FFmpeg
srtenc.c
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1 /*
2  * SubRip subtitle muxer
3  * Copyright (c) 2012 Nicolas George <nicolas.george@normalesup.org>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "avformat.h"
23 #include "internal.h"
24 #include "libavutil/log.h"
25 #include "libavutil/intreadwrite.h"
26 
27 /* TODO: add options for:
28  - character encoding;
29  - LF / CRLF;
30  - byte order mark.
31  */
32 
33 typedef struct SRTContext{
34  unsigned index;
35 } SRTContext;
36 
38 {
39  SRTContext *srt = avf->priv_data;
40 
41  if (avf->nb_streams != 1 ||
43  av_log(avf, AV_LOG_ERROR,
44  "SRT supports only a single subtitles stream.\n");
45  return AVERROR(EINVAL);
46  }
47  if (avf->streams[0]->codecpar->codec_id != AV_CODEC_ID_TEXT &&
49  av_log(avf, AV_LOG_ERROR,
50  "Unsupported subtitles codec: %s\n",
52  return AVERROR(EINVAL);
53  }
54  avpriv_set_pts_info(avf->streams[0], 64, 1, 1000);
55  srt->index = 1;
56  return 0;
57 }
58 
60 {
61  SRTContext *srt = avf->priv_data;
62 
63  int64_t s = pkt->pts, e, d = pkt->duration;
64  size_t size;
65  int x1 = -1, y1 = -1, x2 = -1, y2 = -1;
66  const uint8_t *p;
67 
69  if (p && size == 16) {
70  x1 = AV_RL32(p );
71  y1 = AV_RL32(p + 4);
72  x2 = AV_RL32(p + 8);
73  y2 = AV_RL32(p + 12);
74  }
75 
76  if (s == AV_NOPTS_VALUE || d < 0) {
78  "Insufficient timestamps in event number %d.\n", srt->index);
79  return 0;
80  }
81  e = s + d;
82  avio_printf(avf->pb, "%d\n%02d:%02d:%02d,%03d --> %02d:%02d:%02d,%03d",
83  srt->index,
84  (int)(s / 3600000), (int)(s / 60000) % 60,
85  (int)(s / 1000) % 60, (int)(s % 1000),
86  (int)(e / 3600000), (int)(e / 60000) % 60,
87  (int)(e / 1000) % 60, (int)(e % 1000));
88  if (p)
89  avio_printf(avf->pb, " X1:%03d X2:%03d Y1:%03d Y2:%03d",
90  x1, x2, y1, y2);
91  avio_printf(avf->pb, "\n");
92 
93  avio_write(avf->pb, pkt->data, pkt->size);
94  avio_write(avf->pb, "\n\n", 2);
95  srt->index++;
96  return 0;
97 }
98 
100  .name = "srt",
101  .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
102  .mime_type = "application/x-subrip",
103  .extensions = "srt",
104  .priv_data_size = sizeof(SRTContext),
108  .subtitle_codec = AV_CODEC_ID_SUBRIP,
109 };
AVMEDIA_TYPE_SUBTITLE
@ AVMEDIA_TYPE_SUBTITLE
Definition: avutil.h:204
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:186
AVOutputFormat::name
const char * name
Definition: avformat.h:496
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
AVFMT_VARIABLE_FPS
#define AVFMT_VARIABLE_FPS
Format allows variable fps.
Definition: avformat.h:470
AVFormatContext::streams
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1165
SRTContext
Definition: srtenc.c:33
AVPacket::data
uint8_t * data
Definition: packet.h:373
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:391
srt_write_header
static int srt_write_header(AVFormatContext *avf)
Definition: srtenc.c:37
pkt
AVPacket * pkt
Definition: movenc.c:59
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:257
AVFormatContext
Format I/O context.
Definition: avformat.h:1097
internal.h
ff_srt_muxer
const AVOutputFormat ff_srt_muxer
Definition: srtenc.c:99
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:992
AVFormatContext::pb
AVIOContext * pb
I/O context.
Definition: avformat.h:1139
AV_PKT_DATA_SUBTITLE_POSITION
@ AV_PKT_DATA_SUBTITLE_POSITION
Subtitle event position.
Definition: packet.h:183
AVFormatContext::nb_streams
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1153
AVPacket::size
int size
Definition: packet.h:374
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
size
int size
Definition: twinvq_data.h:10344
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
avio_write
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:218
write_packet
static void write_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost, int unqueue)
Definition: ffmpeg.c:731
avcodec_get_name
const char * avcodec_get_name(enum AVCodecID id)
Get the name of a codec.
Definition: utils.c:447
log.h
AVOutputFormat
Definition: avformat.h:495
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:366
av_packet_get_side_data
uint8_t * av_packet_get_side_data(const AVPacket *pkt, enum AVPacketSideDataType type, size_t *size)
Get side information from packet.
Definition: avpacket.c:246
AV_CODEC_ID_SUBRIP
@ AV_CODEC_ID_SUBRIP
Definition: codec_id.h:538
SRTContext::index
unsigned index
Definition: srtenc.c:34
AVFMT_TS_NONSTRICT
#define AVFMT_TS_NONSTRICT
Format does not require strictly increasing timestamps, but they must still be monotonic.
Definition: avformat.h:477
avformat.h
srt_write_packet
static int srt_write_packet(AVFormatContext *avf, AVPacket *pkt)
Definition: srtenc.c:59
AV_CODEC_ID_TEXT
@ AV_CODEC_ID_TEXT
raw UTF-8 text
Definition: codec_id.h:523
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
avio_printf
int avio_printf(AVIOContext *s, const char *fmt,...) av_printf_format(2
Writes a formatted string to the context.
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:1146
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
AVPacket
This structure stores compressed data.
Definition: packet.h:350
d
d
Definition: ffmpeg_filter.c:156
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
write_header
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:347
AVFormatContext::priv_data
void * priv_data
Format private data.
Definition: avformat.h:1125