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 "codec_internal.h" 24#include "libavutil/colorspace.h" 25 26typedef struct DVBSubtitleContext { 27 int object_version; 28} DVBSubtitleContext; 29 30#define PUTBITS2(val)\ 31{\ 32 bitbuf |= (val) << bitcnt;\ 33 bitcnt -= 2;\ 34 if (bitcnt < 0) {\ 35 bitcnt = 6;\ 36 *q++ = bitbuf;\ 37 bitbuf = 0;\ 38 }\ 39} 40 41static int dvb_encode_rle2(uint8_t **pq, int buf_size, 42 const uint8_t *bitmap, int linesize, 43 int w, int h) 44{ 45 uint8_t *q, *line_begin; 46 unsigned int bitbuf; 47 int bitcnt; 48 int x, y, len, x1, v, color; 49 50 q = *pq; 51 52 for(y = 0; y < h; y++) { 53 // Worst case line is 3 bits per value + 4 bytes overhead 54 if (buf_size * 8 < w * 3 + 32) 55 return AVERROR_BUFFER_TOO_SMALL; 56 line_begin = q; 57 *q++ = 0x10; 58 bitbuf = 0; 59 bitcnt = 6; 60 61 x = 0; 62 while (x < w) { 63 x1 = x; 64 color = bitmap[x1++]; 65 while (x1 < w && bitmap[x1] == color) 66 x1++; 67 len = x1 - x; 68 if (color == 0 && len == 2) { 69 PUTBITS2(0); 70 PUTBITS2(0); 71 PUTBITS2(1); 72 } else if (len >= 3 && len <= 10) { 73 v = len - 3; 74 PUTBITS2(0); 75 PUTBITS2((v >> 2) | 2); 76 PUTBITS2(v & 3); 77 PUTBITS2(color); 78 } else if (len >= 12 && len <= 27) { 79 v = len - 12; 80 PUTBITS2(0); 81 PUTBITS2(0); 82 PUTBITS2(2); 83 PUTBITS2(v >> 2); 84 PUTBITS2(v & 3); 85 PUTBITS2(color); 86 } else if (len >= 29) { 87 /* length = 29 ... 284 */ 88 if (len > 284) 89 len = 284; 90 v = len - 29; 91 PUTBITS2(0); 92 PUTBITS2(0); 93 PUTBITS2(3); 94 PUTBITS2((v >> 6)); 95 PUTBITS2((v >> 4) & 3); 96 PUTBITS2((v >> 2) & 3); 97 PUTBITS2(v & 3); 98 PUTBITS2(color); 99 } else { 100 PUTBITS2(color); 101 if (color == 0) { 102 PUTBITS2(1); 103 } 104 len = 1; 105 } 106 x += len; 107 } 108 /* end of line */ 109 PUTBITS2(0); 110 PUTBITS2(0); 111 PUTBITS2(0); 112 if (bitcnt != 6) { 113 *q++ = bitbuf; 114 } 115 *q++ = 0xf0; 116 bitmap += linesize; 117 buf_size -= q - line_begin; 118 } 119 len = q - *pq; 120 *pq = q; 121 return len; 122} 123 124#define PUTBITS4(val)\ 125{\ 126 bitbuf |= (val) << bitcnt;\ 127 bitcnt -= 4;\ 128 if (bitcnt < 0) {\ 129 bitcnt = 4;\ 130 *q++ = bitbuf;\ 131 bitbuf = 0;\ 132 }\ 133} 134 135/* some DVB decoders only implement 4 bits/pixel */ 136static int dvb_encode_rle4(uint8_t **pq, int buf_size, 137 const uint8_t *bitmap, int linesize, 138 int w, int h) 139{ 140 uint8_t *q, *line_begin; 141 unsigned int bitbuf; 142 int bitcnt; 143 int x, y, len, x1, v, color; 144 145 q = *pq; 146 147 for(y = 0; y < h; y++) { 148 // Worst case line is 6 bits per value, + 4 bytes overhead 149 if (buf_size * 8 < w * 6 + 32) 150 return AVERROR_BUFFER_TOO_SMALL; 151 line_begin = q; 152 *q++ = 0x11; 153 bitbuf = 0; 154 bitcnt = 4; 155 156 x = 0; 157 while (x < w) { 158 x1 = x; 159 color = bitmap[x1++]; 160 while (x1 < w && bitmap[x1] == color) 161 x1++; 162 len = x1 - x; 163 if (color == 0 && len == 2) { 164 PUTBITS4(0); 165 PUTBITS4(0xd); 166 } else if (color == 0 && (len >= 3 && len <= 9)) { 167 PUTBITS4(0); 168 PUTBITS4(len - 2); 169 } else if (len >= 4 && len <= 7) { 170 PUTBITS4(0); 171 PUTBITS4(8 + len - 4); 172 PUTBITS4(color); 173 } else if (len >= 9 && len <= 24) { 174 PUTBITS4(0); 175 PUTBITS4(0xe); 176 PUTBITS4(len - 9); 177 PUTBITS4(color); 178 } else if (len >= 25) { 179 if (len > 280) 180 len = 280; 181 v = len - 25; 182 PUTBITS4(0); 183 PUTBITS4(0xf); 184 PUTBITS4(v >> 4); 185 PUTBITS4(v & 0xf); 186 PUTBITS4(color); 187 } else { 188 PUTBITS4(color); 189 if (color == 0) { 190 PUTBITS4(0xc); 191 } 192 len = 1; 193 } 194 x += len; 195 } 196 /* end of line */ 197 PUTBITS4(0); 198 PUTBITS4(0); 199 if (bitcnt != 4) { 200 *q++ = bitbuf; 201 } 202 *q++ = 0xf0; 203 bitmap += linesize; 204 buf_size -= q - line_begin; 205 } 206 len = q - *pq; 207 *pq = q; 208 return len; 209} 210 211static int dvb_encode_rle8(uint8_t **pq, int buf_size, 212 const uint8_t *bitmap, int linesize, 213 int w, int h) 214{ 215 uint8_t *q, *line_begin; 216 int x, y, len, x1, color; 217 218 q = *pq; 219 220 for (y = 0; y < h; y++) { 221 // Worst case line is 12 bits per value, + 3 bytes overhead 222 if (buf_size * 8 < w * 12 + 24) 223 return AVERROR_BUFFER_TOO_SMALL; 224 line_begin = q; 225 *q++ = 0x12; 226 227 x = 0; 228 while (x < w) { 229 x1 = x; 230 color = bitmap[x1++]; 231 while (x1 < w && bitmap[x1] == color) 232 x1++; 233 len = x1 - x; 234 if (len == 1 && color) { 235 // 00000001 to 11111111 1 pixel in colour x 236 *q++ = color; 237 } else { 238 if (color == 0x00) { 239 // 00000000 0LLLLLLL L pixels (1-127) in colour 0 (L > 0) 240 len = FFMIN(len, 127); 241 *q++ = 0x00; 242 *q++ = len; 243 } else if (len > 2) { 244 // 00000000 1LLLLLLL CCCCCCCC L pixels (3-127) in colour C (L > 2) 245 len = FFMIN(len, 127); 246 *q++ = 0x00; 247 *q++ = 0x80+len; 248 *q++ = color; 249 } 250 else if (len == 2) { 251 *q++ = color; 252 *q++ = color; 253 } else { 254 *q++ = color; 255 len = 1; 256 } 257 } 258 x += len; 259 } 260 /* end of line */ 261 // 00000000 end of 8-bit/pixel_code_string 262 *q++ = 0x00; 263 *q++ = 0xf0; 264 bitmap += linesize; 265 buf_size -= q - line_begin; 266 } 267 len = q - *pq; 268 *pq = q; 269 return len; 270} 271 272static int dvbsub_encode(AVCodecContext *avctx, uint8_t *outbuf, int buf_size, 273 const AVSubtitle *h) 274{ 275 DVBSubtitleContext *s = avctx->priv_data; 276 uint8_t *q, *pseg_len; 277 int page_id, region_id, clut_id, object_id, i, bpp_index, page_state; 278 279 280 q = outbuf; 281 282 page_id = 1; 283 284 if (h->num_rects && !h->rects) 285 return AVERROR(EINVAL); 286 287 if (avctx->width > 0 && avctx->height > 0) { 288 if (buf_size < 11) 289 return AVERROR_BUFFER_TOO_SMALL; 290 /* display definition segment */ 291 *q++ = 0x0f; /* sync_byte */ 292 *q++ = 0x14; /* segment_type */ 293 bytestream_put_be16(&q, page_id); 294 pseg_len = q; 295 q += 2; /* segment length */ 296 *q++ = 0x00; /* dds version number & display window flag */ 297 bytestream_put_be16(&q, avctx->width - 1); /* display width */ 298 bytestream_put_be16(&q, avctx->height - 1); /* display height */ 299 bytestream_put_be16(&pseg_len, q - pseg_len - 2); 300 buf_size -= 11; 301 } 302 303 /* page composition segment */ 304 305 if (buf_size < 8 + h->num_rects * 6) 306 return AVERROR_BUFFER_TOO_SMALL; 307 *q++ = 0x0f; /* sync_byte */ 308 *q++ = 0x10; /* segment_type */ 309 bytestream_put_be16(&q, page_id); 310 pseg_len = q; 311 q += 2; /* segment length */ 312 *q++ = 30; /* page_timeout (seconds) */ 313 page_state = 2; /* mode change */ 314 /* page_version = 0 + page_state */ 315 *q++ = (s->object_version << 4) | (page_state << 2) | 3; 316 317 for (region_id = 0; region_id < h->num_rects; region_id++) { 318 *q++ = region_id; 319 *q++ = 0xff; /* reserved */ 320 bytestream_put_be16(&q, h->rects[region_id]->x); /* left pos */ 321 bytestream_put_be16(&q, h->rects[region_id]->y); /* top pos */ 322 } 323 324 bytestream_put_be16(&pseg_len, q - pseg_len - 2); 325 buf_size -= 8 + h->num_rects * 6; 326 327 if (h->num_rects) { 328 for (clut_id = 0; clut_id < h->num_rects; clut_id++) { 329 if (buf_size < 6 + h->rects[clut_id]->nb_colors * 6) 330 return AVERROR_BUFFER_TOO_SMALL; 331 332 /* CLUT segment */ 333 334 if (h->rects[clut_id]->nb_colors <= 4) { 335 /* 2 bpp, some decoders do not support it correctly */ 336 bpp_index = 0; 337 } else if (h->rects[clut_id]->nb_colors <= 16) { 338 /* 4 bpp, standard encoding */ 339 bpp_index = 1; 340 } else if (h->rects[clut_id]->nb_colors <= 256) { 341 /* 8 bpp, standard encoding */ 342 bpp_index = 2; 343 } else { 344 return AVERROR(EINVAL); 345 } 346 347 348 /* CLUT segment */ 349 *q++ = 0x0f; /* sync byte */ 350 *q++ = 0x12; /* CLUT definition segment */ 351 bytestream_put_be16(&q, page_id); 352 pseg_len = q; 353 q += 2; /* segment length */ 354 *q++ = clut_id; 355 *q++ = (0 << 4) | 0xf; /* version = 0 */ 356 357 for(i = 0; i < h->rects[clut_id]->nb_colors; i++) { 358 *q++ = i; /* clut_entry_id */ 359 *q++ = (1 << (7 - bpp_index)) | (0xf << 1) | 1; /* 2 bits/pixel full range */ 360 { 361 int a, r, g, b; 362 uint32_t x= ((uint32_t*)h->rects[clut_id]->data[1])[i]; 363 a = (x >> 24) & 0xff; 364 r = (x >> 16) & 0xff; 365 g = (x >> 8) & 0xff; 366 b = (x >> 0) & 0xff; 367 368 *q++ = RGB_TO_Y_CCIR(r, g, b); 369 *q++ = RGB_TO_V_CCIR(r, g, b, 0); 370 *q++ = RGB_TO_U_CCIR(r, g, b, 0); 371 *q++ = 255 - a; 372 } 373 } 374 375 bytestream_put_be16(&pseg_len, q - pseg_len - 2); 376 buf_size -= 6 + h->rects[clut_id]->nb_colors * 6; 377 } 378 379 if (buf_size < h->num_rects * 22) 380 return AVERROR_BUFFER_TOO_SMALL; 381 for (region_id = 0; region_id < h->num_rects; region_id++) { 382 383 /* region composition segment */ 384 385 if (h->rects[region_id]->nb_colors <= 4) { 386 /* 2 bpp, some decoders do not support it correctly */ 387 bpp_index = 0; 388 } else if (h->rects[region_id]->nb_colors <= 16) { 389 /* 4 bpp, standard encoding */ 390 bpp_index = 1; 391 } else if (h->rects[region_id]->nb_colors <= 256) { 392 /* 8 bpp, standard encoding */ 393 bpp_index = 2; 394 } else { 395 return AVERROR(EINVAL); 396 } 397 398 *q++ = 0x0f; /* sync_byte */ 399 *q++ = 0x11; /* segment_type */ 400 bytestream_put_be16(&q, page_id); 401 pseg_len = q; 402 q += 2; /* segment length */ 403 *q++ = region_id; 404 *q++ = (s->object_version << 4) | (0 << 3) | 0x07; /* version , no fill */ 405 bytestream_put_be16(&q, h->rects[region_id]->w); /* region width */ 406 bytestream_put_be16(&q, h->rects[region_id]->h); /* region height */ 407 *q++ = ((1 + bpp_index) << 5) | ((1 + bpp_index) << 2) | 0x03; 408 *q++ = region_id; /* clut_id == region_id */ 409 *q++ = 0; /* 8 bit fill colors */ 410 *q++ = 0x03; /* 4 bit and 2 bit fill colors */ 411 412 bytestream_put_be16(&q, region_id); /* object_id == region_id */ 413 *q++ = (0 << 6) | (0 << 4); 414 *q++ = 0; 415 *q++ = 0xf0; 416 *q++ = 0; 417 418 bytestream_put_be16(&pseg_len, q - pseg_len - 2); 419 } 420 buf_size -= h->num_rects * 22; 421 422 for (object_id = 0; object_id < h->num_rects; object_id++) { 423 int (*dvb_encode_rle)(uint8_t **pq, int buf_size, 424 const uint8_t *bitmap, int linesize, 425 int w, int h); 426 427 if (buf_size < 13) 428 return AVERROR_BUFFER_TOO_SMALL; 429 430 /* bpp_index maths */ 431 if (h->rects[object_id]->nb_colors <= 4) { 432 /* 2 bpp, some decoders do not support it correctly */ 433 dvb_encode_rle = dvb_encode_rle2; 434 } else if (h->rects[object_id]->nb_colors <= 16) { 435 /* 4 bpp, standard encoding */ 436 dvb_encode_rle = dvb_encode_rle4; 437 } else if (h->rects[object_id]->nb_colors <= 256) { 438 /* 8 bpp, standard encoding */ 439 dvb_encode_rle = dvb_encode_rle8; 440 } else { 441 return AVERROR(EINVAL); 442 } 443 444 /* Object Data segment */ 445 *q++ = 0x0f; /* sync byte */ 446 *q++ = 0x13; 447 bytestream_put_be16(&q, page_id); 448 pseg_len = q; 449 q += 2; /* segment length */ 450 451 bytestream_put_be16(&q, object_id); 452 *q++ = (s->object_version << 4) | (0 << 2) | (0 << 1) | 1; /* version = 0, 453 object_coding_method, 454 non_modifying_color_flag */ 455 { 456 uint8_t *ptop_field_len, *pbottom_field_len, *top_ptr, *bottom_ptr; 457 int ret; 458 459 ptop_field_len = q; 460 q += 2; 461 pbottom_field_len = q; 462 q += 2; 463 buf_size -= 13; 464 465 top_ptr = q; 466 ret = dvb_encode_rle(&q, buf_size, 467 h->rects[object_id]->data[0], 468 h->rects[object_id]->w * 2, 469 h->rects[object_id]->w, 470 h->rects[object_id]->h >> 1); 471 if (ret < 0) 472 return ret; 473 buf_size -= ret; 474 bottom_ptr = q; 475 ret = dvb_encode_rle(&q, buf_size, 476 h->rects[object_id]->data[0] + h->rects[object_id]->w, 477 h->rects[object_id]->w * 2, 478 h->rects[object_id]->w, 479 h->rects[object_id]->h >> 1); 480 if (ret < 0) 481 return ret; 482 buf_size -= ret; 483 484 bytestream_put_be16(&ptop_field_len, bottom_ptr - top_ptr); 485 bytestream_put_be16(&pbottom_field_len, q - bottom_ptr); 486 } 487 488 bytestream_put_be16(&pseg_len, q - pseg_len - 2); 489 } 490 } 491 492 /* end of display set segment */ 493 494 if (buf_size < 6) 495 return AVERROR_BUFFER_TOO_SMALL; 496 *q++ = 0x0f; /* sync_byte */ 497 *q++ = 0x80; /* segment_type */ 498 bytestream_put_be16(&q, page_id); 499 pseg_len = q; 500 q += 2; /* segment length */ 501 502 bytestream_put_be16(&pseg_len, q - pseg_len - 2); 503 buf_size -= 6; 504 505 s->object_version = (s->object_version + 1) & 0xf; 506 return q - outbuf; 507} 508 509const FFCodec ff_dvbsub_encoder = { 510 .p.name = "dvbsub", 511 .p.long_name = NULL_IF_CONFIG_SMALL("DVB subtitles"), 512 .p.type = AVMEDIA_TYPE_SUBTITLE, 513 .p.id = AV_CODEC_ID_DVB_SUBTITLE, 514 .priv_data_size = sizeof(DVBSubtitleContext), 515 FF_CODEC_ENCODE_SUB_CB(dvbsub_encode), 516}; 517