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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. * @file vqavideo.c
  23. * VQA Video Decoder by Mike Melanson (melanson@pcisys.net)
  24. * For more information about the VQA format, visit:
  25. * http://wiki.multimedia.cx/index.php?title=VQA
  26. *
  27. * The VQA video decoder outputs PAL8 or RGB555 colorspace data, depending
  28. * on the type of data in the file.
  29. *
  30. * This decoder needs the 42-byte VQHD header from the beginning
  31. * of the VQA file passed through the extradata field. The VQHD header
  32. * is laid out as:
  33. *
  34. * bytes 0-3 chunk fourcc: 'VQHD'
  35. * bytes 4-7 chunk size in big-endian format, should be 0x0000002A
  36. * bytes 8-49 VQHD chunk data
  37. *
  38. * Bytes 8-49 are what this decoder expects to see.
  39. *
  40. * Briefly, VQA is a vector quantized animation format that operates in a
  41. * VGA palettized colorspace. It operates on pixel vectors (blocks)
  42. * of either 4x2 or 4x4 in size. Compressed VQA chunks can contain vector
  43. * codebooks, palette information, and code maps for rendering vectors onto
  44. * frames. Any of these components can also be compressed with a run-length
  45. * encoding (RLE) algorithm commonly referred to as "format80".
  46. *
  47. * VQA takes a novel approach to rate control. Each group of n frames
  48. * (usually, n = 8) relies on a different vector codebook. Rather than
  49. * transporting an entire codebook every 8th frame, the new codebook is
  50. * broken up into 8 pieces and sent along with the compressed video chunks
  51. * for each of the 8 frames preceding the 8 frames which require the
  52. * codebook. A full codebook is also sent on the very first frame of a
  53. * file. This is an interesting technique, although it makes random file
  54. * seeking difficult despite the fact that the frames are all intracoded.
  55. *
  56. * V1,2 VQA uses 12-bit codebook indices. If the 12-bit indices were
  57. * packed into bytes and then RLE compressed, bytewise, the results would
  58. * be poor. That is why the coding method divides each index into 2 parts,
  59. * the top 4 bits and the bottom 8 bits, then RL encodes the 4-bit pieces
  60. * together and the 8-bit pieces together. If most of the vectors are
  61. * clustered into one group of 256 vectors, most of the 4-bit index pieces
  62. * should be the same.
  63. */
  64. #include <stdio.h>
  65. #include <stdlib.h>
  66. #include <string.h>
  67. #include <unistd.h>
  68. #include "avcodec.h"
  69. #include "dsputil.h"
  70. #define PALETTE_COUNT 256
  71. #define VQA_HEADER_SIZE 0x2A
  72. #define CHUNK_PREAMBLE_SIZE 8
  73. /* allocate the maximum vector space, regardless of the file version:
  74. * (0xFF00 codebook vectors + 0x100 solid pixel vectors) * (4x4 pixels/block) */
  75. #define MAX_CODEBOOK_VECTORS 0xFF00
  76. #define SOLID_PIXEL_VECTORS 0x100
  77. #define MAX_VECTORS (MAX_CODEBOOK_VECTORS + SOLID_PIXEL_VECTORS)
  78. #define MAX_CODEBOOK_SIZE (MAX_VECTORS * 4 * 4)
  79. #define CBF0_TAG MKBETAG('C', 'B', 'F', '0')
  80. #define CBFZ_TAG MKBETAG('C', 'B', 'F', 'Z')
  81. #define CBP0_TAG MKBETAG('C', 'B', 'P', '0')
  82. #define CBPZ_TAG MKBETAG('C', 'B', 'P', 'Z')
  83. #define CPL0_TAG MKBETAG('C', 'P', 'L', '0')
  84. #define CPLZ_TAG MKBETAG('C', 'P', 'L', 'Z')
  85. #define VPTZ_TAG MKBETAG('V', 'P', 'T', 'Z')
  86. #define VQA_DEBUG 0
  87. #if VQA_DEBUG
  88. #define vqa_debug printf
  89. #else
  90. static inline void vqa_debug(const char *format, ...) { }
  91. #endif
  92. typedef struct VqaContext {
  93. AVCodecContext *avctx;
  94. DSPContext dsp;
  95. AVFrame frame;
  96. unsigned char *buf;
  97. int size;
  98. uint32_t palette[PALETTE_COUNT];
  99. int width; /* width of a frame */
  100. int height; /* height of a frame */
  101. int vector_width; /* width of individual vector */
  102. int vector_height; /* height of individual vector */
  103. int vqa_version; /* this should be either 1, 2 or 3 */
  104. unsigned char *codebook; /* the current codebook */
  105. int codebook_size;
  106. unsigned char *next_codebook_buffer; /* accumulator for next codebook */
  107. int next_codebook_buffer_index;
  108. unsigned char *decode_buffer;
  109. int decode_buffer_size;
  110. /* number of frames to go before replacing codebook */
  111. int partial_countdown;
  112. int partial_count;
  113. } VqaContext;
  114. static int vqa_decode_init(AVCodecContext *avctx)
  115. {
  116. VqaContext *s = avctx->priv_data;
  117. unsigned char *vqa_header;
  118. int i, j, codebook_index;;
  119. s->avctx = avctx;
  120. avctx->pix_fmt = PIX_FMT_PAL8;
  121. dsputil_init(&s->dsp, avctx);
  122. /* make sure the extradata made it */
  123. if (s->avctx->extradata_size != VQA_HEADER_SIZE) {
  124. av_log(s->avctx, AV_LOG_ERROR, " VQA video: expected extradata size of %d\n", VQA_HEADER_SIZE);
  125. return -1;
  126. }
  127. /* load up the VQA parameters from the header */
  128. vqa_header = (unsigned char *)s->avctx->extradata;
  129. s->vqa_version = vqa_header[0];
  130. s->width = AV_RL16(&vqa_header[6]);
  131. s->height = AV_RL16(&vqa_header[8]);
  132. if(avcodec_check_dimensions(avctx, s->width, s->height)){
  133. s->width= s->height= 0;
  134. return -1;
  135. }
  136. s->vector_width = vqa_header[10];
  137. s->vector_height = vqa_header[11];
  138. s->partial_count = s->partial_countdown = vqa_header[13];
  139. /* the vector dimensions have to meet very stringent requirements */
  140. if ((s->vector_width != 4) ||
  141. ((s->vector_height != 2) && (s->vector_height != 4))) {
  142. /* return without further initialization */
  143. return -1;
  144. }
  145. /* allocate codebooks */
  146. s->codebook_size = MAX_CODEBOOK_SIZE;
  147. s->codebook = av_malloc(s->codebook_size);
  148. s->next_codebook_buffer = av_malloc(s->codebook_size);
  149. /* initialize the solid-color vectors */
  150. if (s->vector_height == 4) {
  151. codebook_index = 0xFF00 * 16;
  152. for (i = 0; i < 256; i++)
  153. for (j = 0; j < 16; j++)
  154. s->codebook[codebook_index++] = i;
  155. } else {
  156. codebook_index = 0xF00 * 8;
  157. for (i = 0; i < 256; i++)
  158. for (j = 0; j < 8; j++)
  159. s->codebook[codebook_index++] = i;
  160. }
  161. s->next_codebook_buffer_index = 0;
  162. /* allocate decode buffer */
  163. s->decode_buffer_size = (s->width / s->vector_width) *
  164. (s->height / s->vector_height) * 2;
  165. s->decode_buffer = av_malloc(s->decode_buffer_size);
  166. s->frame.data[0] = NULL;
  167. return 0;
  168. }
  169. #define CHECK_COUNT() \
  170. if (dest_index + count > dest_size) { \
  171. av_log(NULL, AV_LOG_ERROR, " VQA video: decode_format80 problem: next op would overflow dest_index\n"); \
  172. av_log(NULL, AV_LOG_ERROR, " VQA video: current dest_index = %d, count = %d, dest_size = %d\n", \
  173. dest_index, count, dest_size); \
  174. return; \
  175. }
  176. static void decode_format80(unsigned char *src, int src_size,
  177. unsigned char *dest, int dest_size, int check_size) {
  178. int src_index = 0;
  179. int dest_index = 0;
  180. int count;
  181. int src_pos;
  182. unsigned char color;
  183. int i;
  184. while (src_index < src_size) {
  185. vqa_debug(" opcode %02X: ", src[src_index]);
  186. /* 0x80 means that frame is finished */
  187. if (src[src_index] == 0x80)
  188. return;
  189. if (dest_index >= dest_size) {
  190. av_log(NULL, AV_LOG_ERROR, " VQA video: decode_format80 problem: dest_index (%d) exceeded dest_size (%d)\n",
  191. dest_index, dest_size);
  192. return;
  193. }
  194. if (src[src_index] == 0xFF) {
  195. src_index++;
  196. count = AV_RL16(&src[src_index]);
  197. src_index += 2;
  198. src_pos = AV_RL16(&src[src_index]);
  199. src_index += 2;
  200. vqa_debug("(1) copy %X bytes from absolute pos %X\n", count, src_pos);
  201. CHECK_COUNT();
  202. for (i = 0; i < count; i++)
  203. dest[dest_index + i] = dest[src_pos + i];
  204. dest_index += count;
  205. } else if (src[src_index] == 0xFE) {
  206. src_index++;
  207. count = AV_RL16(&src[src_index]);
  208. src_index += 2;
  209. color = src[src_index++];
  210. vqa_debug("(2) set %X bytes to %02X\n", count, color);
  211. CHECK_COUNT();
  212. memset(&dest[dest_index], color, count);
  213. dest_index += count;
  214. } else if ((src[src_index] & 0xC0) == 0xC0) {
  215. count = (src[src_index++] & 0x3F) + 3;
  216. src_pos = AV_RL16(&src[src_index]);
  217. src_index += 2;
  218. vqa_debug("(3) copy %X bytes from absolute pos %X\n", count, src_pos);
  219. CHECK_COUNT();
  220. for (i = 0; i < count; i++)
  221. dest[dest_index + i] = dest[src_pos + i];
  222. dest_index += count;
  223. } else if (src[src_index] > 0x80) {
  224. count = src[src_index++] & 0x3F;
  225. vqa_debug("(4) copy %X bytes from source to dest\n", count);
  226. CHECK_COUNT();
  227. memcpy(&dest[dest_index], &src[src_index], count);
  228. src_index += count;
  229. dest_index += count;
  230. } else {
  231. count = ((src[src_index] & 0x70) >> 4) + 3;
  232. src_pos = AV_RB16(&src[src_index]) & 0x0FFF;
  233. src_index += 2;
  234. vqa_debug("(5) copy %X bytes from relpos %X\n", count, src_pos);
  235. CHECK_COUNT();
  236. for (i = 0; i < count; i++)
  237. dest[dest_index + i] = dest[dest_index - src_pos + i];
  238. dest_index += count;
  239. }
  240. }
  241. /* validate that the entire destination buffer was filled; this is
  242. * important for decoding frame maps since each vector needs to have a
  243. * codebook entry; it is not important for compressed codebooks because
  244. * not every entry needs to be filled */
  245. if (check_size)
  246. if (dest_index < dest_size)
  247. av_log(NULL, AV_LOG_ERROR, " VQA video: decode_format80 problem: decode finished with dest_index (%d) < dest_size (%d)\n",
  248. dest_index, dest_size);
  249. }
  250. static void vqa_decode_chunk(VqaContext *s)
  251. {
  252. unsigned int chunk_type;
  253. unsigned int chunk_size;
  254. int byte_skip;
  255. unsigned int index = 0;
  256. int i;
  257. unsigned char r, g, b;
  258. int index_shift;
  259. int cbf0_chunk = -1;
  260. int cbfz_chunk = -1;
  261. int cbp0_chunk = -1;
  262. int cbpz_chunk = -1;
  263. int cpl0_chunk = -1;
  264. int cplz_chunk = -1;
  265. int vptz_chunk = -1;
  266. int x, y;
  267. int lines = 0;
  268. int pixel_ptr;
  269. int vector_index = 0;
  270. int lobyte = 0;
  271. int hibyte = 0;
  272. int lobytes = 0;
  273. int hibytes = s->decode_buffer_size / 2;
  274. /* first, traverse through the frame and find the subchunks */
  275. while (index < s->size) {
  276. chunk_type = AV_RB32(&s->buf[index]);
  277. chunk_size = AV_RB32(&s->buf[index + 4]);
  278. switch (chunk_type) {
  279. case CBF0_TAG:
  280. cbf0_chunk = index;
  281. break;
  282. case CBFZ_TAG:
  283. cbfz_chunk = index;
  284. break;
  285. case CBP0_TAG:
  286. cbp0_chunk = index;
  287. break;
  288. case CBPZ_TAG:
  289. cbpz_chunk = index;
  290. break;
  291. case CPL0_TAG:
  292. cpl0_chunk = index;
  293. break;
  294. case CPLZ_TAG:
  295. cplz_chunk = index;
  296. break;
  297. case VPTZ_TAG:
  298. vptz_chunk = index;
  299. break;
  300. default:
  301. av_log(s->avctx, AV_LOG_ERROR, " VQA video: Found unknown chunk type: %c%c%c%c (%08X)\n",
  302. (chunk_type >> 24) & 0xFF,
  303. (chunk_type >> 16) & 0xFF,
  304. (chunk_type >> 8) & 0xFF,
  305. (chunk_type >> 0) & 0xFF,
  306. chunk_type);
  307. break;
  308. }
  309. byte_skip = chunk_size & 0x01;
  310. index += (CHUNK_PREAMBLE_SIZE + chunk_size + byte_skip);
  311. }
  312. /* next, deal with the palette */
  313. if ((cpl0_chunk != -1) && (cplz_chunk != -1)) {
  314. /* a chunk should not have both chunk types */
  315. av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found both CPL0 and CPLZ chunks\n");
  316. return;
  317. }
  318. /* decompress the palette chunk */
  319. if (cplz_chunk != -1) {
  320. /* yet to be handled */
  321. }
  322. /* convert the RGB palette into the machine's endian format */
  323. if (cpl0_chunk != -1) {
  324. chunk_size = AV_RB32(&s->buf[cpl0_chunk + 4]);
  325. /* sanity check the palette size */
  326. if (chunk_size / 3 > 256) {
  327. av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found a palette chunk with %d colors\n",
  328. chunk_size / 3);
  329. return;
  330. }
  331. cpl0_chunk += CHUNK_PREAMBLE_SIZE;
  332. for (i = 0; i < chunk_size / 3; i++) {
  333. /* scale by 4 to transform 6-bit palette -> 8-bit */
  334. r = s->buf[cpl0_chunk++] * 4;
  335. g = s->buf[cpl0_chunk++] * 4;
  336. b = s->buf[cpl0_chunk++] * 4;
  337. s->palette[i] = (r << 16) | (g << 8) | (b);
  338. }
  339. }
  340. /* next, look for a full codebook */
  341. if ((cbf0_chunk != -1) && (cbfz_chunk != -1)) {
  342. /* a chunk should not have both chunk types */
  343. av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found both CBF0 and CBFZ chunks\n");
  344. return;
  345. }
  346. /* decompress the full codebook chunk */
  347. if (cbfz_chunk != -1) {
  348. chunk_size = AV_RB32(&s->buf[cbfz_chunk + 4]);
  349. cbfz_chunk += CHUNK_PREAMBLE_SIZE;
  350. decode_format80(&s->buf[cbfz_chunk], chunk_size,
  351. s->codebook, s->codebook_size, 0);
  352. }
  353. /* copy a full codebook */
  354. if (cbf0_chunk != -1) {
  355. chunk_size = AV_RB32(&s->buf[cbf0_chunk + 4]);
  356. /* sanity check the full codebook size */
  357. if (chunk_size > MAX_CODEBOOK_SIZE) {
  358. av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: CBF0 chunk too large (0x%X bytes)\n",
  359. chunk_size);
  360. return;
  361. }
  362. cbf0_chunk += CHUNK_PREAMBLE_SIZE;
  363. memcpy(s->codebook, &s->buf[cbf0_chunk], chunk_size);
  364. }
  365. /* decode the frame */
  366. if (vptz_chunk == -1) {
  367. /* something is wrong if there is no VPTZ chunk */
  368. av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: no VPTZ chunk found\n");
  369. return;
  370. }
  371. chunk_size = AV_RB32(&s->buf[vptz_chunk + 4]);
  372. vptz_chunk += CHUNK_PREAMBLE_SIZE;
  373. decode_format80(&s->buf[vptz_chunk], chunk_size,
  374. s->decode_buffer, s->decode_buffer_size, 1);
  375. /* render the final PAL8 frame */
  376. if (s->vector_height == 4)
  377. index_shift = 4;
  378. else
  379. index_shift = 3;
  380. for (y = 0; y < s->frame.linesize[0] * s->height;
  381. y += s->frame.linesize[0] * s->vector_height) {
  382. for (x = y; x < y + s->width; x += 4, lobytes++, hibytes++) {
  383. pixel_ptr = x;
  384. /* get the vector index, the method for which varies according to
  385. * VQA file version */
  386. switch (s->vqa_version) {
  387. case 1:
  388. /* still need sample media for this case (only one game, "Legend of
  389. * Kyrandia III : Malcolm's Revenge", is known to use this version) */
  390. lobyte = s->decode_buffer[lobytes * 2];
  391. hibyte = s->decode_buffer[(lobytes * 2) + 1];
  392. vector_index = ((hibyte << 8) | lobyte) >> 3;
  393. vector_index <<= index_shift;
  394. lines = s->vector_height;
  395. /* uniform color fill - a quick hack */
  396. if (hibyte == 0xFF) {
  397. while (lines--) {
  398. s->frame.data[0][pixel_ptr + 0] = 255 - lobyte;
  399. s->frame.data[0][pixel_ptr + 1] = 255 - lobyte;
  400. s->frame.data[0][pixel_ptr + 2] = 255 - lobyte;
  401. s->frame.data[0][pixel_ptr + 3] = 255 - lobyte;
  402. pixel_ptr += s->frame.linesize[0];
  403. }
  404. lines=0;
  405. }
  406. break;
  407. case 2:
  408. lobyte = s->decode_buffer[lobytes];
  409. hibyte = s->decode_buffer[hibytes];
  410. vector_index = (hibyte << 8) | lobyte;
  411. vector_index <<= index_shift;
  412. lines = s->vector_height;
  413. break;
  414. case 3:
  415. /* not implemented yet */
  416. lines = 0;
  417. break;
  418. }
  419. while (lines--) {
  420. s->frame.data[0][pixel_ptr + 0] = s->codebook[vector_index++];
  421. s->frame.data[0][pixel_ptr + 1] = s->codebook[vector_index++];
  422. s->frame.data[0][pixel_ptr + 2] = s->codebook[vector_index++];
  423. s->frame.data[0][pixel_ptr + 3] = s->codebook[vector_index++];
  424. pixel_ptr += s->frame.linesize[0];
  425. }
  426. }
  427. }
  428. /* handle partial codebook */
  429. if ((cbp0_chunk != -1) && (cbpz_chunk != -1)) {
  430. /* a chunk should not have both chunk types */
  431. av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found both CBP0 and CBPZ chunks\n");
  432. return;
  433. }
  434. if (cbp0_chunk != -1) {
  435. chunk_size = AV_RB32(&s->buf[cbp0_chunk + 4]);
  436. cbp0_chunk += CHUNK_PREAMBLE_SIZE;
  437. /* accumulate partial codebook */
  438. memcpy(&s->next_codebook_buffer[s->next_codebook_buffer_index],
  439. &s->buf[cbp0_chunk], chunk_size);
  440. s->next_codebook_buffer_index += chunk_size;
  441. s->partial_countdown--;
  442. if (s->partial_countdown == 0) {
  443. /* time to replace codebook */
  444. memcpy(s->codebook, s->next_codebook_buffer,
  445. s->next_codebook_buffer_index);
  446. /* reset accounting */
  447. s->next_codebook_buffer_index = 0;
  448. s->partial_countdown = s->partial_count;
  449. }
  450. }
  451. if (cbpz_chunk != -1) {
  452. chunk_size = AV_RB32(&s->buf[cbpz_chunk + 4]);
  453. cbpz_chunk += CHUNK_PREAMBLE_SIZE;
  454. /* accumulate partial codebook */
  455. memcpy(&s->next_codebook_buffer[s->next_codebook_buffer_index],
  456. &s->buf[cbpz_chunk], chunk_size);
  457. s->next_codebook_buffer_index += chunk_size;
  458. s->partial_countdown--;
  459. if (s->partial_countdown == 0) {
  460. /* decompress codebook */
  461. decode_format80(s->next_codebook_buffer,
  462. s->next_codebook_buffer_index,
  463. s->codebook, s->codebook_size, 0);
  464. /* reset accounting */
  465. s->next_codebook_buffer_index = 0;
  466. s->partial_countdown = s->partial_count;
  467. }
  468. }
  469. }
  470. static int vqa_decode_frame(AVCodecContext *avctx,
  471. void *data, int *data_size,
  472. uint8_t *buf, int buf_size)
  473. {
  474. VqaContext *s = avctx->priv_data;
  475. s->buf = buf;
  476. s->size = buf_size;
  477. if (s->frame.data[0])
  478. avctx->release_buffer(avctx, &s->frame);
  479. if (avctx->get_buffer(avctx, &s->frame)) {
  480. av_log(s->avctx, AV_LOG_ERROR, " VQA Video: get_buffer() failed\n");
  481. return -1;
  482. }
  483. vqa_decode_chunk(s);
  484. /* make the palette available on the way out */
  485. memcpy(s->frame.data[1], s->palette, PALETTE_COUNT * 4);
  486. s->frame.palette_has_changed = 1;
  487. *data_size = sizeof(AVFrame);
  488. *(AVFrame*)data = s->frame;
  489. /* report that the buffer was completely consumed */
  490. return buf_size;
  491. }
  492. static int vqa_decode_end(AVCodecContext *avctx)
  493. {
  494. VqaContext *s = avctx->priv_data;
  495. av_free(s->codebook);
  496. av_free(s->next_codebook_buffer);
  497. av_free(s->decode_buffer);
  498. if (s->frame.data[0])
  499. avctx->release_buffer(avctx, &s->frame);
  500. return 0;
  501. }
  502. AVCodec vqa_decoder = {
  503. "vqavideo",
  504. CODEC_TYPE_VIDEO,
  505. CODEC_ID_WS_VQA,
  506. sizeof(VqaContext),
  507. vqa_decode_init,
  508. NULL,
  509. vqa_decode_end,
  510. vqa_decode_frame,
  511. CODEC_CAP_DR1,
  512. };