FFmpeg  4.4.4
subviewerdec.c
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1 /*
2  * Copyright (c) 2012 Clément Bœsch
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file
23  * SubViewer subtitle demuxer
24  * @see https://en.wikipedia.org/wiki/SubViewer
25  */
26 
27 #include "avformat.h"
28 #include "internal.h"
29 #include "subtitles.h"
30 #include "avio_internal.h"
31 #include "libavcodec/internal.h"
32 #include "libavutil/avstring.h"
33 #include "libavutil/bprint.h"
34 #include "libavutil/intreadwrite.h"
35 
36 typedef struct {
39 
40 static int subviewer_probe(const AVProbeData *p)
41 {
42  char c;
43  const unsigned char *ptr = p->buf;
44 
45  if (AV_RB24(ptr) == 0xEFBBBF)
46  ptr += 3; /* skip UTF-8 BOM */
47  if (sscanf(ptr, "%*u:%*u:%*u.%*u,%*u:%*u:%*u.%*u%c", &c) == 1)
49  if (!strncmp(ptr, "[INFORMATION]", 13))
50  return AVPROBE_SCORE_MAX/3;
51  return 0;
52 }
53 
54 static int get_multiplier(int e) {
55  switch (e) {
56  case 1 : return 100;
57  case 2 : return 10;
58  case 3 : return 1;
59  default : return -1;
60  }
61 }
62 
63 static int read_ts(const char *s, int64_t *start, int *duration)
64 {
65  int64_t end;
66  int hh1, mm1, ss1, ms1;
67  int hh2, mm2, ss2, ms2;
68  int multiplier1, multiplier2;
69  int ms1p1, ms1p2, ms2p1, ms2p2;
70 
71  if (sscanf(s, "%u:%u:%u.%n%u%n,%u:%u:%u.%n%u%n",
72  &hh1, &mm1, &ss1, &ms1p1, &ms1, &ms1p2, &hh2, &mm2, &ss2, &ms2p1, &ms2, &ms2p2) == 8) {
73  multiplier1 = get_multiplier(ms1p2 - ms1p1);
74  multiplier2 = get_multiplier(ms2p2 - ms2p1);
75  if (multiplier1 <= 0 ||multiplier2 <= 0)
76  return -1;
77 
78  end = (hh2*3600LL + mm2*60LL + ss2) * 1000LL + ms2 * multiplier2;
79  *start = (hh1*3600LL + mm1*60LL + ss1) * 1000LL + ms1 * multiplier1;
80  *duration = end - *start;
81  return 0;
82  }
83  return -1;
84 }
85 
87 {
88  SubViewerContext *subviewer = s->priv_data;
90  AVBPrint header;
91  int res = 0, new_event = 1;
92  int64_t pts_start = AV_NOPTS_VALUE;
93  int duration = -1;
94  AVPacket *sub = NULL;
95 
96  if (!st)
97  return AVERROR(ENOMEM);
98  res = ffio_ensure_seekback(s->pb, 3);
99  if (res < 0)
100  return res;
101  if (avio_rb24(s->pb) != 0xefbbbf)
102  avio_seek(s->pb, -3, SEEK_CUR);
103  avpriv_set_pts_info(st, 64, 1, 1000);
106 
108 
109  while (!avio_feof(s->pb)) {
110  char line[2048];
111  int64_t pos = 0;
112  int len = ff_get_line(s->pb, line, sizeof(line));
113 
114  if (!len)
115  break;
116 
117  line[strcspn(line, "\r\n")] = 0;
118 
119  if (line[0] == '[' && strncmp(line, "[br]", 4)) {
120 
121  /* ignore event style, XXX: add to side_data? */
122  if (strstr(line, "[COLF]") || strstr(line, "[SIZE]") ||
123  strstr(line, "[FONT]") || strstr(line, "[STYLE]"))
124  continue;
125 
126  if (!st->codecpar->extradata) { // header not finalized yet
127  av_bprintf(&header, "%s\n", line);
128  if (!strncmp(line, "[END INFORMATION]", 17) || !strncmp(line, "[SUBTITLE]", 10)) {
129  /* end of header */
131  if (res < 0)
132  goto end;
133  } else if (strncmp(line, "[INFORMATION]", 13)) {
134  /* assume file metadata at this point */
135  int i, j = 0;
136  char key[32], value[128];
137 
138  for (i = 1; i < sizeof(key) - 1 && line[i] && line[i] != ']'; i++)
139  key[i - 1] = av_tolower(line[i]);
140  key[i - 1] = 0;
141 
142  if (line[i] == ']')
143  i++;
144  while (line[i] == ' ')
145  i++;
146  while (j < sizeof(value) - 1 && line[i] && line[i] != ']')
147  value[j++] = line[i++];
148  value[j] = 0;
149 
150  av_dict_set(&s->metadata, key, value, 0);
151  }
152  }
153  } else if (read_ts(line, &pts_start, &duration) >= 0) {
154  new_event = 1;
155  pos = avio_tell(s->pb);
156  } else if (*line) {
157  if (pts_start == AV_NOPTS_VALUE) {
158  res = AVERROR_INVALIDDATA;
159  goto end;
160  }
161  if (!new_event) {
162  sub = ff_subtitles_queue_insert(&subviewer->q, "\n", 1, 1);
163  if (!sub) {
164  res = AVERROR(ENOMEM);
165  goto end;
166  }
167  }
168  sub = ff_subtitles_queue_insert(&subviewer->q, line, strlen(line), !new_event);
169  if (!sub) {
170  res = AVERROR(ENOMEM);
171  goto end;
172  }
173  if (new_event) {
174  sub->pos = pos;
175  sub->pts = pts_start;
176  sub->duration = duration;
177  }
178  new_event = 0;
179  }
180  }
181 
182  ff_subtitles_queue_finalize(s, &subviewer->q);
183 
184 end:
185  if (res < 0)
186  ff_subtitles_queue_clean(&subviewer->q);
188  return res;
189 }
190 
192 {
193  SubViewerContext *subviewer = s->priv_data;
194  return ff_subtitles_queue_read_packet(&subviewer->q, pkt);
195 }
196 
197 static int subviewer_read_seek(AVFormatContext *s, int stream_index,
198  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
199 {
200  SubViewerContext *subviewer = s->priv_data;
201  return ff_subtitles_queue_seek(&subviewer->q, s, stream_index,
202  min_ts, ts, max_ts, flags);
203 }
204 
206 {
207  SubViewerContext *subviewer = s->priv_data;
208  ff_subtitles_queue_clean(&subviewer->q);
209  return 0;
210 }
211 
213  .name = "subviewer",
214  .long_name = NULL_IF_CONFIG_SMALL("SubViewer subtitle format"),
215  .priv_data_size = sizeof(SubViewerContext),
219  .read_seek2 = subviewer_read_seek,
221  .extensions = "sub",
222 };
Main libavformat public API header.
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:451
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:253
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:364
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
unsigned int avio_rb24(AVIOContext *s)
Definition: aviobuf.c:774
int ffio_ensure_seekback(AVIOContext *s, int64_t buf_size)
Ensures that the requested seekback buffer size will be available.
Definition: aviobuf.c:998
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
int ff_get_line(AVIOContext *s, char *buf, int maxlen)
Read a whole line of text from AVIOContext.
Definition: aviobuf.c:789
#define AV_RB24
Definition: intreadwrite.h:64
void av_bprintf(AVBPrint *buf, const char *fmt,...)
Definition: bprint.c:94
void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max)
Definition: bprint.c:69
int av_bprint_finalize(AVBPrint *buf, char **ret_str)
Finalize a print buffer.
Definition: bprint.c:235
#define AV_BPRINT_SIZE_UNLIMITED
#define flags(name, subs,...)
Definition: cbs_av1.c:561
#define s(width, name)
Definition: cbs_vp9.c:257
#define NULL
Definition: coverity.c:32
static float sub(float src0, float src1)
double value
Definition: eval.c:98
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:545
@ AV_CODEC_ID_SUBVIEWER
Definition: codec_id.h:540
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4509
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:70
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#define AVERROR(e)
Definition: error.h:43
@ AVMEDIA_TYPE_SUBTITLE
Definition: avutil.h:204
static av_const int av_tolower(int c)
Locale-independent conversion of ASCII characters to lowercase.
Definition: avstring.h:246
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
const char * key
int i
Definition: input.c:407
common internal api header.
int ff_bprint_to_codecpar_extradata(AVCodecParameters *par, struct AVBPrint *buf)
Finalize buf into extradata and set its size appropriately.
Definition: utils.c:5755
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:4945
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
static int subviewer_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: subviewerdec.c:191
static int subviewer_read_close(AVFormatContext *s)
Definition: subviewerdec.c:205
static int get_multiplier(int e)
Definition: subviewerdec.c:54
static int read_ts(const char *s, int64_t *start, int *duration)
Definition: subviewerdec.c:63
static int subviewer_probe(const AVProbeData *p)
Definition: subviewerdec.c:40
static int subviewer_read_header(AVFormatContext *s)
Definition: subviewerdec.c:86
static int subviewer_read_seek(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Definition: subviewerdec.c:197
AVInputFormat ff_subviewer_demuxer
Definition: subviewerdec.c:212
common internal API header
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
static const uint8_t header[24]
Definition: sdr2.c:67
unsigned int pos
Definition: spdifenc.c:412
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: codec_par.h:74
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
Format I/O context.
Definition: avformat.h:1232
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:645
This structure stores compressed data.
Definition: packet.h:346
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
Stream structure.
Definition: avformat.h:873
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1038
FFDemuxSubtitlesQueue q
Definition: subviewerdec.c:37
Definition: graph2dot.c:48
int ff_subtitles_queue_seek(FFDemuxSubtitlesQueue *q, AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Update current_sub_idx to emulate a seek.
Definition: subtitles.c:255
int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q, AVPacket *pkt)
Generic read_packet() callback for subtitles demuxers using this queue system.
Definition: subtitles.c:216
void ff_subtitles_queue_finalize(void *log_ctx, FFDemuxSubtitlesQueue *q)
Set missing durations, sort subtitles by PTS (and then byte position), and drop duplicated events.
Definition: subtitles.c:198
void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q)
Remove and destroy all the subtitles packets.
Definition: subtitles.c:307
AVPacket * ff_subtitles_queue_insert(FFDemuxSubtitlesQueue *q, const uint8_t *event, size_t len, int merge)
Insert a new subtitle event.
Definition: subtitles.c:111
int64_t duration
Definition: movenc.c:64
AVPacket * pkt
Definition: movenc.c:59
int len
static double c[64]