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vqavideo.c
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1 /*
2  * Westwood Studios VQA 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  * VQA Video Decoder
25  * @author Mike Melanson (melanson@pcisys.net)
26  * @see http://wiki.multimedia.cx/index.php?title=VQA
27  *
28  * The VQA video decoder outputs PAL8 or RGB555 colorspace data, depending
29  * on the type of data in the file.
30  *
31  * This decoder needs the 42-byte VQHD header from the beginning
32  * of the VQA file passed through the extradata field. The VQHD header
33  * is laid out as:
34  *
35  * bytes 0-3 chunk fourcc: 'VQHD'
36  * bytes 4-7 chunk size in big-endian format, should be 0x0000002A
37  * bytes 8-49 VQHD chunk data
38  *
39  * Bytes 8-49 are what this decoder expects to see.
40  *
41  * Briefly, VQA is a vector quantized animation format that operates in a
42  * VGA palettized colorspace. It operates on pixel vectors (blocks)
43  * of either 4x2 or 4x4 in size. Compressed VQA chunks can contain vector
44  * codebooks, palette information, and code maps for rendering vectors onto
45  * frames. Any of these components can also be compressed with a run-length
46  * encoding (RLE) algorithm commonly referred to as "format80".
47  *
48  * VQA takes a novel approach to rate control. Each group of n frames
49  * (usually, n = 8) relies on a different vector codebook. Rather than
50  * transporting an entire codebook every 8th frame, the new codebook is
51  * broken up into 8 pieces and sent along with the compressed video chunks
52  * for each of the 8 frames preceding the 8 frames which require the
53  * codebook. A full codebook is also sent on the very first frame of a
54  * file. This is an interesting technique, although it makes random file
55  * seeking difficult despite the fact that the frames are all intracoded.
56  *
57  * V1,2 VQA uses 12-bit codebook indexes. If the 12-bit indexes were
58  * packed into bytes and then RLE compressed, bytewise, the results would
59  * be poor. That is why the coding method divides each index into 2 parts,
60  * the top 4 bits and the bottom 8 bits, then RL encodes the 4-bit pieces
61  * together and the 8-bit pieces together. If most of the vectors are
62  * clustered into one group of 256 vectors, most of the 4-bit index pieces
63  * should be the same.
64  */
65 
66 #include <stdio.h>
67 #include <stdlib.h>
68 #include <string.h>
69 
70 #include "libavutil/intreadwrite.h"
71 #include "libavutil/imgutils.h"
72 #include "avcodec.h"
73 #include "bytestream.h"
74 #include "internal.h"
75 
76 #define PALETTE_COUNT 256
77 #define VQA_HEADER_SIZE 0x2A
78 
79 /* allocate the maximum vector space, regardless of the file version:
80  * (0xFF00 codebook vectors + 0x100 solid pixel vectors) * (4x4 pixels/block) */
81 #define MAX_CODEBOOK_VECTORS 0xFF00
82 #define SOLID_PIXEL_VECTORS 0x100
83 #define MAX_VECTORS (MAX_CODEBOOK_VECTORS + SOLID_PIXEL_VECTORS)
84 #define MAX_CODEBOOK_SIZE (MAX_VECTORS * 4 * 4)
85 
86 #define CBF0_TAG MKBETAG('C', 'B', 'F', '0')
87 #define CBFZ_TAG MKBETAG('C', 'B', 'F', 'Z')
88 #define CBP0_TAG MKBETAG('C', 'B', 'P', '0')
89 #define CBPZ_TAG MKBETAG('C', 'B', 'P', 'Z')
90 #define CPL0_TAG MKBETAG('C', 'P', 'L', '0')
91 #define CPLZ_TAG MKBETAG('C', 'P', 'L', 'Z')
92 #define VPTZ_TAG MKBETAG('V', 'P', 'T', 'Z')
93 
94 typedef struct VqaContext {
95 
98 
100 
101  int width; /* width of a frame */
102  int height; /* height of a frame */
103  int vector_width; /* width of individual vector */
104  int vector_height; /* height of individual vector */
105  int vqa_version; /* this should be either 1, 2 or 3 */
106 
107  unsigned char *codebook; /* the current codebook */
109  unsigned char *next_codebook_buffer; /* accumulator for next codebook */
111 
112  unsigned char *decode_buffer;
114 
115  /* number of frames to go before replacing codebook */
118 
119 } VqaContext;
120 
122 {
123  VqaContext *s = avctx->priv_data;
124  int i, j, codebook_index, ret;
125 
126  s->avctx = avctx;
127  avctx->pix_fmt = AV_PIX_FMT_PAL8;
128 
129  /* make sure the extradata made it */
130  if (s->avctx->extradata_size != VQA_HEADER_SIZE) {
131  av_log(s->avctx, AV_LOG_ERROR, "expected extradata size of %d\n", VQA_HEADER_SIZE);
132  return AVERROR(EINVAL);
133  }
134 
135  /* load up the VQA parameters from the header */
136  s->vqa_version = s->avctx->extradata[0];
137  switch (s->vqa_version) {
138  case 1:
139  case 2:
140  break;
141  case 3:
142  avpriv_report_missing_feature(avctx, "VQA Version %d", s->vqa_version);
143  return AVERROR_PATCHWELCOME;
144  default:
145  avpriv_request_sample(avctx, "VQA Version %i", s->vqa_version);
146  return AVERROR_PATCHWELCOME;
147  }
148  s->width = AV_RL16(&s->avctx->extradata[6]);
149  s->height = AV_RL16(&s->avctx->extradata[8]);
150  if ((ret = av_image_check_size(s->width, s->height, 0, avctx)) < 0) {
151  s->width= s->height= 0;
152  return ret;
153  }
154  s->vector_width = s->avctx->extradata[10];
155  s->vector_height = s->avctx->extradata[11];
157 
158  /* the vector dimensions have to meet very stringent requirements */
159  if ((s->vector_width != 4) ||
160  ((s->vector_height != 2) && (s->vector_height != 4))) {
161  /* return without further initialization */
162  return AVERROR_INVALIDDATA;
163  }
164 
165  if (s->width % s->vector_width || s->height % s->vector_height) {
166  av_log(avctx, AV_LOG_ERROR, "Image size not multiple of block size\n");
167  return AVERROR_INVALIDDATA;
168  }
169 
170  /* allocate codebooks */
173  if (!s->codebook)
174  goto fail;
176  if (!s->next_codebook_buffer)
177  goto fail;
178 
179  /* allocate decode buffer */
180  s->decode_buffer_size = (s->width / s->vector_width) *
181  (s->height / s->vector_height) * 2;
183  if (!s->decode_buffer)
184  goto fail;
185 
186  /* initialize the solid-color vectors */
187  if (s->vector_height == 4) {
188  codebook_index = 0xFF00 * 16;
189  for (i = 0; i < 256; i++)
190  for (j = 0; j < 16; j++)
191  s->codebook[codebook_index++] = i;
192  } else {
193  codebook_index = 0xF00 * 8;
194  for (i = 0; i < 256; i++)
195  for (j = 0; j < 8; j++)
196  s->codebook[codebook_index++] = i;
197  }
199 
200  return 0;
201 fail:
202  av_freep(&s->codebook);
204  av_freep(&s->decode_buffer);
205  return AVERROR(ENOMEM);
206 }
207 
208 #define CHECK_COUNT() \
209  if (dest_index + count > dest_size) { \
210  av_log(s->avctx, AV_LOG_ERROR, "decode_format80 problem: next op would overflow dest_index\n"); \
211  av_log(s->avctx, AV_LOG_ERROR, "current dest_index = %d, count = %d, dest_size = %d\n", \
212  dest_index, count, dest_size); \
213  return AVERROR_INVALIDDATA; \
214  }
215 
216 #define CHECK_COPY(idx) \
217  if (idx < 0 || idx + count > dest_size) { \
218  av_log(s->avctx, AV_LOG_ERROR, "decode_format80 problem: next op would overflow dest_index\n"); \
219  av_log(s->avctx, AV_LOG_ERROR, "current src_pos = %d, count = %d, dest_size = %d\n", \
220  src_pos, count, dest_size); \
221  return AVERROR_INVALIDDATA; \
222  }
223 
224 
225 static int decode_format80(VqaContext *s, int src_size,
226  unsigned char *dest, int dest_size, int check_size) {
227 
228  int dest_index = 0;
229  int count, opcode, start;
230  int src_pos;
231  unsigned char color;
232  int i;
233 
234  start = bytestream2_tell(&s->gb);
235  while (bytestream2_tell(&s->gb) - start < src_size) {
236  opcode = bytestream2_get_byte(&s->gb);
237  ff_tlog(s->avctx, "opcode %02X: ", opcode);
238 
239  /* 0x80 means that frame is finished */
240  if (opcode == 0x80)
241  break;
242 
243  if (dest_index >= dest_size) {
244  av_log(s->avctx, AV_LOG_ERROR, "decode_format80 problem: dest_index (%d) exceeded dest_size (%d)\n",
245  dest_index, dest_size);
246  return AVERROR_INVALIDDATA;
247  }
248 
249  if (opcode == 0xFF) {
250 
251  count = bytestream2_get_le16(&s->gb);
252  src_pos = bytestream2_get_le16(&s->gb);
253  ff_tlog(s->avctx, "(1) copy %X bytes from absolute pos %X\n", count, src_pos);
254  CHECK_COUNT();
255  CHECK_COPY(src_pos);
256  for (i = 0; i < count; i++)
257  dest[dest_index + i] = dest[src_pos + i];
258  dest_index += count;
259 
260  } else if (opcode == 0xFE) {
261 
262  count = bytestream2_get_le16(&s->gb);
263  color = bytestream2_get_byte(&s->gb);
264  ff_tlog(s->avctx, "(2) set %X bytes to %02X\n", count, color);
265  CHECK_COUNT();
266  memset(&dest[dest_index], color, count);
267  dest_index += count;
268 
269  } else if ((opcode & 0xC0) == 0xC0) {
270 
271  count = (opcode & 0x3F) + 3;
272  src_pos = bytestream2_get_le16(&s->gb);
273  ff_tlog(s->avctx, "(3) copy %X bytes from absolute pos %X\n", count, src_pos);
274  CHECK_COUNT();
275  CHECK_COPY(src_pos);
276  for (i = 0; i < count; i++)
277  dest[dest_index + i] = dest[src_pos + i];
278  dest_index += count;
279 
280  } else if (opcode > 0x80) {
281 
282  count = opcode & 0x3F;
283  ff_tlog(s->avctx, "(4) copy %X bytes from source to dest\n", count);
284  CHECK_COUNT();
285  bytestream2_get_buffer(&s->gb, &dest[dest_index], count);
286  dest_index += count;
287 
288  } else {
289 
290  count = ((opcode & 0x70) >> 4) + 3;
291  src_pos = bytestream2_get_byte(&s->gb) | ((opcode & 0x0F) << 8);
292  ff_tlog(s->avctx, "(5) copy %X bytes from relpos %X\n", count, src_pos);
293  CHECK_COUNT();
294  CHECK_COPY(dest_index - src_pos);
295  for (i = 0; i < count; i++)
296  dest[dest_index + i] = dest[dest_index - src_pos + i];
297  dest_index += count;
298  }
299  }
300 
301  /* validate that the entire destination buffer was filled; this is
302  * important for decoding frame maps since each vector needs to have a
303  * codebook entry; it is not important for compressed codebooks because
304  * not every entry needs to be filled */
305  if (check_size)
306  if (dest_index < dest_size) {
307  av_log(s->avctx, AV_LOG_ERROR, "decode_format80 problem: decode finished with dest_index (%d) < dest_size (%d)\n",
308  dest_index, dest_size);
309  memset(dest + dest_index, 0, dest_size - dest_index);
310  }
311 
312  return 0; // let's display what we decoded anyway
313 }
314 
316 {
317  unsigned int chunk_type;
318  unsigned int chunk_size;
319  int byte_skip;
320  unsigned int index = 0;
321  int i;
322  unsigned char r, g, b;
323  int index_shift;
324  int res;
325 
326  int cbf0_chunk = -1;
327  int cbfz_chunk = -1;
328  int cbp0_chunk = -1;
329  int cbpz_chunk = -1;
330  int cpl0_chunk = -1;
331  int cplz_chunk = -1;
332  int vptz_chunk = -1;
333 
334  int x, y;
335  int lines = 0;
336  int pixel_ptr;
337  int vector_index = 0;
338  int lobyte = 0;
339  int hibyte = 0;
340  int lobytes = 0;
341  int hibytes = s->decode_buffer_size / 2;
342 
343  /* first, traverse through the frame and find the subchunks */
344  while (bytestream2_get_bytes_left(&s->gb) >= 8) {
345 
346  chunk_type = bytestream2_get_be32u(&s->gb);
347  index = bytestream2_tell(&s->gb);
348  chunk_size = bytestream2_get_be32u(&s->gb);
349 
350  switch (chunk_type) {
351 
352  case CBF0_TAG:
353  cbf0_chunk = index;
354  break;
355 
356  case CBFZ_TAG:
357  cbfz_chunk = index;
358  break;
359 
360  case CBP0_TAG:
361  cbp0_chunk = index;
362  break;
363 
364  case CBPZ_TAG:
365  cbpz_chunk = index;
366  break;
367 
368  case CPL0_TAG:
369  cpl0_chunk = index;
370  break;
371 
372  case CPLZ_TAG:
373  cplz_chunk = index;
374  break;
375 
376  case VPTZ_TAG:
377  vptz_chunk = index;
378  break;
379 
380  default:
381  av_log(s->avctx, AV_LOG_ERROR, "Found unknown chunk type: %c%c%c%c (%08X)\n",
382  (chunk_type >> 24) & 0xFF,
383  (chunk_type >> 16) & 0xFF,
384  (chunk_type >> 8) & 0xFF,
385  (chunk_type >> 0) & 0xFF,
386  chunk_type);
387  break;
388  }
389 
390  byte_skip = chunk_size & 0x01;
391  bytestream2_skip(&s->gb, chunk_size + byte_skip);
392  }
393 
394  /* next, deal with the palette */
395  if ((cpl0_chunk != -1) && (cplz_chunk != -1)) {
396 
397  /* a chunk should not have both chunk types */
398  av_log(s->avctx, AV_LOG_ERROR, "problem: found both CPL0 and CPLZ chunks\n");
399  return AVERROR_INVALIDDATA;
400  }
401 
402  /* decompress the palette chunk */
403  if (cplz_chunk != -1) {
404 
405 /* yet to be handled */
406 
407  }
408 
409  /* convert the RGB palette into the machine's endian format */
410  if (cpl0_chunk != -1) {
411 
412  bytestream2_seek(&s->gb, cpl0_chunk, SEEK_SET);
413  chunk_size = bytestream2_get_be32(&s->gb);
414  /* sanity check the palette size */
415  if (chunk_size / 3 > 256 || chunk_size > bytestream2_get_bytes_left(&s->gb)) {
416  av_log(s->avctx, AV_LOG_ERROR, "problem: found a palette chunk with %d colors\n",
417  chunk_size / 3);
418  return AVERROR_INVALIDDATA;
419  }
420  for (i = 0; i < chunk_size / 3; i++) {
421  /* scale by 4 to transform 6-bit palette -> 8-bit */
422  r = bytestream2_get_byteu(&s->gb) * 4;
423  g = bytestream2_get_byteu(&s->gb) * 4;
424  b = bytestream2_get_byteu(&s->gb) * 4;
425  s->palette[i] = 0xFFU << 24 | r << 16 | g << 8 | b;
426  s->palette[i] |= s->palette[i] >> 6 & 0x30303;
427  }
428  }
429 
430  /* next, look for a full codebook */
431  if ((cbf0_chunk != -1) && (cbfz_chunk != -1)) {
432 
433  /* a chunk should not have both chunk types */
434  av_log(s->avctx, AV_LOG_ERROR, "problem: found both CBF0 and CBFZ chunks\n");
435  return AVERROR_INVALIDDATA;
436  }
437 
438  /* decompress the full codebook chunk */
439  if (cbfz_chunk != -1) {
440 
441  bytestream2_seek(&s->gb, cbfz_chunk, SEEK_SET);
442  chunk_size = bytestream2_get_be32(&s->gb);
443  if ((res = decode_format80(s, chunk_size, s->codebook,
444  s->codebook_size, 0)) < 0)
445  return res;
446  }
447 
448  /* copy a full codebook */
449  if (cbf0_chunk != -1) {
450 
451  bytestream2_seek(&s->gb, cbf0_chunk, SEEK_SET);
452  chunk_size = bytestream2_get_be32(&s->gb);
453  /* sanity check the full codebook size */
454  if (chunk_size > MAX_CODEBOOK_SIZE) {
455  av_log(s->avctx, AV_LOG_ERROR, "problem: CBF0 chunk too large (0x%X bytes)\n",
456  chunk_size);
457  return AVERROR_INVALIDDATA;
458  }
459 
460  bytestream2_get_buffer(&s->gb, s->codebook, chunk_size);
461  }
462 
463  /* decode the frame */
464  if (vptz_chunk == -1) {
465 
466  /* something is wrong if there is no VPTZ chunk */
467  av_log(s->avctx, AV_LOG_ERROR, "problem: no VPTZ chunk found\n");
468  return AVERROR_INVALIDDATA;
469  }
470 
471  bytestream2_seek(&s->gb, vptz_chunk, SEEK_SET);
472  chunk_size = bytestream2_get_be32(&s->gb);
473  if ((res = decode_format80(s, chunk_size,
474  s->decode_buffer, s->decode_buffer_size, 1)) < 0)
475  return res;
476 
477  /* render the final PAL8 frame */
478  if (s->vector_height == 4)
479  index_shift = 4;
480  else
481  index_shift = 3;
482  for (y = 0; y < s->height; y += s->vector_height) {
483  for (x = 0; x < s->width; x += 4, lobytes++, hibytes++) {
484  pixel_ptr = y * frame->linesize[0] + x;
485 
486  /* get the vector index, the method for which varies according to
487  * VQA file version */
488  switch (s->vqa_version) {
489 
490  case 1:
491  lobyte = s->decode_buffer[lobytes * 2];
492  hibyte = s->decode_buffer[(lobytes * 2) + 1];
493  vector_index = ((hibyte << 8) | lobyte) >> 3;
494  vector_index <<= index_shift;
495  lines = s->vector_height;
496  /* uniform color fill - a quick hack */
497  if (hibyte == 0xFF) {
498  while (lines--) {
499  frame->data[0][pixel_ptr + 0] = 255 - lobyte;
500  frame->data[0][pixel_ptr + 1] = 255 - lobyte;
501  frame->data[0][pixel_ptr + 2] = 255 - lobyte;
502  frame->data[0][pixel_ptr + 3] = 255 - lobyte;
503  pixel_ptr += frame->linesize[0];
504  }
505  lines=0;
506  }
507  break;
508 
509  case 2:
510  lobyte = s->decode_buffer[lobytes];
511  hibyte = s->decode_buffer[hibytes];
512  vector_index = (hibyte << 8) | lobyte;
513  vector_index <<= index_shift;
514  lines = s->vector_height;
515  break;
516 
517  case 3:
518 /* not implemented yet */
519  lines = 0;
520  break;
521  }
522 
523  while (lines--) {
524  frame->data[0][pixel_ptr + 0] = s->codebook[vector_index++];
525  frame->data[0][pixel_ptr + 1] = s->codebook[vector_index++];
526  frame->data[0][pixel_ptr + 2] = s->codebook[vector_index++];
527  frame->data[0][pixel_ptr + 3] = s->codebook[vector_index++];
528  pixel_ptr += frame->linesize[0];
529  }
530  }
531  }
532 
533  /* handle partial codebook */
534  if ((cbp0_chunk != -1) && (cbpz_chunk != -1)) {
535  /* a chunk should not have both chunk types */
536  av_log(s->avctx, AV_LOG_ERROR, "problem: found both CBP0 and CBPZ chunks\n");
537  return AVERROR_INVALIDDATA;
538  }
539 
540  if (cbp0_chunk != -1) {
541 
542  bytestream2_seek(&s->gb, cbp0_chunk, SEEK_SET);
543  chunk_size = bytestream2_get_be32(&s->gb);
544 
545  if (chunk_size > MAX_CODEBOOK_SIZE - s->next_codebook_buffer_index) {
546  av_log(s->avctx, AV_LOG_ERROR, "cbp0 chunk too large (%u bytes)\n",
547  chunk_size);
548  return AVERROR_INVALIDDATA;
549  }
550 
551  /* accumulate partial codebook */
553  chunk_size);
554  s->next_codebook_buffer_index += chunk_size;
555 
556  s->partial_countdown--;
557  if (s->partial_countdown <= 0) {
558 
559  /* time to replace codebook */
560  memcpy(s->codebook, s->next_codebook_buffer,
562 
563  /* reset accounting */
566  }
567  }
568 
569  if (cbpz_chunk != -1) {
570 
571  bytestream2_seek(&s->gb, cbpz_chunk, SEEK_SET);
572  chunk_size = bytestream2_get_be32(&s->gb);
573 
574  if (chunk_size > MAX_CODEBOOK_SIZE - s->next_codebook_buffer_index) {
575  av_log(s->avctx, AV_LOG_ERROR, "cbpz chunk too large (%u bytes)\n",
576  chunk_size);
577  return AVERROR_INVALIDDATA;
578  }
579 
580  /* accumulate partial codebook */
582  chunk_size);
583  s->next_codebook_buffer_index += chunk_size;
584 
585  s->partial_countdown--;
586  if (s->partial_countdown <= 0) {
588  /* decompress codebook */
590  s->codebook, s->codebook_size, 0)) < 0)
591  return res;
592 
593  /* reset accounting */
596  }
597  }
598 
599  return 0;
600 }
601 
603  void *data, int *got_frame,
604  AVPacket *avpkt)
605 {
606  VqaContext *s = avctx->priv_data;
607  AVFrame *frame = data;
608  int res;
609 
610  if ((res = ff_get_buffer(avctx, frame, 0)) < 0)
611  return res;
612 
613  bytestream2_init(&s->gb, avpkt->data, avpkt->size);
614  if ((res = vqa_decode_chunk(s, frame)) < 0)
615  return res;
616 
617  /* make the palette available on the way out */
618  memcpy(frame->data[1], s->palette, PALETTE_COUNT * 4);
619  frame->palette_has_changed = 1;
620 
621  *got_frame = 1;
622 
623  /* report that the buffer was completely consumed */
624  return avpkt->size;
625 }
626 
628 {
629  VqaContext *s = avctx->priv_data;
630 
631  av_freep(&s->codebook);
633  av_freep(&s->decode_buffer);
634 
635  return 0;
636 }
637 
639  .name = "vqavideo",
640  .long_name = NULL_IF_CONFIG_SMALL("Westwood Studios VQA (Vector Quantized Animation) video"),
641  .type = AVMEDIA_TYPE_VIDEO,
642  .id = AV_CODEC_ID_WS_VQA,
643  .priv_data_size = sizeof(VqaContext),
645  .close = vqa_decode_end,
647  .capabilities = CODEC_CAP_DR1,
648 };