FFmpeg/libavformat/srtenc.c
Andreas Rheinhardt f4167842c1 avformat/mux: Add flag for "not more than one stream of each type"
More exactly: Not more than one stream of each type for which
a default codec (i.e. AVOutputFormat.(audio|video|subtitle)_codec)
is set; for those types for which no such codec is set (or for
which no designated default codec in AVOutputFormat exists at all)
no streams are permitted.

Given that with this flag set the default codecs become more important,
they are now set explicitly to AV_CODEC_ID_NONE for "unset";
the earlier code relied on AV_CODEC_ID_NONE being equal to zero,
so that default static initialization set it accordingly;
but this is not how one is supposed to use an enum.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2024-03-22 23:57:19 +01:00

108 lines
3.5 KiB
C

/*
* SubRip subtitle muxer
* Copyright (c) 2012 Nicolas George <nicolas.george@normalesup.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 "mux.h"
#include "libavutil/log.h"
#include "libavutil/intreadwrite.h"
/* TODO: add options for:
- character encoding;
- LF / CRLF;
- byte order mark.
*/
typedef struct SRTContext{
unsigned index;
} SRTContext;
static int srt_write_header(AVFormatContext *avf)
{
SRTContext *srt = avf->priv_data;
if (avf->streams[0]->codecpar->codec_id != AV_CODEC_ID_TEXT &&
avf->streams[0]->codecpar->codec_id != AV_CODEC_ID_SUBRIP) {
av_log(avf, AV_LOG_ERROR,
"Unsupported subtitles codec: %s\n",
avcodec_get_name(avf->streams[0]->codecpar->codec_id));
return AVERROR(EINVAL);
}
avpriv_set_pts_info(avf->streams[0], 64, 1, 1000);
srt->index = 1;
return 0;
}
static int srt_write_packet(AVFormatContext *avf, AVPacket *pkt)
{
SRTContext *srt = avf->priv_data;
int64_t s = pkt->pts, e, d = pkt->duration;
size_t size;
int x1 = -1, y1 = -1, x2 = -1, y2 = -1;
const uint8_t *p;
p = av_packet_get_side_data(pkt, AV_PKT_DATA_SUBTITLE_POSITION, &size);
if (p && size == 16) {
x1 = AV_RL32(p );
y1 = AV_RL32(p + 4);
x2 = AV_RL32(p + 8);
y2 = AV_RL32(p + 12);
}
if (s == AV_NOPTS_VALUE || d < 0) {
av_log(avf, AV_LOG_WARNING,
"Insufficient timestamps in event number %d.\n", srt->index);
return 0;
}
e = s + d;
avio_printf(avf->pb, "%d\n%02d:%02d:%02d,%03d --> %02d:%02d:%02d,%03d",
srt->index,
(int)(s / 3600000), (int)(s / 60000) % 60,
(int)(s / 1000) % 60, (int)(s % 1000),
(int)(e / 3600000), (int)(e / 60000) % 60,
(int)(e / 1000) % 60, (int)(e % 1000));
if (p)
avio_printf(avf->pb, " X1:%03d X2:%03d Y1:%03d Y2:%03d",
x1, x2, y1, y2);
avio_printf(avf->pb, "\n");
avio_write(avf->pb, pkt->data, pkt->size);
avio_write(avf->pb, "\n\n", 2);
srt->index++;
return 0;
}
const FFOutputFormat ff_srt_muxer = {
.p.name = "srt",
.p.long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
.p.mime_type = "application/x-subrip",
.p.extensions = "srt",
.p.flags = AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT,
.p.video_codec = AV_CODEC_ID_NONE,
.p.audio_codec = AV_CODEC_ID_NONE,
.p.subtitle_codec = AV_CODEC_ID_SUBRIP,
.flags_internal = FF_OFMT_FLAG_MAX_ONE_OF_EACH,
.priv_data_size = sizeof(SRTContext),
.write_header = srt_write_header,
.write_packet = srt_write_packet,
};