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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 
99 
101 
102  int width; /* width of a frame */
103  int height; /* height of a frame */
104  int vector_width; /* width of individual vector */
105  int vector_height; /* height of individual vector */
106  int vqa_version; /* this should be either 1, 2 or 3 */
107 
108  unsigned char *codebook; /* the current codebook */
110  unsigned char *next_codebook_buffer; /* accumulator for next codebook */
112 
113  unsigned char *decode_buffer;
115 
116  /* number of frames to go before replacing codebook */
119 
120 } VqaContext;
121 
123 {
124  VqaContext *s = avctx->priv_data;
125  int i, j, codebook_index, ret;
126 
127  s->avctx = avctx;
128  avctx->pix_fmt = AV_PIX_FMT_PAL8;
129 
130  /* make sure the extradata made it */
131  if (s->avctx->extradata_size != VQA_HEADER_SIZE) {
132  av_log(s->avctx, AV_LOG_ERROR, "expected extradata size of %d\n", VQA_HEADER_SIZE);
133  return AVERROR(EINVAL);
134  }
135 
136  /* load up the VQA parameters from the header */
137  s->vqa_version = s->avctx->extradata[0];
138  if (s->vqa_version < 1 || s->vqa_version > 3) {
139  av_log(s->avctx, AV_LOG_ERROR, "unsupported version %d\n", s->vqa_version);
140  return AVERROR_PATCHWELCOME;
141  }
142  s->width = AV_RL16(&s->avctx->extradata[6]);
143  s->height = AV_RL16(&s->avctx->extradata[8]);
144  if ((ret = av_image_check_size(s->width, s->height, 0, avctx)) < 0) {
145  s->width= s->height= 0;
146  return ret;
147  }
148  s->vector_width = s->avctx->extradata[10];
149  s->vector_height = s->avctx->extradata[11];
151 
152  /* the vector dimensions have to meet very stringent requirements */
153  if ((s->vector_width != 4) ||
154  ((s->vector_height != 2) && (s->vector_height != 4))) {
155  /* return without further initialization */
156  return AVERROR_INVALIDDATA;
157  }
158 
159  if (s->width % s->vector_width || s->height % s->vector_height) {
160  av_log(avctx, AV_LOG_ERROR, "Image size not multiple of block size\n");
161  return AVERROR_INVALIDDATA;
162  }
163 
164  /* allocate codebooks */
167  if (!s->codebook)
168  goto fail;
170  if (!s->next_codebook_buffer)
171  goto fail;
172 
173  /* allocate decode buffer */
174  s->decode_buffer_size = (s->width / s->vector_width) *
175  (s->height / s->vector_height) * 2;
177  if (!s->decode_buffer)
178  goto fail;
179 
180  /* initialize the solid-color vectors */
181  if (s->vector_height == 4) {
182  codebook_index = 0xFF00 * 16;
183  for (i = 0; i < 256; i++)
184  for (j = 0; j < 16; j++)
185  s->codebook[codebook_index++] = i;
186  } else {
187  codebook_index = 0xF00 * 8;
188  for (i = 0; i < 256; i++)
189  for (j = 0; j < 8; j++)
190  s->codebook[codebook_index++] = i;
191  }
193 
195  s->frame.data[0] = NULL;
196 
197  return 0;
198 fail:
199  av_freep(&s->codebook);
201  av_freep(&s->decode_buffer);
202  return AVERROR(ENOMEM);
203 }
204 
205 #define CHECK_COUNT() \
206  if (dest_index + count > dest_size) { \
207  av_log(s->avctx, AV_LOG_ERROR, "decode_format80 problem: next op would overflow dest_index\n"); \
208  av_log(s->avctx, AV_LOG_ERROR, "current dest_index = %d, count = %d, dest_size = %d\n", \
209  dest_index, count, dest_size); \
210  return AVERROR_INVALIDDATA; \
211  }
212 
213 #define CHECK_COPY(idx) \
214  if (idx < 0 || idx + count > dest_size) { \
215  av_log(s->avctx, AV_LOG_ERROR, "decode_format80 problem: next op would overflow dest_index\n"); \
216  av_log(s->avctx, AV_LOG_ERROR, "current src_pos = %d, count = %d, dest_size = %d\n", \
217  src_pos, count, dest_size); \
218  return AVERROR_INVALIDDATA; \
219  }
220 
221 
222 static int decode_format80(VqaContext *s, int src_size,
223  unsigned char *dest, int dest_size, int check_size) {
224 
225  int dest_index = 0;
226  int count, opcode, start;
227  int src_pos;
228  unsigned char color;
229  int i;
230 
231  start = bytestream2_tell(&s->gb);
232  while (bytestream2_tell(&s->gb) - start < src_size) {
233  opcode = bytestream2_get_byte(&s->gb);
234  av_dlog(s->avctx, "opcode %02X: ", opcode);
235 
236  /* 0x80 means that frame is finished */
237  if (opcode == 0x80)
238  return 0;
239 
240  if (dest_index >= dest_size) {
241  av_log(s->avctx, AV_LOG_ERROR, "decode_format80 problem: dest_index (%d) exceeded dest_size (%d)\n",
242  dest_index, dest_size);
243  return AVERROR_INVALIDDATA;
244  }
245 
246  if (opcode == 0xFF) {
247 
248  count = bytestream2_get_le16(&s->gb);
249  src_pos = bytestream2_get_le16(&s->gb);
250  av_dlog(s->avctx, "(1) copy %X bytes from absolute pos %X\n", count, src_pos);
251  CHECK_COUNT();
252  CHECK_COPY(src_pos);
253  for (i = 0; i < count; i++)
254  dest[dest_index + i] = dest[src_pos + i];
255  dest_index += count;
256 
257  } else if (opcode == 0xFE) {
258 
259  count = bytestream2_get_le16(&s->gb);
260  color = bytestream2_get_byte(&s->gb);
261  av_dlog(s->avctx, "(2) set %X bytes to %02X\n", count, color);
262  CHECK_COUNT();
263  memset(&dest[dest_index], color, count);
264  dest_index += count;
265 
266  } else if ((opcode & 0xC0) == 0xC0) {
267 
268  count = (opcode & 0x3F) + 3;
269  src_pos = bytestream2_get_le16(&s->gb);
270  av_dlog(s->avctx, "(3) copy %X bytes from absolute pos %X\n", count, src_pos);
271  CHECK_COUNT();
272  CHECK_COPY(src_pos);
273  for (i = 0; i < count; i++)
274  dest[dest_index + i] = dest[src_pos + i];
275  dest_index += count;
276 
277  } else if (opcode > 0x80) {
278 
279  count = opcode & 0x3F;
280  av_dlog(s->avctx, "(4) copy %X bytes from source to dest\n", count);
281  CHECK_COUNT();
282  bytestream2_get_buffer(&s->gb, &dest[dest_index], count);
283  dest_index += count;
284 
285  } else {
286 
287  count = ((opcode & 0x70) >> 4) + 3;
288  src_pos = bytestream2_get_byte(&s->gb) | ((opcode & 0x0F) << 8);
289  av_dlog(s->avctx, "(5) copy %X bytes from relpos %X\n", count, src_pos);
290  CHECK_COUNT();
291  CHECK_COPY(dest_index - src_pos);
292  for (i = 0; i < count; i++)
293  dest[dest_index + i] = dest[dest_index - src_pos + i];
294  dest_index += count;
295  }
296  }
297 
298  /* validate that the entire destination buffer was filled; this is
299  * important for decoding frame maps since each vector needs to have a
300  * codebook entry; it is not important for compressed codebooks because
301  * not every entry needs to be filled */
302  if (check_size)
303  if (dest_index < dest_size)
304  av_log(s->avctx, AV_LOG_ERROR, "decode_format80 problem: decode finished with dest_index (%d) < dest_size (%d)\n",
305  dest_index, dest_size);
306 
307  return 0; // let's display what we decoded anyway
308 }
309 
311 {
312  unsigned int chunk_type;
313  unsigned int chunk_size;
314  int byte_skip;
315  unsigned int index = 0;
316  int i;
317  unsigned char r, g, b;
318  int index_shift;
319  int res;
320 
321  int cbf0_chunk = -1;
322  int cbfz_chunk = -1;
323  int cbp0_chunk = -1;
324  int cbpz_chunk = -1;
325  int cpl0_chunk = -1;
326  int cplz_chunk = -1;
327  int vptz_chunk = -1;
328 
329  int x, y;
330  int lines = 0;
331  int pixel_ptr;
332  int vector_index = 0;
333  int lobyte = 0;
334  int hibyte = 0;
335  int lobytes = 0;
336  int hibytes = s->decode_buffer_size / 2;
337 
338  /* first, traverse through the frame and find the subchunks */
339  while (bytestream2_get_bytes_left(&s->gb) >= 8) {
340 
341  chunk_type = bytestream2_get_be32u(&s->gb);
342  index = bytestream2_tell(&s->gb);
343  chunk_size = bytestream2_get_be32u(&s->gb);
344 
345  switch (chunk_type) {
346 
347  case CBF0_TAG:
348  cbf0_chunk = index;
349  break;
350 
351  case CBFZ_TAG:
352  cbfz_chunk = index;
353  break;
354 
355  case CBP0_TAG:
356  cbp0_chunk = index;
357  break;
358 
359  case CBPZ_TAG:
360  cbpz_chunk = index;
361  break;
362 
363  case CPL0_TAG:
364  cpl0_chunk = index;
365  break;
366 
367  case CPLZ_TAG:
368  cplz_chunk = index;
369  break;
370 
371  case VPTZ_TAG:
372  vptz_chunk = index;
373  break;
374 
375  default:
376  av_log(s->avctx, AV_LOG_ERROR, "Found unknown chunk type: %c%c%c%c (%08X)\n",
377  (chunk_type >> 24) & 0xFF,
378  (chunk_type >> 16) & 0xFF,
379  (chunk_type >> 8) & 0xFF,
380  (chunk_type >> 0) & 0xFF,
381  chunk_type);
382  break;
383  }
384 
385  byte_skip = chunk_size & 0x01;
386  bytestream2_skip(&s->gb, chunk_size + byte_skip);
387  }
388 
389  /* next, deal with the palette */
390  if ((cpl0_chunk != -1) && (cplz_chunk != -1)) {
391 
392  /* a chunk should not have both chunk types */
393  av_log(s->avctx, AV_LOG_ERROR, "problem: found both CPL0 and CPLZ chunks\n");
394  return AVERROR_INVALIDDATA;
395  }
396 
397  /* decompress the palette chunk */
398  if (cplz_chunk != -1) {
399 
400 /* yet to be handled */
401 
402  }
403 
404  /* convert the RGB palette into the machine's endian format */
405  if (cpl0_chunk != -1) {
406 
407  bytestream2_seek(&s->gb, cpl0_chunk, SEEK_SET);
408  chunk_size = bytestream2_get_be32(&s->gb);
409  /* sanity check the palette size */
410  if (chunk_size / 3 > 256 || chunk_size > bytestream2_get_bytes_left(&s->gb)) {
411  av_log(s->avctx, AV_LOG_ERROR, "problem: found a palette chunk with %d colors\n",
412  chunk_size / 3);
413  return AVERROR_INVALIDDATA;
414  }
415  for (i = 0; i < chunk_size / 3; i++) {
416  /* scale by 4 to transform 6-bit palette -> 8-bit */
417  r = bytestream2_get_byteu(&s->gb) * 4;
418  g = bytestream2_get_byteu(&s->gb) * 4;
419  b = bytestream2_get_byteu(&s->gb) * 4;
420  s->palette[i] = 0xFFU << 24 | r << 16 | g << 8 | b;
421  s->palette[i] |= s->palette[i] >> 6 & 0x30303;
422  }
423  }
424 
425  /* next, look for a full codebook */
426  if ((cbf0_chunk != -1) && (cbfz_chunk != -1)) {
427 
428  /* a chunk should not have both chunk types */
429  av_log(s->avctx, AV_LOG_ERROR, "problem: found both CBF0 and CBFZ chunks\n");
430  return AVERROR_INVALIDDATA;
431  }
432 
433  /* decompress the full codebook chunk */
434  if (cbfz_chunk != -1) {
435 
436  bytestream2_seek(&s->gb, cbfz_chunk, SEEK_SET);
437  chunk_size = bytestream2_get_be32(&s->gb);
438  if ((res = decode_format80(s, chunk_size, s->codebook,
439  s->codebook_size, 0)) < 0)
440  return res;
441  }
442 
443  /* copy a full codebook */
444  if (cbf0_chunk != -1) {
445 
446  bytestream2_seek(&s->gb, cbf0_chunk, SEEK_SET);
447  chunk_size = bytestream2_get_be32(&s->gb);
448  /* sanity check the full codebook size */
449  if (chunk_size > MAX_CODEBOOK_SIZE) {
450  av_log(s->avctx, AV_LOG_ERROR, "problem: CBF0 chunk too large (0x%X bytes)\n",
451  chunk_size);
452  return AVERROR_INVALIDDATA;
453  }
454 
455  bytestream2_get_buffer(&s->gb, s->codebook, chunk_size);
456  }
457 
458  /* decode the frame */
459  if (vptz_chunk == -1) {
460 
461  /* something is wrong if there is no VPTZ chunk */
462  av_log(s->avctx, AV_LOG_ERROR, "problem: no VPTZ chunk found\n");
463  return AVERROR_INVALIDDATA;
464  }
465 
466  bytestream2_seek(&s->gb, vptz_chunk, SEEK_SET);
467  chunk_size = bytestream2_get_be32(&s->gb);
468  if ((res = decode_format80(s, chunk_size,
469  s->decode_buffer, s->decode_buffer_size, 1)) < 0)
470  return res;
471 
472  /* render the final PAL8 frame */
473  if (s->vector_height == 4)
474  index_shift = 4;
475  else
476  index_shift = 3;
477  for (y = 0; y < s->height; y += s->vector_height) {
478  for (x = 0; x < s->width; x += 4, lobytes++, hibytes++) {
479  pixel_ptr = y * s->frame.linesize[0] + x;
480 
481  /* get the vector index, the method for which varies according to
482  * VQA file version */
483  switch (s->vqa_version) {
484 
485  case 1:
486  lobyte = s->decode_buffer[lobytes * 2];
487  hibyte = s->decode_buffer[(lobytes * 2) + 1];
488  vector_index = ((hibyte << 8) | lobyte) >> 3;
489  vector_index <<= index_shift;
490  lines = s->vector_height;
491  /* uniform color fill - a quick hack */
492  if (hibyte == 0xFF) {
493  while (lines--) {
494  s->frame.data[0][pixel_ptr + 0] = 255 - lobyte;
495  s->frame.data[0][pixel_ptr + 1] = 255 - lobyte;
496  s->frame.data[0][pixel_ptr + 2] = 255 - lobyte;
497  s->frame.data[0][pixel_ptr + 3] = 255 - lobyte;
498  pixel_ptr += s->frame.linesize[0];
499  }
500  lines=0;
501  }
502  break;
503 
504  case 2:
505  lobyte = s->decode_buffer[lobytes];
506  hibyte = s->decode_buffer[hibytes];
507  vector_index = (hibyte << 8) | lobyte;
508  vector_index <<= index_shift;
509  lines = s->vector_height;
510  break;
511 
512  case 3:
513 /* not implemented yet */
514  lines = 0;
515  break;
516  }
517 
518  while (lines--) {
519  s->frame.data[0][pixel_ptr + 0] = s->codebook[vector_index++];
520  s->frame.data[0][pixel_ptr + 1] = s->codebook[vector_index++];
521  s->frame.data[0][pixel_ptr + 2] = s->codebook[vector_index++];
522  s->frame.data[0][pixel_ptr + 3] = s->codebook[vector_index++];
523  pixel_ptr += s->frame.linesize[0];
524  }
525  }
526  }
527 
528  /* handle partial codebook */
529  if ((cbp0_chunk != -1) && (cbpz_chunk != -1)) {
530  /* a chunk should not have both chunk types */
531  av_log(s->avctx, AV_LOG_ERROR, "problem: found both CBP0 and CBPZ chunks\n");
532  return AVERROR_INVALIDDATA;
533  }
534 
535  if (cbp0_chunk != -1) {
536 
537  bytestream2_seek(&s->gb, cbp0_chunk, SEEK_SET);
538  chunk_size = bytestream2_get_be32(&s->gb);
539 
540  if (chunk_size > MAX_CODEBOOK_SIZE - s->next_codebook_buffer_index) {
541  av_log(s->avctx, AV_LOG_ERROR, "cbp0 chunk too large (%u bytes)\n",
542  chunk_size);
543  return AVERROR_INVALIDDATA;
544  }
545 
546  /* accumulate partial codebook */
548  chunk_size);
549  s->next_codebook_buffer_index += chunk_size;
550 
551  s->partial_countdown--;
552  if (s->partial_countdown <= 0) {
553 
554  /* time to replace codebook */
555  memcpy(s->codebook, s->next_codebook_buffer,
557 
558  /* reset accounting */
561  }
562  }
563 
564  if (cbpz_chunk != -1) {
565 
566  bytestream2_seek(&s->gb, cbpz_chunk, SEEK_SET);
567  chunk_size = bytestream2_get_be32(&s->gb);
568 
569  if (chunk_size > MAX_CODEBOOK_SIZE - s->next_codebook_buffer_index) {
570  av_log(s->avctx, AV_LOG_ERROR, "cbpz chunk too large (%u bytes)\n",
571  chunk_size);
572  return AVERROR_INVALIDDATA;
573  }
574 
575  /* accumulate partial codebook */
577  chunk_size);
578  s->next_codebook_buffer_index += chunk_size;
579 
580  s->partial_countdown--;
581  if (s->partial_countdown <= 0) {
583  /* decompress codebook */
585  s->codebook, s->codebook_size, 0)) < 0)
586  return res;
587 
588  /* reset accounting */
591  }
592  }
593 
594  return 0;
595 }
596 
598  void *data, int *got_frame,
599  AVPacket *avpkt)
600 {
601  VqaContext *s = avctx->priv_data;
602  int res;
603 
604  if (s->frame.data[0])
605  avctx->release_buffer(avctx, &s->frame);
606 
607  if ((res = ff_get_buffer(avctx, &s->frame)) < 0) {
608  av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");
609  return res;
610  }
611 
612  bytestream2_init(&s->gb, avpkt->data, avpkt->size);
613  if ((res = vqa_decode_chunk(s)) < 0)
614  return res;
615 
616  /* make the palette available on the way out */
617  memcpy(s->frame.data[1], s->palette, PALETTE_COUNT * 4);
618  s->frame.palette_has_changed = 1;
619 
620  *got_frame = 1;
621  *(AVFrame*)data = s->frame;
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  if (s->frame.data[0])
636  avctx->release_buffer(avctx, &s->frame);
637 
638  return 0;
639 }
640 
642  .name = "vqavideo",
643  .type = AVMEDIA_TYPE_VIDEO,
644  .id = AV_CODEC_ID_WS_VQA,
645  .priv_data_size = sizeof(VqaContext),
649  .capabilities = CODEC_CAP_DR1,
650  .long_name = NULL_IF_CONFIG_SMALL("Westwood Studios VQA (Vector Quantized Animation) video"),
651 };