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srtdec.c
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1 /*
2  * SubRip subtitle decoder
3  * Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org>
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/avstring.h"
23 #include "libavutil/common.h"
24 #include "libavutil/intreadwrite.h"
25 #include "libavutil/parseutils.h"
26 #include "avcodec.h"
27 #include "ass.h"
28 
29 static int html_color_parse(AVCodecContext *avctx, const char *str)
30 {
31  uint8_t rgba[4];
32  if (av_parse_color(rgba, str, strcspn(str, "\" >"), avctx) < 0)
33  return -1;
34  return rgba[0] | rgba[1] << 8 | rgba[2] << 16;
35 }
36 
37 enum {
43 };
44 
45 typedef struct SrtStack {
46  char tag[128];
47  char param[PARAM_NUMBER][128];
48 } SrtStack;
49 
50 static void rstrip_spaces_buf(AVBPrint *buf)
51 {
52  while (buf->len > 0 && buf->str[buf->len - 1] == ' ')
53  buf->str[--buf->len] = 0;
54 }
55 
56 static void srt_to_ass(AVCodecContext *avctx, AVBPrint *dst,
57  const char *in, int x1, int y1, int x2, int y2)
58 {
59  char *param, buffer[128], tmp[128];
60  int len, tag_close, sptr = 1, line_start = 1, an = 0, end = 0;
61  SrtStack stack[16];
62 
63  stack[0].tag[0] = 0;
64  strcpy(stack[0].param[PARAM_SIZE], "{\\fs}");
65  strcpy(stack[0].param[PARAM_COLOR], "{\\c}");
66  strcpy(stack[0].param[PARAM_FACE], "{\\fn}");
67 
68  if (x1 >= 0 && y1 >= 0) {
69  /* XXX: here we rescale coordinate assuming they are in DVD resolution
70  * (720x480) since we don't have anything better */
71 
72  if (x2 >= 0 && y2 >= 0 && (x2 != x1 || y2 != y1) && x2 >= x1 && y2 >= y1) {
73  /* text rectangle defined, write the text at the center of the rectangle */
74  const int cx = x1 + (x2 - x1)/2;
75  const int cy = y1 + (y2 - y1)/2;
76  const int scaled_x = cx * ASS_DEFAULT_PLAYRESX / 720;
77  const int scaled_y = cy * ASS_DEFAULT_PLAYRESY / 480;
78  av_bprintf(dst, "{\\an5}{\\pos(%d,%d)}", scaled_x, scaled_y);
79  } else {
80  /* only the top left corner, assume the text starts in that corner */
81  const int scaled_x = x1 * ASS_DEFAULT_PLAYRESX / 720;
82  const int scaled_y = y1 * ASS_DEFAULT_PLAYRESY / 480;
83  av_bprintf(dst, "{\\an1}{\\pos(%d,%d)}", scaled_x, scaled_y);
84  }
85  }
86 
87  for (; !end && *in; in++) {
88  switch (*in) {
89  case '\r':
90  break;
91  case '\n':
92  if (line_start) {
93  end = 1;
94  break;
95  }
96  rstrip_spaces_buf(dst);
97  av_bprintf(dst, "\\N");
98  line_start = 1;
99  break;
100  case ' ':
101  if (!line_start)
102  av_bprint_chars(dst, *in, 1);
103  break;
104  case '{': /* skip all {\xxx} substrings except for {\an%d}
105  and all microdvd like styles such as {Y:xxx} */
106  len = 0;
107  an += sscanf(in, "{\\an%*1u}%n", &len) >= 0 && len > 0;
108  if ((an != 1 && (len = 0, sscanf(in, "{\\%*[^}]}%n", &len) >= 0 && len > 0)) ||
109  (len = 0, sscanf(in, "{%*1[CcFfoPSsYy]:%*[^}]}%n", &len) >= 0 && len > 0)) {
110  in += len - 1;
111  } else
112  av_bprint_chars(dst, *in, 1);
113  break;
114  case '<':
115  tag_close = in[1] == '/';
116  len = 0;
117  if (sscanf(in+tag_close+1, "%127[^>]>%n", buffer, &len) >= 1 && len > 0) {
118  if ((param = strchr(buffer, ' ')))
119  *param++ = 0;
120  if ((!tag_close && sptr < FF_ARRAY_ELEMS(stack)) ||
121  ( tag_close && sptr > 0 && !strcmp(stack[sptr-1].tag, buffer))) {
122  int i, j, unknown = 0;
123  in += len + tag_close;
124  if (!tag_close)
125  memset(stack+sptr, 0, sizeof(*stack));
126  if (!strcmp(buffer, "font")) {
127  if (tag_close) {
128  for (i=PARAM_NUMBER-1; i>=0; i--)
129  if (stack[sptr-1].param[i][0])
130  for (j=sptr-2; j>=0; j--)
131  if (stack[j].param[i][0]) {
132  av_bprintf(dst, "%s", stack[j].param[i]);
133  break;
134  }
135  } else {
136  while (param) {
137  if (!strncmp(param, "size=", 5)) {
138  unsigned font_size;
139  param += 5 + (param[5] == '"');
140  if (sscanf(param, "%u", &font_size) == 1) {
141  snprintf(stack[sptr].param[PARAM_SIZE],
142  sizeof(stack[0].param[PARAM_SIZE]),
143  "{\\fs%u}", font_size);
144  }
145  } else if (!strncmp(param, "color=", 6)) {
146  param += 6 + (param[6] == '"');
147  snprintf(stack[sptr].param[PARAM_COLOR],
148  sizeof(stack[0].param[PARAM_COLOR]),
149  "{\\c&H%X&}",
150  html_color_parse(avctx, param));
151  } else if (!strncmp(param, "face=", 5)) {
152  param += 5 + (param[5] == '"');
153  len = strcspn(param,
154  param[-1] == '"' ? "\"" :" ");
155  av_strlcpy(tmp, param,
156  FFMIN(sizeof(tmp), len+1));
157  param += len;
158  snprintf(stack[sptr].param[PARAM_FACE],
159  sizeof(stack[0].param[PARAM_FACE]),
160  "{\\fn%s}", tmp);
161  }
162  if ((param = strchr(param, ' ')))
163  param++;
164  }
165  for (i=0; i<PARAM_NUMBER; i++)
166  if (stack[sptr].param[i][0])
167  av_bprintf(dst, "%s", stack[sptr].param[i]);
168  }
169  } else if (!buffer[1] && strspn(buffer, "bisu") == 1) {
170  av_bprintf(dst, "{\\%c%d}", buffer[0], !tag_close);
171  } else {
172  unknown = 1;
173  snprintf(tmp, sizeof(tmp), "</%s>", buffer);
174  }
175  if (tag_close) {
176  sptr--;
177  } else if (unknown && !strstr(in, tmp)) {
178  in -= len + tag_close;
179  av_bprint_chars(dst, *in, 1);
180  } else
181  av_strlcpy(stack[sptr++].tag, buffer,
182  sizeof(stack[0].tag));
183  break;
184  }
185  }
186  default:
187  av_bprint_chars(dst, *in, 1);
188  break;
189  }
190  if (*in != ' ' && *in != '\r' && *in != '\n')
191  line_start = 0;
192  }
193 
194  while (dst->len >= 2 && !strncmp(&dst->str[dst->len - 2], "\\N", 2))
195  dst->len -= 2;
196  dst->str[dst->len] = 0;
197  rstrip_spaces_buf(dst);
198 }
199 
201  void *data, int *got_sub_ptr, AVPacket *avpkt)
202 {
203  AVSubtitle *sub = data;
204  AVBPrint buffer;
205  int ts_start, ts_end, x1 = -1, y1 = -1, x2 = -1, y2 = -1;
206  int size, ret;
208 
209  if (p && size == 16) {
210  x1 = AV_RL32(p );
211  y1 = AV_RL32(p + 4);
212  x2 = AV_RL32(p + 8);
213  y2 = AV_RL32(p + 12);
214  }
215 
216  if (avpkt->size <= 0)
217  return avpkt->size;
218 
220 
221  // TODO: reindent
222  // Do final divide-by-10 outside rescale to force rounding down.
223  ts_start = av_rescale_q(avpkt->pts,
224  avctx->time_base,
225  (AVRational){1,100});
226  ts_end = av_rescale_q(avpkt->pts + avpkt->duration,
227  avctx->time_base,
228  (AVRational){1,100});
229 
230  srt_to_ass(avctx, &buffer, avpkt->data, x1, y1, x2, y2);
231  ret = ff_ass_add_rect_bprint(sub, &buffer, ts_start, ts_end-ts_start);
233  if (ret < 0)
234  return ret;
235 
236  *got_sub_ptr = sub->num_rects > 0;
237  return avpkt->size;
238 }
239 
240 #if CONFIG_SRT_DECODER
241 /* deprecated decoder */
242 AVCodec ff_srt_decoder = {
243  .name = "srt",
244  .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
245  .type = AVMEDIA_TYPE_SUBTITLE,
246  .id = AV_CODEC_ID_SUBRIP,
248  .decode = srt_decode_frame,
249 };
250 #endif
251 
252 #if CONFIG_SUBRIP_DECODER
253 AVCodec ff_subrip_decoder = {
254  .name = "subrip",
255  .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
256  .type = AVMEDIA_TYPE_SUBTITLE,
257  .id = AV_CODEC_ID_SUBRIP,
259  .decode = srt_decode_frame,
260 };
261 #endif
#define NULL
Definition: coverity.c:32
void av_bprintf(AVBPrint *buf, const char *fmt,...)
Definition: bprint.c:94
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
char tag[128]
Definition: srtdec.c:46
Subtitle event position.
Definition: avcodec.h:1341
int size
Definition: avcodec.h:1424
AVCodec.
Definition: avcodec.h:3472
int av_bprint_finalize(AVBPrint *buf, char **ret_str)
Finalize a print buffer.
Definition: bprint.c:235
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented...
Definition: avcodec.h:1631
static void srt_to_ass(AVCodecContext *avctx, AVBPrint *dst, const char *in, int x1, int y1, int x2, int y2)
Definition: srtdec.c:56
uint8_t
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
int ff_ass_subtitle_header_default(AVCodecContext *avctx)
Generate a suitable AVCodecContext.subtitle_header for SUBTITLE_ASS with default style.
Definition: ass.c:80
uint32_t tag
Definition: movenc.c:1334
ptrdiff_t size
Definition: opengl_enc.c:101
#define ASS_DEFAULT_PLAYRESY
Definition: ass.h:29
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:348
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
Definition: mathematics.c:140
#define AV_BPRINT_SIZE_UNLIMITED
static int html_color_parse(AVCodecContext *avctx, const char *str)
Definition: srtdec.c:29
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:175
void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max)
Definition: bprint.c:69
static void rstrip_spaces_buf(AVBPrint *buf)
Definition: srtdec.c:50
const char * name
Name of the codec implementation.
Definition: avcodec.h:3479
Libavcodec external API header.
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
#define FFMIN(a, b)
Definition: common.h:81
#define FF_ARRAY_ELEMS(a)
char param[PARAM_NUMBER][128]
Definition: srtdec.c:47
int ff_ass_add_rect_bprint(AVSubtitle *sub, AVBPrint *buf, int ts_start, int duration)
Same as ff_ass_add_rect_bprint, but taking an AVBPrint buffer instead of a string, and assuming raw=0.
Definition: ass.c:178
main external API structure.
Definition: avcodec.h:1502
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_log(ac->avr, AV_LOG_TRACE,"%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
void * buf
Definition: avisynth_c.h:553
rational number numerator/denominator
Definition: rational.h:43
#define snprintf
Definition: snprintf.h:34
misc parsing utilities
common internal and external API header
int len
uint8_t * av_packet_get_side_data(AVPacket *pkt, enum AVPacketSideDataType type, int *size)
Get side information from packet.
Definition: avpacket.c:324
static int srt_decode_frame(AVCodecContext *avctx, void *data, int *got_sub_ptr, AVPacket *avpkt)
Definition: srtdec.c:200
#define ASS_DEFAULT_PLAYRESX
Definition: ass.h:28
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:87
This structure stores compressed data.
Definition: avcodec.h:1400
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1416
GLuint buffer
Definition: opengl_enc.c:102
void av_bprint_chars(AVBPrint *buf, char c, unsigned n)
Append char c n times to a print buffer.
Definition: bprint.c:140