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   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 cinepak.c
  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 #include <unistd.h>
  36
  37 #include "avcodec.h"
  38 #include "dsputil.h"
  39
  40
  41 typedef struct {
  42     uint8_t  y0, y1, y2, y3;
  43     uint8_t  u, v;
  44 } cvid_codebook_t;
  45
  46 #define MAX_STRIPS      32
  47
  48 typedef struct {
  49     uint16_t          id;
  50     uint16_t          x1, y1;
  51     uint16_t          x2, y2;
  52     cvid_codebook_t   v4_codebook[256];
  53     cvid_codebook_t   v1_codebook[256];
  54 } cvid_strip_t;
  55
  56 typedef struct CinepakContext {
  57
  58     AVCodecContext *avctx;
  59     DSPContext dsp;
  60     AVFrame frame;
  61
  62     unsigned char *data;
  63     int size;
  64
  65     int width, height;
  66
  67     int palette_video;
  68     cvid_strip_t strips[MAX_STRIPS];
  69
  70     int sega_film_skip_bytes;
  71
  72 } CinepakContext;
  73
  74 static void cinepak_decode_codebook (cvid_codebook_t *codebook,
  75                                      int chunk_id, int size, uint8_t *data)
  76 {
  77     uint8_t *eod = (data + size);
  78     uint32_t flag, mask;
  79     int      i, n;
  80
  81     /* check if this chunk contains 4- or 6-element vectors */
  82     n    = (chunk_id & 0x0400) ? 4 : 6;
  83     flag = 0;
  84     mask = 0;
  85
  86     for (i=0; i < 256; i++) {
  87         if ((chunk_id & 0x0100) && !(mask >>= 1)) {
  88             if ((data + 4) > eod)
  89                 break;
  90
  91             flag  = AV_RB32 (data);
  92             data += 4;
  93             mask  = 0x80000000;
  94         }
  95
  96         if (!(chunk_id & 0x0100) || (flag & mask)) {
  97             if ((data + n) > eod)
  98                 break;
  99
 100             if (n == 6) {
 101                 codebook[i].y0 = *data++;
 102                 codebook[i].y1 = *data++;
 103                 codebook[i].y2 = *data++;
 104                 codebook[i].y3 = *data++;
 105                 codebook[i].u  = 128 + *data++;
 106                 codebook[i].v  = 128 + *data++;
 107             } else {
 108                 /* this codebook type indicates either greyscale or
 109                  * palettized video; if palettized, U & V components will
 110                  * not be used so it is safe to set them to 128 for the
 111                  * benefit of greyscale rendering in YUV420P */
 112                 codebook[i].y0 = *data++;
 113                 codebook[i].y1 = *data++;
 114                 codebook[i].y2 = *data++;
 115                 codebook[i].y3 = *data++;
 116                 codebook[i].u  = 128;
 117                 codebook[i].v  = 128;
 118             }
 119         }
 120     }
 121 }
 122
 123 static int cinepak_decode_vectors (CinepakContext *s, cvid_strip_t *strip,
 124                                    int chunk_id, int size, uint8_t *data)
 125 {
 126     uint8_t         *eod = (data + size);
 127     uint32_t         flag, mask;
 128     cvid_codebook_t *codebook;
 129     unsigned int     x, y;
 130     uint32_t         iy[4];
 131     uint32_t         iu[2];
 132     uint32_t         iv[2];
 133
 134     flag = 0;
 135     mask = 0;
 136
 137     for (y=strip->y1; y < strip->y2; y+=4) {
 138
 139         iy[0] = strip->x1 + (y * s->frame.linesize[0]);
 140         iy[1] = iy[0] + s->frame.linesize[0];
 141         iy[2] = iy[1] + s->frame.linesize[0];
 142         iy[3] = iy[2] + s->frame.linesize[0];
 143         iu[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[1]);
 144         iu[1] = iu[0] + s->frame.linesize[1];
 145         iv[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[2]);
 146         iv[1] = iv[0] + s->frame.linesize[2];
 147
 148         for (x=strip->x1; x < strip->x2; x+=4) {
 149             if ((chunk_id & 0x0100) && !(mask >>= 1)) {
 150                 if ((data + 4) > eod)
 151                     return -1;
 152
 153                 flag  = AV_RB32 (data);
 154                 data += 4;
 155                 mask  = 0x80000000;
 156             }
 157
 158             if (!(chunk_id & 0x0100) || (flag & mask)) {
 159                 if (!(chunk_id & 0x0200) && !(mask >>= 1)) {
 160                     if ((data + 4) > eod)
 161                         return -1;
 162
 163                     flag  = AV_RB32 (data);
 164                     data += 4;
 165                     mask  = 0x80000000;
 166                 }
 167
 168                 if ((chunk_id & 0x0200) || (~flag & mask)) {
 169                     if (data >= eod)
 170                         return -1;
 171
 172                     codebook = &strip->v1_codebook[*data++];
 173                     s->frame.data[0][iy[0] + 0] = codebook->y0;
 174                     s->frame.data[0][iy[0] + 1] = codebook->y0;
 175                     s->frame.data[0][iy[1] + 0] = codebook->y0;
 176                     s->frame.data[0][iy[1] + 1] = codebook->y0;
 177                     if (!s->palette_video) {
 178                         s->frame.data[1][iu[0]] = codebook->u;
 179                         s->frame.data[2][iv[0]] = codebook->v;
 180                     }
 181
 182                     s->frame.data[0][iy[0] + 2] = codebook->y1;
 183                     s->frame.data[0][iy[0] + 3] = codebook->y1;
 184                     s->frame.data[0][iy[1] + 2] = codebook->y1;
 185                     s->frame.data[0][iy[1] + 3] = codebook->y1;
 186                     if (!s->palette_video) {
 187                         s->frame.data[1][iu[0] + 1] = codebook->u;
 188                         s->frame.data[2][iv[0] + 1] = codebook->v;
 189                     }
 190
 191                     s->frame.data[0][iy[2] + 0] = codebook->y2;
 192                     s->frame.data[0][iy[2] + 1] = codebook->y2;
 193                     s->frame.data[0][iy[3] + 0] = codebook->y2;
 194                     s->frame.data[0][iy[3] + 1] = codebook->y2;
 195                     if (!s->palette_video) {
 196                         s->frame.data[1][iu[1]] = codebook->u;
 197                         s->frame.data[2][iv[1]] = codebook->v;
 198                     }
 199
 200                     s->frame.data[0][iy[2] + 2] = codebook->y3;
 201                     s->frame.data[0][iy[2] + 3] = codebook->y3;
 202                     s->frame.data[0][iy[3] + 2] = codebook->y3;
 203                     s->frame.data[0][iy[3] + 3] = codebook->y3;
 204                     if (!s->palette_video) {
 205                         s->frame.data[1][iu[1] + 1] = codebook->u;
 206                         s->frame.data[2][iv[1] + 1] = codebook->v;
 207                     }
 208
 209                 } else if (flag & mask) {
 210                     if ((data + 4) > eod)
 211                         return -1;
 212
 213                     codebook = &strip->v4_codebook[*data++];
 214                     s->frame.data[0][iy[0] + 0] = codebook->y0;
 215                     s->frame.data[0][iy[0] + 1] = codebook->y1;
 216                     s->frame.data[0][iy[1] + 0] = codebook->y2;
 217                     s->frame.data[0][iy[1] + 1] = codebook->y3;
 218                     if (!s->palette_video) {
 219                         s->frame.data[1][iu[0]] = codebook->u;
 220                         s->frame.data[2][iv[0]] = codebook->v;
 221                     }
 222
 223                     codebook = &strip->v4_codebook[*data++];
 224                     s->frame.data[0][iy[0] + 2] = codebook->y0;
 225                     s->frame.data[0][iy[0] + 3] = codebook->y1;
 226                     s->frame.data[0][iy[1] + 2] = codebook->y2;
 227                     s->frame.data[0][iy[1] + 3] = codebook->y3;
 228                     if (!s->palette_video) {
 229                         s->frame.data[1][iu[0] + 1] = codebook->u;
 230                         s->frame.data[2][iv[0] + 1] = codebook->v;
 231                     }
 232
 233                     codebook = &strip->v4_codebook[*data++];
 234                     s->frame.data[0][iy[2] + 0] = codebook->y0;
 235                     s->frame.data[0][iy[2] + 1] = codebook->y1;
 236                     s->frame.data[0][iy[3] + 0] = codebook->y2;
 237                     s->frame.data[0][iy[3] + 1] = codebook->y3;
 238                     if (!s->palette_video) {
 239                         s->frame.data[1][iu[1]] = codebook->u;
 240                         s->frame.data[2][iv[1]] = codebook->v;
 241                     }
 242
 243                     codebook = &strip->v4_codebook[*data++];
 244                     s->frame.data[0][iy[2] + 2] = codebook->y0;
 245                     s->frame.data[0][iy[2] + 3] = codebook->y1;
 246                     s->frame.data[0][iy[3] + 2] = codebook->y2;
 247                     s->frame.data[0][iy[3] + 3] = codebook->y3;
 248                     if (!s->palette_video) {
 249                         s->frame.data[1][iu[1] + 1] = codebook->u;
 250                         s->frame.data[2][iv[1] + 1] = codebook->v;
 251                     }
 252
 253                 }
 254             }
 255
 256             iy[0] += 4;  iy[1] += 4;
 257             iy[2] += 4;  iy[3] += 4;
 258             iu[0] += 2;  iu[1] += 2;
 259             iv[0] += 2;  iv[1] += 2;
 260         }
 261     }
 262
 263     return 0;
 264 }
 265
 266 static int cinepak_decode_strip (CinepakContext *s,
 267                                  cvid_strip_t *strip, uint8_t *data, int size)
 268 {
 269     uint8_t *eod = (data + size);
 270     int      chunk_id, chunk_size;
 271
 272     /* coordinate sanity checks */
 273     if (strip->x1 >= s->width  || strip->x2 > s->width  ||
 274         strip->y1 >= s->height || strip->y2 > s->height ||
 275         strip->x1 >= strip->x2 || strip->y1 >= strip->y2)
 276         return -1;
 277
 278     while ((data + 4) <= eod) {
 279         chunk_id   = AV_RB16 (&data[0]);
 280         chunk_size = AV_RB16 (&data[2]) - 4;
 281         if(chunk_size < 0)
 282             return -1;
 283
 284         data      += 4;
 285         chunk_size = ((data + chunk_size) > eod) ? (eod - data) : chunk_size;
 286
 287         switch (chunk_id) {
 288
 289         case 0x2000:
 290         case 0x2100:
 291         case 0x2400:
 292         case 0x2500:
 293             cinepak_decode_codebook (strip->v4_codebook, chunk_id,
 294                 chunk_size, data);
 295             break;
 296
 297         case 0x2200:
 298         case 0x2300:
 299         case 0x2600:
 300         case 0x2700:
 301             cinepak_decode_codebook (strip->v1_codebook, chunk_id,
 302                 chunk_size, data);
 303             break;
 304
 305         case 0x3000:
 306         case 0x3100:
 307         case 0x3200:
 308             return cinepak_decode_vectors (s, strip, chunk_id,
 309                 chunk_size, data);
 310         }
 311
 312         data += chunk_size;
 313     }
 314
 315     return -1;
 316 }
 317
 318 static int cinepak_decode (CinepakContext *s)
 319 {
 320     uint8_t      *eod = (s->data + s->size);
 321     int           i, result, strip_size, frame_flags, num_strips;
 322     int           y0 = 0;
 323     int           encoded_buf_size;
 324
 325     if (s->size < 10)
 326         return -1;
 327
 328     frame_flags = s->data[0];
 329     num_strips  = AV_RB16 (&s->data[8]);
 330     encoded_buf_size = ((s->data[1] << 16) | AV_RB16 (&s->data[2]));
 331
 332     /* if this is the first frame, check for deviant Sega FILM data */
 333     if (s->sega_film_skip_bytes == -1) {
 334         if (encoded_buf_size != s->size) {
 335             /* If the encoded frame size differs from the frame size as indicated
 336              * by the container file, this data likely comes from a Sega FILM/CPK file.
 337              * If the frame header is followed by the bytes FE 00 00 06 00 00 then
 338              * this is probably one of the two known files that have 6 extra bytes
 339              * after the frame header. Else, assume 2 extra bytes. */
 340             if ((s->data[10] == 0xFE) &&
 341                 (s->data[11] == 0x00) &&
 342                 (s->data[12] == 0x00) &&
 343                 (s->data[13] == 0x06) &&
 344                 (s->data[14] == 0x00) &&
 345                 (s->data[15] == 0x00))
 346                 s->sega_film_skip_bytes = 6;
 347             else
 348                 s->sega_film_skip_bytes = 2;
 349         } else
 350             s->sega_film_skip_bytes = 0;
 351     }
 352
 353     s->data += 10 + s->sega_film_skip_bytes;
 354
 355     if (num_strips > MAX_STRIPS)
 356         num_strips = MAX_STRIPS;
 357
 358     for (i=0; i < num_strips; i++) {
 359         if ((s->data + 12) > eod)
 360             return -1;
 361
 362         s->strips[i].id = AV_RB16 (s->data);
 363         s->strips[i].y1 = y0;
 364         s->strips[i].x1 = 0;
 365         s->strips[i].y2 = y0 + AV_RB16 (&s->data[8]);
 366         s->strips[i].x2 = s->avctx->width;
 367
 368         strip_size = AV_RB16 (&s->data[2]) - 12;
 369         s->data   += 12;
 370         strip_size = ((s->data + strip_size) > eod) ? (eod - s->data) : strip_size;
 371
 372         if ((i > 0) && !(frame_flags & 0x01)) {
 373             memcpy (s->strips[i].v4_codebook, s->strips[i-1].v4_codebook,
 374                 sizeof(s->strips[i].v4_codebook));
 375             memcpy (s->strips[i].v1_codebook, s->strips[i-1].v1_codebook,
 376                 sizeof(s->strips[i].v1_codebook));
 377         }
 378
 379         result = cinepak_decode_strip (s, &s->strips[i], s->data, strip_size);
 380
 381         if (result != 0)
 382             return result;
 383
 384         s->data += strip_size;
 385         y0    = s->strips[i].y2;
 386     }
 387     return 0;
 388 }
 389
 390 static int cinepak_decode_init(AVCodecContext *avctx)
 391 {
 392     CinepakContext *s = avctx->priv_data;
 393
 394     s->avctx = avctx;
 395     s->width = (avctx->width + 3) & ~3;
 396     s->height = (avctx->height + 3) & ~3;
 397     s->sega_film_skip_bytes = -1;  /* uninitialized state */
 398
 399     // check for paletted data
 400     if ((avctx->palctrl == NULL) || (avctx->bits_per_sample == 40)) {
 401         s->palette_video = 0;
 402         avctx->pix_fmt = PIX_FMT_YUV420P;
 403     } else {
 404         s->palette_video = 1;
 405         avctx->pix_fmt = PIX_FMT_PAL8;
 406     }
 407
 408     dsputil_init(&s->dsp, avctx);
 409
 410     s->frame.data[0] = NULL;
 411
 412     return 0;
 413 }
 414
 415 static int cinepak_decode_frame(AVCodecContext *avctx,
 416                                 void *data, int *data_size,
 417                                 uint8_t *buf, int buf_size)
 418 {
 419     CinepakContext *s = avctx->priv_data;
 420
 421     s->data = buf;
 422     s->size = buf_size;
 423
 424     s->frame.reference = 1;
 425     s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
 426                             FF_BUFFER_HINTS_REUSABLE;
 427     if (avctx->reget_buffer(avctx, &s->frame)) {
 428         av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
 429         return -1;
 430     }
 431
 432     cinepak_decode(s);
 433
 434     if (s->palette_video) {
 435         memcpy (s->frame.data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
 436         if (avctx->palctrl->palette_changed) {
 437             s->frame.palette_has_changed = 1;
 438             avctx->palctrl->palette_changed = 0;
 439         } else
 440             s->frame.palette_has_changed = 0;
 441     }
 442
 443     *data_size = sizeof(AVFrame);
 444     *(AVFrame*)data = s->frame;
 445
 446     /* report that the buffer was completely consumed */
 447     return buf_size;
 448 }
 449
 450 static int cinepak_decode_end(AVCodecContext *avctx)
 451 {
 452     CinepakContext *s = avctx->priv_data;
 453
 454     if (s->frame.data[0])
 455         avctx->release_buffer(avctx, &s->frame);
 456
 457     return 0;
 458 }
 459
 460 AVCodec cinepak_decoder = {
 461     "cinepak",
 462     CODEC_TYPE_VIDEO,
 463     CODEC_ID_CINEPAK,
 464     sizeof(CinepakContext),
 465     cinepak_decode_init,
 466     NULL,
 467     cinepak_decode_end,
 468     cinepak_decode_frame,
 469     CODEC_CAP_DR1,
 470 };