ffmpeg / libavcodec / dvdsub.c @ 5509bffa
History | View | Annotate | Download (13.9 KB)
1 |
/*
|
---|---|
2 |
* DVD subtitle decoding for ffmpeg
|
3 |
* Copyright (c) 2005 Fabrice Bellard.
|
4 |
*
|
5 |
* This library is free software; you can redistribute it and/or
|
6 |
* modify it under the terms of the GNU Lesser General Public
|
7 |
* License as published by the Free Software Foundation; either
|
8 |
* version 2 of the License, or (at your option) any later version.
|
9 |
*
|
10 |
* This library is distributed in the hope that it will be useful,
|
11 |
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
12 |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
13 |
* Lesser General Public License for more details.
|
14 |
*
|
15 |
* You should have received a copy of the GNU Lesser General Public
|
16 |
* License along with this library; if not, write to the Free Software
|
17 |
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
18 |
*/
|
19 |
#include "avcodec.h" |
20 |
|
21 |
//#define DEBUG
|
22 |
|
23 |
typedef struct DVDSubContext { |
24 |
} DVDSubContext; |
25 |
|
26 |
static int dvdsub_init_decoder(AVCodecContext *avctx) |
27 |
{ |
28 |
return 0; |
29 |
} |
30 |
|
31 |
uint16_t getbe16(const uint8_t *p)
|
32 |
{ |
33 |
return (p[0] << 8) | p[1]; |
34 |
} |
35 |
|
36 |
int get_nibble(const uint8_t *buf, int nibble_offset) |
37 |
{ |
38 |
return (buf[nibble_offset >> 1] >> ((1 - (nibble_offset & 1)) << 2)) & 0xf; |
39 |
} |
40 |
|
41 |
static int decode_rle(uint8_t *bitmap, int linesize, int w, int h, |
42 |
const uint8_t *buf, int nibble_offset, int buf_size) |
43 |
{ |
44 |
unsigned int v; |
45 |
int x, y, len, color, nibble_end;
|
46 |
uint8_t *d; |
47 |
|
48 |
nibble_end = buf_size * 2;
|
49 |
x = 0;
|
50 |
y = 0;
|
51 |
d = bitmap; |
52 |
for(;;) {
|
53 |
if (nibble_offset >= nibble_end)
|
54 |
return -1; |
55 |
v = get_nibble(buf, nibble_offset++); |
56 |
if (v < 0x4) { |
57 |
v = (v << 4) | get_nibble(buf, nibble_offset++);
|
58 |
if (v < 0x10) { |
59 |
v = (v << 4) | get_nibble(buf, nibble_offset++);
|
60 |
if (v < 0x040) { |
61 |
v = (v << 4) | get_nibble(buf, nibble_offset++);
|
62 |
if (v < 4) { |
63 |
v |= (w - x) << 2;
|
64 |
} |
65 |
} |
66 |
} |
67 |
} |
68 |
len = v >> 2;
|
69 |
if (len > (w - x))
|
70 |
len = (w - x); |
71 |
color = v & 0x03;
|
72 |
memset(d + x, color, len); |
73 |
x += len; |
74 |
if (x >= w) {
|
75 |
y++; |
76 |
if (y >= h)
|
77 |
break;
|
78 |
d += linesize; |
79 |
x = 0;
|
80 |
/* byte align */
|
81 |
nibble_offset += (nibble_offset & 1);
|
82 |
} |
83 |
} |
84 |
return 0; |
85 |
} |
86 |
|
87 |
static void guess_palette(uint32_t *rgba_palette, |
88 |
uint8_t *palette, |
89 |
uint8_t *alpha, |
90 |
uint32_t subtitle_color) |
91 |
{ |
92 |
uint8_t color_used[16];
|
93 |
int nb_opaque_colors, i, level, j, r, g, b;
|
94 |
|
95 |
for(i = 0; i < 4; i++) |
96 |
rgba_palette[i] = 0;
|
97 |
|
98 |
memset(color_used, 0, 16); |
99 |
nb_opaque_colors = 0;
|
100 |
for(i = 0; i < 4; i++) { |
101 |
if (alpha[i] != 0 && !color_used[palette[i]]) { |
102 |
color_used[palette[i]] = 1;
|
103 |
nb_opaque_colors++; |
104 |
} |
105 |
} |
106 |
|
107 |
if (nb_opaque_colors == 0) |
108 |
return;
|
109 |
|
110 |
j = nb_opaque_colors; |
111 |
memset(color_used, 0, 16); |
112 |
for(i = 0; i < 4; i++) { |
113 |
if (alpha[i] != 0) { |
114 |
if (!color_used[palette[i]]) {
|
115 |
level = (0xff * j) / nb_opaque_colors;
|
116 |
r = (((subtitle_color >> 16) & 0xff) * level) >> 8; |
117 |
g = (((subtitle_color >> 8) & 0xff) * level) >> 8; |
118 |
b = (((subtitle_color >> 0) & 0xff) * level) >> 8; |
119 |
rgba_palette[i] = b | (g << 8) | (r << 16) | ((alpha[i] * 17) << 24); |
120 |
color_used[palette[i]] = (i + 1);
|
121 |
j--; |
122 |
} else {
|
123 |
rgba_palette[i] = (rgba_palette[color_used[palette[i]] - 1] & 0x00ffffff) | |
124 |
((alpha[i] * 17) << 24); |
125 |
} |
126 |
} |
127 |
} |
128 |
} |
129 |
|
130 |
static int decode_dvd_subtitles(AVSubtitle *sub_header, |
131 |
const uint8_t *buf, int buf_size) |
132 |
{ |
133 |
int cmd_pos, pos, cmd, x1, y1, x2, y2, offset1, offset2, next_cmd_pos;
|
134 |
uint8_t palette[4], alpha[4]; |
135 |
int date;
|
136 |
int i;
|
137 |
int is_menu = 0; |
138 |
|
139 |
if (buf_size < 4) |
140 |
return -1; |
141 |
sub_header->rects = NULL;
|
142 |
sub_header->num_rects = 0;
|
143 |
sub_header->start_display_time = 0;
|
144 |
sub_header->end_display_time = 0;
|
145 |
|
146 |
cmd_pos = getbe16(buf + 2);
|
147 |
while ((cmd_pos + 4) < buf_size) { |
148 |
date = getbe16(buf + cmd_pos); |
149 |
next_cmd_pos = getbe16(buf + cmd_pos + 2);
|
150 |
#ifdef DEBUG
|
151 |
av_log(NULL, AV_LOG_INFO, "cmd_pos=0x%04x next=0x%04x date=%d\n", |
152 |
cmd_pos, next_cmd_pos, date); |
153 |
#endif
|
154 |
pos = cmd_pos + 4;
|
155 |
offset1 = -1;
|
156 |
offset2 = -1;
|
157 |
x1 = y1 = x2 = y2 = 0;
|
158 |
while (pos < buf_size) {
|
159 |
cmd = buf[pos++]; |
160 |
#ifdef DEBUG
|
161 |
av_log(NULL, AV_LOG_INFO, "cmd=%02x\n", cmd); |
162 |
#endif
|
163 |
switch(cmd) {
|
164 |
case 0x00: |
165 |
/* menu subpicture */
|
166 |
is_menu = 1;
|
167 |
break;
|
168 |
case 0x01: |
169 |
/* set start date */
|
170 |
sub_header->start_display_time = (date << 10) / 90; |
171 |
break;
|
172 |
case 0x02: |
173 |
/* set end date */
|
174 |
sub_header->end_display_time = (date << 10) / 90; |
175 |
break;
|
176 |
case 0x03: |
177 |
/* set palette */
|
178 |
if ((buf_size - pos) < 2) |
179 |
goto fail;
|
180 |
palette[3] = buf[pos] >> 4; |
181 |
palette[2] = buf[pos] & 0x0f; |
182 |
palette[1] = buf[pos + 1] >> 4; |
183 |
palette[0] = buf[pos + 1] & 0x0f; |
184 |
pos += 2;
|
185 |
break;
|
186 |
case 0x04: |
187 |
/* set alpha */
|
188 |
if ((buf_size - pos) < 2) |
189 |
goto fail;
|
190 |
alpha[3] = buf[pos] >> 4; |
191 |
alpha[2] = buf[pos] & 0x0f; |
192 |
alpha[1] = buf[pos + 1] >> 4; |
193 |
alpha[0] = buf[pos + 1] & 0x0f; |
194 |
pos += 2;
|
195 |
#ifdef DEBUG
|
196 |
av_log(NULL, AV_LOG_INFO, "alpha=%x%x%x%x\n", alpha[0],alpha[1],alpha[2],alpha[3]); |
197 |
#endif
|
198 |
break;
|
199 |
case 0x05: |
200 |
if ((buf_size - pos) < 6) |
201 |
goto fail;
|
202 |
x1 = (buf[pos] << 4) | (buf[pos + 1] >> 4); |
203 |
x2 = ((buf[pos + 1] & 0x0f) << 8) | buf[pos + 2]; |
204 |
y1 = (buf[pos + 3] << 4) | (buf[pos + 4] >> 4); |
205 |
y2 = ((buf[pos + 4] & 0x0f) << 8) | buf[pos + 5]; |
206 |
#ifdef DEBUG
|
207 |
av_log(NULL, AV_LOG_INFO, "x1=%d x2=%d y1=%d y2=%d\n", |
208 |
x1, x2, y1, y2); |
209 |
#endif
|
210 |
pos += 6;
|
211 |
break;
|
212 |
case 0x06: |
213 |
if ((buf_size - pos) < 4) |
214 |
goto fail;
|
215 |
offset1 = getbe16(buf + pos); |
216 |
offset2 = getbe16(buf + pos + 2);
|
217 |
#ifdef DEBUG
|
218 |
av_log(NULL, AV_LOG_INFO, "offset1=0x%04x offset2=0x%04x\n", offset1, offset2); |
219 |
#endif
|
220 |
pos += 4;
|
221 |
break;
|
222 |
case 0xff: |
223 |
default:
|
224 |
goto the_end;
|
225 |
} |
226 |
} |
227 |
the_end:
|
228 |
if (offset1 >= 0) { |
229 |
int w, h;
|
230 |
uint8_t *bitmap; |
231 |
|
232 |
/* decode the bitmap */
|
233 |
w = x2 - x1 + 1;
|
234 |
if (w < 0) |
235 |
w = 0;
|
236 |
h = y2 - y1; |
237 |
if (h < 0) |
238 |
h = 0;
|
239 |
if (w > 0 && h > 0) { |
240 |
if (sub_header->rects != NULL) { |
241 |
for (i = 0; i < sub_header->num_rects; i++) { |
242 |
av_free(sub_header->rects[i].bitmap); |
243 |
av_free(sub_header->rects[i].rgba_palette); |
244 |
} |
245 |
av_freep(&sub_header->rects); |
246 |
sub_header->num_rects = 0;
|
247 |
} |
248 |
|
249 |
bitmap = av_malloc(w * h); |
250 |
sub_header->rects = av_mallocz(sizeof(AVSubtitleRect));
|
251 |
sub_header->num_rects = 1;
|
252 |
sub_header->rects[0].rgba_palette = av_malloc(4 * 4); |
253 |
decode_rle(bitmap, w * 2, w, h / 2, |
254 |
buf, offset1 * 2, buf_size);
|
255 |
decode_rle(bitmap + w, w * 2, w, h / 2, |
256 |
buf, offset2 * 2, buf_size);
|
257 |
guess_palette(sub_header->rects[0].rgba_palette,
|
258 |
palette, alpha, 0xffff00);
|
259 |
sub_header->rects[0].x = x1;
|
260 |
sub_header->rects[0].y = y1;
|
261 |
sub_header->rects[0].w = w;
|
262 |
sub_header->rects[0].h = h;
|
263 |
sub_header->rects[0].nb_colors = 4; |
264 |
sub_header->rects[0].linesize = w;
|
265 |
sub_header->rects[0].bitmap = bitmap;
|
266 |
} |
267 |
} |
268 |
if (next_cmd_pos == cmd_pos)
|
269 |
break;
|
270 |
cmd_pos = next_cmd_pos; |
271 |
} |
272 |
if (sub_header->num_rects > 0) |
273 |
return is_menu;
|
274 |
fail:
|
275 |
return -1; |
276 |
} |
277 |
|
278 |
static int is_transp(const uint8_t *buf, int pitch, int n, |
279 |
const uint8_t *transp_color)
|
280 |
{ |
281 |
int i;
|
282 |
for(i = 0; i < n; i++) { |
283 |
if (!transp_color[*buf])
|
284 |
return 0; |
285 |
buf += pitch; |
286 |
} |
287 |
return 1; |
288 |
} |
289 |
|
290 |
/* return 0 if empty rectangle, 1 if non empty */
|
291 |
static int find_smallest_bounding_rectangle(AVSubtitle *s) |
292 |
{ |
293 |
uint8_t transp_color[256];
|
294 |
int y1, y2, x1, x2, y, w, h, i;
|
295 |
uint8_t *bitmap; |
296 |
|
297 |
if (s->num_rects == 0 || s->rects == NULL || s->rects[0].w <= 0 || s->rects[0].h <= 0) |
298 |
return 0; |
299 |
|
300 |
memset(transp_color, 0, 256); |
301 |
for(i = 0; i < s->rects[0].nb_colors; i++) { |
302 |
if ((s->rects[0].rgba_palette[i] >> 24) == 0) |
303 |
transp_color[i] = 1;
|
304 |
} |
305 |
y1 = 0;
|
306 |
while (y1 < s->rects[0].h && is_transp(s->rects[0].bitmap + y1 * s->rects[0].linesize, |
307 |
1, s->rects[0].w, transp_color)) |
308 |
y1++; |
309 |
if (y1 == s->rects[0].h) { |
310 |
av_freep(&s->rects[0].bitmap);
|
311 |
s->rects[0].w = s->rects[0].h = 0; |
312 |
return 0; |
313 |
} |
314 |
|
315 |
y2 = s->rects[0].h - 1; |
316 |
while (y2 > 0 && is_transp(s->rects[0].bitmap + y2 * s->rects[0].linesize, 1, |
317 |
s->rects[0].w, transp_color))
|
318 |
y2--; |
319 |
x1 = 0;
|
320 |
while (x1 < (s->rects[0].w - 1) && is_transp(s->rects[0].bitmap + x1, s->rects[0].linesize, |
321 |
s->rects[0].h, transp_color))
|
322 |
x1++; |
323 |
x2 = s->rects[0].w - 1; |
324 |
while (x2 > 0 && is_transp(s->rects[0].bitmap + x2, s->rects[0].linesize, s->rects[0].h, |
325 |
transp_color)) |
326 |
x2--; |
327 |
w = x2 - x1 + 1;
|
328 |
h = y2 - y1 + 1;
|
329 |
bitmap = av_malloc(w * h); |
330 |
if (!bitmap)
|
331 |
return 1; |
332 |
for(y = 0; y < h; y++) { |
333 |
memcpy(bitmap + w * y, s->rects[0].bitmap + x1 + (y1 + y) * s->rects[0].linesize, w); |
334 |
} |
335 |
av_freep(&s->rects[0].bitmap);
|
336 |
s->rects[0].bitmap = bitmap;
|
337 |
s->rects[0].linesize = w;
|
338 |
s->rects[0].w = w;
|
339 |
s->rects[0].h = h;
|
340 |
s->rects[0].x += x1;
|
341 |
s->rects[0].y += y1;
|
342 |
return 1; |
343 |
} |
344 |
|
345 |
static int dvdsub_close_decoder(AVCodecContext *avctx) |
346 |
{ |
347 |
return 0; |
348 |
} |
349 |
|
350 |
#ifdef DEBUG
|
351 |
#undef fprintf
|
352 |
static void ppm_save(const char *filename, uint8_t *bitmap, int w, int h, |
353 |
uint32_t *rgba_palette) |
354 |
{ |
355 |
int x, y, v;
|
356 |
FILE *f; |
357 |
|
358 |
f = fopen(filename, "w");
|
359 |
if (!f) {
|
360 |
perror(filename); |
361 |
exit(1);
|
362 |
} |
363 |
fprintf(f, "P6\n"
|
364 |
"%d %d\n"
|
365 |
"%d\n",
|
366 |
w, h, 255);
|
367 |
for(y = 0; y < h; y++) { |
368 |
for(x = 0; x < w; x++) { |
369 |
v = rgba_palette[bitmap[y * w + x]]; |
370 |
putc((v >> 16) & 0xff, f); |
371 |
putc((v >> 8) & 0xff, f); |
372 |
putc((v >> 0) & 0xff, f); |
373 |
} |
374 |
} |
375 |
fclose(f); |
376 |
} |
377 |
#endif
|
378 |
|
379 |
static int dvdsub_decode(AVCodecContext *avctx, |
380 |
void *data, int *data_size, |
381 |
uint8_t *buf, int buf_size)
|
382 |
{ |
383 |
AVSubtitle *sub = (void *)data;
|
384 |
int is_menu;
|
385 |
|
386 |
is_menu = decode_dvd_subtitles(sub, buf, buf_size); |
387 |
|
388 |
if (is_menu < 0) { |
389 |
no_subtitle:
|
390 |
*data_size = 0;
|
391 |
|
392 |
return buf_size;
|
393 |
} |
394 |
if (!is_menu && find_smallest_bounding_rectangle(sub) == 0) |
395 |
goto no_subtitle;
|
396 |
|
397 |
#if defined(DEBUG)
|
398 |
av_log(NULL, AV_LOG_INFO, "start=%d ms end =%d ms\n", |
399 |
sub->start_display_time, |
400 |
sub->end_display_time); |
401 |
ppm_save("/tmp/a.ppm", sub->rects[0].bitmap, |
402 |
sub->rects[0].w, sub->rects[0].h, sub->rects[0].rgba_palette); |
403 |
#endif
|
404 |
|
405 |
*data_size = 1;
|
406 |
return buf_size;
|
407 |
} |
408 |
|
409 |
AVCodec dvdsub_decoder = { |
410 |
"dvdsub",
|
411 |
CODEC_TYPE_SUBTITLE, |
412 |
CODEC_ID_DVD_SUBTITLE, |
413 |
sizeof(DVDSubContext),
|
414 |
dvdsub_init_decoder, |
415 |
NULL,
|
416 |
dvdsub_close_decoder, |
417 |
dvdsub_decode, |
418 |
}; |
419 |
|
420 |
/* parser definition */
|
421 |
typedef struct DVDSubParseContext { |
422 |
uint8_t *packet; |
423 |
int packet_len;
|
424 |
int packet_index;
|
425 |
} DVDSubParseContext; |
426 |
|
427 |
static int dvdsub_parse_init(AVCodecParserContext *s) |
428 |
{ |
429 |
return 0; |
430 |
} |
431 |
|
432 |
static int dvdsub_parse(AVCodecParserContext *s, |
433 |
AVCodecContext *avctx, |
434 |
uint8_t **poutbuf, int *poutbuf_size,
|
435 |
const uint8_t *buf, int buf_size) |
436 |
{ |
437 |
DVDSubParseContext *pc = s->priv_data; |
438 |
|
439 |
if (pc->packet_index == 0) { |
440 |
if (buf_size < 2) |
441 |
return 0; |
442 |
pc->packet_len = (buf[0] << 8) | buf[1]; |
443 |
av_freep(&pc->packet); |
444 |
pc->packet = av_malloc(pc->packet_len); |
445 |
} |
446 |
if (pc->packet) {
|
447 |
if (pc->packet_index + buf_size <= pc->packet_len) {
|
448 |
memcpy(pc->packet + pc->packet_index, buf, buf_size); |
449 |
pc->packet_index += buf_size; |
450 |
if (pc->packet_index >= pc->packet_len) {
|
451 |
*poutbuf = pc->packet; |
452 |
*poutbuf_size = pc->packet_len; |
453 |
pc->packet_index = 0;
|
454 |
return buf_size;
|
455 |
} |
456 |
} else {
|
457 |
/* erroneous size */
|
458 |
pc->packet_index = 0;
|
459 |
} |
460 |
} |
461 |
*poutbuf = NULL;
|
462 |
*poutbuf_size = 0;
|
463 |
return buf_size;
|
464 |
} |
465 |
|
466 |
static void dvdsub_parse_close(AVCodecParserContext *s) |
467 |
{ |
468 |
DVDSubParseContext *pc = s->priv_data; |
469 |
av_freep(&pc->packet); |
470 |
} |
471 |
|
472 |
AVCodecParser dvdsub_parser = { |
473 |
{ CODEC_ID_DVD_SUBTITLE }, |
474 |
sizeof(DVDSubParseContext),
|
475 |
dvdsub_parse_init, |
476 |
dvdsub_parse, |
477 |
dvdsub_parse_close, |
478 |
}; |