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/*
* MicroDVD subtitle demuxer
* Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org>
* Copyright (c) 2012 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/intreadwrite.h"
#include "libavutil/opt.h"
#define MAX_LINESIZE 2048
typedef struct {
const AVClass *class;
FFDemuxSubtitlesQueue q;
AVRational frame_rate;
} MicroDVDContext;
static int microdvd_probe(const AVProbeData *p)
{
unsigned char c;
const uint8_t *ptr = p->buf;
int i;
if (AV_RB24(ptr) == 0xEFBBBF)
ptr += 3; /* skip UTF-8 BOM */
for (i=0; i<3; i++) {
if (sscanf(ptr, "{%*d}{}%c", &c) != 1 &&
sscanf(ptr, "{%*d}{%*d}%c", &c) != 1 &&
sscanf(ptr, "{DEFAULT}{}%c", &c) != 1)
return 0;
ptr += ff_subtitles_next_line(ptr);
}
return AVPROBE_SCORE_MAX;
}
static int64_t get_pts(const char *buf)
{
int frame;
char c;
if (sscanf(buf, "{%d}{%c", &frame, &c) == 2)
return frame;
return AV_NOPTS_VALUE;
}
static int64_t get_duration(const char *buf)
{
int frame_start, frame_end;
if (sscanf(buf, "{%d}{%d}", &frame_start, &frame_end) == 2)
return frame_end - (int64_t)frame_start;
return -1;
}
static const char *bom = "\xEF\xBB\xBF";
static int microdvd_read_header(AVFormatContext *s)
{
AVRational pts_info = (AVRational){ 2997, 125 }; /* default: 23.976 fps */
MicroDVDContext *microdvd = s->priv_data;
AVStream *st = avformat_new_stream(s, NULL);
int i = 0, ret;
char line_buf[MAX_LINESIZE];
int has_real_fps = 0;
if (!st)
return AVERROR(ENOMEM);
while (!avio_feof(s->pb)) {
char *p;
AVPacket *sub;
int64_t pos = avio_tell(s->pb);
int len = ff_get_line(s->pb, line_buf, sizeof(line_buf));
char *line = line_buf;
int64_t pts;
if (!strncmp(line, bom, 3))
line += 3;
p = line;
if (!len)
break;
line[strcspn(line, "\r\n")] = 0;
if (!*p)
continue;
if (i++ < 3) {
int frame;
double fps;
char c;
if ((sscanf(line, "{%d}{}%6lf", &frame, &fps) == 2 ||
sscanf(line, "{%d}{%*d}%6lf", &frame, &fps) == 2)
&& frame <= 1 && fps > 3 && fps < 100) {
pts_info = av_d2q(fps, 100000);
has_real_fps = 1;
continue;
}
if (!st->codecpar->extradata && sscanf(line, "{DEFAULT}{}%c", &c) == 1) {
int size = strlen(line + 11);
ret = ff_alloc_extradata(st->codecpar, size);
if (ret < 0)
goto fail;
memcpy(st->codecpar->extradata, line + 11, size);
continue;
}
}
#define SKIP_FRAME_ID \
p = strchr(p, '}'); \
if (!p) { \
av_log(s, AV_LOG_WARNING, "Invalid event \"%s\"" \
" at line %d\n", line, i); \
continue; \
} \
p++
SKIP_FRAME_ID;
SKIP_FRAME_ID;
if (!*p)
continue;
pts = get_pts(line);
if (pts == AV_NOPTS_VALUE)
continue;
sub = ff_subtitles_queue_insert(µdvd->q, p, strlen(p), 0);
if (!sub) {
ret = AVERROR(ENOMEM);
goto fail;
}
sub->pos = pos;
sub->pts = pts;
sub->duration = get_duration(line);
}
ff_subtitles_queue_finalize(s, µdvd->q);
if (has_real_fps) {
/* export the FPS info only if set in the file */
microdvd->frame_rate = pts_info;
} else if (microdvd->frame_rate.num) {
/* fallback on user specified frame rate */
pts_info = microdvd->frame_rate;
}
avpriv_set_pts_info(st, 64, pts_info.den, pts_info.num);
st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
st->codecpar->codec_id = AV_CODEC_ID_MICRODVD;
return 0;
fail:
ff_subtitles_queue_clean(µdvd->q);
return ret;
}
static int microdvd_read_packet(AVFormatContext *s, AVPacket *pkt)
{
MicroDVDContext *microdvd = s->priv_data;
return ff_subtitles_queue_read_packet(µdvd->q, pkt);
}
static int microdvd_read_seek(AVFormatContext *s, int stream_index,
int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
{
MicroDVDContext *microdvd = s->priv_data;
return ff_subtitles_queue_seek(µdvd->q, s, stream_index,
min_ts, ts, max_ts, flags);
}
static int microdvd_read_close(AVFormatContext *s)
{
MicroDVDContext *microdvd = s->priv_data;
ff_subtitles_queue_clean(µdvd->q);
return 0;
}
#define OFFSET(x) offsetof(MicroDVDContext, x)
#define SD AV_OPT_FLAG_SUBTITLE_PARAM|AV_OPT_FLAG_DECODING_PARAM
static const AVOption microdvd_options[] = {
{ "subfps", "set the movie frame rate fallback", OFFSET(frame_rate), AV_OPT_TYPE_RATIONAL, {.dbl=0}, 0, INT_MAX, SD },
{ NULL }
};
static const AVClass microdvd_class = {
.class_name = "microdvddec",
.item_name = av_default_item_name,
.option = microdvd_options,
.version = LIBAVUTIL_VERSION_INT,
};
const AVInputFormat ff_microdvd_demuxer = {
.name = "microdvd",
.long_name = NULL_IF_CONFIG_SMALL("MicroDVD subtitle format"),
.priv_data_size = sizeof(MicroDVDContext),
.read_probe = microdvd_probe,
.read_header = microdvd_read_header,
.read_packet = microdvd_read_packet,
.read_seek2 = microdvd_read_seek,
.read_close = microdvd_read_close,
.priv_class = µdvd_class,
};
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