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 
111  /* timed format */
112  if (sscanf(buf, "%u:%u:%u.%u %u:%u:%u.%u %n",
113  &hs, &ms, &ss, &fs,
114  &he, &me, &se, &fe, &len) == 8) {
115  ts_start = (hs*3600 + ms*60 + ss) * jacosub->timeres + fs;
116  ts_end = (he*3600 + me*60 + se) * jacosub->timeres + fe;
117  goto shift_and_ret;
118  }
119 
120  /* timestamps format */
121  if (sscanf(buf, "@%u @%u %n", &ts_start, &ts_end, &len) == 2)
122  goto shift_and_ret;
123 
124  return NULL;
125 
126 shift_and_ret:
127  ts_start = (ts_start + jacosub->shift) * 100 / jacosub->timeres;
128  ts_end = (ts_end + jacosub->shift) * 100 / jacosub->timeres;
129  *start = ts_start;
130  *duration = ts_end - ts_start;
131  return buf + len;
132 }
133 
134 static int get_shift(int timeres, const char *buf)
135 {
136  int sign = 1;
137  int a = 0, b = 0, c = 0, d = 0;
138 #define SSEP "%*1[.:]"
139  int n = sscanf(buf, "%d"SSEP"%d"SSEP"%d"SSEP"%d", &a, &b, &c, &d);
140 #undef SSEP
141 
142  if (*buf == '-' || a < 0) {
143  sign = -1;
144  a = FFABS(a);
145  }
146 
147  switch (n) {
148  case 4: return sign * ((a*3600 + b*60 + c) * timeres + d);
149  case 3: return sign * (( a*60 + b) * timeres + c);
150  case 2: return sign * (( a) * timeres + b);
151  }
152 
153  return 0;
154 }
155 
157 {
158  AVBPrint header;
159  AVIOContext *pb = s->pb;
160  char line[JSS_MAX_LINESIZE];
161  JACOsubContext *jacosub = s->priv_data;
162  int shift_set = 0; // only the first shift matters
163  int merge_line = 0;
164  int i, ret;
165 
167  if (!st)
168  return AVERROR(ENOMEM);
169  avpriv_set_pts_info(st, 64, 1, 100);
172 
173  jacosub->timeres = 30;
174 
175  av_bprint_init(&header, 1024+AV_INPUT_BUFFER_PADDING_SIZE, 4096);
176 
177  while (!avio_feof(pb)) {
178  int cmd_len;
179  const char *p = line;
180  int64_t pos = avio_tell(pb);
181  int len = ff_get_line(pb, line, sizeof(line));
182 
183  p = jss_skip_whitespace(p);
184 
185  /* queue timed line */
186  if (merge_line || timed_line(p)) {
187  AVPacket *sub;
188 
189  sub = ff_subtitles_queue_insert(&jacosub->q, line, len, merge_line);
190  if (!sub)
191  return AVERROR(ENOMEM);
192  sub->pos = pos;
193  merge_line = len > 1 && !strcmp(&line[len - 2], "\\\n");
194  continue;
195  }
196 
197  /* skip all non-compiler commands and focus on the command */
198  if (*p != '#')
199  continue;
200  p++;
201  i = get_jss_cmd(p[0]);
202  if (i == -1)
203  continue;
204 
205  /* trim command + spaces */
206  cmd_len = strlen(cmds[i]);
207  if (av_strncasecmp(p, cmds[i], cmd_len) == 0)
208  p += cmd_len;
209  else
210  p++;
211  p = jss_skip_whitespace(p);
212 
213  /* handle commands which affect the whole script */
214  switch (cmds[i][0]) {
215  case 'S': // SHIFT command affect the whole script...
216  if (!shift_set) {
217  jacosub->shift = get_shift(jacosub->timeres, p);
218  shift_set = 1;
219  }
220  av_bprintf(&header, "#S %s", p);
221  break;
222  case 'T': // ...but must be placed after TIMERES
223  jacosub->timeres = strtol(p, NULL, 10);
224  if (!jacosub->timeres)
225  jacosub->timeres = 30;
226  else
227  av_bprintf(&header, "#T %s", p);
228  break;
229  }
230  }
231 
232  /* general/essential directives in the extradata */
233  ret = ff_bprint_to_codecpar_extradata(st->codecpar, &header);
234  if (ret < 0)
235  goto fail;
236 
237  /* SHIFT and TIMERES affect the whole script so packet timing can only be
238  * done in a second pass */
239  for (i = 0; i < jacosub->q.nb_subs; i++) {
240  AVPacket *sub = &jacosub->q.subs[i];
241  read_ts(jacosub, sub->data, &sub->pts, &sub->duration);
242  }
243  ff_subtitles_queue_finalize(s, &jacosub->q);
244 
245  return 0;
246 fail:
248  return ret;
249 }
250 
252 {
253  JACOsubContext *jacosub = s->priv_data;
254  return ff_subtitles_queue_read_packet(&jacosub->q, pkt);
255 }
256 
257 static int jacosub_read_seek(AVFormatContext *s, int stream_index,
258  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
259 {
260  JACOsubContext *jacosub = s->priv_data;
261  return ff_subtitles_queue_seek(&jacosub->q, s, stream_index,
262  min_ts, ts, max_ts, flags);
263 }
264 
266  .name = "jacosub",
267  .long_name = NULL_IF_CONFIG_SMALL("JACOsub subtitle format"),
268  .priv_data_size = sizeof(JACOsubContext),
272  .read_seek2 = jacosub_read_seek,
274 };
#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:264
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1497
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:4882
static int jacosub_read_header(AVFormatContext *s)
Definition: jacosubdec.c:156
#define me
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3953
void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q)
Remove and destroy all the subtitles packets.
Definition: subtitles.c:297
int av_strncasecmp(const char *a, const char *b, size_t n)
Locale-independent case-insensitive compare.
Definition: avstring.c:223
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:1358
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:208
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1495
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:4455
int64_t duration
Definition: movenc.c:63
uint8_t * data
Definition: avcodec.h:1477
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
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:260
static int get_shift(int timeres, const char *buf)
Definition: jacosubdec.c:134
#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:186
void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max)
Definition: bprint.c:69
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3949
Definition: graph2dot.c:48
#define fail()
Definition: checkasm.h:120
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:449
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:448
#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:257
#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 n
Definition: avisynth_c.h:760
int ff_get_line(AVIOContext *s, char *buf, int maxlen)
Read a whole line of text from AVIOContext.
Definition: aviobuf.c:809
#define FF_ARRAY_ELEMS(a)
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
Stream structure.
Definition: avformat.h:881
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:245
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:87
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
AVInputFormat ff_jacosub_demuxer
Definition: jacosubdec.c:265
static int jacosub_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: jacosubdec.c:251
unsigned timeres
Definition: jacosubdec.c:39
void * buf
Definition: avisynth_c.h:766
static av_const int av_toupper(int c)
Locale-independent conversion of ASCII characters to uppercase.
Definition: avstring.h:231
int ff_bprint_to_codecpar_extradata(AVCodecParameters *par, struct AVBPrint *buf)
Finalize buf into extradata and set its size appropriately.
Definition: utils.c:5700
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:456
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
#define flags(name, subs,...)
Definition: cbs_av1.c:561
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:790
int len
void * priv_data
Format private data.
Definition: avformat.h:1386
void INT64 start
Definition: avisynth_c.h:766
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:358
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: avcodec.h:1454
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:193
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1470