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/jacosub.h"
32 #include "libavutil/avstring.h"
33 #include "libavutil/bprint.h"
34 #include "libavutil/intreadwrite.h"
35 
36 typedef struct {
38  int shift;
39  unsigned timeres;
41 
42 static int timed_line(const char *ptr)
43 {
44  char c;
45  int fs, fe;
46  return (sscanf(ptr, "%*u:%*u:%*u.%*u %*u:%*u:%*u.%*u %c", &c) == 1 ||
47  (sscanf(ptr, "@%u @%u %c", &fs, &fe, &c) == 3 && fs < fe));
48 }
49 
50 static int jacosub_probe(const AVProbeData *p)
51 {
52  const char *ptr = p->buf;
53  const char *ptr_end = p->buf + p->buf_size;
54 
55  if (AV_RB24(ptr) == 0xEFBBBF)
56  ptr += 3; /* skip UTF-8 BOM */
57 
58  while (ptr < ptr_end) {
59  while (jss_whitespace(*ptr))
60  ptr++;
61  if (*ptr != '#' && *ptr != '\n') {
62  if (timed_line(ptr))
63  return AVPROBE_SCORE_EXTENSION + 1;
64  return 0;
65  }
66  ptr += ff_subtitles_next_line(ptr);
67  }
68  return 0;
69 }
70 
71 static const char * const cmds[] = {
72  "CLOCKPAUSE",
73  "DIRECTIVE",
74  "FONT",
75  "HRES",
76  "INCLUDE",
77  "PALETTE",
78  "QUANTIZE",
79  "RAMP",
80  "SHIFT",
81  "TIMERES",
82 };
83 
84 static int get_jss_cmd(char k)
85 {
86  int i;
87 
88  k = av_toupper(k);
89  for (i = 0; i < FF_ARRAY_ELEMS(cmds); i++)
90  if (k == cmds[i][0])
91  return i;
92  return -1;
93 }
94 
95 static const char *read_ts(JACOsubContext *jacosub, const char *buf,
96  int64_t *start, int64_t *duration)
97 {
98  int len;
99  unsigned hs, ms, ss, fs; // hours, minutes, seconds, frame start
100  unsigned he, me, se, fe; // hours, minutes, seconds, frame end
101  int ts_start, ts_end;
102  int64_t ts_start64, ts_end64;
103 
104  /* timed format */
105  if (sscanf(buf, "%u:%u:%u.%u %u:%u:%u.%u %n",
106  &hs, &ms, &ss, &fs,
107  &he, &me, &se, &fe, &len) == 8) {
108  ts_start = (hs*3600 + ms*60 + ss) * jacosub->timeres + fs;
109  ts_end = (he*3600 + me*60 + se) * jacosub->timeres + fe;
110  goto shift_and_ret;
111  }
112 
113  /* timestamps format */
114  if (sscanf(buf, "@%u @%u %n", &ts_start, &ts_end, &len) == 2)
115  goto shift_and_ret;
116 
117  return NULL;
118 
119 shift_and_ret:
120  ts_start64 = (ts_start + (int64_t)jacosub->shift) * 100LL / jacosub->timeres;
121  ts_end64 = (ts_end + (int64_t)jacosub->shift) * 100LL / jacosub->timeres;
122  *start = ts_start64;
123  *duration = ts_end64 - ts_start64;
124  return buf + len;
125 }
126 
127 static int get_shift(unsigned timeres, const char *buf)
128 {
129  int sign = 1;
130  int a = 0, b = 0, c = 0, d = 0;
131  int64_t ret;
132 #define SSEP "%*1[.:]"
133  int n = sscanf(buf, "%d"SSEP"%d"SSEP"%d"SSEP"%d", &a, &b, &c, &d);
134 #undef SSEP
135 
136  if (a == INT_MIN)
137  return 0;
138 
139  if (*buf == '-' || a < 0) {
140  sign = -1;
141  a = FFABS(a);
142  }
143 
144  ret = 0;
145  switch (n) {
146  case 1: a = 0;
147  case 2: c = b; b = a; a = 0;
148  case 3: d = c; c = b; b = a; a = 0;
149  }
150 
151  ret = (int64_t)a*3600 + (int64_t)b*60 + c;
152  if (FFABS(ret) > (INT64_MAX - FFABS(d)) / timeres)
153  return 0;
154  ret = sign * (ret * timeres + d);
155 
156  if ((int)ret != ret)
157  ret = 0;
158 
159  return ret;
160 }
161 
163 {
164  AVBPrint header;
165  AVIOContext *pb = s->pb;
166  char line[JSS_MAX_LINESIZE];
167  JACOsubContext *jacosub = s->priv_data;
168  int shift_set = 0; // only the first shift matters
169  int merge_line = 0;
170  int i, ret;
171 
173  if (!st)
174  return AVERROR(ENOMEM);
175  avpriv_set_pts_info(st, 64, 1, 100);
178 
179  jacosub->timeres = 30;
180 
182 
183  while (!avio_feof(pb)) {
184  int cmd_len;
185  const char *p = line;
186  int64_t pos = avio_tell(pb);
187  int len = ff_get_line(pb, line, sizeof(line));
188 
189  p = jss_skip_whitespace(p);
190 
191  /* queue timed line */
192  if (merge_line || timed_line(p)) {
193  AVPacket *sub;
194 
195  sub = ff_subtitles_queue_insert(&jacosub->q, line, len, merge_line);
196  if (!sub) {
198  return AVERROR(ENOMEM);
199  }
200  sub->pos = pos;
201  merge_line = len > 1 && !strcmp(&line[len - 2], "\\\n");
202  continue;
203  }
204 
205  /* skip all non-compiler commands and focus on the command */
206  if (*p != '#')
207  continue;
208  p++;
209  i = get_jss_cmd(p[0]);
210  if (i == -1)
211  continue;
212 
213  /* trim command + spaces */
214  cmd_len = strlen(cmds[i]);
215  if (av_strncasecmp(p, cmds[i], cmd_len) == 0)
216  p += cmd_len;
217  else
218  p++;
219  p = jss_skip_whitespace(p);
220 
221  /* handle commands which affect the whole script */
222  switch (cmds[i][0]) {
223  case 'S': // SHIFT command affect the whole script...
224  if (!shift_set) {
225  jacosub->shift = get_shift(jacosub->timeres, p);
226  shift_set = 1;
227  }
228  av_bprintf(&header, "#S %s", p);
229  break;
230  case 'T': { // ...but must be placed after TIMERES
231  int64_t timeres = strtol(p, NULL, 10);
232  if (timeres <= 0 || timeres > UINT32_MAX) {
233  jacosub->timeres = 30;
234  } else {
235  jacosub->timeres = timeres;
236  av_bprintf(&header, "#T %s", p);
237  }
238  break;
239  }
240  }
241  }
242 
243  /* general/essential directives in the extradata */
245  if (ret < 0)
246  return ret;
247 
248  /* SHIFT and TIMERES affect the whole script so packet timing can only be
249  * done in a second pass */
250  for (i = 0; i < jacosub->q.nb_subs; i++) {
251  AVPacket *sub = jacosub->q.subs[i];
252  read_ts(jacosub, sub->data, &sub->pts, &sub->duration);
253  }
254  ff_subtitles_queue_finalize(s, &jacosub->q);
255 
256  return 0;
257 }
258 
260  .name = "jacosub",
261  .long_name = NULL_IF_CONFIG_SMALL("JACOsub subtitle format"),
262  .priv_data_size = sizeof(JACOsubContext),
263  .flags_internal = FF_FMT_INIT_CLEANUP,
267  .read_seek2 = ff_subtitles_read_seek,
269 };
AVMEDIA_TYPE_SUBTITLE
@ AVMEDIA_TYPE_SUBTITLE
Definition: avutil.h:204
ff_subtitles_read_close
int ff_subtitles_read_close(AVFormatContext *s)
Definition: subtitles.c:337
FF_FMT_INIT_CLEANUP
#define FF_FMT_INIT_CLEANUP
For an AVInputFormat with this flag set read_close() needs to be called by the caller upon read_heade...
Definition: internal.h:46
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
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:51
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:84
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const struct AVCodec *c)
Add a new stream to a media file.
FFDemuxSubtitlesQueue::nb_subs
int nb_subs
number of subtitles packets
Definition: subtitles.h:105
se
#define se(name, range_min, range_max)
Definition: cbs_h2645.c:259
AVPacket::data
uint8_t * data
Definition: packet.h:522
b
#define b
Definition: input.c:41
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:540
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:455
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:584
get_shift
static int get_shift(unsigned timeres, const char *buf)
Definition: jacosubdec.c:127
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:843
read_close
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:143
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:513
JSS_MAX_LINESIZE
#define JSS_MAX_LINESIZE
Definition: jacosub.h:31
AV_CODEC_ID_JACOSUB
@ AV_CODEC_ID_JACOSUB
Definition: codec_id.h:563
ss
#define ss(width, name, subs,...)
Definition: cbs_vp9.c:202
AVInputFormat
Definition: avformat.h:549
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:162
ff_subtitles_read_packet
int ff_subtitles_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: subtitles.c:323
duration
int64_t duration
Definition: movenc.c:64
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_read_callback.c:41
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:198
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:554
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:454
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:36
AVFormatContext
Format I/O context.
Definition: avformat.h:1363
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:864
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:550
NULL
#define NULL
Definition: coverity.c:32
fs
#define fs(width, name, subs,...)
Definition: cbs_vp9.c:200
cmds
static const char *const cmds[]
Definition: jacosubdec.c:71
me
#define me
Definition: vf_colormatrix.c:102
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:452
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:109
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:462
jacosub_probe
static int jacosub_probe(const AVProbeData *p)
Definition: jacosubdec.c:50
jacosub.h
av_strncasecmp
int av_strncasecmp(const char *a, const char *b, size_t n)
Locale-independent case-insensitive compare.
Definition: avstring.c:217
AVIOContext
Bytestream IO Context.
Definition: avio.h:166
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:106
av_bprint_finalize
int av_bprint_finalize(AVBPrint *buf, char **ret_str)
Finalize a print buffer.
Definition: bprint.c:240
jss_whitespace
static av_always_inline int jss_whitespace(char c)
Definition: jacosub.h:33
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:204
FFDemuxSubtitlesQueue
Definition: subtitles.h:103
header
static const uint8_t header[24]
Definition: sdr2.c:67
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
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
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:255
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:515
FFDemuxSubtitlesQueue::subs
AVPacket ** subs
array of subtitles packets
Definition: subtitles.h:104
JACOsubContext::q
FFDemuxSubtitlesQueue q
Definition: jacosubdec.c:37
av_toupper
static av_const int av_toupper(int c)
Locale-independent conversion of ASCII characters to uppercase.
Definition: avstring.h:227
ff_subtitles_read_seek
int ff_subtitles_read_seek(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Definition: subtitles.c:329
ff_get_line
int ff_get_line(AVIOContext *s, char *buf, int maxlen)
Read a whole line of text from AVIOContext.
Definition: aviobuf.c:816
len
int len
Definition: vorbis_enc_data.h:426
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:841
pos
unsigned int pos
Definition: spdifenc.c:413
avformat.h
av_bprintf
void av_bprintf(AVBPrint *buf, const char *fmt,...)
Definition: bprint.c:99
AV_INPUT_BUFFER_PADDING_SIZE
#define AV_INPUT_BUFFER_PADDING_SIZE
Definition: defs.h:40
subtitles.h
read_ts
static const char * read_ts(JACOsubContext *jacosub, const char *buf, int64_t *start, int64_t *duration)
Definition: jacosubdec.c:95
read_probe
static int read_probe(const AVProbeData *p)
Definition: cdg.c:29
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:55
AVPacket
This structure stores compressed data.
Definition: packet.h:499
JACOsubContext::timeres
unsigned timeres
Definition: jacosubdec.c:39
AVPacket::pos
int64_t pos
byte position in stream, -1 if unknown
Definition: packet.h:542
d
d
Definition: ffmpeg_filter.c:424
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:205
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:42
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:393
ff_jacosub_demuxer
const AVInputFormat ff_jacosub_demuxer
Definition: jacosubdec.c:259