FFmpeg
jacosubdec.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  * JACOsub subtitle demuxer
24  * @see http://unicorn.us.com/jacosub/jscripts.html
25  * @todo Support P[ALETTE] directive.
26  */
27 
28 #include "avformat.h"
29 #include "internal.h"
30 #include "subtitles.h"
31 #include "libavcodec/internal.h"
32 #include "libavcodec/jacosub.h"
33 #include "libavutil/avstring.h"
34 #include "libavutil/bprint.h"
35 #include "libavutil/intreadwrite.h"
36 
37 typedef struct {
38  int shift;
39  unsigned timeres;
42 
43 static int timed_line(const char *ptr)
44 {
45  char c;
46  int fs, fe;
47  return (sscanf(ptr, "%*u:%*u:%*u.%*u %*u:%*u:%*u.%*u %c", &c) == 1 ||
48  (sscanf(ptr, "@%u @%u %c", &fs, &fe, &c) == 3 && fs < fe));
49 }
50 
51 static int jacosub_probe(const AVProbeData *p)
52 {
53  const char *ptr = p->buf;
54  const char *ptr_end = p->buf + p->buf_size;
55 
56  if (AV_RB24(ptr) == 0xEFBBBF)
57  ptr += 3; /* skip UTF-8 BOM */
58 
59  while (ptr < ptr_end) {
60  while (jss_whitespace(*ptr))
61  ptr++;
62  if (*ptr != '#' && *ptr != '\n') {
63  if (timed_line(ptr))
64  return AVPROBE_SCORE_EXTENSION + 1;
65  return 0;
66  }
67  ptr += ff_subtitles_next_line(ptr);
68  }
69  return 0;
70 }
71 
72 static const char * const cmds[] = {
73  "CLOCKPAUSE",
74  "DIRECTIVE",
75  "FONT",
76  "HRES",
77  "INCLUDE",
78  "PALETTE",
79  "QUANTIZE",
80  "RAMP",
81  "SHIFT",
82  "TIMERES",
83 };
84 
85 static int get_jss_cmd(char k)
86 {
87  int i;
88 
89  k = av_toupper(k);
90  for (i = 0; i < FF_ARRAY_ELEMS(cmds); i++)
91  if (k == cmds[i][0])
92  return i;
93  return -1;
94 }
95 
97 {
98  JACOsubContext *jacosub = s->priv_data;
99  ff_subtitles_queue_clean(&jacosub->q);
100  return 0;
101 }
102 
103 static const char *read_ts(JACOsubContext *jacosub, const char *buf,
104  int64_t *start, int64_t *duration)
105 {
106  int len;
107  unsigned hs, ms, ss, fs; // hours, minutes, seconds, frame start
108  unsigned he, me, se, fe; // hours, minutes, seconds, frame end
109  int ts_start, ts_end;
110  int64_t ts_start64, ts_end64;
111 
112  /* timed format */
113  if (sscanf(buf, "%u:%u:%u.%u %u:%u:%u.%u %n",
114  &hs, &ms, &ss, &fs,
115  &he, &me, &se, &fe, &len) == 8) {
116  ts_start = (hs*3600 + ms*60 + ss) * jacosub->timeres + fs;
117  ts_end = (he*3600 + me*60 + se) * jacosub->timeres + fe;
118  goto shift_and_ret;
119  }
120 
121  /* timestamps format */
122  if (sscanf(buf, "@%u @%u %n", &ts_start, &ts_end, &len) == 2)
123  goto shift_and_ret;
124 
125  return NULL;
126 
127 shift_and_ret:
128  ts_start64 = (ts_start + jacosub->shift) * 100LL / jacosub->timeres;
129  ts_end64 = (ts_end + jacosub->shift) * 100LL / jacosub->timeres;
130  *start = ts_start64;
131  *duration = ts_end64 - ts_start64;
132  return buf + len;
133 }
134 
135 static int get_shift(int timeres, const char *buf)
136 {
137  int sign = 1;
138  int a = 0, b = 0, c = 0, d = 0;
139 #define SSEP "%*1[.:]"
140  int n = sscanf(buf, "%d"SSEP"%d"SSEP"%d"SSEP"%d", &a, &b, &c, &d);
141 #undef SSEP
142 
143  if (*buf == '-' || a < 0) {
144  sign = -1;
145  a = FFABS(a);
146  }
147 
148  switch (n) {
149  case 4: return sign * ((a*3600 + b*60 + c) * timeres + d);
150  case 3: return sign * (( a*60 + b) * timeres + c);
151  case 2: return sign * (( a) * timeres + b);
152  }
153 
154  return 0;
155 }
156 
158 {
159  AVBPrint header;
160  AVIOContext *pb = s->pb;
161  char line[JSS_MAX_LINESIZE];
162  JACOsubContext *jacosub = s->priv_data;
163  int shift_set = 0; // only the first shift matters
164  int merge_line = 0;
165  int i, ret;
166 
168  if (!st)
169  return AVERROR(ENOMEM);
170  avpriv_set_pts_info(st, 64, 1, 100);
173 
174  jacosub->timeres = 30;
175 
176  av_bprint_init(&header, 1024+AV_INPUT_BUFFER_PADDING_SIZE, 4096);
177 
178  while (!avio_feof(pb)) {
179  int cmd_len;
180  const char *p = line;
181  int64_t pos = avio_tell(pb);
182  int len = ff_get_line(pb, line, sizeof(line));
183 
184  p = jss_skip_whitespace(p);
185 
186  /* queue timed line */
187  if (merge_line || timed_line(p)) {
188  AVPacket *sub;
189 
190  sub = ff_subtitles_queue_insert(&jacosub->q, line, len, merge_line);
191  if (!sub) {
192  ret = AVERROR(ENOMEM);
193  goto fail;
194  }
195  sub->pos = pos;
196  merge_line = len > 1 && !strcmp(&line[len - 2], "\\\n");
197  continue;
198  }
199 
200  /* skip all non-compiler commands and focus on the command */
201  if (*p != '#')
202  continue;
203  p++;
204  i = get_jss_cmd(p[0]);
205  if (i == -1)
206  continue;
207 
208  /* trim command + spaces */
209  cmd_len = strlen(cmds[i]);
210  if (av_strncasecmp(p, cmds[i], cmd_len) == 0)
211  p += cmd_len;
212  else
213  p++;
214  p = jss_skip_whitespace(p);
215 
216  /* handle commands which affect the whole script */
217  switch (cmds[i][0]) {
218  case 'S': // SHIFT command affect the whole script...
219  if (!shift_set) {
220  jacosub->shift = get_shift(jacosub->timeres, p);
221  shift_set = 1;
222  }
223  av_bprintf(&header, "#S %s", p);
224  break;
225  case 'T': // ...but must be placed after TIMERES
226  jacosub->timeres = strtol(p, NULL, 10);
227  if (!jacosub->timeres)
228  jacosub->timeres = 30;
229  else
230  av_bprintf(&header, "#T %s", p);
231  break;
232  }
233  }
234 
235  /* general/essential directives in the extradata */
236  ret = ff_bprint_to_codecpar_extradata(st->codecpar, &header);
237  if (ret < 0)
238  goto fail;
239 
240  /* SHIFT and TIMERES affect the whole script so packet timing can only be
241  * done in a second pass */
242  for (i = 0; i < jacosub->q.nb_subs; i++) {
243  AVPacket *sub = &jacosub->q.subs[i];
244  read_ts(jacosub, sub->data, &sub->pts, &sub->duration);
245  }
246  ff_subtitles_queue_finalize(s, &jacosub->q);
247 
248  return 0;
249 fail:
251  return ret;
252 }
253 
255 {
256  JACOsubContext *jacosub = s->priv_data;
257  return ff_subtitles_queue_read_packet(&jacosub->q, pkt);
258 }
259 
260 static int jacosub_read_seek(AVFormatContext *s, int stream_index,
261  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
262 {
263  JACOsubContext *jacosub = s->priv_data;
264  return ff_subtitles_queue_seek(&jacosub->q, s, stream_index,
265  min_ts, ts, max_ts, flags);
266 }
267 
269  .name = "jacosub",
270  .long_name = NULL_IF_CONFIG_SMALL("JACOsub subtitle format"),
271  .priv_data_size = sizeof(JACOsubContext),
275  .read_seek2 = jacosub_read_seek,
277 };
#define NULL
Definition: coverity.c:32
Bytestream IO Context.
Definition: avio.h:161
void av_bprintf(AVBPrint *buf, const char *fmt,...)
Definition: bprint.c:94
#define se(name, range_min, range_max)
Definition: cbs_h2645.c:273
int64_t pos
byte position in stream, -1 if unknown
Definition: packet.h:383
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:4868
static int jacosub_read_header(AVFormatContext *s)
Definition: jacosubdec.c:157
#define me
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q)
Remove and destroy all the subtitles packets.
Definition: subtitles.c:302
int av_strncasecmp(const char *a, const char *b, size_t n)
Locale-independent case-insensitive compare.
Definition: avstring.c:225
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:36
JACOsub shared utils.
static AVPacket pkt
Format I/O context.
Definition: avformat.h:1355
static const char *const cmds[]
Definition: jacosubdec.c:72
#define fs(width, name, subs,...)
Definition: cbs_vp9.c:259
int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q, AVPacket *pkt)
Generic read_packet() callback for subtitles demuxers using this queue system.
Definition: subtitles.c:212
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:381
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4449
int64_t duration
Definition: movenc.c:63
uint8_t * data
Definition: packet.h:363
FFDemuxSubtitlesQueue q
Definition: jacosubdec.c:40
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
static const uint8_t header[24]
Definition: sdr2.c:67
static int get_shift(int timeres, const char *buf)
Definition: jacosubdec.c:135
#define JSS_MAX_LINESIZE
Definition: jacosub.h:31
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:153
void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max)
Definition: bprint.c:69
unsigned int pos
Definition: spdifenc.c:410
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
Definition: graph2dot.c:48
#define fail()
Definition: checkasm.h:123
static const char * read_ts(JACOsubContext *jacosub, const char *buf, int64_t *start, int64_t *duration)
Definition: jacosubdec.c:103
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
static int jacosub_read_close(AVFormatContext *s)
Definition: jacosubdec.c:96
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
#define ss(width, name, subs,...)
Definition: cbs_vp9.c:261
#define b
Definition: input.c:41
static int jacosub_read_seek(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Definition: jacosubdec.c:260
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:72
#define s(width, name)
Definition: cbs_vp9.c:257
int ff_get_line(AVIOContext *s, char *buf, int maxlen)
Read a whole line of text from AVIOContext.
Definition: aviobuf.c:791
#define FF_ARRAY_ELEMS(a)
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:527
Stream structure.
Definition: avformat.h:880
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
static av_always_inline int jss_whitespace(char c)
Definition: jacosub.h:33
static int jacosub_probe(const AVProbeData *p)
Definition: jacosubdec.c:51
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:250
static int timed_line(const char *ptr)
Definition: jacosubdec.c:43
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_RB24
Definition: bytestream.h:91
AVIOContext * pb
I/O context.
Definition: avformat.h:1397
AVInputFormat ff_jacosub_demuxer
Definition: jacosubdec.c:268
static int jacosub_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: jacosubdec.c:254
unsigned timeres
Definition: jacosubdec.c:39
static av_const int av_toupper(int c)
Locale-independent conversion of ASCII characters to uppercase.
Definition: avstring.h:236
int ff_bprint_to_codecpar_extradata(AVCodecParameters *par, struct AVBPrint *buf)
Finalize buf into extradata and set its size appropriately.
Definition: utils.c:5678
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:451
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
#define flags(name, subs,...)
Definition: cbs_av1.c:560
static av_always_inline int ff_subtitles_next_line(const char *ptr)
Get the number of characters to increment to jump to the next line, or to the end of the string...
Definition: subtitles.h:187
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
Main libavformat public API header.
static av_always_inline const char * jss_skip_whitespace(const char *p)
Definition: jacosub.h:38
The official guide to swscale for confused that consecutive non overlapping rectangles of slice_bottom special converter These generally are unscaled converters of common like for each output line the vertical scaler pulls lines from a ring buffer When the ring buffer does not contain the wanted line
Definition: swscale.txt:33
common internal api header.
AVPacket * subs
array of subtitles packets
Definition: subtitles.h:103
static int get_jss_cmd(char k)
Definition: jacosubdec.c:85
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:215
int len
void * priv_data
Format private data.
Definition: avformat.h:1383
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:652
static float sub(float src0, float src1)
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1027
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:368
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
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
#define SSEP
This structure stores compressed data.
Definition: packet.h:340
int nb_subs
number of subtitles packets
Definition: subtitles.h:104
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:194
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:356
int i
Definition: input.c:407