vp9: decode_mode context optimizations.
[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 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 {
38     PARAM_UNKNOWN = -1,
39     PARAM_SIZE,
40     PARAM_COLOR,
41     PARAM_FACE,
42     PARAM_NUMBER
43 };
44
45 typedef struct {
46     char tag[128];
47     char param[PARAM_NUMBER][128];
48 } SrtStack;
49
50 static const char *srt_to_ass(AVCodecContext *avctx, char *out, char *out_end,
51                               const char *in, int x1, int y1, int x2, int y2)
52 {
53     char *param, buffer[128], tmp[128];
54     int len, tag_close, sptr = 1, line_start = 1, an = 0, end = 0;
55     SrtStack stack[16];
56
57     stack[0].tag[0] = 0;
58     strcpy(stack[0].param[PARAM_SIZE],  "{\\fs}");
59     strcpy(stack[0].param[PARAM_COLOR], "{\\c}");
60     strcpy(stack[0].param[PARAM_FACE],  "{\\fn}");
61
62     if (x1 >= 0 && y1 >= 0) {
63         if (x2 >= 0 && y2 >= 0 && (x2 != x1 || y2 != y1))
64             snprintf(out, out_end-out,
65                             "{\\an1}{\\move(%d,%d,%d,%d)}", x1, y1, x2, y2);
66         else
67             snprintf(out, out_end-out, "{\\an1}{\\pos(%d,%d)}", x1, y1);
68         out += strlen(out);
69     }
70
71     for (; out < out_end && !end && *in; in++) {
72         switch (*in) {
73         case '\r':
74             break;
75         case '\n':
76             if (line_start) {
77                 end = 1;
78                 break;
79             }
80             while (out[-1] == ' ')
81                 out--;
82             snprintf(out, out_end-out, "\\N");
83             if(out<out_end) out += strlen(out);
84             line_start = 1;
85             break;
86         case ' ':
87             if (!line_start)
88                 *out++ = *in;
89             break;
90         case '{':    /* skip all {\xxx} substrings except for {\an%d}
91                         and all microdvd like styles such as {Y:xxx} */
92             len = 0;
93             an += sscanf(in, "{\\an%*1u}%n", &len) >= 0 && len > 0;
94             if ((an != 1 && (len = 0, sscanf(in, "{\\%*[^}]}%n", &len) >= 0 && len > 0)) ||
95                 (len = 0, sscanf(in, "{%*1[CcFfoPSsYy]:%*[^}]}%n", &len) >= 0 && len > 0)) {
96                 in += len - 1;
97             } else
98                 *out++ = *in;
99             break;
100         case '<':
101             tag_close = in[1] == '/';
102             len = 0;
103             if (sscanf(in+tag_close+1, "%127[^>]>%n", buffer, &len) >= 1 && len > 0) {
104                 if ((param = strchr(buffer, ' ')))
105                     *param++ = 0;
106                 if ((!tag_close && sptr < FF_ARRAY_ELEMS(stack)) ||
107                     ( tag_close && sptr > 0 && !strcmp(stack[sptr-1].tag, buffer))) {
108                     int i, j, unknown = 0;
109                     in += len + tag_close;
110                     if (!tag_close)
111                         memset(stack+sptr, 0, sizeof(*stack));
112                     if (!strcmp(buffer, "font")) {
113                         if (tag_close) {
114                             for (i=PARAM_NUMBER-1; i>=0; i--)
115                                 if (stack[sptr-1].param[i][0])
116                                     for (j=sptr-2; j>=0; j--)
117                                         if (stack[j].param[i][0]) {
118                                             snprintf(out, out_end-out,
119                                                             "%s", stack[j].param[i]);
120                                             if(out<out_end) out += strlen(out);
121                                             break;
122                                         }
123                         } else {
124                             while (param) {
125                                 if (!strncmp(param, "size=", 5)) {
126                                     unsigned font_size;
127                                     param += 5 + (param[5] == '"');
128                                     if (sscanf(param, "%u", &font_size) == 1) {
129                                         snprintf(stack[sptr].param[PARAM_SIZE],
130                                              sizeof(stack[0].param[PARAM_SIZE]),
131                                              "{\\fs%u}", font_size);
132                                     }
133                                 } else if (!strncmp(param, "color=", 6)) {
134                                     param += 6 + (param[6] == '"');
135                                     snprintf(stack[sptr].param[PARAM_COLOR],
136                                          sizeof(stack[0].param[PARAM_COLOR]),
137                                          "{\\c&H%X&}",
138                                          html_color_parse(avctx, param));
139                                 } else if (!strncmp(param, "face=", 5)) {
140                                     param += 5 + (param[5] == '"');
141                                     len = strcspn(param,
142                                                   param[-1] == '"' ? "\"" :" ");
143                                     av_strlcpy(tmp, param,
144                                                FFMIN(sizeof(tmp), len+1));
145                                     param += len;
146                                     snprintf(stack[sptr].param[PARAM_FACE],
147                                              sizeof(stack[0].param[PARAM_FACE]),
148                                              "{\\fn%s}", tmp);
149                                 }
150                                 if ((param = strchr(param, ' ')))
151                                     param++;
152                             }
153                             for (i=0; i<PARAM_NUMBER; i++)
154                                 if (stack[sptr].param[i][0]) {
155                                     snprintf(out, out_end-out,
156                                                     "%s", stack[sptr].param[i]);
157                                     if(out<out_end) out += strlen(out);
158                                 }
159                         }
160                     } else if (!buffer[1] && strspn(buffer, "bisu") == 1) {
161                         snprintf(out, out_end-out,
162                                         "{\\%c%d}", buffer[0], !tag_close);
163                         if(out<out_end) out += strlen(out);
164                     } else {
165                         unknown = 1;
166                         snprintf(tmp, sizeof(tmp), "</%s>", buffer);
167                     }
168                     if (tag_close) {
169                         sptr--;
170                     } else if (unknown && !strstr(in, tmp)) {
171                         in -= len + tag_close;
172                         *out++ = *in;
173                     } else
174                         av_strlcpy(stack[sptr++].tag, buffer,
175                                    sizeof(stack[0].tag));
176                     break;
177                 }
178             }
179         default:
180             *out++ = *in;
181             break;
182         }
183         if (*in != ' ' && *in != '\r' && *in != '\n')
184             line_start = 0;
185     }
186
187     out = FFMIN(out, out_end-3);
188     while (!strncmp(out-2, "\\N", 2))
189         out -= 2;
190     while (out[-1] == ' ')
191         out--;
192     snprintf(out, out_end-out, "\r\n");
193     return in;
194 }
195
196 static const char *read_ts(const char *buf, int *ts_start, int *ts_end,
197                            int *x1, int *y1, int *x2, int *y2)
198 {
199     int i, hs, ms, ss, he, me, se;
200
201     for (i=0; i<2; i++) {
202         /* try to read timestamps in either the first or second line */
203         int c = sscanf(buf, "%d:%2d:%2d%*1[,.]%3d --> %d:%2d:%2d%*1[,.]%3d"
204                        "%*[ ]X1:%u X2:%u Y1:%u Y2:%u",
205                        &hs, &ms, &ss, ts_start, &he, &me, &se, ts_end,
206                        x1, x2, y1, y2);
207         buf += strcspn(buf, "\n");
208         buf += !!*buf;
209         if (c >= 8) {
210             *ts_start = 100*(ss + 60*(ms + 60*hs)) + *ts_start/10;
211             *ts_end   = 100*(se + 60*(me + 60*he)) + *ts_end  /10;
212             return buf;
213         }
214     }
215     return NULL;
216 }
217
218 static int srt_decode_frame(AVCodecContext *avctx,
219                             void *data, int *got_sub_ptr, AVPacket *avpkt)
220 {
221     AVSubtitle *sub = data;
222     int ts_start, ts_end, x1 = -1, y1 = -1, x2 = -1, y2 = -1;
223     char buffer[2048];
224     const char *ptr = avpkt->data;
225     const char *end = avpkt->data + avpkt->size;
226     int size;
227     const uint8_t *p = av_packet_get_side_data(avpkt, AV_PKT_DATA_SUBTITLE_POSITION, &size);
228
229     if (p && size == 16) {
230         x1 = AV_RL32(p     );
231         y1 = AV_RL32(p +  4);
232         x2 = AV_RL32(p +  8);
233         y2 = AV_RL32(p + 12);
234     }
235
236     if (avpkt->size <= 0)
237         return avpkt->size;
238
239     while (ptr < end && *ptr) {
240         if (avctx->codec->id == AV_CODEC_ID_SRT) {
241             ptr = read_ts(ptr, &ts_start, &ts_end, &x1, &y1, &x2, &y2);
242             if (!ptr)
243                 break;
244         } else {
245             // Do final divide-by-10 outside rescale to force rounding down.
246             ts_start = av_rescale_q(avpkt->pts,
247                                     avctx->time_base,
248                                     (AVRational){1,100});
249             ts_end   = av_rescale_q(avpkt->pts + avpkt->duration,
250                                     avctx->time_base,
251                                     (AVRational){1,100});
252         }
253         ptr = srt_to_ass(avctx, buffer, buffer+sizeof(buffer), ptr,
254                          x1, y1, x2, y2);
255         ff_ass_add_rect(sub, buffer, ts_start, ts_end-ts_start, 0);
256     }
257
258     *got_sub_ptr = sub->num_rects > 0;
259     return avpkt->size;
260 }
261
262 #if CONFIG_SRT_DECODER
263 /* deprecated decoder */
264 AVCodec ff_srt_decoder = {
265     .name         = "srt",
266     .long_name    = NULL_IF_CONFIG_SMALL("SubRip subtitle with embedded timing"),
267     .type         = AVMEDIA_TYPE_SUBTITLE,
268     .id           = AV_CODEC_ID_SRT,
269     .init         = ff_ass_subtitle_header_default,
270     .decode       = srt_decode_frame,
271 };
272 #endif
273
274 #if CONFIG_SUBRIP_DECODER
275 AVCodec ff_subrip_decoder = {
276     .name         = "subrip",
277     .long_name    = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
278     .type         = AVMEDIA_TYPE_SUBTITLE,
279     .id           = AV_CODEC_ID_SUBRIP,
280     .init         = ff_ass_subtitle_header_default,
281     .decode       = srt_decode_frame,
282 };
283 #endif