext {
FFDemuxSubtitlesQueue q;
unsigned readorder;
} ASSContext;
static int ass_probe(const AVProbeData *p)
{
char buf[13];
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);
ff_text_read(&tr, buf, sizeof(buf));
if (!memcmp(buf, "[Script Info]", 13))
return AVPROBE_SCORE_MAX;
return 0;
}
static int ass_read_close(AVFormatContext *s)
{
ASSContext *ass = s->priv_data;
ff_subtitles_queue_clean(&ass->q);
return 0;
}
static int read_dialogue(ASSContext *ass, AVBPrint *dst, const uint8_t *p,
int64_t *start, int *duration)
{
int pos = 0;
int64_t end;
int hh1, mm1, ss1, ms1;
int hh2, mm2, ss2, ms2;
if (sscanf(p, "Dialogue: %*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d,%n",
&hh1, &mm1, &ss1, &ms1,
&hh2, &mm2, &ss2, &ms2, &pos) >= 8 && pos > 0) {
/* This is not part of the sscanf itself in order to handle an actual
* number (which would be the Layer) or the form "Marked=N" (which is
* the old SSA field, now replaced by Layer, and will lead to Layer
* being 0 here). */
const int layer = atoi(p + 10);
end = (hh2*3600LL + mm2*60LL + ss2) * 100LL + ms2;
*start = (hh1*3600LL + mm1*60LL + ss1) * 100LL + ms1;
*duration = end - *start;
av_bprint_clear(dst);
av_bprintf(dst, "%u,%d,%s", ass->readorder++, layer, p + pos);
/* right strip the buffer */
while (dst->len > 0 &&
dst->str[dst->len - 1] == '\r' ||
dst->str[dst->len - 1] == '\n')
dst->str[--dst->len] = 0;
return 0;
}
return -1;
}
static int64_t get_line(AVBPrint *buf, FFTextReader *tr)
{
int64_t pos = ff_text_pos(tr);
av_bprint_clear(buf);
for (;;) {
char c = ff_text_r8(tr);
if (!c)
break;
av_bprint_chars(buf, c, 1);
if (c == '\n')
break;
}
return pos;
}
static int ass_read_header(AVFormatContext *s)
{
ASSContext *ass = s->priv_data;
AVBPrint header, line, rline;
int res = 0;
AVStream *st;
FFTextReader tr;
ff_text_init_avio(s, &tr, s->pb);
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
avpriv_set_pts_info(st, 64, 1, 100);
st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
st->codecpar->codec_id = AV_CODEC_ID_ASS;
av_bprint_init(&header, 0, AV_BPRINT_SIZE_UNLIMITED);
av_bprint_init(&line, 0, AV_BPRINT_SIZE_UNLIMITED);
av_bprint_init(&rline, 0, AV_BPRINT_SIZE_UNLIMITED);
ass->q.keep_duplicates = 1;
for (;;) {
int64_t pos = get_line(&line, &tr);
int64_t ts_start = AV_NOPTS_VALUE;
int duration = -1;
AVPacket *sub;
if (!line.str[0]) // EOF
break;
if (read_dialogue(ass, &rline, line.str, &ts_start, &duration) < 0) {
av_bprintf(&header, "%s", line.str);
continue;
}
sub = ff_subtitles_queue_insert(&ass->q, rline.str, rline.len, 0);
if (!sub) {
res = AVERROR(ENOMEM);
goto end;
}
sub->pos = pos;
sub->pts = ts_start;
sub->duration = duration;
}
res = ff_bprint_to_codecpar_extradata(st->codecpar, &header);
if (res < 0)
goto end;
ff_subtitles_queue_finalize(s, &ass->q);
end:
av_bprint_finalize(&header, NULL);
av_bprint_finalize(&line, NULL);
av_bprint_finalize(&rline, NULL);
return res;
}
static int ass_read_packet(AVFormatContext *s, AVPacket *pkt)
{
ASSContext *ass = s->priv_data;
return ff_subtitles_queue_read_packet(&ass->q, pkt);
}
static int ass_read_seek(AVFormatContext *s, int stream_index,
int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
{
ASSContext *ass = s->priv_data;
return ff_subtitles_queue_seek(&ass->q, s, stream_index,
min_ts, ts, max_ts, flags);
}
const AVInputFormat ff_ass_demuxer = {
.name = "ass",
.long_name = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"),
.flags_internal = FF_FMT_INIT_CLEANUP,
.priv_data_size = sizeof(ASSContext),
.read_probe = ass_probe,
.read_header = ass_read_header,
.read_packet = ass_read_packet,
.read_close = ass_read_close,
.read_seek2 = ass_read_seek,
};
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