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 /* some samples have lines that start with a / indicating non persistent italic
71 static char *check_for_italic_slash_marker(struct microdvd_tag *tags, char *s)
74 struct microdvd_tag tag = tags[indexof(MICRODVD_TAGS, 'y')];
76 tag.data1 |= 1 << 0 /* 'i' position in MICRODVD_STYLES */;
77 microdvd_set_tag(tags, tag);
83 static char *microdvd_load_tags(struct microdvd_tag *tags, char *s)
85 s = check_for_italic_slash_marker(tags, s);
89 char tag_char = *(s + 1);
90 struct microdvd_tag tag = {0};
92 if (!tag_char || *(s + 2) != ':')
100 tag.persistent = MICRODVD_PERSISTENT_ON;
102 while (*s && *s != '}') {
103 int style_index = indexof(MICRODVD_STYLES, *s);
105 if (style_index >= 0)
106 tag.data1 |= (1 << style_index);
111 /* We must distinguish persistent and non-persistent styles
112 * to handle this kind of style tags: {y:ib}{Y:us} */
118 tag.persistent = MICRODVD_PERSISTENT_ON;
120 while (*s == '$' || *s == '#')
122 tag.data1 = strtol(s, &s, 16) & 0x00ffffff;
130 tag.persistent = MICRODVD_PERSISTENT_ON;
132 int len = indexof(s, '}');
136 tag.data_string_len = len;
144 tag.persistent = MICRODVD_PERSISTENT_ON;
146 tag.data1 = strtol(s, &s, 10);
154 //TODO: not yet handled, just parsed.
155 int len = indexof(s, '}');
159 tag.data_string_len = len;
167 tag.persistent = MICRODVD_PERSISTENT_ON;
168 tag.data1 = (*s++ == '1');
176 tag.persistent = MICRODVD_PERSISTENT_ON;
177 tag.data1 = strtol(s, &s, 10);
181 tag.data2 = strtol(s, &s, 10);
187 default: /* Unknown tag, we consider it's text */
194 microdvd_set_tag(tags, tag);
197 return check_for_italic_slash_marker(tags, s);
200 static void microdvd_open_tags(AVBPrint *new_line, struct microdvd_tag *tags)
203 for (i = 0; i < sizeof(MICRODVD_TAGS) - 1; i++) {
204 if (tags[i].persistent == MICRODVD_PERSISTENT_OPENED)
206 switch (tags[i].key) {
209 for (sidx = 0; sidx < sizeof(MICRODVD_STYLES) - 1; sidx++)
210 if (tags[i].data1 & (1 << sidx))
211 av_bprintf(new_line, "{\\%c1}", MICRODVD_STYLES[sidx]);
215 av_bprintf(new_line, "{\\c&H%06X&}", tags[i].data1);
219 av_bprintf(new_line, "{\\fn%.*s}",
220 tags[i].data_string_len, tags[i].data_string);
224 av_bprintf(new_line, "{\\fs%d}", tags[i].data1);
228 if (tags[i].data1 == 0)
229 av_bprintf(new_line, "{\\an8}");
233 av_bprintf(new_line, "{\\pos(%d,%d)}",
234 tags[i].data1, tags[i].data2);
237 if (tags[i].persistent == MICRODVD_PERSISTENT_ON)
238 tags[i].persistent = MICRODVD_PERSISTENT_OPENED;
242 static void microdvd_close_no_persistent_tags(AVBPrint *new_line,
243 struct microdvd_tag *tags)
247 for (i = sizeof(MICRODVD_TAGS) - 2; i >= 0; i--) {
248 if (tags[i].persistent != MICRODVD_PERSISTENT_OFF)
250 switch (tags[i].key) {
253 for (sidx = sizeof(MICRODVD_STYLES) - 2; sidx >= 0; sidx--)
254 if (tags[i].data1 & (1 << sidx))
255 av_bprintf(new_line, "{\\%c0}", MICRODVD_STYLES[sidx]);
259 av_bprintf(new_line, "{\\c}");
263 av_bprintf(new_line, "{\\fn}");
267 av_bprintf(new_line, "{\\fs}");
274 static int microdvd_decode_frame(AVCodecContext *avctx,
275 void *data, int *got_sub_ptr, AVPacket *avpkt)
277 AVSubtitle *sub = data;
279 char *line = avpkt->data;
280 char *end = avpkt->data + avpkt->size;
281 struct microdvd_tag tags[sizeof(MICRODVD_TAGS) - 1] = {{0}};
283 if (avpkt->size <= 0)
286 av_bprint_init(&new_line, 0, 2048);
289 while (line < end && *line) {
291 // parse MicroDVD tags, and open them in ASS
292 line = microdvd_load_tags(tags, line);
293 microdvd_open_tags(&new_line, tags);
295 // simple copy until EOL or forced carriage return
296 while (line < end && *line && *line != '|') {
297 av_bprint_chars(&new_line, *line, 1);
302 if (line < end && *line == '|') {
303 microdvd_close_no_persistent_tags(&new_line, tags);
304 av_bprintf(&new_line, "\\N");
310 int64_t start = avpkt->pts;
311 int64_t duration = avpkt->duration;
312 int ts_start = av_rescale_q(start, avctx->time_base, (AVRational){1,100});
313 int ts_duration = duration != -1 ?
314 av_rescale_q(duration, avctx->time_base, (AVRational){1,100}) : -1;
316 ret = ff_ass_add_rect_bprint(sub, &new_line, ts_start, ts_duration);
317 av_bprint_finalize(&new_line, NULL);
322 *got_sub_ptr = sub->num_rects > 0;
326 static int microdvd_init(AVCodecContext *avctx)
330 int font_size = ASS_DEFAULT_FONT_SIZE;
331 int color = ASS_DEFAULT_COLOR;
332 int bold = ASS_DEFAULT_BOLD;
333 int italic = ASS_DEFAULT_ITALIC;
334 int underline = ASS_DEFAULT_UNDERLINE;
335 int alignment = ASS_DEFAULT_ALIGNMENT;
336 struct microdvd_tag tags[sizeof(MICRODVD_TAGS) - 1] = {{0}};
338 av_bprint_init(&font_buf, 0, AV_BPRINT_SIZE_AUTOMATIC);
339 av_bprintf(&font_buf, "%s", ASS_DEFAULT_FONT);
341 if (avctx->extradata) {
342 microdvd_load_tags(tags, avctx->extradata);
343 for (i = 0; i < sizeof(MICRODVD_TAGS) - 1; i++) {
344 switch (av_tolower(tags[i].key)) {
346 for (sidx = 0; sidx < sizeof(MICRODVD_STYLES) - 1; sidx++) {
347 if (tags[i].data1 & (1 << sidx)) {
348 switch (MICRODVD_STYLES[sidx]) {
349 case 'i': italic = 1; break;
350 case 'b': bold = 1; break;
351 case 'u': underline = 1; break;
357 case 'c': color = tags[i].data1; break;
358 case 's': font_size = tags[i].data1; break;
359 case 'p': alignment = 8; break;
362 av_bprint_clear(&font_buf);
363 av_bprintf(&font_buf, "%.*s",
364 tags[i].data_string_len, tags[i].data_string);
369 return ff_ass_subtitle_header(avctx, font_buf.str, font_size, color,
370 ASS_DEFAULT_BACK_COLOR, bold, italic,
371 underline, alignment);
374 AVCodec ff_microdvd_decoder = {
376 .long_name = NULL_IF_CONFIG_SMALL("MicroDVD subtitle"),
377 .type = AVMEDIA_TYPE_SUBTITLE,
378 .id = AV_CODEC_ID_MICRODVD,
379 .init = microdvd_init,
380 .decode = microdvd_decode_frame,