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/*
* SCC subtitle demuxer
* Copyright (c) 2017 Paul B Mahol
*
* 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/avstring.h"
#include "libavutil/bprint.h"
#include "libavutil/intreadwrite.h"
typedef struct SCCContext {
FFDemuxSubtitlesQueue q;
} SCCContext;
static int scc_probe(const AVProbeData *p)
{
char buf[18];
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, "Scenarist_SCC V1.0", 18))
return AVPROBE_SCORE_MAX;
return 0;
}
static int convert(uint8_t x)
{
if (x >= 'a')
x -= 87;
else if (x >= 'A')
x -= 55;
else
x -= '0';
return x;
}
static int scc_read_header(AVFormatContext *s)
{
SCCContext *scc = s->priv_data;
AVStream *st = avformat_new_stream(s, NULL);
char line2[4096], line[4096];
int64_t pos, ts, next_ts = AV_NOPTS_VALUE;
int ret = 0;
ptrdiff_t len;
uint8_t out[4096];
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_EIA_608;
while (!ff_text_eof(&tr) || next_ts == AV_NOPTS_VALUE || line2[0]) {
char *saveptr = NULL, *lline;
int hh, mm, ss, fs, i;
AVPacket *sub;
if (next_ts == AV_NOPTS_VALUE) {
while (!ff_text_eof(&tr)) {
len = ff_subtitles_read_line(&tr, line, sizeof(line));
if (len <= 13)
continue;
if (!strncmp(line, "Scenarist_SCC V1.0", 18))
continue;
if (av_sscanf(line, "%d:%d:%d%*[:;]%d", &hh, &mm, &ss, &fs) == 4)
break;
}
ts = (hh * 3600LL + mm * 60LL + ss) * 1000LL + fs * 33;
while (!ff_text_eof(&tr)) {
len = ff_subtitles_read_line(&tr, line2, sizeof(line2));
if (len <= 13)
continue;
if (av_sscanf(line2, "%d:%d:%d%*[:;]%d", &hh, &mm, &ss, &fs) == 4)
break;
}
} else {
memmove(line, line2, sizeof(line));
line2[0] = 0;
while (!ff_text_eof(&tr)) {
len = ff_subtitles_read_line(&tr, line2, sizeof(line2));
if (len <= 13)
continue;
if (av_sscanf(line2, "%d:%d:%d%*[:;]%d", &hh, &mm, &ss, &fs) == 4)
break;
}
}
next_ts = (hh * 3600LL + mm * 60LL + ss) * 1000LL + fs * 33;
pos = ff_text_pos(&tr);
lline = (char *)&line;
lline += 12;
for (i = 0; i < 4095; i += 3) {
char *ptr = av_strtok(lline, " ", &saveptr);
char c1, c2, c3, c4;
uint8_t o1, o2;
if (!ptr)
break;
if (av_sscanf(ptr, "%c%c%c%c", &c1, &c2, &c3, &c4) != 4)
break;
o1 = convert(c2) | (convert(c1) << 4);
o2 = convert(c4) | (convert(c3) << 4);
lline = NULL;
if (i > 12 && o1 == 0x94 && o2 == 0x20 && saveptr &&
(av_strncasecmp(saveptr, "942f", 4) && !av_strncasecmp(saveptr, "942c", 4))) {
out[i] = 0;
sub = ff_subtitles_queue_insert(&scc->q, out, i, 0);
if (!sub)
goto fail;
sub->pos = pos;
pos += i;
sub->pts = ts;
sub->duration = i * 11;
ts += sub->duration;
i = 0;
}
out[i+0] = 0xfc;
out[i+1] = o1;
out[i+2] = o2;
}
out[i] = 0;
sub = ff_subtitles_queue_insert(&scc->q, out, i, 0);
if (!sub)
goto fail;
sub->pos = pos;
sub->pts = ts;
sub->duration = next_ts - ts;
ts = next_ts;
}
ff_subtitles_queue_finalize(s, &scc->q);
return ret;
fail:
ff_subtitles_queue_clean(&scc->q);
return AVERROR(ENOMEM);
}
static int scc_read_packet(AVFormatContext *s, AVPacket *pkt)
{
SCCContext *scc = s->priv_data;
return ff_subtitles_queue_read_packet(&scc->q, pkt);
}
static int scc_read_seek(AVFormatContext *s, int stream_index,
int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
{
SCCContext *scc = s->priv_data;
return ff_subtitles_queue_seek(&scc->q, s, stream_index,
min_ts, ts, max_ts, flags);
}
static int scc_read_close(AVFormatContext *s)
{
SCCContext *scc = s->priv_data;
ff_subtitles_queue_clean(&scc->q);
return 0;
}
AVInputFormat ff_scc_demuxer = {
.name = "scc",
.long_name = NULL_IF_CONFIG_SMALL("Scenarist Closed Captions"),
.priv_data_size = sizeof(SCCContext),
.read_probe = scc_probe,
.read_header = scc_read_header,
.read_packet = scc_read_packet,
.read_seek2 = scc_read_seek,
.read_close = scc_read_close,
.extensions = "scc",
};
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