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  int size, x1 = -1, y1 = -1, x2 = -1, y2 = -1;
65  const uint8_t *p;
66 
68  if (p && size == 16) {
69  x1 = AV_RL32(p );
70  y1 = AV_RL32(p + 4);
71  x2 = AV_RL32(p + 8);
72  y2 = AV_RL32(p + 12);
73  }
74 
75 #if FF_API_CONVERGENCE_DURATION
77  if (d <= 0)
78  /* For backward compatibility, fallback to convergence_duration. */
79  d = pkt->convergence_duration;
81 #endif
82  if (s == AV_NOPTS_VALUE || d < 0) {
84  "Insufficient timestamps in event number %d.\n", srt->index);
85  return 0;
86  }
87  e = s + d;
88  avio_printf(avf->pb, "%d\n%02d:%02d:%02d,%03d --> %02d:%02d:%02d,%03d",
89  srt->index,
90  (int)(s / 3600000), (int)(s / 60000) % 60,
91  (int)(s / 1000) % 60, (int)(s % 1000),
92  (int)(e / 3600000), (int)(e / 60000) % 60,
93  (int)(e / 1000) % 60, (int)(e % 1000));
94  if (p)
95  avio_printf(avf->pb, " X1:%03d X2:%03d Y1:%03d Y2:%03d",
96  x1, x2, y1, y2);
97  avio_printf(avf->pb, "\n");
98 
99  avio_write(avf->pb, pkt->data, pkt->size);
100  avio_write(avf->pb, "\n\n", 2);
101  srt->index++;
102  return 0;
103 }
104 
106  .name = "srt",
107  .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
108  .mime_type = "application/x-subrip",
109  .extensions = "srt",
110  .priv_data_size = sizeof(SRTContext),
114  .subtitle_codec = AV_CODEC_ID_SUBRIP,
115 };
static void write_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost, int unqueue)
Definition: ffmpeg.c:689
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
void avpriv_set_pts_info(AVStream *s, 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:4892
Subtitle event position.
Definition: avcodec.h:1327
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3957
static int srt_write_header(AVFormatContext *avf)
Definition: srtenc.c:37
int size
Definition: avcodec.h:1478
static AVPacket pkt
#define AVFMT_TS_NONSTRICT
Format does not require strictly increasing timestamps, but they must still be monotonic.
Definition: avformat.h:477
static int srt_write_packet(AVFormatContext *avf, AVPacket *pkt)
Definition: srtenc.c:59
Format I/O context.
Definition: avformat.h:1358
uint8_t
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1495
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1426
uint8_t * data
Definition: avcodec.h:1477
ptrdiff_t size
Definition: opengl_enc.c:100
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:218
#define av_log(a,...)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
uint8_t * av_packet_get_side_data(const AVPacket *pkt, enum AVPacketSideDataType type, int *size)
Get side information from packet.
Definition: avpacket.c:350
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3953
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1414
unsigned index
Definition: srtenc.c:34
const char * name
Definition: avformat.h:505
#define s(width, name)
Definition: cbs_vp9.c:257
const char * avcodec_get_name(enum AVCodecID id)
Get the name of a codec.
Definition: utils.c:1147
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
#define flags(name, subs,...)
Definition: cbs_av1.c:561
Main libavformat public API header.
attribute_deprecated int64_t convergence_duration
Definition: avcodec.h:1506
#define FF_DISABLE_DEPRECATION_WARNINGS
Definition: internal.h:84
raw UTF-8 text
Definition: avcodec.h:660
#define AVFMT_VARIABLE_FPS
Format allows variable fps.
Definition: avformat.h:470
#define FF_ENABLE_DEPRECATION_WARNINGS
Definition: internal.h:85
void * priv_data
Format private data.
Definition: avformat.h:1386
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:337
AVOutputFormat ff_srt_muxer
Definition: srtenc.c:105
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
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
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:87
This structure stores compressed data.
Definition: avcodec.h:1454
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1470
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
int avio_printf(AVIOContext *s, const char *fmt,...) av_printf_format(2
Writes a formatted string to the context.