1/* 2 * Cinepak Video Decoder 3 * Copyright (C) 2003 the ffmpeg project 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 22/** 23 * @file 24 * Cinepak video decoder 25 * by Ewald Snel <ewald@rambo.its.tudelft.nl> 26 * For more information on the Cinepak algorithm, visit: 27 * http://www.csse.monash.edu.au/~timf/ 28 * For more information on the quirky data inside Sega FILM/CPK files, visit: 29 * http://wiki.multimedia.cx/index.php?title=Sega_FILM 30 */ 31 32#include <stdio.h> 33#include <stdlib.h> 34#include <string.h> 35 36#include "libavutil/intreadwrite.h" 37#include "avcodec.h" 38 39 40typedef struct { 41 uint8_t y0, y1, y2, y3; 42 uint8_t u, v; 43} cvid_codebook; 44 45#define MAX_STRIPS 32 46 47typedef struct { 48 uint16_t id; 49 uint16_t x1, y1; 50 uint16_t x2, y2; 51 cvid_codebook v4_codebook[256]; 52 cvid_codebook v1_codebook[256]; 53} cvid_strip; 54 55typedef struct CinepakContext { 56 57 AVCodecContext *avctx; 58 AVFrame frame; 59 60 const unsigned char *data; 61 int size; 62 63 int width, height; 64 65 int palette_video; 66 cvid_strip strips[MAX_STRIPS]; 67 68 int sega_film_skip_bytes; 69 70} CinepakContext; 71 72static void cinepak_decode_codebook (cvid_codebook *codebook, 73 int chunk_id, int size, const uint8_t *data) 74{ 75 const uint8_t *eod = (data + size); 76 uint32_t flag, mask; 77 int i, n; 78 79 /* check if this chunk contains 4- or 6-element vectors */ 80 n = (chunk_id & 0x04) ? 4 : 6; 81 flag = 0; 82 mask = 0; 83 84 for (i=0; i < 256; i++) { 85 if ((chunk_id & 0x01) && !(mask >>= 1)) { 86 if ((data + 4) > eod) 87 break; 88 89 flag = AV_RB32 (data); 90 data += 4; 91 mask = 0x80000000; 92 } 93 94 if (!(chunk_id & 0x01) || (flag & mask)) { 95 if ((data + n) > eod) 96 break; 97 98 if (n == 6) { 99 codebook[i].y0 = *data++; 100 codebook[i].y1 = *data++; 101 codebook[i].y2 = *data++; 102 codebook[i].y3 = *data++; 103 codebook[i].u = 128 + *data++; 104 codebook[i].v = 128 + *data++; 105 } else { 106 /* this codebook type indicates either greyscale or 107 * palettized video; if palettized, U & V components will 108 * not be used so it is safe to set them to 128 for the 109 * benefit of greyscale rendering in YUV420P */ 110 codebook[i].y0 = *data++; 111 codebook[i].y1 = *data++; 112 codebook[i].y2 = *data++; 113 codebook[i].y3 = *data++; 114 codebook[i].u = 128; 115 codebook[i].v = 128; 116 } 117 } 118 } 119} 120 121static int cinepak_decode_vectors (CinepakContext *s, cvid_strip *strip, 122 int chunk_id, int size, const uint8_t *data) 123{ 124 const uint8_t *eod = (data + size); 125 uint32_t flag, mask; 126 cvid_codebook *codebook; 127 unsigned int x, y; 128 uint32_t iy[4]; 129 uint32_t iu[2]; 130 uint32_t iv[2]; 131 132 flag = 0; 133 mask = 0; 134 135 for (y=strip->y1; y < strip->y2; y+=4) { 136 137 iy[0] = strip->x1 + (y * s->frame.linesize[0]); 138 iy[1] = iy[0] + s->frame.linesize[0]; 139 iy[2] = iy[1] + s->frame.linesize[0]; 140 iy[3] = iy[2] + s->frame.linesize[0]; 141 iu[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[1]); 142 iu[1] = iu[0] + s->frame.linesize[1]; 143 iv[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[2]); 144 iv[1] = iv[0] + s->frame.linesize[2]; 145 146 for (x=strip->x1; x < strip->x2; x+=4) { 147 if ((chunk_id & 0x01) && !(mask >>= 1)) { 148 if ((data + 4) > eod) 149 return -1; 150 151 flag = AV_RB32 (data); 152 data += 4; 153 mask = 0x80000000; 154 } 155 156 if (!(chunk_id & 0x01) || (flag & mask)) { 157 if (!(chunk_id & 0x02) && !(mask >>= 1)) { 158 if ((data + 4) > eod) 159 return -1; 160 161 flag = AV_RB32 (data); 162 data += 4; 163 mask = 0x80000000; 164 } 165 166 if ((chunk_id & 0x02) || (~flag & mask)) { 167 if (data >= eod) 168 return -1; 169 170 codebook = &strip->v1_codebook[*data++]; 171 s->frame.data[0][iy[0] + 0] = codebook->y0; 172 s->frame.data[0][iy[0] + 1] = codebook->y0; 173 s->frame.data[0][iy[1] + 0] = codebook->y0; 174 s->frame.data[0][iy[1] + 1] = codebook->y0; 175 if (!s->palette_video) { 176 s->frame.data[1][iu[0]] = codebook->u; 177 s->frame.data[2][iv[0]] = codebook->v; 178 } 179 180 s->frame.data[0][iy[0] + 2] = codebook->y1; 181 s->frame.data[0][iy[0] + 3] = codebook->y1; 182 s->frame.data[0][iy[1] + 2] = codebook->y1; 183 s->frame.data[0][iy[1] + 3] = codebook->y1; 184 if (!s->palette_video) { 185 s->frame.data[1][iu[0] + 1] = codebook->u; 186 s->frame.data[2][iv[0] + 1] = codebook->v; 187 } 188 189 s->frame.data[0][iy[2] + 0] = codebook->y2; 190 s->frame.data[0][iy[2] + 1] = codebook->y2; 191 s->frame.data[0][iy[3] + 0] = codebook->y2; 192 s->frame.data[0][iy[3] + 1] = codebook->y2; 193 if (!s->palette_video) { 194 s->frame.data[1][iu[1]] = codebook->u; 195 s->frame.data[2][iv[1]] = codebook->v; 196 } 197 198 s->frame.data[0][iy[2] + 2] = codebook->y3; 199 s->frame.data[0][iy[2] + 3] = codebook->y3; 200 s->frame.data[0][iy[3] + 2] = codebook->y3; 201 s->frame.data[0][iy[3] + 3] = codebook->y3; 202 if (!s->palette_video) { 203 s->frame.data[1][iu[1] + 1] = codebook->u; 204 s->frame.data[2][iv[1] + 1] = codebook->v; 205 } 206 207 } else if (flag & mask) { 208 if ((data + 4) > eod) 209 return -1; 210 211 codebook = &strip->v4_codebook[*data++]; 212 s->frame.data[0][iy[0] + 0] = codebook->y0; 213 s->frame.data[0][iy[0] + 1] = codebook->y1; 214 s->frame.data[0][iy[1] + 0] = codebook->y2; 215 s->frame.data[0][iy[1] + 1] = codebook->y3; 216 if (!s->palette_video) { 217 s->frame.data[1][iu[0]] = codebook->u; 218 s->frame.data[2][iv[0]] = codebook->v; 219 } 220 221 codebook = &strip->v4_codebook[*data++]; 222 s->frame.data[0][iy[0] + 2] = codebook->y0; 223 s->frame.data[0][iy[0] + 3] = codebook->y1; 224 s->frame.data[0][iy[1] + 2] = codebook->y2; 225 s->frame.data[0][iy[1] + 3] = codebook->y3; 226 if (!s->palette_video) { 227 s->frame.data[1][iu[0] + 1] = codebook->u; 228 s->frame.data[2][iv[0] + 1] = codebook->v; 229 } 230 231 codebook = &strip->v4_codebook[*data++]; 232 s->frame.data[0][iy[2] + 0] = codebook->y0; 233 s->frame.data[0][iy[2] + 1] = codebook->y1; 234 s->frame.data[0][iy[3] + 0] = codebook->y2; 235 s->frame.data[0][iy[3] + 1] = codebook->y3; 236 if (!s->palette_video) { 237 s->frame.data[1][iu[1]] = codebook->u; 238 s->frame.data[2][iv[1]] = codebook->v; 239 } 240 241 codebook = &strip->v4_codebook[*data++]; 242 s->frame.data[0][iy[2] + 2] = codebook->y0; 243 s->frame.data[0][iy[2] + 3] = codebook->y1; 244 s->frame.data[0][iy[3] + 2] = codebook->y2; 245 s->frame.data[0][iy[3] + 3] = codebook->y3; 246 if (!s->palette_video) { 247 s->frame.data[1][iu[1] + 1] = codebook->u; 248 s->frame.data[2][iv[1] + 1] = codebook->v; 249 } 250 251 } 252 } 253 254 iy[0] += 4; iy[1] += 4; 255 iy[2] += 4; iy[3] += 4; 256 iu[0] += 2; iu[1] += 2; 257 iv[0] += 2; iv[1] += 2; 258 } 259 } 260 261 return 0; 262} 263 264static int cinepak_decode_strip (CinepakContext *s, 265 cvid_strip *strip, const uint8_t *data, int size) 266{ 267 const uint8_t *eod = (data + size); 268 int chunk_id, chunk_size; 269 270 /* coordinate sanity checks */ 271 if (strip->x1 >= s->width || strip->x2 > s->width || 272 strip->y1 >= s->height || strip->y2 > s->height || 273 strip->x1 >= strip->x2 || strip->y1 >= strip->y2) 274 return -1; 275 276 while ((data + 4) <= eod) { 277 chunk_id = data[0]; 278 chunk_size = AV_RB24 (&data[1]) - 4; 279 if(chunk_size < 0) 280 return -1; 281 282 data += 4; 283 chunk_size = ((data + chunk_size) > eod) ? (eod - data) : chunk_size; 284 285 switch (chunk_id) { 286 287 case 0x20: 288 case 0x21: 289 case 0x24: 290 case 0x25: 291 cinepak_decode_codebook (strip->v4_codebook, chunk_id, 292 chunk_size, data); 293 break; 294 295 case 0x22: 296 case 0x23: 297 case 0x26: 298 case 0x27: 299 cinepak_decode_codebook (strip->v1_codebook, chunk_id, 300 chunk_size, data); 301 break; 302 303 case 0x30: 304 case 0x31: 305 case 0x32: 306 return cinepak_decode_vectors (s, strip, chunk_id, 307 chunk_size, data); 308 } 309 310 data += chunk_size; 311 } 312 313 return -1; 314} 315 316static int cinepak_decode (CinepakContext *s) 317{ 318 const uint8_t *eod = (s->data + s->size); 319 int i, result, strip_size, frame_flags, num_strips; 320 int y0 = 0; 321 int encoded_buf_size; 322 323 if (s->size < 10) 324 return -1; 325 326 frame_flags = s->data[0]; 327 num_strips = AV_RB16 (&s->data[8]); 328 encoded_buf_size = ((s->data[1] << 16) | AV_RB16 (&s->data[2])); 329 330 /* if this is the first frame, check for deviant Sega FILM data */ 331 if (s->sega_film_skip_bytes == -1) { 332 if (encoded_buf_size != s->size) { 333 /* If the encoded frame size differs from the frame size as indicated 334 * by the container file, this data likely comes from a Sega FILM/CPK file. 335 * If the frame header is followed by the bytes FE 00 00 06 00 00 then 336 * this is probably one of the two known files that have 6 extra bytes 337 * after the frame header. Else, assume 2 extra bytes. */ 338 if ((s->data[10] == 0xFE) && 339 (s->data[11] == 0x00) && 340 (s->data[12] == 0x00) && 341 (s->data[13] == 0x06) && 342 (s->data[14] == 0x00) && 343 (s->data[15] == 0x00)) 344 s->sega_film_skip_bytes = 6; 345 else 346 s->sega_film_skip_bytes = 2; 347 } else 348 s->sega_film_skip_bytes = 0; 349 } 350 351 s->data += 10 + s->sega_film_skip_bytes; 352 353 if (num_strips > MAX_STRIPS) 354 num_strips = MAX_STRIPS; 355 356 for (i=0; i < num_strips; i++) { 357 if ((s->data + 12) > eod) 358 return -1; 359 360 s->strips[i].id = s->data[0]; 361 s->strips[i].y1 = y0; 362 s->strips[i].x1 = 0; 363 s->strips[i].y2 = y0 + AV_RB16 (&s->data[8]); 364 s->strips[i].x2 = s->avctx->width; 365 366 strip_size = AV_RB24 (&s->data[1]) - 12; 367 s->data += 12; 368 strip_size = ((s->data + strip_size) > eod) ? (eod - s->data) : strip_size; 369 370 if ((i > 0) && !(frame_flags & 0x01)) { 371 memcpy (s->strips[i].v4_codebook, s->strips[i-1].v4_codebook, 372 sizeof(s->strips[i].v4_codebook)); 373 memcpy (s->strips[i].v1_codebook, s->strips[i-1].v1_codebook, 374 sizeof(s->strips[i].v1_codebook)); 375 } 376 377 result = cinepak_decode_strip (s, &s->strips[i], s->data, strip_size); 378 379 if (result != 0) 380 return result; 381 382 s->data += strip_size; 383 y0 = s->strips[i].y2; 384 } 385 return 0; 386} 387 388static av_cold int cinepak_decode_init(AVCodecContext *avctx) 389{ 390 CinepakContext *s = avctx->priv_data; 391 392 s->avctx = avctx; 393 s->width = (avctx->width + 3) & ~3; 394 s->height = (avctx->height + 3) & ~3; 395 s->sega_film_skip_bytes = -1; /* uninitialized state */ 396 397 // check for paletted data 398 if ((avctx->palctrl == NULL) || (avctx->bits_per_coded_sample == 40)) { 399 s->palette_video = 0; 400 avctx->pix_fmt = PIX_FMT_YUV420P; 401 } else { 402 s->palette_video = 1; 403 avctx->pix_fmt = PIX_FMT_PAL8; 404 } 405 406 s->frame.data[0] = NULL; 407 408 return 0; 409} 410 411static int cinepak_decode_frame(AVCodecContext *avctx, 412 void *data, int *data_size, 413 AVPacket *avpkt) 414{ 415 const uint8_t *buf = avpkt->data; 416 int buf_size = avpkt->size; 417 CinepakContext *s = avctx->priv_data; 418 419 s->data = buf; 420 s->size = buf_size; 421 422 s->frame.reference = 1; 423 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | 424 FF_BUFFER_HINTS_REUSABLE; 425 if (avctx->reget_buffer(avctx, &s->frame)) { 426 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); 427 return -1; 428 } 429 430 cinepak_decode(s); 431 432 if (s->palette_video) { 433 memcpy (s->frame.data[1], avctx->palctrl->palette, AVPALETTE_SIZE); 434 if (avctx->palctrl->palette_changed) { 435 s->frame.palette_has_changed = 1; 436 avctx->palctrl->palette_changed = 0; 437 } else 438 s->frame.palette_has_changed = 0; 439 } 440 441 *data_size = sizeof(AVFrame); 442 *(AVFrame*)data = s->frame; 443 444 /* report that the buffer was completely consumed */ 445 return buf_size; 446} 447 448static av_cold int cinepak_decode_end(AVCodecContext *avctx) 449{ 450 CinepakContext *s = avctx->priv_data; 451 452 if (s->frame.data[0]) 453 avctx->release_buffer(avctx, &s->frame); 454 455 return 0; 456} 457 458AVCodec cinepak_decoder = { 459 "cinepak", 460 AVMEDIA_TYPE_VIDEO, 461 CODEC_ID_CINEPAK, 462 sizeof(CinepakContext), 463 cinepak_decode_init, 464 NULL, 465 cinepak_decode_end, 466 cinepak_decode_frame, 467 CODEC_CAP_DR1, 468 .long_name = NULL_IF_CONFIG_SMALL("Cinepak"), 469}; 470