Libav
srtdec.c
Go to the documentation of this file.
1 /*
2  * SubRip subtitle decoder
3  * Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org>
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; 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/avstring.h"
23 #include "libavutil/common.h"
24 #include "libavutil/parseutils.h"
25 #include "avcodec.h"
26 #include "ass.h"
27 
28 static int html_color_parse(AVCodecContext *avctx, const char *str)
29 {
30  uint8_t rgba[4];
31  if (av_parse_color(rgba, str, strcspn(str, "\" >"), avctx) < 0)
32  return -1;
33  return rgba[0] | rgba[1] << 8 | rgba[2] << 16;
34 }
35 
36 enum {
42 };
43 
44 typedef struct {
45  char tag[128];
46  char param[PARAM_NUMBER][128];
47 } SrtStack;
48 
49 static const char *srt_to_ass(AVCodecContext *avctx, char *out, char *out_end,
50  const char *in, int x1, int y1, int x2, int y2)
51 {
52  char c, *param, buffer[128], tmp[128];
53  int len, tag_close, sptr = 1, line_start = 1, an = 0, end = 0;
54  SrtStack stack[16];
55 
56  stack[0].tag[0] = 0;
57  strcpy(stack[0].param[PARAM_SIZE], "{\\fs}");
58  strcpy(stack[0].param[PARAM_COLOR], "{\\c}");
59  strcpy(stack[0].param[PARAM_FACE], "{\\fn}");
60 
61  if (x1 >= 0 && y1 >= 0) {
62  if (x2 >= 0 && y2 >= 0 && (x2 != x1 || y2 != y1))
63  out += snprintf(out, out_end-out,
64  "{\\an1}{\\move(%d,%d,%d,%d)}", x1, y1, x2, y2);
65  else
66  out += snprintf(out, out_end-out, "{\\an1}{\\pos(%d,%d)}", x1, y1);
67  }
68 
69  for (; out < out_end && !end && *in; in++) {
70  switch (*in) {
71  case '\r':
72  break;
73  case '\n':
74  if (line_start) {
75  end = 1;
76  break;
77  }
78  while (out[-1] == ' ')
79  out--;
80  out += snprintf(out, out_end-out, "\\N");
81  line_start = 1;
82  break;
83  case ' ':
84  if (!line_start)
85  *out++ = *in;
86  break;
87  case '{': /* skip all {\xxx} substrings except for {\an%d}
88  and all microdvd like styles such as {Y:xxx} */
89  an += sscanf(in, "{\\an%*1u}%c", &c) == 1;
90  if ((an != 1 && sscanf(in, "{\\%*[^}]}%n%c", &len, &c) > 0) ||
91  sscanf(in, "{%*1[CcFfoPSsYy]:%*[^}]}%n%c", &len, &c) > 0) {
92  in += len - 1;
93  } else
94  *out++ = *in;
95  break;
96  case '<':
97  tag_close = in[1] == '/';
98  if (sscanf(in+tag_close+1, "%127[^>]>%n%c", buffer, &len,&c) >= 2) {
99  if ((param = strchr(buffer, ' ')))
100  *param++ = 0;
101  if ((!tag_close && sptr < FF_ARRAY_ELEMS(stack)) ||
102  ( tag_close && sptr > 0 && !strcmp(stack[sptr-1].tag, buffer))) {
103  int i, j, unknown = 0;
104  in += len + tag_close;
105  if (!tag_close)
106  memset(stack+sptr, 0, sizeof(*stack));
107  if (!strcmp(buffer, "font")) {
108  if (tag_close) {
109  for (i=PARAM_NUMBER-1; i>=0; i--)
110  if (stack[sptr-1].param[i][0])
111  for (j=sptr-2; j>=0; j--)
112  if (stack[j].param[i][0]) {
113  out += snprintf(out, out_end-out,
114  "%s", stack[j].param[i]);
115  break;
116  }
117  } else {
118  while (param) {
119  if (!strncmp(param, "size=", 5)) {
120  unsigned font_size;
121  param += 5 + (param[5] == '"');
122  if (sscanf(param, "%u", &font_size) == 1) {
123  snprintf(stack[sptr].param[PARAM_SIZE],
124  sizeof(stack[0].param[PARAM_SIZE]),
125  "{\\fs%u}", font_size);
126  }
127  } else if (!strncmp(param, "color=", 6)) {
128  param += 6 + (param[6] == '"');
129  snprintf(stack[sptr].param[PARAM_COLOR],
130  sizeof(stack[0].param[PARAM_COLOR]),
131  "{\\c&H%X&}",
132  html_color_parse(avctx, param));
133  } else if (!strncmp(param, "face=", 5)) {
134  param += 5 + (param[5] == '"');
135  len = strcspn(param,
136  param[-1] == '"' ? "\"" :" ");
137  av_strlcpy(tmp, param,
138  FFMIN(sizeof(tmp), len+1));
139  param += len;
140  snprintf(stack[sptr].param[PARAM_FACE],
141  sizeof(stack[0].param[PARAM_FACE]),
142  "{\\fn%s}", tmp);
143  }
144  if ((param = strchr(param, ' ')))
145  param++;
146  }
147  for (i=0; i<PARAM_NUMBER; i++)
148  if (stack[sptr].param[i][0])
149  out += snprintf(out, out_end-out,
150  "%s", stack[sptr].param[i]);
151  }
152  } else if (!buffer[1] && strspn(buffer, "bisu") == 1) {
153  out += snprintf(out, out_end-out,
154  "{\\%c%d}", buffer[0], !tag_close);
155  } else {
156  unknown = 1;
157  snprintf(tmp, sizeof(tmp), "</%s>", buffer);
158  }
159  if (tag_close) {
160  sptr--;
161  } else if (unknown && !strstr(in, tmp)) {
162  in -= len + tag_close;
163  *out++ = *in;
164  } else
165  av_strlcpy(stack[sptr++].tag, buffer,
166  sizeof(stack[0].tag));
167  break;
168  }
169  }
170  default:
171  *out++ = *in;
172  break;
173  }
174  if (*in != ' ' && *in != '\r' && *in != '\n')
175  line_start = 0;
176  }
177 
178  out = FFMIN(out, out_end-3);
179  while (!strncmp(out-2, "\\N", 2))
180  out -= 2;
181  while (out[-1] == ' ')
182  out--;
183  out += snprintf(out, out_end-out, "\r\n");
184  return in;
185 }
186 
187 static const char *read_ts(const char *buf, int *ts_start, int *ts_end,
188  int *x1, int *y1, int *x2, int *y2)
189 {
190  int i, hs, ms, ss, he, me, se;
191 
192  for (i=0; i<2; i++) {
193  /* try to read timestamps in either the first or second line */
194  int c = sscanf(buf, "%d:%2d:%2d%*1[,.]%3d --> %d:%2d:%2d%*1[,.]%3d"
195  "%*[ ]X1:%u X2:%u Y1:%u Y2:%u",
196  &hs, &ms, &ss, ts_start, &he, &me, &se, ts_end,
197  x1, x2, y1, y2);
198  buf += strcspn(buf, "\n") + 1;
199  if (c >= 8) {
200  *ts_start = 100*(ss + 60*(ms + 60*hs)) + *ts_start/10;
201  *ts_end = 100*(se + 60*(me + 60*he)) + *ts_end /10;
202  return buf;
203  }
204  }
205  return NULL;
206 }
207 
209  void *data, int *got_sub_ptr, AVPacket *avpkt)
210 {
211  AVSubtitle *sub = data;
212  int ts_start, ts_end, x1 = -1, y1 = -1, x2 = -1, y2 = -1;
213  char buffer[2048];
214  const char *ptr = avpkt->data;
215  const char *end = avpkt->data + avpkt->size;
216 
217  if (avpkt->size <= 0)
218  return avpkt->size;
219 
220  ff_ass_init(sub);
221 
222  while (ptr < end && *ptr) {
223  ptr = read_ts(ptr, &ts_start, &ts_end, &x1, &y1, &x2, &y2);
224  if (!ptr)
225  break;
226  ptr = srt_to_ass(avctx, buffer, buffer+sizeof(buffer), ptr,
227  x1, y1, x2, y2);
228  ff_ass_add_rect(sub, buffer, ts_start, ts_end, 0);
229  }
230 
231  *got_sub_ptr = sub->num_rects > 0;
232  return avpkt->size;
233 }
234 
236  .name = "srt",
237  .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
238  .type = AVMEDIA_TYPE_SUBTITLE,
239  .id = AV_CODEC_ID_SRT,
241  .decode = srt_decode_frame,
242 };
static const char * read_ts(const char *buf, int *ts_start, int *ts_end, int *x1, int *y1, int *x2, int *y2)
Definition: srtdec.c:187
AVCodec ff_srt_decoder
Definition: srtdec.c:235
char tag[128]
Definition: srtdec.c:45
int size
Definition: avcodec.h:974
static const char * srt_to_ass(AVCodecContext *avctx, char *out, char *out_end, const char *in, int x1, int y1, int x2, int y2)
Definition: srtdec.c:49
uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(constuint8_t *) pi-0x80)*(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(constuint8_t *) pi-0x80)*(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(constint16_t *) pi >>8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t,*(constint16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t,*(constint16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(constint32_t *) pi >>24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t,*(constint32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t,*(constint32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(constfloat *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(constfloat *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(constfloat *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(constdouble *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(constdouble *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(constdouble *) pi *(1U<< 31))))#defineSET_CONV_FUNC_GROUP(ofmt, ifmt) staticvoidset_generic_function(AudioConvert *ac){}voidff_audio_convert_free(AudioConvert **ac){if(!*ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);}AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enumAVSampleFormatout_fmt, enumAVSampleFormatin_fmt, intchannels, intsample_rate, intapply_map){AudioConvert *ac;intin_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) returnNULL;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);returnNULL;}returnac;}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;}elseif(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;elseac->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);returnac;}intff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in){intuse_generic=1;intlen=in->nb_samples;intp;if(ac->dc){av_dlog(ac->avr,"%dsamples-audio_convert:%sto%s(dithered)\n", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));returnff_convert_dither(ac-> in
unsigned num_rects
Definition: avcodec.h:3087
#define FF_ARRAY_ELEMS(a)
AVCodec.
Definition: avcodec.h:2796
uint8_t
int ff_ass_subtitle_header_default(AVCodecContext *avctx)
Generate a suitable AVCodecContext.subtitle_header for SUBTITLE_ASS with default style.
Definition: ass.c:70
const char data[16]
Definition: mxf.c:70
uint8_t * data
Definition: avcodec.h:973
uint32_t tag
Definition: movenc.c:844
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:300
static int html_color_parse(AVCodecContext *avctx, const char *str)
Definition: srtdec.c:28
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:150
void ff_ass_init(AVSubtitle *sub)
Initialize an AVSubtitle structure for use with ff_ass_add_rect().
Definition: ass.c:82
const char * name
Name of the codec implementation.
Definition: avcodec.h:2803
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:81
#define FFMIN(a, b)
Definition: common.h:57
static char buffer[20]
Definition: seek-test.c:31
NULL
Definition: eval.c:55
Libavcodec external API header.
main external API structure.
Definition: avcodec.h:1050
misc parsing utilities
uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(constuint8_t *) pi-0x80)*(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(constuint8_t *) pi-0x80)*(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(constint16_t *) pi >>8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t,*(constint16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t,*(constint16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(constint32_t *) pi >>24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t,*(constint32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t,*(constint32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(constfloat *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(constfloat *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(constfloat *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(constdouble *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(constdouble *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(constdouble *) pi *(1U<< 31))))#defineSET_CONV_FUNC_GROUP(ofmt, ifmt) staticvoidset_generic_function(AudioConvert *ac){}voidff_audio_convert_free(AudioConvert **ac){if(!*ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);}AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enumAVSampleFormatout_fmt, enumAVSampleFormatin_fmt, intchannels, intsample_rate, intapply_map){AudioConvert *ac;intin_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) returnNULL;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);returnNULL;}returnac;}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;}elseif(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;elseac->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);returnac;}intff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in){intuse_generic=1;intlen=in->nb_samples;intp;if(ac->dc){av_dlog(ac->avr,"%dsamples-audio_convert:%sto%s(dithered)\n", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));returnff_convert_dither(ac-> out
common internal and external API header
int len
int ff_ass_add_rect(AVSubtitle *sub, const char *dialog, int ts_start, int ts_end, int raw)
Add an ASS dialog line to an AVSubtitle as a new AVSubtitleRect.
Definition: ass.c:96
static int srt_decode_frame(AVCodecContext *avctx, void *data, int *got_sub_ptr, AVPacket *avpkt)
Definition: srtdec.c:208
This structure stores compressed data.
Definition: avcodec.h:950