1 /*
2 * DVB subtitle encoding
3 * Copyright (c) 2005 Fabrice Bellard
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 #include "avcodec.h"
22 #include "bytestream.h"
23 #include "libavutil/colorspace.h"
24
25 typedef struct DVBSubtitleContext {
26 int object_version;
27 } DVBSubtitleContext;
28
29 #define PUTBITS2(val)\
30 {\
31 bitbuf |= (val) << bitcnt;\
32 bitcnt -= 2;\
33 if (bitcnt < 0) {\
34 bitcnt = 6;\
35 *q++ = bitbuf;\
36 bitbuf = 0;\
37 }\
38 }
39
dvb_encode_rle2(uint8_t ** pq,const uint8_t * bitmap,int linesize,int w,int h)40 static void dvb_encode_rle2(uint8_t **pq,
41 const uint8_t *bitmap, int linesize,
42 int w, int h)
43 {
44 uint8_t *q;
45 unsigned int bitbuf;
46 int bitcnt;
47 int x, y, len, x1, v, color;
48
49 q = *pq;
50
51 for(y = 0; y < h; y++) {
52 *q++ = 0x10;
53 bitbuf = 0;
54 bitcnt = 6;
55
56 x = 0;
57 while (x < w) {
58 x1 = x;
59 color = bitmap[x1++];
60 while (x1 < w && bitmap[x1] == color)
61 x1++;
62 len = x1 - x;
63 if (color == 0 && len == 2) {
64 PUTBITS2(0);
65 PUTBITS2(0);
66 PUTBITS2(1);
67 } else if (len >= 3 && len <= 10) {
68 v = len - 3;
69 PUTBITS2(0);
70 PUTBITS2((v >> 2) | 2);
71 PUTBITS2(v & 3);
72 PUTBITS2(color);
73 } else if (len >= 12 && len <= 27) {
74 v = len - 12;
75 PUTBITS2(0);
76 PUTBITS2(0);
77 PUTBITS2(2);
78 PUTBITS2(v >> 2);
79 PUTBITS2(v & 3);
80 PUTBITS2(color);
81 } else if (len >= 29) {
82 /* length = 29 ... 284 */
83 if (len > 284)
84 len = 284;
85 v = len - 29;
86 PUTBITS2(0);
87 PUTBITS2(0);
88 PUTBITS2(3);
89 PUTBITS2((v >> 6));
90 PUTBITS2((v >> 4) & 3);
91 PUTBITS2((v >> 2) & 3);
92 PUTBITS2(v & 3);
93 PUTBITS2(color);
94 } else {
95 PUTBITS2(color);
96 if (color == 0) {
97 PUTBITS2(1);
98 }
99 len = 1;
100 }
101 x += len;
102 }
103 /* end of line */
104 PUTBITS2(0);
105 PUTBITS2(0);
106 PUTBITS2(0);
107 if (bitcnt != 6) {
108 *q++ = bitbuf;
109 }
110 *q++ = 0xf0;
111 bitmap += linesize;
112 }
113 *pq = q;
114 }
115
116 #define PUTBITS4(val)\
117 {\
118 bitbuf |= (val) << bitcnt;\
119 bitcnt -= 4;\
120 if (bitcnt < 0) {\
121 bitcnt = 4;\
122 *q++ = bitbuf;\
123 bitbuf = 0;\
124 }\
125 }
126
127 /* some DVB decoders only implement 4 bits/pixel */
dvb_encode_rle4(uint8_t ** pq,const uint8_t * bitmap,int linesize,int w,int h)128 static void dvb_encode_rle4(uint8_t **pq,
129 const uint8_t *bitmap, int linesize,
130 int w, int h)
131 {
132 uint8_t *q;
133 unsigned int bitbuf;
134 int bitcnt;
135 int x, y, len, x1, v, color;
136
137 q = *pq;
138
139 for(y = 0; y < h; y++) {
140 *q++ = 0x11;
141 bitbuf = 0;
142 bitcnt = 4;
143
144 x = 0;
145 while (x < w) {
146 x1 = x;
147 color = bitmap[x1++];
148 while (x1 < w && bitmap[x1] == color)
149 x1++;
150 len = x1 - x;
151 if (color == 0 && len == 2) {
152 PUTBITS4(0);
153 PUTBITS4(0xd);
154 } else if (color == 0 && (len >= 3 && len <= 9)) {
155 PUTBITS4(0);
156 PUTBITS4(len - 2);
157 } else if (len >= 4 && len <= 7) {
158 PUTBITS4(0);
159 PUTBITS4(8 + len - 4);
160 PUTBITS4(color);
161 } else if (len >= 9 && len <= 24) {
162 PUTBITS4(0);
163 PUTBITS4(0xe);
164 PUTBITS4(len - 9);
165 PUTBITS4(color);
166 } else if (len >= 25) {
167 if (len > 280)
168 len = 280;
169 v = len - 25;
170 PUTBITS4(0);
171 PUTBITS4(0xf);
172 PUTBITS4(v >> 4);
173 PUTBITS4(v & 0xf);
174 PUTBITS4(color);
175 } else {
176 PUTBITS4(color);
177 if (color == 0) {
178 PUTBITS4(0xc);
179 }
180 len = 1;
181 }
182 x += len;
183 }
184 /* end of line */
185 PUTBITS4(0);
186 PUTBITS4(0);
187 if (bitcnt != 4) {
188 *q++ = bitbuf;
189 }
190 *q++ = 0xf0;
191 bitmap += linesize;
192 }
193 *pq = q;
194 }
195
dvb_encode_rle8(uint8_t ** pq,const uint8_t * bitmap,int linesize,int w,int h)196 static void dvb_encode_rle8(uint8_t **pq,
197 const uint8_t *bitmap, int linesize,
198 int w, int h)
199 {
200 uint8_t *q;
201 int x, y, len, x1, color;
202
203 q = *pq;
204
205 for (y = 0; y < h; y++) {
206 *q++ = 0x12;
207
208 x = 0;
209 while (x < w) {
210 x1 = x;
211 color = bitmap[x1++];
212 while (x1 < w && bitmap[x1] == color)
213 x1++;
214 len = x1 - x;
215 if (len == 1 && color) {
216 // 00000001 to 11111111 1 pixel in colour x
217 *q++ = color;
218 } else {
219 if (color == 0x00) {
220 // 00000000 0LLLLLLL L pixels (1-127) in colour 0 (L > 0)
221 len = FFMIN(len, 127);
222 *q++ = 0x00;
223 *q++ = len;
224 } else if (len > 2) {
225 // 00000000 1LLLLLLL CCCCCCCC L pixels (3-127) in colour C (L > 2)
226 len = FFMIN(len, 127);
227 *q++ = 0x00;
228 *q++ = 0x80+len;
229 *q++ = color;
230 }
231 else if (len == 2) {
232 *q++ = color;
233 *q++ = color;
234 } else {
235 *q++ = color;
236 len = 1;
237 }
238 }
239 x += len;
240 }
241 /* end of line */
242 // 00000000 00000000 end of 8-bit/pixel_code_string
243 *q++ = 0x00;
244 *q++ = 0x00;
245 bitmap += linesize;
246 }
247 *pq = q;
248 }
249
encode_dvb_subtitles(DVBSubtitleContext * s,uint8_t * outbuf,const AVSubtitle * h)250 static int encode_dvb_subtitles(DVBSubtitleContext *s,
251 uint8_t *outbuf, const AVSubtitle *h)
252 {
253 uint8_t *q, *pseg_len;
254 int page_id, region_id, clut_id, object_id, i, bpp_index, page_state;
255
256
257 q = outbuf;
258
259 page_id = 1;
260
261 if (h->num_rects && !h->rects)
262 return -1;
263
264 /* page composition segment */
265
266 *q++ = 0x0f; /* sync_byte */
267 *q++ = 0x10; /* segment_type */
268 bytestream_put_be16(&q, page_id);
269 pseg_len = q;
270 q += 2; /* segment length */
271 *q++ = 30; /* page_timeout (seconds) */
272 page_state = 2; /* mode change */
273 /* page_version = 0 + page_state */
274 *q++ = (s->object_version << 4) | (page_state << 2) | 3;
275
276 for (region_id = 0; region_id < h->num_rects; region_id++) {
277 *q++ = region_id;
278 *q++ = 0xff; /* reserved */
279 bytestream_put_be16(&q, h->rects[region_id]->x); /* left pos */
280 bytestream_put_be16(&q, h->rects[region_id]->y); /* top pos */
281 }
282
283 bytestream_put_be16(&pseg_len, q - pseg_len - 2);
284
285 if (h->num_rects) {
286 for (clut_id = 0; clut_id < h->num_rects; clut_id++) {
287
288 /* CLUT segment */
289
290 if (h->rects[clut_id]->nb_colors <= 4) {
291 /* 2 bpp, some decoders do not support it correctly */
292 bpp_index = 0;
293 } else if (h->rects[clut_id]->nb_colors <= 16) {
294 /* 4 bpp, standard encoding */
295 bpp_index = 1;
296 } else if (h->rects[clut_id]->nb_colors <= 256) {
297 /* 8 bpp, standard encoding */
298 bpp_index = 2;
299 } else {
300 return -1;
301 }
302
303
304 /* CLUT segment */
305 *q++ = 0x0f; /* sync byte */
306 *q++ = 0x12; /* CLUT definition segment */
307 bytestream_put_be16(&q, page_id);
308 pseg_len = q;
309 q += 2; /* segment length */
310 *q++ = clut_id;
311 *q++ = (0 << 4) | 0xf; /* version = 0 */
312
313 for(i = 0; i < h->rects[clut_id]->nb_colors; i++) {
314 *q++ = i; /* clut_entry_id */
315 *q++ = (1 << (7 - bpp_index)) | (0xf << 1) | 1; /* 2 bits/pixel full range */
316 {
317 int a, r, g, b;
318 uint32_t x= ((uint32_t*)h->rects[clut_id]->pict.data[1])[i];
319 a = (x >> 24) & 0xff;
320 r = (x >> 16) & 0xff;
321 g = (x >> 8) & 0xff;
322 b = (x >> 0) & 0xff;
323
324 *q++ = RGB_TO_Y_CCIR(r, g, b);
325 *q++ = RGB_TO_V_CCIR(r, g, b, 0);
326 *q++ = RGB_TO_U_CCIR(r, g, b, 0);
327 *q++ = 255 - a;
328 }
329 }
330
331 bytestream_put_be16(&pseg_len, q - pseg_len - 2);
332 }
333 }
334
335 for (region_id = 0; region_id < h->num_rects; region_id++) {
336
337 /* region composition segment */
338
339 if (h->rects[region_id]->nb_colors <= 4) {
340 /* 2 bpp, some decoders do not support it correctly */
341 bpp_index = 0;
342 } else if (h->rects[region_id]->nb_colors <= 16) {
343 /* 4 bpp, standard encoding */
344 bpp_index = 1;
345 } else {
346 return -1;
347 }
348
349 *q++ = 0x0f; /* sync_byte */
350 *q++ = 0x11; /* segment_type */
351 bytestream_put_be16(&q, page_id);
352 pseg_len = q;
353 q += 2; /* segment length */
354 *q++ = region_id;
355 *q++ = (s->object_version << 4) | (0 << 3) | 0x07; /* version , no fill */
356 bytestream_put_be16(&q, h->rects[region_id]->w); /* region width */
357 bytestream_put_be16(&q, h->rects[region_id]->h); /* region height */
358 *q++ = ((1 + bpp_index) << 5) | ((1 + bpp_index) << 2) | 0x03;
359 *q++ = region_id; /* clut_id == region_id */
360 *q++ = 0; /* 8 bit fill colors */
361 *q++ = 0x03; /* 4 bit and 2 bit fill colors */
362
363 bytestream_put_be16(&q, region_id); /* object_id == region_id */
364 *q++ = (0 << 6) | (0 << 4);
365 *q++ = 0;
366 *q++ = 0xf0;
367 *q++ = 0;
368
369 bytestream_put_be16(&pseg_len, q - pseg_len - 2);
370 }
371
372 if (h->num_rects) {
373
374 for (object_id = 0; object_id < h->num_rects; object_id++) {
375 void (*dvb_encode_rle)(uint8_t **pq,
376 const uint8_t *bitmap, int linesize,
377 int w, int h);
378
379 /* bpp_index maths */
380 if (h->rects[object_id]->nb_colors <= 4) {
381 /* 2 bpp, some decoders do not support it correctly */
382 dvb_encode_rle = dvb_encode_rle2;
383 } else if (h->rects[object_id]->nb_colors <= 16) {
384 /* 4 bpp, standard encoding */
385 dvb_encode_rle = dvb_encode_rle4;
386 } else if (h->rects[object_id]->nb_colors <= 256) {
387 /* 8 bpp, standard encoding */
388 dvb_encode_rle = dvb_encode_rle8;
389 } else {
390 return -1;
391 }
392
393 /* Object Data segment */
394 *q++ = 0x0f; /* sync byte */
395 *q++ = 0x13;
396 bytestream_put_be16(&q, page_id);
397 pseg_len = q;
398 q += 2; /* segment length */
399
400 bytestream_put_be16(&q, object_id);
401 *q++ = (s->object_version << 4) | (0 << 2) | (0 << 1) | 1; /* version = 0,
402 onject_coding_method,
403 non_modifying_color_flag */
404 {
405 uint8_t *ptop_field_len, *pbottom_field_len, *top_ptr, *bottom_ptr;
406
407 ptop_field_len = q;
408 q += 2;
409 pbottom_field_len = q;
410 q += 2;
411
412 top_ptr = q;
413 dvb_encode_rle(&q, h->rects[object_id]->pict.data[0], h->rects[object_id]->w * 2,
414 h->rects[object_id]->w, h->rects[object_id]->h >> 1);
415 bottom_ptr = q;
416 dvb_encode_rle(&q, h->rects[object_id]->pict.data[0] + h->rects[object_id]->w,
417 h->rects[object_id]->w * 2, h->rects[object_id]->w,
418 h->rects[object_id]->h >> 1);
419
420 bytestream_put_be16(&ptop_field_len, bottom_ptr - top_ptr);
421 bytestream_put_be16(&pbottom_field_len, q - bottom_ptr);
422 }
423
424 bytestream_put_be16(&pseg_len, q - pseg_len - 2);
425 }
426 }
427
428 /* end of display set segment */
429
430 *q++ = 0x0f; /* sync_byte */
431 *q++ = 0x80; /* segment_type */
432 bytestream_put_be16(&q, page_id);
433 pseg_len = q;
434 q += 2; /* segment length */
435
436 bytestream_put_be16(&pseg_len, q - pseg_len - 2);
437
438 s->object_version = (s->object_version + 1) & 0xf;
439 return q - outbuf;
440 }
441
dvbsub_encode(AVCodecContext * avctx,unsigned char * buf,int buf_size,const AVSubtitle * sub)442 static int dvbsub_encode(AVCodecContext *avctx,
443 unsigned char *buf, int buf_size,
444 const AVSubtitle *sub)
445 {
446 DVBSubtitleContext *s = avctx->priv_data;
447 int ret;
448
449 ret = encode_dvb_subtitles(s, buf, sub);
450 return ret;
451 }
452
453 AVCodec ff_dvbsub_encoder = {
454 .name = "dvbsub",
455 .long_name = NULL_IF_CONFIG_SMALL("DVB subtitles"),
456 .type = AVMEDIA_TYPE_SUBTITLE,
457 .id = AV_CODEC_ID_DVB_SUBTITLE,
458 .priv_data_size = sizeof(DVBSubtitleContext),
459 .encode_sub = dvbsub_encode,
460 };
461