indeo: Do not reference mismatched tiles
[ffmpeg.git] / libavcodec / srtdec.c
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 {
37     PARAM_UNKNOWN = -1,
38     PARAM_SIZE,
39     PARAM_COLOR,
40     PARAM_FACE,
41     PARAM_NUMBER
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
208 static int srt_decode_frame(AVCodecContext *avctx,
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
235 AVCodec ff_srt_decoder = {
236     .name         = "srt",
237     .long_name    = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
238     .type         = AVMEDIA_TYPE_SUBTITLE,
239     .id           = AV_CODEC_ID_SRT,
240     .init         = ff_ass_subtitle_header_default,
241     .decode       = srt_decode_frame,
242 };