FFmpeg  4.4.4
htmlsubtitles.c
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1 /*
2  * Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org>
3  * Copyright (c) 2017 Clément Bœsch <u@pkh.me>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "libavutil/avassert.h"
23 #include "libavutil/avstring.h"
24 #include "libavutil/common.h"
25 #include "libavutil/parseutils.h"
26 #include "htmlsubtitles.h"
27 #include <ctype.h>
28 
29 static int html_color_parse(void *log_ctx, const char *str)
30 {
31  uint8_t rgba[4];
32  int nb_sharps = 0;
33  while (str[nb_sharps] == '#')
34  nb_sharps++;
35  str += FFMAX(0, nb_sharps - 1);
36  if (av_parse_color(rgba, str, strcspn(str, "\" >"), log_ctx) < 0)
37  return -1;
38  return rgba[0] | rgba[1] << 8 | rgba[2] << 16;
39 }
40 
41 static void rstrip_spaces_buf(AVBPrint *buf)
42 {
43  if (av_bprint_is_complete(buf))
44  while (buf->len > 0 && buf->str[buf->len - 1] == ' ')
45  buf->str[--buf->len] = 0;
46 }
47 
48 /*
49  * Fast code for scanning text enclosed in braces. Functionally
50  * equivalent to this sscanf call:
51  *
52  * sscanf(in, "{\\an%*1u}%n", &len) >= 0 && len > 0
53  */
54 static int scanbraces(const char* in) {
55  if (strncmp(in, "{\\an", 4) != 0) {
56  return 0;
57  }
58  if (!av_isdigit(in[4])) {
59  return 0;
60  }
61  if (in[5] != '}') {
62  return 0;
63  }
64  return 1;
65 }
66 
67 /* skip all {\xxx} substrings except for {\an%d}
68  and all microdvd like styles such as {Y:xxx} */
69 static void handle_open_brace(AVBPrint *dst, const char **inp, int *an, int *closing_brace_missing)
70 {
71  const char *in = *inp;
72 
73  *an += scanbraces(in);
74 
75  if (!*closing_brace_missing) {
76  if ( (*an != 1 && in[1] == '\\')
77  || (in[1] && strchr("CcFfoPSsYy", in[1]) && in[2] == ':')) {
78  char *bracep = strchr(in+2, '}');
79  if (bracep) {
80  *inp = bracep;
81  return;
82  } else
83  *closing_brace_missing = 1;
84  }
85  }
86 
87  av_bprint_chars(dst, *in, 1);
88 }
89 
90 struct font_tag {
91  char face[128];
92  int size;
93  uint32_t color;
94 };
95 
96 /*
97  * Fast code for scanning the rest of a tag. Functionally equivalent to
98  * this sscanf call:
99  *
100  * sscanf(in, "%127[^<>]>%n", buffer, lenp) == 2
101  */
102 static int scantag(const char* in, char* buffer, int* lenp) {
103  int len;
104 
105  for (len = 0; len < 128; len++) {
106  const char c = *in++;
107  switch (c) {
108  case '\0':
109  return 0;
110  case '<':
111  return 0;
112  case '>':
113  buffer[len] = '\0';
114  *lenp = len+1;
115  return 1;
116  default:
117  break;
118  }
119  buffer[len] = c;
120  }
121  return 0;
122 }
123 
124 /*
125  * The general politic of the convert is to mask unsupported tags or formatting
126  * errors (but still alert the user/subtitles writer with an error/warning)
127  * without dropping any actual text content for the final user.
128  */
129 int ff_htmlmarkup_to_ass(void *log_ctx, AVBPrint *dst, const char *in)
130 {
131  char *param, buffer[128];
132  int len, tag_close, sptr = 0, line_start = 1, an = 0, end = 0;
133  int closing_brace_missing = 0;
134  int i, likely_a_tag;
135 
136  /*
137  * state stack is only present for fonts since they are the only tags where
138  * the state is not binary. Here is a typical use case:
139  *
140  * <font color="red" size=10>
141  * red 10
142  * <font size=50> RED AND BIG </font>
143  * red 10 again
144  * </font>
145  *
146  * On the other hand, using the state system for all the tags should be
147  * avoided because it breaks wrongly nested tags such as:
148  *
149  * <b> foo <i> bar </b> bla </i>
150  *
151  * We don't want to break here; instead, we will treat all these tags as
152  * binary state markers. Basically, "<b>" will activate bold, and "</b>"
153  * will deactivate it, whatever the current state.
154  *
155  * This will also prevents cases where we have a random closing tag
156  * remaining after the opening one was dropped. Yes, this happens and we
157  * still don't want to print a "</b>" at the end of the dialog event.
158  */
159  struct font_tag stack[16];
160 
161  memset(&stack[0], 0, sizeof(stack[0]));
162 
163  for (; !end && *in; in++) {
164  switch (*in) {
165  case '\r':
166  break;
167  case '\n':
168  if (line_start) {
169  end = 1;
170  break;
171  }
172  rstrip_spaces_buf(dst);
173  av_bprintf(dst, "\\N");
174  line_start = 1;
175  break;
176  case ' ':
177  if (!line_start)
178  av_bprint_chars(dst, *in, 1);
179  break;
180  case '{':
181  handle_open_brace(dst, &in, &an, &closing_brace_missing);
182  break;
183  case '<':
184  /*
185  * "<<" are likely latin guillemets in ASCII or some kind of random
186  * style effect; see sub/badsyntax.srt in the FATE samples
187  * directory for real test cases.
188  */
189 
190  likely_a_tag = 1;
191  for (i = 0; in[1] == '<'; i++) {
192  av_bprint_chars(dst, '<', 1);
193  likely_a_tag = 0;
194  in++;
195  }
196 
197  tag_close = in[1] == '/';
198  if (tag_close)
199  likely_a_tag = 1;
200 
201  av_assert0(in[0] == '<');
202 
203  len = 0;
204 
205  if (scantag(in+tag_close+1, buffer, &len) && len > 0) {
206  const int skip = len + tag_close;
207  const char *tagname = buffer;
208  while (*tagname == ' ') {
209  likely_a_tag = 0;
210  tagname++;
211  }
212  if ((param = strchr(tagname, ' ')))
213  *param++ = 0;
214 
215  /* Check if this is likely a tag */
216 #define LIKELY_A_TAG_CHAR(x) (((x) >= '0' && (x) <= '9') || \
217  ((x) >= 'a' && (x) <= 'z') || \
218  ((x) >= 'A' && (x) <= 'Z') || \
219  (x) == '_' || (x) == '/')
220  for (i = 0; tagname[i]; i++) {
221  if (!LIKELY_A_TAG_CHAR(tagname[i])) {
222  likely_a_tag = 0;
223  break;
224  }
225  }
226 
227  if (!av_strcasecmp(tagname, "font")) {
228  if (tag_close && sptr > 0) {
229  struct font_tag *cur_tag = &stack[sptr--];
230  struct font_tag *last_tag = &stack[sptr];
231 
232  if (cur_tag->size) {
233  if (!last_tag->size)
234  av_bprintf(dst, "{\\fs}");
235  else if (last_tag->size != cur_tag->size)
236  av_bprintf(dst, "{\\fs%d}", last_tag->size);
237  }
238 
239  if (cur_tag->color & 0xff000000) {
240  if (!(last_tag->color & 0xff000000))
241  av_bprintf(dst, "{\\c}");
242  else if (last_tag->color != cur_tag->color)
243  av_bprintf(dst, "{\\c&H%"PRIX32"&}", last_tag->color & 0xffffff);
244  }
245 
246  if (cur_tag->face[0]) {
247  if (!last_tag->face[0])
248  av_bprintf(dst, "{\\fn}");
249  else if (strcmp(last_tag->face, cur_tag->face))
250  av_bprintf(dst, "{\\fn%s}", last_tag->face);
251  }
252  } else if (!tag_close && sptr < FF_ARRAY_ELEMS(stack) - 1) {
253  struct font_tag *new_tag = &stack[sptr + 1];
254 
255  *new_tag = stack[sptr++];
256 
257  while (param) {
258  if (!av_strncasecmp(param, "size=", 5)) {
259  param += 5 + (param[5] == '"');
260  if (sscanf(param, "%u", &new_tag->size) == 1)
261  av_bprintf(dst, "{\\fs%u}", new_tag->size);
262  } else if (!av_strncasecmp(param, "color=", 6)) {
263  int color;
264  param += 6 + (param[6] == '"');
265  color = html_color_parse(log_ctx, param);
266  if (color >= 0) {
267  new_tag->color = 0xff000000 | color;
268  av_bprintf(dst, "{\\c&H%"PRIX32"&}", new_tag->color & 0xffffff);
269  }
270  } else if (!av_strncasecmp(param, "face=", 5)) {
271  param += 5 + (param[5] == '"');
272  len = strcspn(param,
273  param[-1] == '"' ? "\"" :" ");
274  av_strlcpy(new_tag->face, param,
275  FFMIN(sizeof(new_tag->face), len+1));
276  param += len;
277  av_bprintf(dst, "{\\fn%s}", new_tag->face);
278  }
279  if ((param = strchr(param, ' ')))
280  param++;
281  }
282  }
283  in += skip;
284  } else if (tagname[0] && !tagname[1] && strchr("bisu", av_tolower(tagname[0]))) {
285  av_bprintf(dst, "{\\%c%d}", (char)av_tolower(tagname[0]), !tag_close);
286  in += skip;
287  } else if (!av_strncasecmp(tagname, "br", 2) &&
288  (!tagname[2] || (tagname[2] == '/' && !tagname[3]))) {
289  av_bprintf(dst, "\\N");
290  in += skip;
291  } else if (likely_a_tag) {
292  if (!tag_close) // warn only once
293  av_log(log_ctx, AV_LOG_WARNING, "Unrecognized tag %s\n", tagname);
294  in += skip;
295  } else {
296  av_bprint_chars(dst, '<', 1);
297  }
298  } else {
299  av_bprint_chars(dst, *in, 1);
300  }
301  break;
302  default:
303  av_bprint_chars(dst, *in, 1);
304  break;
305  }
306  if (*in != ' ' && *in != '\r' && *in != '\n')
307  line_start = 0;
308  }
309 
310  if (!av_bprint_is_complete(dst))
311  return AVERROR(ENOMEM);
312 
313  while (dst->len >= 2 && !strncmp(&dst->str[dst->len - 2], "\\N", 2))
314  dst->len -= 2;
315  dst->str[dst->len] = 0;
316  rstrip_spaces_buf(dst);
317 
318  return 0;
319 }
uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi - 0x80) *(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi - 0x80) *(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(const int16_t *) pi >> 8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t, *(const int16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t, *(const int16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(const int32_t *) pi >> 24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t, *(const int32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t, *(const int32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(const float *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(const float *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(const float *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(const double *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(const double *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(const double *) pi *(1U<< 31)))) #define SET_CONV_FUNC_GROUP(ofmt, ifmt) static void set_generic_function(AudioConvert *ac) { } void ff_audio_convert_free(AudioConvert **ac) { if(! *ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);} AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt, int channels, int sample_rate, int apply_map) { AudioConvert *ac;int in_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) return NULL;ac->avr=avr;ac->out_fmt=out_fmt;ac->in_fmt=in_fmt;ac->channels=channels;ac->apply_map=apply_map;if(avr->dither_method !=AV_RESAMPLE_DITHER_NONE &&av_get_packed_sample_fmt(out_fmt)==AV_SAMPLE_FMT_S16 &&av_get_bytes_per_sample(in_fmt) > 2) { ac->dc=ff_dither_alloc(avr, out_fmt, in_fmt, channels, sample_rate, apply_map);if(!ac->dc) { av_free(ac);return NULL;} return ac;} in_planar=ff_sample_fmt_is_planar(in_fmt, channels);out_planar=ff_sample_fmt_is_planar(out_fmt, channels);if(in_planar==out_planar) { ac->func_type=CONV_FUNC_TYPE_FLAT;ac->planes=in_planar ? ac->channels :1;} else if(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;else ac->func_type=CONV_FUNC_TYPE_DEINTERLEAVE;set_generic_function(ac);if(ARCH_AARCH64) ff_audio_convert_init_aarch64(ac);if(ARCH_ARM) ff_audio_convert_init_arm(ac);if(ARCH_X86) ff_audio_convert_init_x86(ac);return ac;} int ff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in) { int use_generic=1;int len=in->nb_samples;int p;if(ac->dc) { av_log(ac->avr, AV_LOG_TRACE, "%d samples - audio_convert: %s to %s (dithered)\n", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));return ff_convert_dither(ac-> in
uint8_t
simple assert() macros that are a bit more flexible than ISO C assert().
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
void av_bprintf(AVBPrint *buf, const char *fmt,...)
Definition: bprint.c:94
void av_bprint_chars(AVBPrint *buf, char c, unsigned n)
Append char c n times to a print buffer.
Definition: bprint.c:140
static int av_bprint_is_complete(const AVBPrint *buf)
Test if the print buffer is complete (not truncated).
Definition: bprint.h:185
common internal and external API header
#define FFMIN(a, b)
Definition: common.h:105
#define FFMAX(a, b)
Definition: common.h:103
#define AVERROR(e)
Definition: error.h:43
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:200
static av_const int av_tolower(int c)
Locale-independent conversion of ASCII characters to lowercase.
Definition: avstring.h:246
int av_strcasecmp(const char *a, const char *b)
Locale-independent case-insensitive compare.
Definition: avstring.c:215
static av_const int av_isdigit(int c)
Locale-independent conversion of ASCII isdigit.
Definition: avstring.h:211
size_t av_strlcpy(char *dst, const char *src, size_t size)
Copy the string src to dst, but no more than size - 1 bytes, and null-terminate dst.
Definition: avstring.c:83
int av_strncasecmp(const char *a, const char *b, size_t n)
Locale-independent case-insensitive compare.
Definition: avstring.c:225
int ff_htmlmarkup_to_ass(void *log_ctx, AVBPrint *dst, const char *in)
static int scantag(const char *in, char *buffer, int *lenp)
#define LIKELY_A_TAG_CHAR(x)
static int scanbraces(const char *in)
Definition: htmlsubtitles.c:54
static void handle_open_brace(AVBPrint *dst, const char **inp, int *an, int *closing_brace_missing)
Definition: htmlsubtitles.c:69
static int html_color_parse(void *log_ctx, const char *str)
Definition: htmlsubtitles.c:29
static void rstrip_spaces_buf(AVBPrint *buf)
Definition: htmlsubtitles.c:41
int i
Definition: input.c:407
static const uint32_t color[16+AV_CLASS_CATEGORY_NB]
Definition: log.c:92
int av_parse_color(uint8_t *rgba_color, const char *color_string, int slen, void *log_ctx)
Put the RGBA values that correspond to color_string in rgba_color.
Definition: parseutils.c:354
misc parsing utilities
static char buffer[20]
Definition: seek.c:32
#define FF_ARRAY_ELEMS(a)
char face[128]
Definition: htmlsubtitles.c:91
uint32_t color
Definition: htmlsubtitles.c:93
#define av_log(a,...)
int len
static double c[64]