| 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 | |
| 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 */ |
| 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 | |
| 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 | |
| 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 | |
| 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 | }; |