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/parseutils.h" 24#include "avcodec.h" 25#include "ass.h" 26 27static int html_color_parse(AVCodecContext *avctx, const char *str) 28{ 29 uint8_t rgba[4]; 30 if (av_parse_color(rgba, str, strcspn(str, "\" >"), avctx) < 0) 31 return -1; 32 return rgba[0] | rgba[1] << 8 | rgba[2] << 16; 33} 34 35enum { 36 PARAM_UNKNOWN = -1, 37 PARAM_SIZE, 38 PARAM_COLOR, 39 PARAM_FACE, 40 PARAM_NUMBER 41}; 42 43typedef struct { 44 char tag[128]; 45 char param[PARAM_NUMBER][128]; 46} SrtStack; 47 48static const char *srt_to_ass(AVCodecContext *avctx, char *out, char *out_end, 49 const char *in, int x1, int y1, int x2, int y2) 50{ 51 char c, *param, buffer[128], tmp[128]; 52 int len, tag_close, sptr = 1, line_start = 1, an = 0, end = 0; 53 SrtStack stack[16]; 54 55 stack[0].tag[0] = 0; 56 strcpy(stack[0].param[PARAM_SIZE], "{\\fs}"); 57 strcpy(stack[0].param[PARAM_COLOR], "{\\c}"); 58 strcpy(stack[0].param[PARAM_FACE], "{\\fn}"); 59 60 if (x1 >= 0 && y1 >= 0) { 61 if (x2 >= 0 && y2 >= 0 && (x2 != x1 || y2 != y1)) 62 out += snprintf(out, out_end-out, 63 "{\\an1}{\\move(%d,%d,%d,%d)}", x1, y1, x2, y2); 64 else 65 out += snprintf(out, out_end-out, "{\\an1}{\\pos(%d,%d)}", x1, y1); 66 } 67 68 for (; out < out_end && !end && *in; in++) { 69 switch (*in) { 70 case '\r': 71 break; 72 case '\n': 73 if (line_start) { 74 end = 1; 75 break; 76 } 77 while (out[-1] == ' ') 78 out--; 79 out += snprintf(out, out_end-out, "\\N"); 80 line_start = 1; 81 break; 82 case ' ': 83 if (!line_start) 84 *out++ = *in; 85 break; 86 case '{': /* skip all {\xxx} substrings except for {\an%d} 87 and all microdvd like styles such as {Y:xxx} */ 88 an += sscanf(in, "{\\an%*1u}%c", &c) == 1; 89 if ((an != 1 && sscanf(in, "{\\%*[^}]}%n%c", &len, &c) > 0) || 90 sscanf(in, "{%*1[CcFfoPSsYy]:%*[^}]}%n%c", &len, &c) > 0) { 91 in += len - 1; 92 } else 93 *out++ = *in; 94 break; 95 case '<': 96 tag_close = in[1] == '/'; 97 if (sscanf(in+tag_close+1, "%127[^>]>%n%c", buffer, &len,&c) >= 2) { 98 if ((param = strchr(buffer, ' '))) 99 *param++ = 0; 100 if ((!tag_close && sptr < FF_ARRAY_ELEMS(stack)) || 101 ( tag_close && sptr > 0 && !strcmp(stack[sptr-1].tag, buffer))) { 102 int i, j, unknown = 0; 103 in += len + tag_close; 104 if (!tag_close) 105 memset(stack+sptr, 0, sizeof(*stack)); 106 if (!strcmp(buffer, "font")) { 107 if (tag_close) { 108 for (i=PARAM_NUMBER-1; i>=0; i--) 109 if (stack[sptr-1].param[i][0]) 110 for (j=sptr-2; j>=0; j--) 111 if (stack[j].param[i][0]) { 112 out += snprintf(out, out_end-out, 113 "%s", stack[j].param[i]); 114 break; 115 } 116 } else { 117 while (param) { 118 if (!strncmp(param, "size=", 5)) { 119 unsigned font_size; 120 param += 5 + (param[5] == '"'); 121 if (sscanf(param, "%u", &font_size) == 1) { 122 snprintf(stack[sptr].param[PARAM_SIZE], 123 sizeof(stack[0].param[PARAM_SIZE]), 124 "{\\fs%u}", font_size); 125 } 126 } else if (!strncmp(param, "color=", 6)) { 127 param += 6 + (param[6] == '"'); 128 snprintf(stack[sptr].param[PARAM_COLOR], 129 sizeof(stack[0].param[PARAM_COLOR]), 130 "{\\c&H%X&}", 131 html_color_parse(avctx, param)); 132 } else if (!strncmp(param, "face=", 5)) { 133 param += 5 + (param[5] == '"'); 134 len = strcspn(param, 135 param[-1] == '"' ? "\"" :" "); 136 av_strlcpy(tmp, param, 137 FFMIN(sizeof(tmp), len+1)); 138 param += len; 139 snprintf(stack[sptr].param[PARAM_FACE], 140 sizeof(stack[0].param[PARAM_FACE]), 141 "{\\fn%s}", tmp); 142 } 143 if ((param = strchr(param, ' '))) 144 param++; 145 } 146 for (i=0; i<PARAM_NUMBER; i++) 147 if (stack[sptr].param[i][0]) 148 out += snprintf(out, out_end-out, 149 "%s", stack[sptr].param[i]); 150 } 151 } else if (!buffer[1] && strspn(buffer, "bisu") == 1) { 152 out += snprintf(out, out_end-out, 153 "{\\%c%d}", buffer[0], !tag_close); 154 } else { 155 unknown = 1; 156 snprintf(tmp, sizeof(tmp), "</%s>", buffer); 157 } 158 if (tag_close) { 159 sptr--; 160 } else if (unknown && !strstr(in, tmp)) { 161 in -= len + tag_close; 162 *out++ = *in; 163 } else 164 av_strlcpy(stack[sptr++].tag, buffer, 165 sizeof(stack[0].tag)); 166 break; 167 } 168 } 169 default: 170 *out++ = *in; 171 break; 172 } 173 if (*in != ' ' && *in != '\r' && *in != '\n') 174 line_start = 0; 175 } 176 177 out = FFMIN(out, out_end-3); 178 while (!strncmp(out-2, "\\N", 2)) 179 out -= 2; 180 while (out[-1] == ' ') 181 out--; 182 out += snprintf(out, out_end-out, "\r\n"); 183 return in; 184} 185 186static const char *read_ts(const char *buf, int *ts_start, int *ts_end, 187 int *x1, int *y1, int *x2, int *y2) 188{ 189 int i, hs, ms, ss, he, me, se; 190 191 for (i=0; i<2; i++) { 192 /* try to read timestamps in either the first or second line */ 193 int c = sscanf(buf, "%d:%2d:%2d%*1[,.]%3d --> %d:%2d:%2d%*1[,.]%3d" 194 "%*[ ]X1:%u X2:%u Y1:%u Y2:%u", 195 &hs, &ms, &ss, ts_start, &he, &me, &se, ts_end, 196 x1, x2, y1, y2); 197 buf += strcspn(buf, "\n") + 1; 198 if (c >= 8) { 199 *ts_start = 100*(ss + 60*(ms + 60*hs)) + *ts_start/10; 200 *ts_end = 100*(se + 60*(me + 60*he)) + *ts_end /10; 201 return buf; 202 } 203 } 204 return NULL; 205} 206 207static int srt_decode_frame(AVCodecContext *avctx, 208 void *data, int *got_sub_ptr, AVPacket *avpkt) 209{ 210 AVSubtitle *sub = data; 211 int ts_start, ts_end, x1 = -1, y1 = -1, x2 = -1, y2 = -1; 212 char buffer[2048]; 213 const char *ptr = avpkt->data; 214 const char *end = avpkt->data + avpkt->size; 215 216 if (avpkt->size <= 0) 217 return avpkt->size; 218 219 ff_ass_init(sub); 220 221 while (ptr < end && *ptr) { 222 ptr = read_ts(ptr, &ts_start, &ts_end, &x1, &y1, &x2, &y2); 223 if (!ptr) 224 break; 225 ptr = srt_to_ass(avctx, buffer, buffer+sizeof(buffer), ptr, 226 x1, y1, x2, y2); 227 ff_ass_add_rect(sub, buffer, ts_start, ts_end, 0); 228 } 229 230 *got_sub_ptr = sub->num_rects > 0; 231 return avpkt->size; 232} 233 234AVCodec ff_srt_decoder = { 235 .name = "srt", 236 .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"), 237 .type = AVMEDIA_TYPE_SUBTITLE, 238 .id = CODEC_ID_SRT, 239 .init = ff_ass_subtitle_header_default, 240 .decode = srt_decode_frame, 241}; 242