2 * Copyright (c) 2012 Clément Bœsch
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * MicroDVD subtitle decoder
25 * Based on the specifications found here:
26 * https://trac.videolan.org/vlc/ticket/1825#comment:6
29 #include "libavutil/avstring.h"
30 #include "libavutil/parseutils.h"
31 #include "libavutil/bprint.h"
35 static int indexof(const char *s, int c)
37 char *f = strchr(s, c);
38 return f ? (f - s) : -1;
50 #define MICRODVD_PERSISTENT_OFF 0
51 #define MICRODVD_PERSISTENT_ON 1
52 #define MICRODVD_PERSISTENT_OPENED 2
54 // Color, Font, Size, cHarset, stYle, Position, cOordinate
55 #define MICRODVD_TAGS "cfshyYpo"
57 static void microdvd_set_tag(struct microdvd_tag *tags, struct microdvd_tag tag)
59 int tag_index = indexof(MICRODVD_TAGS, tag.key);
63 memcpy(&tags[tag_index], &tag, sizeof(tag));
66 // italic, bold, underline, strike-through
67 #define MICRODVD_STYLES "ibus"
69 static char *microdvd_load_tags(struct microdvd_tag *tags, char *s)
73 char tag_char = *(s + 1);
74 struct microdvd_tag tag = {0};
76 if (!tag_char || *(s + 2) != ':')
84 tag.persistent = MICRODVD_PERSISTENT_ON;
86 while (*s && *s != '}') {
87 int style_index = indexof(MICRODVD_STYLES, *s);
90 tag.data1 |= (1 << style_index);
95 /* We must distinguish persistent and non-persistent styles
96 * to handle this kind of style tags: {y:ib}{Y:us} */
102 tag.persistent = MICRODVD_PERSISTENT_ON;
104 tag.data1 = strtol(s, &s, 16) & 0x00ffffff;
112 tag.persistent = MICRODVD_PERSISTENT_ON;
114 int len = indexof(s, '}');
118 tag.data_string_len = len;
126 tag.persistent = MICRODVD_PERSISTENT_ON;
128 tag.data1 = strtol(s, &s, 10);
136 //TODO: not yet handled, just parsed.
137 int len = indexof(s, '}');
141 tag.data_string_len = len;
149 tag.persistent = MICRODVD_PERSISTENT_ON;
150 tag.data1 = (*s++ == '1');
158 tag.persistent = MICRODVD_PERSISTENT_ON;
159 tag.data1 = strtol(s, &s, 10);
163 tag.data2 = strtol(s, &s, 10);
169 default: /* Unknown tag, we consider it's text */
176 microdvd_set_tag(tags, tag);
182 static void microdvd_open_tags(AVBPrint *new_line, struct microdvd_tag *tags)
185 for (i = 0; i < sizeof(MICRODVD_TAGS) - 1; i++) {
186 if (tags[i].persistent == MICRODVD_PERSISTENT_OPENED)
188 switch (tags[i].key) {
191 for (sidx = 0; sidx < sizeof(MICRODVD_STYLES) - 1; sidx++)
192 if (tags[i].data1 & (1 << sidx))
193 av_bprintf(new_line, "{\\%c1}", MICRODVD_STYLES[sidx]);
197 av_bprintf(new_line, "{\\c&H%06X&}", tags[i].data1);
201 av_bprintf(new_line, "{\\fn%.*s}",
202 tags[i].data_string_len, tags[i].data_string);
206 av_bprintf(new_line, "{\\fs%d}", tags[i].data1);
210 if (tags[i].data1 == 0)
211 av_bprintf(new_line, "{\\an8}");
215 av_bprintf(new_line, "{\\pos(%d,%d)}",
216 tags[i].data1, tags[i].data2);
219 if (tags[i].persistent == MICRODVD_PERSISTENT_ON)
220 tags[i].persistent = MICRODVD_PERSISTENT_OPENED;
224 static void microdvd_close_no_persistent_tags(AVBPrint *new_line,
225 struct microdvd_tag *tags)
229 for (i = sizeof(MICRODVD_TAGS) - 2; i; i--) {
230 if (tags[i].persistent != MICRODVD_PERSISTENT_OFF)
232 switch (tags[i].key) {
235 for (sidx = sizeof(MICRODVD_STYLES) - 2; sidx >= 0; sidx--)
236 if (tags[i].data1 & (1 << sidx))
237 av_bprintf(new_line, "{\\%c0}", MICRODVD_STYLES[sidx]);
241 av_bprintf(new_line, "{\\c}");
245 av_bprintf(new_line, "{\\fn}");
249 av_bprintf(new_line, "{\\fs}");
256 static int microdvd_decode_frame(AVCodecContext *avctx,
257 void *data, int *got_sub_ptr, AVPacket *avpkt)
259 AVSubtitle *sub = data;
262 char *line = avpkt->data;
263 char *end = avpkt->data + avpkt->size;
264 int64_t frame_start = avpkt->pts;
265 int64_t frame_end = avpkt->pts + avpkt->duration;
266 int ts_start = av_rescale_q(frame_start, avctx->time_base, (AVRational){1,100});
267 int ts_end = av_rescale_q(frame_end, avctx->time_base, (AVRational){1,100});
268 struct microdvd_tag tags[sizeof(MICRODVD_TAGS) - 1] = {{0}};
270 if (avpkt->size <= 0)
273 av_bprint_init(&new_line, 0, 2048);
275 // skip {frame_start}{frame_end}
276 line = strchr(line, '}'); if (!line) goto end; line++;
277 line = strchr(line, '}'); if (!line) goto end; line++;
280 while (line < end && *line) {
282 // parse MicroDVD tags, and open them in ASS
283 line = microdvd_load_tags(tags, line);
284 microdvd_open_tags(&new_line, tags);
286 // simple copy until EOL or forced carriage return
287 while (line < end && *line && *line != '|') {
288 av_bprint_chars(&new_line, *line, 1);
293 if (line < end && *line == '|') {
294 microdvd_close_no_persistent_tags(&new_line, tags);
295 av_bprintf(&new_line, "\\N");
301 av_bprint_finalize(&new_line, &decoded_sub);
303 ff_ass_add_rect(sub, decoded_sub, ts_start, ts_end, 0);
304 av_free(decoded_sub);
306 *got_sub_ptr = sub->num_rects > 0;
310 AVCodec ff_microdvd_decoder = {
312 .long_name = NULL_IF_CONFIG_SMALL("MicroDVD subtitle"),
313 .type = AVMEDIA_TYPE_SUBTITLE,
314 .id = CODEC_ID_MICRODVD,
315 .init = ff_ass_subtitle_header_default,
316 .decode = microdvd_decode_frame,