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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 /**
  24  * @file cinepak.c
  25  * Cinepak video decoder
  26  * by Ewald Snel <ewald@rambo.its.tudelft.nl>
  27  * For more information on the Cinepak algorithm, visit:
  28  *   http://www.csse.monash.edu.au/~timf/
  29  * For more information on the quirky data inside Sega FILM/CPK files, visit:
  30  *   http://wiki.multimedia.cx/index.php?title=Sega_FILM
  31  */
  32
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36 #include <unistd.h>
  37
  38 #include "avcodec.h"
  39 #include "dsputil.h"
  40
  41
  42 typedef struct {
  43     uint8_t  y0, y1, y2, y3;
  44     uint8_t  u, v;
  45 } cvid_codebook_t;
  46
  47 #define MAX_STRIPS      32
  48
  49 typedef struct {
  50     uint16_t          id;
  51     uint16_t          x1, y1;
  52     uint16_t          x2, y2;
  53     cvid_codebook_t   v4_codebook[256];
  54     cvid_codebook_t   v1_codebook[256];
  55 } cvid_strip_t;
  56
  57 typedef struct CinepakContext {
  58
  59     AVCodecContext *avctx;
  60     DSPContext dsp;
  61     AVFrame frame;
  62
  63     unsigned char *data;
  64     int size;
  65
  66     int width, height;
  67
  68     int palette_video;
  69     cvid_strip_t strips[MAX_STRIPS];
  70
  71     int sega_film_skip_bytes;
  72
  73 } CinepakContext;
  74
  75 static void cinepak_decode_codebook (cvid_codebook_t *codebook,
  76                                      int chunk_id, int size, uint8_t *data)
  77 {
  78     uint8_t *eod = (data + size);
  79     uint32_t flag, mask;
  80     int      i, n;
  81
  82     /* check if this chunk contains 4- or 6-element vectors */
  83     n    = (chunk_id & 0x0400) ? 4 : 6;
  84     flag = 0;
  85     mask = 0;
  86
  87     for (i=0; i < 256; i++) {
  88         if ((chunk_id & 0x0100) && !(mask >>= 1)) {
  89             if ((data + 4) > eod)
  90                 break;
  91
  92             flag  = AV_RB32 (data);
  93             data += 4;
  94             mask  = 0x80000000;
  95         }
  96
  97         if (!(chunk_id & 0x0100) || (flag & mask)) {
  98             if ((data + n) > eod)
  99                 break;
 100
 101             if (n == 6) {
 102                 codebook[i].y0 = *data++;
 103                 codebook[i].y1 = *data++;
 104                 codebook[i].y2 = *data++;
 105                 codebook[i].y3 = *data++;
 106                 codebook[i].u  = 128 + *data++;
 107                 codebook[i].v  = 128 + *data++;
 108             } else {
 109                 /* this codebook type indicates either greyscale or
 110                  * palettized video; if palettized, U & V components will
 111                  * not be used so it is safe to set them to 128 for the
 112                  * benefit of greyscale rendering in YUV420P */
 113                 codebook[i].y0 = *data++;
 114                 codebook[i].y1 = *data++;
 115                 codebook[i].y2 = *data++;
 116                 codebook[i].y3 = *data++;
 117                 codebook[i].u  = 128;
 118                 codebook[i].v  = 128;
 119             }
 120         }
 121     }
 122 }
 123
 124 static int cinepak_decode_vectors (CinepakContext *s, cvid_strip_t *strip,
 125                                    int chunk_id, int size, uint8_t *data)
 126 {
 127     uint8_t         *eod = (data + size);
 128     uint32_t         flag, mask;
 129     cvid_codebook_t *codebook;
 130     unsigned int     x, y;
 131     uint32_t         iy[4];
 132     uint32_t         iu[2];
 133     uint32_t         iv[2];
 134
 135     flag = 0;
 136     mask = 0;
 137
 138     for (y=strip->y1; y < strip->y2; y+=4) {
 139
 140         iy[0] = strip->x1 + (y * s->frame.linesize[0]);
 141         iy[1] = iy[0] + s->frame.linesize[0];
 142         iy[2] = iy[1] + s->frame.linesize[0];
 143         iy[3] = iy[2] + s->frame.linesize[0];
 144         iu[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[1]);
 145         iu[1] = iu[0] + s->frame.linesize[1];
 146         iv[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[2]);
 147         iv[1] = iv[0] + s->frame.linesize[2];
 148
 149         for (x=strip->x1; x < strip->x2; x+=4) {
 150             if ((chunk_id & 0x0100) && !(mask >>= 1)) {
 151                 if ((data + 4) > eod)
 152                     return -1;
 153
 154                 flag  = AV_RB32 (data);
 155                 data += 4;
 156                 mask  = 0x80000000;
 157             }
 158
 159             if (!(chunk_id & 0x0100) || (flag & mask)) {
 160                 if (!(chunk_id & 0x0200) && !(mask >>= 1)) {
 161                     if ((data + 4) > eod)
 162                         return -1;
 163
 164                     flag  = AV_RB32 (data);
 165                     data += 4;
 166                     mask  = 0x80000000;
 167                 }
 168
 169                 if ((chunk_id & 0x0200) || (~flag & mask)) {
 170                     if (data >= eod)
 171                         return -1;
 172
 173                     codebook = &strip->v1_codebook[*data++];
 174                     s->frame.data[0][iy[0] + 0] = codebook->y0;
 175                     s->frame.data[0][iy[0] + 1] = codebook->y0;
 176                     s->frame.data[0][iy[1] + 0] = codebook->y0;
 177                     s->frame.data[0][iy[1] + 1] = codebook->y0;
 178                     if (!s->palette_video) {
 179                         s->frame.data[1][iu[0]] = codebook->u;
 180                         s->frame.data[2][iv[0]] = codebook->v;
 181                     }
 182
 183                     s->frame.data[0][iy[0] + 2] = codebook->y1;
 184                     s->frame.data[0][iy[0] + 3] = codebook->y1;
 185                     s->frame.data[0][iy[1] + 2] = codebook->y1;
 186                     s->frame.data[0][iy[1] + 3] = codebook->y1;
 187                     if (!s->palette_video) {
 188                         s->frame.data[1][iu[0] + 1] = codebook->u;
 189                         s->frame.data[2][iv[0] + 1] = codebook->v;
 190                     }
 191
 192                     s->frame.data[0][iy[2] + 0] = codebook->y2;
 193                     s->frame.data[0][iy[2] + 1] = codebook->y2;
 194                     s->frame.data[0][iy[3] + 0] = codebook->y2;
 195                     s->frame.data[0][iy[3] + 1] = codebook->y2;
 196                     if (!s->palette_video) {
 197                         s->frame.data[1][iu[1]] = codebook->u;
 198                         s->frame.data[2][iv[1]] = codebook->v;
 199                     }
 200
 201                     s->frame.data[0][iy[2] + 2] = codebook->y3;
 202                     s->frame.data[0][iy[2] + 3] = codebook->y3;
 203                     s->frame.data[0][iy[3] + 2] = codebook->y3;
 204                     s->frame.data[0][iy[3] + 3] = codebook->y3;
 205                     if (!s->palette_video) {
 206                         s->frame.data[1][iu[1] + 1] = codebook->u;
 207                         s->frame.data[2][iv[1] + 1] = codebook->v;
 208                     }
 209
 210                 } else if (flag & mask) {
 211                     if ((data + 4) > eod)
 212                         return -1;
 213
 214                     codebook = &strip->v4_codebook[*data++];
 215                     s->frame.data[0][iy[0] + 0] = codebook->y0;
 216                     s->frame.data[0][iy[0] + 1] = codebook->y1;
 217                     s->frame.data[0][iy[1] + 0] = codebook->y2;
 218                     s->frame.data[0][iy[1] + 1] = codebook->y3;
 219                     if (!s->palette_video) {
 220                         s->frame.data[1][iu[0]] = codebook->u;
 221                         s->frame.data[2][iv[0]] = codebook->v;
 222                     }
 223
 224                     codebook = &strip->v4_codebook[*data++];
 225                     s->frame.data[0][iy[0] + 2] = codebook->y0;
 226                     s->frame.data[0][iy[0] + 3] = codebook->y1;
 227                     s->frame.data[0][iy[1] + 2] = codebook->y2;
 228                     s->frame.data[0][iy[1] + 3] = codebook->y3;
 229                     if (!s->palette_video) {
 230                         s->frame.data[1][iu[0] + 1] = codebook->u;
 231                         s->frame.data[2][iv[0] + 1] = codebook->v;
 232                     }
 233
 234                     codebook = &strip->v4_codebook[*data++];
 235                     s->frame.data[0][iy[2] + 0] = codebook->y0;
 236                     s->frame.data[0][iy[2] + 1] = codebook->y1;
 237                     s->frame.data[0][iy[3] + 0] = codebook->y2;
 238                     s->frame.data[0][iy[3] + 1] = codebook->y3;
 239                     if (!s->palette_video) {
 240                         s->frame.data[1][iu[1]] = codebook->u;
 241                         s->frame.data[2][iv[1]] = codebook->v;
 242                     }
 243
 244                     codebook = &strip->v4_codebook[*data++];
 245                     s->frame.data[0][iy[2] + 2] = codebook->y0;
 246                     s->frame.data[0][iy[2] + 3] = codebook->y1;
 247                     s->frame.data[0][iy[3] + 2] = codebook->y2;
 248                     s->frame.data[0][iy[3] + 3] = codebook->y3;
 249                     if (!s->palette_video) {
 250                         s->frame.data[1][iu[1] + 1] = codebook->u;
 251                         s->frame.data[2][iv[1] + 1] = codebook->v;
 252                     }
 253
 254                 }
 255             }
 256
 257             iy[0] += 4;  iy[1] += 4;
 258             iy[2] += 4;  iy[3] += 4;
 259             iu[0] += 2;  iu[1] += 2;
 260             iv[0] += 2;  iv[1] += 2;
 261         }
 262     }
 263
 264     return 0;
 265 }
 266
 267 static int cinepak_decode_strip (CinepakContext *s,
 268                                  cvid_strip_t *strip, uint8_t *data, int size)
 269 {
 270     uint8_t *eod = (data + size);
 271     int      chunk_id, chunk_size;
 272
 273     /* coordinate sanity checks */
 274     if (strip->x1 >= s->width  || strip->x2 > s->width  ||
 275         strip->y1 >= s->height || strip->y2 > s->height ||
 276         strip->x1 >= strip->x2 || strip->y1 >= strip->y2)
 277         return -1;
 278
 279     while ((data + 4) <= eod) {
 280         chunk_id   = AV_RB16 (&data[0]);
 281         chunk_size = AV_RB16 (&data[2]) - 4;
 282         if(chunk_size < 0)
 283             return -1;
 284
 285         data      += 4;
 286         chunk_size = ((data + chunk_size) > eod) ? (eod - data) : chunk_size;
 287
 288         switch (chunk_id) {
 289
 290         case 0x2000:
 291         case 0x2100:
 292         case 0x2400:
 293         case 0x2500:
 294             cinepak_decode_codebook (strip->v4_codebook, chunk_id,
 295                 chunk_size, data);
 296             break;
 297
 298         case 0x2200:
 299         case 0x2300:
 300         case 0x2600:
 301         case 0x2700:
 302             cinepak_decode_codebook (strip->v1_codebook, chunk_id,
 303                 chunk_size, data);
 304             break;
 305
 306         case 0x3000:
 307         case 0x3100:
 308         case 0x3200:
 309             return cinepak_decode_vectors (s, strip, chunk_id,
 310                 chunk_size, data);
 311         }
 312
 313         data += chunk_size;
 314     }
 315
 316     return -1;
 317 }
 318
 319 static int cinepak_decode (CinepakContext *s)
 320 {
 321     uint8_t      *eod = (s->data + s->size);
 322     int           i, result, strip_size, frame_flags, num_strips;
 323     int           y0 = 0;
 324     int           encoded_buf_size;
 325
 326     if (s->size < 10)
 327         return -1;
 328
 329     frame_flags = s->data[0];
 330     num_strips  = AV_RB16 (&s->data[8]);
 331     encoded_buf_size = ((s->data[1] << 16) | AV_RB16 (&s->data[2]));
 332
 333     /* if this is the first frame, check for deviant Sega FILM data */
 334     if (s->sega_film_skip_bytes == -1) {
 335         if (encoded_buf_size != s->size) {
 336             /* If the encoded frame size differs from the frame size as indicated
 337              * by the container file, this data likely comes from a Sega FILM/CPK file.
 338              * If the frame header is followed by the bytes FE 00 00 06 00 00 then
 339              * this is probably one of the two known files that have 6 extra bytes
 340              * after the frame header. Else, assume 2 extra bytes. */
 341             if ((s->data[10] == 0xFE) &&
 342                 (s->data[11] == 0x00) &&
 343                 (s->data[12] == 0x00) &&
 344                 (s->data[13] == 0x06) &&
 345                 (s->data[14] == 0x00) &&
 346                 (s->data[15] == 0x00))
 347                 s->sega_film_skip_bytes = 6;
 348             else
 349                 s->sega_film_skip_bytes = 2;
 350         } else
 351             s->sega_film_skip_bytes = 0;
 352     }
 353
 354     s->data += 10 + s->sega_film_skip_bytes;
 355
 356     if (num_strips > MAX_STRIPS)
 357         num_strips = MAX_STRIPS;
 358
 359     for (i=0; i < num_strips; i++) {
 360         if ((s->data + 12) > eod)
 361             return -1;
 362
 363         s->strips[i].id = AV_RB16 (s->data);
 364         s->strips[i].y1 = y0;
 365         s->strips[i].x1 = 0;
 366         s->strips[i].y2 = y0 + AV_RB16 (&s->data[8]);
 367         s->strips[i].x2 = s->avctx->width;
 368
 369         strip_size = AV_RB16 (&s->data[2]) - 12;
 370         s->data   += 12;
 371         strip_size = ((s->data + strip_size) > eod) ? (eod - s->data) : strip_size;
 372
 373         if ((i > 0) && !(frame_flags & 0x01)) {
 374             memcpy (s->strips[i].v4_codebook, s->strips[i-1].v4_codebook,
 375                 sizeof(s->strips[i].v4_codebook));
 376             memcpy (s->strips[i].v1_codebook, s->strips[i-1].v1_codebook,
 377                 sizeof(s->strips[i].v1_codebook));
 378         }
 379
 380         result = cinepak_decode_strip (s, &s->strips[i], s->data, strip_size);
 381
 382         if (result != 0)
 383             return result;
 384
 385         s->data += strip_size;
 386         y0    = s->strips[i].y2;
 387     }
 388     return 0;
 389 }
 390
 391 static int cinepak_decode_init(AVCodecContext *avctx)
 392 {
 393     CinepakContext *s = avctx->priv_data;
 394
 395     s->avctx = avctx;
 396     s->width = (avctx->width + 3) & ~3;
 397     s->height = (avctx->height + 3) & ~3;
 398     s->sega_film_skip_bytes = -1;  /* uninitialized state */
 399
 400     // check for paletted data
 401     if ((avctx->palctrl == NULL) || (avctx->bits_per_sample == 40)) {
 402         s->palette_video = 0;
 403         avctx->pix_fmt = PIX_FMT_YUV420P;
 404     } else {
 405         s->palette_video = 1;
 406         avctx->pix_fmt = PIX_FMT_PAL8;
 407     }
 408
 409     dsputil_init(&s->dsp, avctx);
 410
 411     s->frame.data[0] = NULL;
 412
 413     return 0;
 414 }
 415
 416 static int cinepak_decode_frame(AVCodecContext *avctx,
 417                                 void *data, int *data_size,
 418                                 uint8_t *buf, int buf_size)
 419 {
 420     CinepakContext *s = avctx->priv_data;
 421
 422     s->data = buf;
 423     s->size = buf_size;
 424
 425     s->frame.reference = 1;
 426     s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
 427                             FF_BUFFER_HINTS_REUSABLE;
 428     if (avctx->reget_buffer(avctx, &s->frame)) {
 429         av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
 430         return -1;
 431     }
 432
 433     cinepak_decode(s);
 434
 435     if (s->palette_video) {
 436         memcpy (s->frame.data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
 437         if (avctx->palctrl->palette_changed) {
 438             s->frame.palette_has_changed = 1;
 439             avctx->palctrl->palette_changed = 0;
 440         } else
 441             s->frame.palette_has_changed = 0;
 442     }
 443
 444     *data_size = sizeof(AVFrame);
 445     *(AVFrame*)data = s->frame;
 446
 447     /* report that the buffer was completely consumed */
 448     return buf_size;
 449 }
 450
 451 static int cinepak_decode_end(AVCodecContext *avctx)
 452 {
 453     CinepakContext *s = avctx->priv_data;
 454
 455     if (s->frame.data[0])
 456         avctx->release_buffer(avctx, &s->frame);
 457
 458     return 0;
 459 }
 460
 461 AVCodec cinepak_decoder = {
 462     "cinepak",
 463     CODEC_TYPE_VIDEO,
 464     CODEC_ID_CINEPAK,
 465     sizeof(CinepakContext),
 466     cinepak_decode_init,
 467     NULL,
 468     cinepak_decode_end,
 469     cinepak_decode_frame,
 470     CODEC_CAP_DR1,
 471 };