dpvsimpledecode.c

   1 #include "quakedef.h"
   2 #include "dpvsimpledecode.h"
   3
   4 #define HZREADERROR_OK 0
   5 #define HZREADERROR_EOF 1
   6 #define HZREADERROR_MALLOCFAILED 2
   7
   8 //#define HZREADBLOCKSIZE 16000
   9 #define HZREADBLOCKSIZE 1048576
  10
  11 typedef struct hz_bitstream_read_s
  12 {
  13         qfile_t *file;
  14         int endoffile;
  15 }
  16 hz_bitstream_read_t;
  17
  18 typedef struct hz_bitstream_readblock_s
  19 {
  20         struct hz_bitstream_readblock_s *next;
  21         unsigned int size;
  22         unsigned char data[HZREADBLOCKSIZE];
  23 }
  24 hz_bitstream_readblock_t;
  25
  26 typedef struct hz_bitstream_readblocks_s
  27 {
  28         hz_bitstream_readblock_t *blocks;
  29         hz_bitstream_readblock_t *current;
  30         unsigned int position;
  31         unsigned int store;
  32         int count;
  33 }
  34 hz_bitstream_readblocks_t;
  35
  36 static hz_bitstream_read_t *hz_bitstream_read_open(char *filename)
  37 {
  38         qfile_t *file;
  39         hz_bitstream_read_t *stream;
  40         if ((file = FS_OpenVirtualFile(filename, false)))
  41         {
  42                 stream = (hz_bitstream_read_t *)Z_Malloc(sizeof(hz_bitstream_read_t));
  43                 memset(stream, 0, sizeof(*stream));
  44                 stream->file = file;
  45                 return stream;
  46         }
  47         else
  48                 return NULL;
  49 }
  50
  51 static void hz_bitstream_read_close(hz_bitstream_read_t *stream)
  52 {
  53         if (stream)
  54         {
  55                 FS_Close(stream->file);
  56                 Z_Free(stream);
  57         }
  58 }
  59
  60 static hz_bitstream_readblocks_t *hz_bitstream_read_blocks_new(void)
  61 {
  62         hz_bitstream_readblocks_t *blocks;
  63         blocks = (hz_bitstream_readblocks_t *)Z_Malloc(sizeof(hz_bitstream_readblocks_t));
  64         if (blocks == NULL)
  65                 return NULL;
  66         memset(blocks, 0, sizeof(hz_bitstream_readblocks_t));
  67         return blocks;
  68 }
  69
  70 static void hz_bitstream_read_blocks_free(hz_bitstream_readblocks_t *blocks)
  71 {
  72         hz_bitstream_readblock_t *b, *n;
  73         if (blocks == NULL)
  74                 return;
  75         for (b = blocks->blocks;b;b = n)
  76         {
  77                 n = b->next;
  78                 Z_Free(b);
  79         }
  80         Z_Free(blocks);
  81 }
  82
  83 static void hz_bitstream_read_flushbits(hz_bitstream_readblocks_t *blocks)
  84 {
  85         blocks->store = 0;
  86         blocks->count = 0;
  87 }
  88
  89 static int hz_bitstream_read_blocks_read(hz_bitstream_readblocks_t *blocks, hz_bitstream_read_t *stream, unsigned int size)
  90 {
  91         int s;
  92         hz_bitstream_readblock_t *b, *p;
  93         s = size;
  94         p = NULL;
  95         b = blocks->blocks;
  96         while (s > 0)
  97         {
  98                 if (b == NULL)
  99                 {
 100                         b = (hz_bitstream_readblock_t *)Z_Malloc(sizeof(hz_bitstream_readblock_t));
 101                         if (b == NULL)
 102                                 return HZREADERROR_MALLOCFAILED;
 103                         b->next = NULL;
 104                         b->size = 0;
 105                         if (p != NULL)
 106                                 p->next = b;
 107                         else
 108                                 blocks->blocks = b;
 109                 }
 110                 if (s > HZREADBLOCKSIZE)
 111                         b->size = HZREADBLOCKSIZE;
 112                 else
 113                         b->size = s;
 114                 s -= b->size;
 115                 if (FS_Read(stream->file, b->data, b->size) != (fs_offset_t)b->size)
 116                 {
 117                         stream->endoffile = 1;
 118                         break;
 119                 }
 120                 p = b;
 121                 b = b->next;
 122         }
 123         while (b)
 124         {
 125                 b->size = 0;
 126                 b = b->next;
 127         }
 128         blocks->current = blocks->blocks;
 129         blocks->position = 0;
 130         hz_bitstream_read_flushbits(blocks);
 131         if (stream->endoffile)
 132                 return HZREADERROR_EOF;
 133         return HZREADERROR_OK;
 134 }
 135
 136 static unsigned int hz_bitstream_read_blocks_getbyte(hz_bitstream_readblocks_t *blocks)
 137 {
 138         while (blocks->current != NULL && blocks->position >= blocks->current->size)
 139         {
 140                 blocks->position = 0;
 141                 blocks->current = blocks->current->next;
 142         }
 143         if (blocks->current == NULL)
 144                 return 0;
 145         return blocks->current->data[blocks->position++];
 146 }
 147
 148 static int hz_bitstream_read_bit(hz_bitstream_readblocks_t *blocks)
 149 {
 150         if (!blocks->count)
 151         {
 152                 blocks->count += 8;
 153                 blocks->store <<= 8;
 154                 blocks->store |= hz_bitstream_read_blocks_getbyte(blocks) & 0xFF;
 155         }
 156         blocks->count--;
 157         return (blocks->store >> blocks->count) & 1;
 158 }
 159
 160 static unsigned int hz_bitstream_read_bits(hz_bitstream_readblocks_t *blocks, int size)
 161 {
 162         unsigned int num = 0;
 163         // we can only handle about 24 bits at a time safely
 164         // (there might be up to 7 bits more than we need in the bit store)
 165         if (size > 24)
 166         {
 167                 size -= 8;
 168                 num |= hz_bitstream_read_bits(blocks, 8) << size;
 169         }
 170         while (blocks->count < size)
 171         {
 172                 blocks->count += 8;
 173                 blocks->store <<= 8;
 174                 blocks->store |= hz_bitstream_read_blocks_getbyte(blocks) & 0xFF;
 175         }
 176         blocks->count -= size;
 177         num |= (blocks->store >> blocks->count) & ((1 << size) - 1);
 178         return num;
 179 }
 180
 181 static unsigned int hz_bitstream_read_byte(hz_bitstream_readblocks_t *blocks)
 182 {
 183         return hz_bitstream_read_blocks_getbyte(blocks);
 184 }
 185
 186 static unsigned int hz_bitstream_read_short(hz_bitstream_readblocks_t *blocks)
 187 {
 188         return (hz_bitstream_read_byte(blocks) << 8)
 189              | (hz_bitstream_read_byte(blocks));
 190 }
 191
 192 static unsigned int hz_bitstream_read_int(hz_bitstream_readblocks_t *blocks)
 193 {
 194         return (hz_bitstream_read_byte(blocks) << 24)
 195              | (hz_bitstream_read_byte(blocks) << 16)
 196              | (hz_bitstream_read_byte(blocks) << 8)
 197              | (hz_bitstream_read_byte(blocks));
 198 }
 199
 200 static void hz_bitstream_read_bytes(hz_bitstream_readblocks_t *blocks, void *outdata, unsigned int size)
 201 {
 202         unsigned char *out;
 203         out = (unsigned char *)outdata;
 204         while (size--)
 205                 *out++ = hz_bitstream_read_byte(blocks);
 206 }
 207
 208 #define BLOCKSIZE 8
 209
 210 typedef struct dpvsimpledecodestream_s
 211 {
 212         hz_bitstream_read_t *bitstream;
 213         hz_bitstream_readblocks_t *framedatablocks;
 214
 215         int error;
 216
 217         double info_framerate;
 218         unsigned int info_frames;
 219
 220         unsigned int info_imagewidth;
 221         unsigned int info_imageheight;
 222         unsigned int info_imagebpp;
 223         unsigned int info_imageRloss;
 224         unsigned int info_imageRmask;
 225         unsigned int info_imageRshift;
 226         unsigned int info_imageGloss;
 227         unsigned int info_imageGmask;
 228         unsigned int info_imageGshift;
 229         unsigned int info_imageBloss;
 230         unsigned int info_imageBmask;
 231         unsigned int info_imageBshift;
 232         unsigned int info_imagesize;
 233         double info_aspectratio;
 234
 235         // current video frame (needed because of delta compression)
 236         int videoframenum;
 237         // current video frame data (needed because of delta compression)
 238         unsigned int *videopixels;
 239
 240         // channel the sound file is being played on
 241         int sndchan;
 242 }
 243 dpvsimpledecodestream_t;
 244
 245 static int dpvsimpledecode_setpixelformat(dpvsimpledecodestream_t *s, unsigned int Rmask, unsigned int Gmask, unsigned int Bmask, unsigned int bytesperpixel)
 246 {
 247         int Rshift, Rbits, Gshift, Gbits, Bshift, Bbits;
 248         if (!Rmask)
 249         {
 250                 s->error = DPVSIMPLEDECODEERROR_INVALIDRMASK;
 251                 return s->error;
 252         }
 253         if (!Gmask)
 254         {
 255                 s->error = DPVSIMPLEDECODEERROR_INVALIDGMASK;
 256                 return s->error;
 257         }
 258         if (!Bmask)
 259         {
 260                 s->error = DPVSIMPLEDECODEERROR_INVALIDBMASK;
 261                 return s->error;
 262         }
 263         if (Rmask & Gmask || Rmask & Bmask || Gmask & Bmask)
 264         {
 265                 s->error = DPVSIMPLEDECODEERROR_COLORMASKSOVERLAP;
 266                 return s->error;
 267         }
 268         switch (bytesperpixel)
 269         {
 270         case 2:
 271                 if ((Rmask | Gmask | Bmask) > 65536)
 272                 {
 273                         s->error = DPVSIMPLEDECODEERROR_COLORMASKSEXCEEDBPP;
 274                         return s->error;
 275                 }
 276                 break;
 277         case 4:
 278                 break;
 279         default:
 280                 s->error = DPVSIMPLEDECODEERROR_UNSUPPORTEDBPP;
 281                 return s->error;
 282         }
 283         for (Rshift = 0;!(Rmask & 1);Rshift++, Rmask >>= 1);
 284         for (Gshift = 0;!(Gmask & 1);Gshift++, Gmask >>= 1);
 285         for (Bshift = 0;!(Bmask & 1);Bshift++, Bmask >>= 1);
 286         if (((Rmask + 1) & Rmask) != 0)
 287         {
 288                 s->error = DPVSIMPLEDECODEERROR_INVALIDRMASK;
 289                 return s->error;
 290         }
 291         if (((Gmask + 1) & Gmask) != 0)
 292         {
 293                 s->error = DPVSIMPLEDECODEERROR_INVALIDGMASK;
 294                 return s->error;
 295         }
 296         if (((Bmask + 1) & Bmask) != 0)
 297         {
 298                 s->error = DPVSIMPLEDECODEERROR_INVALIDBMASK;
 299                 return s->error;
 300         }
 301         for (Rbits = 0;Rmask & 1;Rbits++, Rmask >>= 1);
 302         for (Gbits = 0;Gmask & 1;Gbits++, Gmask >>= 1);
 303         for (Bbits = 0;Bmask & 1;Bbits++, Bmask >>= 1);
 304         if (Rbits > 8)
 305         {
 306                 Rshift += (Rbits - 8);
 307                 Rbits = 8;
 308         }
 309         if (Gbits > 8)
 310         {
 311                 Gshift += (Gbits - 8);
 312                 Gbits = 8;
 313         }
 314         if (Bbits > 8)
 315         {
 316                 Bshift += (Bbits - 8);
 317                 Bbits = 8;
 318         }
 319         s->info_imagebpp = bytesperpixel;
 320         s->info_imageRloss = 16 + (8 - Rbits);
 321         s->info_imageGloss =  8 + (8 - Gbits);
 322         s->info_imageBloss =  0 + (8 - Bbits);
 323         s->info_imageRmask = (1 << Rbits) - 1;
 324         s->info_imageGmask = (1 << Gbits) - 1;
 325         s->info_imageBmask = (1 << Bbits) - 1;
 326         s->info_imageRshift = Rshift;
 327         s->info_imageGshift = Gshift;
 328         s->info_imageBshift = Bshift;
 329         s->info_imagesize = s->info_imagewidth * s->info_imageheight * s->info_imagebpp;
 330         return s->error;
 331 }
 332
 333 // opening and closing streams
 334
 335 // opens a stream
 336 void *dpvsimpledecode_open(clvideo_t *video, char *filename, const char **errorstring)
 337 {
 338         dpvsimpledecodestream_t *s;
 339         char t[8], *wavename;
 340         if (errorstring != NULL)
 341                 *errorstring = NULL;
 342         s = (dpvsimpledecodestream_t *)Z_Malloc(sizeof(dpvsimpledecodestream_t));
 343         if (s != NULL)
 344         {
 345                 s->bitstream = hz_bitstream_read_open(filename);
 346                 if (s->bitstream != NULL)
 347                 {
 348                         // check file identification
 349                         s->framedatablocks = hz_bitstream_read_blocks_new();
 350                         if (s->framedatablocks != NULL)
 351                         {
 352                                 hz_bitstream_read_blocks_read(s->framedatablocks, s->bitstream, 8);
 353                                 hz_bitstream_read_bytes(s->framedatablocks, t, 8);
 354                                 if (!memcmp(t, "DPVideo", 8))
 355                                 {
 356                                         // check version number
 357                                         hz_bitstream_read_blocks_read(s->framedatablocks, s->bitstream, 2);
 358                                         if (hz_bitstream_read_short(s->framedatablocks) == 1)
 359                                         {
 360                                                 hz_bitstream_read_blocks_read(s->framedatablocks, s->bitstream, 12);
 361                                                 s->info_imagewidth = hz_bitstream_read_short(s->framedatablocks);
 362                                                 s->info_imageheight = hz_bitstream_read_short(s->framedatablocks);
 363                                                 s->info_framerate = (double) hz_bitstream_read_int(s->framedatablocks) * (1.0 / 65536.0);
 364                                                 s->info_aspectratio = (double)s->info_imagewidth / (double)s->info_imageheight;
 365
 366                                                 if (s->info_framerate > 0.0)
 367                                                 {
 368                                                         s->videopixels = (unsigned int *)Z_Malloc(s->info_imagewidth * s->info_imageheight * sizeof(*s->videopixels));
 369                                                         if (s->videopixels != NULL)
 370                                                         {
 371                                                                 size_t namelen;
 372
 373                                                                 namelen = strlen(filename) + 10;
 374                                                                 wavename = (char *)Z_Malloc(namelen);
 375                                                                 if (wavename)
 376                                                                 {
 377                                                                         sfx_t* sfx;
 378
 379                                                                         FS_StripExtension(filename, wavename, namelen);
 380                                                                         strlcat(wavename, ".wav", namelen);
 381                                                                         sfx = S_PrecacheSound (wavename, false, false);
 382                                                                         if (sfx != NULL)
 383                                                                                 s->sndchan = S_StartSound (-1, 0, sfx, vec3_origin, 1.0f, 0);
 384                                                                         else
 385                                                                                 s->sndchan = -1;
 386                                                                         Z_Free(wavename);
 387                                                                 }
 388                                                                 // all is well...
 389                                                                 // set the module functions
 390                                                                 s->videoframenum = -10000;
 391                                                                 video->close = dpvsimpledecode_close;
 392                                                                 video->getwidth = dpvsimpledecode_getwidth;
 393                                                                 video->getheight = dpvsimpledecode_getheight;
 394                                                                 video->getframerate = dpvsimpledecode_getframerate;
 395                                                                 video->decodeframe = dpvsimpledecode_video;
 396                                                                 video->getaspectratio = dpvsimpledecode_getaspectratio;
 397
 398                                                                 return s;
 399                                                         }
 400                                                         else if (errorstring != NULL)
 401                                                                 *errorstring = "unable to allocate video image buffer";
 402                                                 }
 403                                                 else if (errorstring != NULL)
 404                                                         *errorstring = "error in video info chunk";
 405                                         }
 406                                         else if (errorstring != NULL)
 407                                                 *errorstring = "read error";
 408                                 }
 409                                 else if (errorstring != NULL)
 410                                         *errorstring = "not a dpvideo file";
 411                                 hz_bitstream_read_blocks_free(s->framedatablocks);
 412                         }
 413                         else if (errorstring != NULL)
 414                                 *errorstring = "unable to allocate memory for reading buffer";
 415                         hz_bitstream_read_close(s->bitstream);
 416                 }
 417                 else if (errorstring != NULL)
 418                         *errorstring = "unable to open file";
 419                 Z_Free(s);
 420         }
 421         else if (errorstring != NULL)
 422                 *errorstring = "unable to allocate memory for stream info structure";
 423         return NULL;
 424 }
 425
 426 // closes a stream
 427 void dpvsimpledecode_close(void *stream)
 428 {
 429         dpvsimpledecodestream_t *s = (dpvsimpledecodestream_t *)stream;
 430         if (s == NULL)
 431                 return;
 432         if (s->videopixels)
 433                 Z_Free(s->videopixels);
 434         if (s->sndchan != -1)
 435                 S_StopChannel (s->sndchan, true, true);
 436         if (s->framedatablocks)
 437                 hz_bitstream_read_blocks_free(s->framedatablocks);
 438         if (s->bitstream)
 439                 hz_bitstream_read_close(s->bitstream);
 440         Z_Free(s);
 441 }
 442
 443 // utilitarian functions
 444
 445 // returns the current error number for the stream, and resets the error
 446 // number to DPVSIMPLEDECODEERROR_NONE
 447 // if the supplied string pointer variable is not NULL, it will be set to the
 448 // error message
 449 int dpvsimpledecode_error(void *stream, const char **errorstring)
 450 {
 451         dpvsimpledecodestream_t *s = (dpvsimpledecodestream_t *)stream;
 452         int e;
 453         e = s->error;
 454         s->error = 0;
 455         if (errorstring)
 456         {
 457                 switch (e)
 458                 {
 459                         case DPVSIMPLEDECODEERROR_NONE:
 460                                 *errorstring = "no error";
 461                                 break;
 462                         case DPVSIMPLEDECODEERROR_EOF:
 463                                 *errorstring = "end of file reached (this is not an error)";
 464                                 break;
 465                         case DPVSIMPLEDECODEERROR_READERROR:
 466                                 *errorstring = "read error (corrupt or incomplete file)";
 467                                 break;
 468                         case DPVSIMPLEDECODEERROR_SOUNDBUFFERTOOSMALL:
 469                                 *errorstring = "sound buffer is too small for decoding frame (please allocate it as large as dpvsimpledecode_getneededsoundbufferlength suggests)";
 470                                 break;
 471                         case DPVSIMPLEDECODEERROR_INVALIDRMASK:
 472                                 *errorstring = "invalid red bits mask";
 473                                 break;
 474                         case DPVSIMPLEDECODEERROR_INVALIDGMASK:
 475                                 *errorstring = "invalid green bits mask";
 476                                 break;
 477                         case DPVSIMPLEDECODEERROR_INVALIDBMASK:
 478                                 *errorstring = "invalid blue bits mask";
 479                                 break;
 480                         case DPVSIMPLEDECODEERROR_COLORMASKSOVERLAP:
 481                                 *errorstring = "color bit masks overlap";
 482                                 break;
 483                         case DPVSIMPLEDECODEERROR_COLORMASKSEXCEEDBPP:
 484                                 *errorstring = "color masks too big for specified bytes per pixel";
 485                                 break;
 486                         case DPVSIMPLEDECODEERROR_UNSUPPORTEDBPP:
 487                                 *errorstring = "unsupported bytes per pixel (must be 2 for 16bit, or 4 for 32bit)";
 488                                 break;
 489                         default:
 490                                 *errorstring = "unknown error";
 491                                 break;
 492                 }
 493         }
 494         return e;
 495 }
 496
 497 // returns the width of the image data
 498 unsigned int dpvsimpledecode_getwidth(void *stream)
 499 {
 500         dpvsimpledecodestream_t *s = (dpvsimpledecodestream_t *)stream;
 501         return s->info_imagewidth;
 502 }
 503
 504 // returns the height of the image data
 505 unsigned int dpvsimpledecode_getheight(void *stream)
 506 {
 507         dpvsimpledecodestream_t *s = (dpvsimpledecodestream_t *)stream;
 508         return s->info_imageheight;
 509 }
 510
 511 // returns the framerate of the stream
 512 double dpvsimpledecode_getframerate(void *stream)
 513 {
 514         dpvsimpledecodestream_t *s = (dpvsimpledecodestream_t *)stream;
 515         return s->info_framerate;
 516 }
 517
 518 // return aspect ratio of the stream
 519 double dpvsimpledecode_getaspectratio(void *stream)
 520 {
 521         dpvsimpledecodestream_t *s = (dpvsimpledecodestream_t *)stream;
 522         return s->info_aspectratio;
 523 }
 524
 525 static int dpvsimpledecode_convertpixels(dpvsimpledecodestream_t *s, void *imagedata, int imagebytesperrow)
 526 {
 527         unsigned int a, x, y, width, height;
 528         unsigned int Rloss, Rmask, Rshift, Gloss, Gmask, Gshift, Bloss, Bmask, Bshift;
 529         unsigned int *in;
 530
 531         width = s->info_imagewidth;
 532         height = s->info_imageheight;
 533
 534         Rloss = s->info_imageRloss;
 535         Rmask = s->info_imageRmask;
 536         Rshift = s->info_imageRshift;
 537         Gloss = s->info_imageGloss;
 538         Gmask = s->info_imageGmask;
 539         Gshift = s->info_imageGshift;
 540         Bloss = s->info_imageBloss;
 541         Bmask = s->info_imageBmask;
 542         Bshift = s->info_imageBshift;
 543
 544         in = s->videopixels;
 545         if (s->info_imagebpp == 4)
 546         {
 547                 unsigned int *outrow;
 548                 for (y = 0;y < height;y++)
 549                 {
 550                         outrow = (unsigned int *)((unsigned char *)imagedata + y * imagebytesperrow);
 551                         for (x = 0;x < width;x++)
 552                         {
 553                                 a = *in++;
 554                                 outrow[x] = (((a >> Rloss) & Rmask) << Rshift) | (((a >> Gloss) & Gmask) << Gshift) | (((a >> Bloss) & Bmask) << Bshift);
 555                         }
 556                 }
 557         }
 558         else
 559         {
 560                 unsigned short *outrow;
 561                 for (y = 0;y < height;y++)
 562                 {
 563                         outrow = (unsigned short *)((unsigned char *)imagedata + y * imagebytesperrow);
 564                         if (Rloss == 19 && Gloss == 10 && Bloss == 3 && Rshift == 11 && Gshift == 5 && Bshift == 0)
 565                         {
 566                                 // optimized
 567                                 for (x = 0;x < width;x++)
 568                                 {
 569                                         a = *in++;
 570                                         outrow[x] = ((a >> 8) & 0xF800) | ((a >> 5) & 0x07E0) | ((a >> 3) & 0x001F);
 571                                 }
 572                         }
 573                         else
 574                         {
 575                                 for (x = 0;x < width;x++)
 576                                 {
 577                                         a = *in++;
 578                                         outrow[x] = (((a >> Rloss) & Rmask) << Rshift) | (((a >> Gloss) & Gmask) << Gshift) | (((a >> Bloss) & Bmask) << Bshift);
 579                                 }
 580                         }
 581                 }
 582         }
 583         return s->error;
 584 }
 585
 586 static int dpvsimpledecode_decompressimage(dpvsimpledecodestream_t *s)
 587 {
 588         int i, a, b, colors, g, x1, y1, bw, bh, width, height, palettebits;
 589         unsigned int palette[256], *outrow, *out;
 590         g = BLOCKSIZE;
 591         width = s->info_imagewidth;
 592         height = s->info_imageheight;
 593         for (y1 = 0;y1 < height;y1 += g)
 594         {
 595                 outrow = s->videopixels + y1 * width;
 596                 bh = g;
 597                 if (y1 + bh > height)
 598                         bh = height - y1;
 599                 for (x1 = 0;x1 < width;x1 += g)
 600                 {
 601                         out = outrow + x1;
 602                         bw = g;
 603                         if (x1 + bw > width)
 604                                 bw = width - x1;
 605                         if (hz_bitstream_read_bit(s->framedatablocks))
 606                         {
 607                                 // updated block
 608                                 palettebits = hz_bitstream_read_bits(s->framedatablocks, 3);
 609                                 colors = 1 << palettebits;
 610                                 for (i = 0;i < colors;i++)
 611                                         palette[i] = hz_bitstream_read_bits(s->framedatablocks, 24);
 612                                 if (palettebits)
 613                                 {
 614                                         for (b = 0;b < bh;b++, out += width)
 615                                                 for (a = 0;a < bw;a++)
 616                                                         out[a] = palette[hz_bitstream_read_bits(s->framedatablocks, palettebits)];
 617                                 }
 618                                 else
 619                                 {
 620                                         for (b = 0;b < bh;b++, out += width)
 621                                                 for (a = 0;a < bw;a++)
 622                                                         out[a] = palette[0];
 623                                 }
 624                         }
 625                 }
 626         }
 627         return s->error;
 628 }
 629
 630 // decodes a video frame to the supplied output pixels
 631 int dpvsimpledecode_video(void *stream, void *imagedata, unsigned int Rmask, unsigned int Gmask, unsigned int Bmask, unsigned int bytesperpixel, int imagebytesperrow)
 632 {
 633         dpvsimpledecodestream_t *s = (dpvsimpledecodestream_t *)stream;
 634         unsigned int framedatasize;
 635         char t[4];
 636         s->error = DPVSIMPLEDECODEERROR_NONE;
 637         if (dpvsimpledecode_setpixelformat(s, Rmask, Gmask, Bmask, bytesperpixel))
 638                 return s->error;
 639
 640         hz_bitstream_read_blocks_read(s->framedatablocks, s->bitstream, 8);
 641         hz_bitstream_read_bytes(s->framedatablocks, t, 4);
 642         if (memcmp(t, "VID0", 4))
 643         {
 644                 if (t[0] == 0)
 645                         return (s->error = DPVSIMPLEDECODEERROR_EOF);
 646                 else
 647                         return (s->error = DPVSIMPLEDECODEERROR_READERROR);
 648         }
 649         framedatasize = hz_bitstream_read_int(s->framedatablocks);
 650         hz_bitstream_read_blocks_read(s->framedatablocks, s->bitstream, framedatasize);
 651         if (dpvsimpledecode_decompressimage(s))
 652                 return s->error;
 653
 654         dpvsimpledecode_convertpixels(s, imagedata, imagebytesperrow);
 655         return s->error;
 656 }