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 + (int64_t)jacosub->shift) * 100LL / jacosub->timeres;
129  ts_end64 = (ts_end + (int64_t)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  int64_t ret;
140 #define SSEP "%*1[.:]"
141  int n = sscanf(buf, "%d"SSEP"%d"SSEP"%d"SSEP"%d", &a, &b, &c, &d);
142 #undef SSEP
143 
144  if (*buf == '-' || a < 0) {
145  sign = -1;
146  a = FFABS(a);
147  }
148 
149  ret = 0;
150  switch (n) {
151  case 4:
152  ret = sign * (((int64_t)a*3600 + b*60 + c) * timeres + d);
153  break;
154  case 3:
155  ret = sign * (( (int64_t)a*60 + b) * timeres + c);
156  break;
157  case 2:
158  ret = sign * (( (int64_t)a) * timeres + b);
159  break;
160  }
161  if ((int)ret != ret)
162  ret = 0;
163 
164  return ret;
165 }
166 
168 {
169  AVBPrint header;
170  AVIOContext *pb = s->pb;
171  char line[JSS_MAX_LINESIZE];
172  JACOsubContext *jacosub = s->priv_data;
173  int shift_set = 0; // only the first shift matters
174  int merge_line = 0;
175  int i, ret;
176 
178  if (!st)
179  return AVERROR(ENOMEM);
180  avpriv_set_pts_info(st, 64, 1, 100);
183 
184  jacosub->timeres = 30;
185 
187 
188  while (!avio_feof(pb)) {
189  int cmd_len;
190  const char *p = line;
191  int64_t pos = avio_tell(pb);
192  int len = ff_get_line(pb, line, sizeof(line));
193 
194  p = jss_skip_whitespace(p);
195 
196  /* queue timed line */
197  if (merge_line || timed_line(p)) {
198  AVPacket *sub;
199 
200  sub = ff_subtitles_queue_insert(&jacosub->q, line, len, merge_line);
201  if (!sub) {
203  ret = AVERROR(ENOMEM);
204  goto fail;
205  }
206  sub->pos = pos;
207  merge_line = len > 1 && !strcmp(&line[len - 2], "\\\n");
208  continue;
209  }
210 
211  /* skip all non-compiler commands and focus on the command */
212  if (*p != '#')
213  continue;
214  p++;
215  i = get_jss_cmd(p[0]);
216  if (i == -1)
217  continue;
218 
219  /* trim command + spaces */
220  cmd_len = strlen(cmds[i]);
221  if (av_strncasecmp(p, cmds[i], cmd_len) == 0)
222  p += cmd_len;
223  else
224  p++;
225  p = jss_skip_whitespace(p);
226 
227  /* handle commands which affect the whole script */
228  switch (cmds[i][0]) {
229  case 'S': // SHIFT command affect the whole script...
230  if (!shift_set) {
231  jacosub->shift = get_shift(jacosub->timeres, p);
232  shift_set = 1;
233  }
234  av_bprintf(&header, "#S %s", p);
235  break;
236  case 'T': // ...but must be placed after TIMERES
237  jacosub->timeres = strtol(p, NULL, 10);
238  if (!jacosub->timeres)
239  jacosub->timeres = 30;
240  else
241  av_bprintf(&header, "#T %s", p);
242  break;
243  }
244  }
245 
246  /* general/essential directives in the extradata */
248  if (ret < 0)
249  goto fail;
250 
251  /* SHIFT and TIMERES affect the whole script so packet timing can only be
252  * done in a second pass */
253  for (i = 0; i < jacosub->q.nb_subs; i++) {
254  AVPacket *sub = jacosub->q.subs[i];
255  read_ts(jacosub, sub->data, &sub->pts, &sub->duration);
256  }
257  ff_subtitles_queue_finalize(s, &jacosub->q);
258 
259  return 0;
260 fail:
262  return ret;
263 }
264 
266 {
267  JACOsubContext *jacosub = s->priv_data;
268  return ff_subtitles_queue_read_packet(&jacosub->q, pkt);
269 }
270 
271 static int jacosub_read_seek(AVFormatContext *s, int stream_index,
272  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
273 {
274  JACOsubContext *jacosub = s->priv_data;
275  return ff_subtitles_queue_seek(&jacosub->q, s, stream_index,
276  min_ts, ts, max_ts, flags);
277 }
278 
280  .name = "jacosub",
281  .long_name = NULL_IF_CONFIG_SMALL("JACOsub subtitle format"),
282  .priv_data_size = sizeof(JACOsubContext),
286  .read_seek2 = jacosub_read_seek,
288 };
AVMEDIA_TYPE_SUBTITLE
@ AVMEDIA_TYPE_SUBTITLE
Definition: avutil.h:204
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
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4374
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
av_bprint_finalize
int av_bprint_finalize(AVBPrint *buf, char **ret_str)
Finalize a print buffer.
Definition: bprint.c:235
av_bprint_init
void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max)
Definition: bprint.c:69
get_jss_cmd
static int get_jss_cmd(char k)
Definition: jacosubdec.c:85
sub
static float sub(float src0, float src1)
Definition: dnn_backend_native_layer_mathbinary.c:32
FFDemuxSubtitlesQueue::nb_subs
int nb_subs
number of subtitles packets
Definition: subtitles.h:104
se
#define se(name, range_min, range_max)
Definition: cbs_h2645.c:275
internal.h
b
#define b
Definition: input.c:41
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
ff_bprint_to_codecpar_extradata
int ff_bprint_to_codecpar_extradata(AVCodecParameters *par, struct AVBPrint *buf)
Finalize buf into extradata and set its size appropriately.
Definition: utils.c:5515
fail
#define fail()
Definition: checkasm.h:134
read_close
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
JSS_MAX_LINESIZE
#define JSS_MAX_LINESIZE
Definition: jacosub.h:31
AV_CODEC_ID_JACOSUB
@ AV_CODEC_ID_JACOSUB
Definition: codec_id.h:529
ss
#define ss(width, name, subs,...)
Definition: cbs_vp9.c:261
jacosub_read_packet
static int jacosub_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: jacosubdec.c:265
ff_subtitles_queue_seek
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
pkt
AVPacket * pkt
Definition: movenc.c:59
jacosub_read_seek
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:271
AVInputFormat
Definition: avformat.h:616
FF_ARRAY_ELEMS
#define FF_ARRAY_ELEMS(a)
Definition: sinewin_tablegen.c:29
jacosub_read_header
static int jacosub_read_header(AVFormatContext *s)
Definition: jacosubdec.c:167
duration
int64_t duration
Definition: movenc.c:64
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:257
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:621
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
ff_subtitles_queue_read_packet
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
FFABS
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:72
JACOsubContext
Definition: jacosubdec.c:37
AVFormatContext
Format I/O context.
Definition: avformat.h:1106
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:979
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:527
NULL
#define NULL
Definition: coverity.c:32
read_probe
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
fs
#define fs(width, name, subs,...)
Definition: cbs_vp9.c:259
cmds
static const char *const cmds[]
Definition: jacosubdec.c:72
me
#define me
Definition: vf_colormatrix.c:104
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
ff_subtitles_queue_insert
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
c
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
AVPROBE_SCORE_EXTENSION
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:451
jacosub_probe
static int jacosub_probe(const AVProbeData *p)
Definition: jacosubdec.c:51
jacosub.h
av_strncasecmp
int av_strncasecmp(const char *a, const char *b, size_t n)
Locale-independent case-insensitive compare.
Definition: avstring.c:225
AVIOContext
Bytestream IO Context.
Definition: avio.h:161
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
jss_whitespace
static av_always_inline int jss_whitespace(char c)
Definition: jacosub.h:33
avpriv_set_pts_info
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:4799
ff_subtitles_queue_finalize
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
FFDemuxSubtitlesQueue
Definition: subtitles.h:102
header
static const uint8_t header[24]
Definition: sdr2.c:67
get_shift
static int get_shift(int timeres, const char *buf)
Definition: jacosubdec.c:135
a
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:41
ff_subtitles_queue_clean
void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q)
Remove and destroy all the subtitles packets.
Definition: subtitles.c:307
JACOsubContext::shift
int shift
Definition: jacosubdec.c:38
line
Definition: graph2dot.c:48
jss_skip_whitespace
static const av_always_inline char * jss_skip_whitespace(const char *p)
Definition: jacosub.h:38
SSEP
#define SSEP
bprint.h
i
int i
Definition: input.c:407
FFDemuxSubtitlesQueue::subs
AVPacket ** subs
array of subtitles packets
Definition: subtitles.h:103
JACOsubContext::q
FFDemuxSubtitlesQueue q
Definition: jacosubdec.c:40
jacosub_read_close
static int jacosub_read_close(AVFormatContext *s)
Definition: jacosubdec.c:96
av_toupper
static av_const int av_toupper(int c)
Locale-independent conversion of ASCII characters to uppercase.
Definition: avstring.h:236
ff_get_line
int ff_get_line(AVIOContext *s, char *buf, int maxlen)
Read a whole line of text from AVIOContext.
Definition: aviobuf.c:772
len
int len
Definition: vorbis_enc_data.h:452
ret
ret
Definition: filter_design.txt:187
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
AVStream
Stream structure.
Definition: avformat.h:832
pos
unsigned int pos
Definition: spdifenc.c:412
avformat.h
av_bprintf
void av_bprintf(AVBPrint *buf, const char *fmt,...)
Definition: bprint.c:94
AV_INPUT_BUFFER_PADDING_SIZE
#define AV_INPUT_BUFFER_PADDING_SIZE
Definition: avcodec.h:192
subtitles.h
read_ts
static const char * read_ts(JACOsubContext *jacosub, const char *buf, int64_t *start, int64_t *duration)
Definition: jacosubdec.c:103
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:342
JACOsubContext::timeres
unsigned timeres
Definition: jacosubdec.c:39
d
d
Definition: ffmpeg_filter.c:156
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
ff_subtitles_next_line
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
avstring.h
AV_RB24
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:97
line
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:40
timed_line
static int timed_line(const char *ptr)
Definition: jacosubdec.c:43
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:354
ff_jacosub_demuxer
const AVInputFormat ff_jacosub_demuxer
Definition: jacosubdec.c:279