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1 | /* |
2 | * Wing Commander/Xan 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 | * Xan video decoder for Wing Commander III computer game | |
25 | * by Mario Brito (mbrito@student.dei.uc.pt) | |
26 | * and Mike Melanson (melanson@pcisys.net) | |
27 | * | |
28 | * The xan_wc3 decoder outputs PAL8 data. | |
29 | */ | |
30 | ||
31 | #include <stdio.h> | |
32 | #include <stdlib.h> | |
33 | #include <string.h> | |
34 | ||
35 | #include "libavutil/intreadwrite.h" | |
36 | #include "libavutil/mem.h" | |
37 | #include "avcodec.h" | |
38 | #include "bytestream.h" | |
39 | #define BITSTREAM_READER_LE | |
40 | #include "get_bits.h" | |
41 | #include "internal.h" | |
42 | ||
43 | #define RUNTIME_GAMMA 0 | |
44 | ||
45 | #define VGA__TAG MKTAG('V', 'G', 'A', ' ') | |
46 | #define PALT_TAG MKTAG('P', 'A', 'L', 'T') | |
47 | #define SHOT_TAG MKTAG('S', 'H', 'O', 'T') | |
48 | #define PALETTE_COUNT 256 | |
49 | #define PALETTE_SIZE (PALETTE_COUNT * 3) | |
50 | #define PALETTES_MAX 256 | |
51 | ||
52 | typedef struct XanContext { | |
53 | ||
54 | AVCodecContext *avctx; | |
55 | AVFrame *last_frame; | |
56 | ||
57 | const uint8_t *buf; | |
58 | int size; | |
59 | ||
60 | /* scratch space */ | |
61 | uint8_t *buffer1; | |
62 | int buffer1_size; | |
63 | uint8_t *buffer2; | |
64 | int buffer2_size; | |
65 | ||
66 | unsigned *palettes; | |
67 | int palettes_count; | |
68 | int cur_palette; | |
69 | ||
70 | int frame_size; | |
71 | ||
72 | } XanContext; | |
73 | ||
74 | static av_cold int xan_decode_end(AVCodecContext *avctx) | |
75 | { | |
76 | XanContext *s = avctx->priv_data; | |
77 | ||
78 | av_frame_free(&s->last_frame); | |
79 | ||
80 | av_freep(&s->buffer1); | |
81 | av_freep(&s->buffer2); | |
82 | av_freep(&s->palettes); | |
83 | ||
84 | return 0; | |
85 | } | |
86 | ||
87 | static av_cold int xan_decode_init(AVCodecContext *avctx) | |
88 | { | |
89 | XanContext *s = avctx->priv_data; | |
90 | ||
91 | s->avctx = avctx; | |
92 | s->frame_size = 0; | |
93 | ||
94 | avctx->pix_fmt = AV_PIX_FMT_PAL8; | |
95 | ||
96 | s->buffer1_size = avctx->width * avctx->height; | |
97 | s->buffer1 = av_malloc(s->buffer1_size); | |
98 | if (!s->buffer1) | |
99 | return AVERROR(ENOMEM); | |
100 | s->buffer2_size = avctx->width * avctx->height; | |
101 | s->buffer2 = av_malloc(s->buffer2_size + 130); | |
102 | if (!s->buffer2) { | |
103 | av_freep(&s->buffer1); | |
104 | return AVERROR(ENOMEM); | |
105 | } | |
106 | ||
107 | s->last_frame = av_frame_alloc(); | |
108 | if (!s->last_frame) { | |
109 | xan_decode_end(avctx); | |
110 | return AVERROR(ENOMEM); | |
111 | } | |
112 | ||
113 | return 0; | |
114 | } | |
115 | ||
116 | static int xan_huffman_decode(uint8_t *dest, int dest_len, | |
117 | const uint8_t *src, int src_len) | |
118 | { | |
119 | uint8_t byte = *src++; | |
120 | uint8_t ival = byte + 0x16; | |
121 | const uint8_t * ptr = src + byte*2; | |
122 | int ptr_len = src_len - 1 - byte*2; | |
123 | uint8_t val = ival; | |
124 | uint8_t *dest_end = dest + dest_len; | |
125 | uint8_t *dest_start = dest; | |
126 | int ret; | |
127 | GetBitContext gb; | |
128 | ||
129 | if ((ret = init_get_bits8(&gb, ptr, ptr_len)) < 0) | |
130 | return ret; | |
131 | ||
132 | while (val != 0x16) { | |
133 | unsigned idx = val - 0x17 + get_bits1(&gb) * byte; | |
134 | if (idx >= 2 * byte) | |
135 | return AVERROR_INVALIDDATA; | |
136 | val = src[idx]; | |
137 | ||
138 | if (val < 0x16) { | |
139 | if (dest >= dest_end) | |
140 | return dest_len; | |
141 | *dest++ = val; | |
142 | val = ival; | |
143 | } | |
144 | } | |
145 | ||
146 | return dest - dest_start; | |
147 | } | |
148 | ||
149 | /** | |
150 | * unpack simple compression | |
151 | * | |
152 | * @param dest destination buffer of dest_len, must be padded with at least 130 bytes | |
153 | */ | |
154 | static void xan_unpack(uint8_t *dest, int dest_len, | |
155 | const uint8_t *src, int src_len) | |
156 | { | |
157 | uint8_t opcode; | |
158 | int size; | |
159 | uint8_t *dest_org = dest; | |
160 | uint8_t *dest_end = dest + dest_len; | |
161 | GetByteContext ctx; | |
162 | ||
163 | bytestream2_init(&ctx, src, src_len); | |
164 | while (dest < dest_end && bytestream2_get_bytes_left(&ctx)) { | |
165 | opcode = bytestream2_get_byte(&ctx); | |
166 | ||
167 | if (opcode < 0xe0) { | |
168 | int size2, back; | |
169 | if ((opcode & 0x80) == 0) { | |
170 | size = opcode & 3; | |
171 | ||
172 | back = ((opcode & 0x60) << 3) + bytestream2_get_byte(&ctx) + 1; | |
173 | size2 = ((opcode & 0x1c) >> 2) + 3; | |
174 | } else if ((opcode & 0x40) == 0) { | |
175 | size = bytestream2_peek_byte(&ctx) >> 6; | |
176 | ||
177 | back = (bytestream2_get_be16(&ctx) & 0x3fff) + 1; | |
178 | size2 = (opcode & 0x3f) + 4; | |
179 | } else { | |
180 | size = opcode & 3; | |
181 | ||
182 | back = ((opcode & 0x10) << 12) + bytestream2_get_be16(&ctx) + 1; | |
183 | size2 = ((opcode & 0x0c) << 6) + bytestream2_get_byte(&ctx) + 5; | |
184 | } | |
185 | ||
186 | if (dest_end - dest < size + size2 || | |
187 | dest + size - dest_org < back || | |
188 | bytestream2_get_bytes_left(&ctx) < size) | |
189 | return; | |
190 | bytestream2_get_buffer(&ctx, dest, size); | |
191 | dest += size; | |
192 | av_memcpy_backptr(dest, back, size2); | |
193 | dest += size2; | |
194 | } else { | |
195 | int finish = opcode >= 0xfc; | |
196 | size = finish ? opcode & 3 : ((opcode & 0x1f) << 2) + 4; | |
197 | ||
198 | if (dest_end - dest < size || bytestream2_get_bytes_left(&ctx) < size) | |
199 | return; | |
200 | bytestream2_get_buffer(&ctx, dest, size); | |
201 | dest += size; | |
202 | if (finish) | |
203 | return; | |
204 | } | |
205 | } | |
206 | } | |
207 | ||
208 | static inline void xan_wc3_output_pixel_run(XanContext *s, AVFrame *frame, | |
209 | const uint8_t *pixel_buffer, int x, int y, int pixel_count) | |
210 | { | |
211 | int stride; | |
212 | int line_inc; | |
213 | int index; | |
214 | int current_x; | |
215 | int width = s->avctx->width; | |
216 | uint8_t *palette_plane; | |
217 | ||
218 | palette_plane = frame->data[0]; | |
219 | stride = frame->linesize[0]; | |
220 | line_inc = stride - width; | |
221 | index = y * stride + x; | |
222 | current_x = x; | |
223 | while (pixel_count && index < s->frame_size) { | |
224 | int count = FFMIN(pixel_count, width - current_x); | |
225 | memcpy(palette_plane + index, pixel_buffer, count); | |
226 | pixel_count -= count; | |
227 | index += count; | |
228 | pixel_buffer += count; | |
229 | current_x += count; | |
230 | ||
231 | if (current_x >= width) { | |
232 | index += line_inc; | |
233 | current_x = 0; | |
234 | } | |
235 | } | |
236 | } | |
237 | ||
238 | static inline void xan_wc3_copy_pixel_run(XanContext *s, AVFrame *frame, | |
239 | int x, int y, | |
240 | int pixel_count, int motion_x, | |
241 | int motion_y) | |
242 | { | |
243 | int stride; | |
244 | int line_inc; | |
245 | int curframe_index, prevframe_index; | |
246 | int curframe_x, prevframe_x; | |
247 | int width = s->avctx->width; | |
248 | uint8_t *palette_plane, *prev_palette_plane; | |
249 | ||
250 | if (y + motion_y < 0 || y + motion_y >= s->avctx->height || | |
251 | x + motion_x < 0 || x + motion_x >= s->avctx->width) | |
252 | return; | |
253 | ||
254 | palette_plane = frame->data[0]; | |
255 | prev_palette_plane = s->last_frame->data[0]; | |
256 | if (!prev_palette_plane) | |
257 | prev_palette_plane = palette_plane; | |
258 | stride = frame->linesize[0]; | |
259 | line_inc = stride - width; | |
260 | curframe_index = y * stride + x; | |
261 | curframe_x = x; | |
262 | prevframe_index = (y + motion_y) * stride + x + motion_x; | |
263 | prevframe_x = x + motion_x; | |
264 | ||
265 | if (prev_palette_plane == palette_plane && FFABS(curframe_index - prevframe_index) < pixel_count) { | |
266 | avpriv_request_sample(s->avctx, "Overlapping copy\n"); | |
267 | return ; | |
268 | } | |
269 | ||
270 | while (pixel_count && | |
271 | curframe_index < s->frame_size && | |
272 | prevframe_index < s->frame_size) { | |
273 | int count = FFMIN3(pixel_count, width - curframe_x, | |
274 | width - prevframe_x); | |
275 | ||
276 | memcpy(palette_plane + curframe_index, | |
277 | prev_palette_plane + prevframe_index, count); | |
278 | pixel_count -= count; | |
279 | curframe_index += count; | |
280 | prevframe_index += count; | |
281 | curframe_x += count; | |
282 | prevframe_x += count; | |
283 | ||
284 | if (curframe_x >= width) { | |
285 | curframe_index += line_inc; | |
286 | curframe_x = 0; | |
287 | } | |
288 | ||
289 | if (prevframe_x >= width) { | |
290 | prevframe_index += line_inc; | |
291 | prevframe_x = 0; | |
292 | } | |
293 | } | |
294 | } | |
295 | ||
296 | static int xan_wc3_decode_frame(XanContext *s, AVFrame *frame) | |
297 | { | |
298 | ||
299 | int width = s->avctx->width; | |
300 | int height = s->avctx->height; | |
301 | int total_pixels = width * height; | |
302 | uint8_t opcode; | |
303 | uint8_t flag = 0; | |
304 | int size = 0; | |
305 | int motion_x, motion_y; | |
306 | int x, y, ret; | |
307 | ||
308 | uint8_t *opcode_buffer = s->buffer1; | |
309 | uint8_t *opcode_buffer_end = s->buffer1 + s->buffer1_size; | |
310 | int opcode_buffer_size = s->buffer1_size; | |
311 | const uint8_t *imagedata_buffer = s->buffer2; | |
312 | ||
313 | /* pointers to segments inside the compressed chunk */ | |
314 | const uint8_t *huffman_segment; | |
315 | GetByteContext size_segment; | |
316 | GetByteContext vector_segment; | |
317 | const uint8_t *imagedata_segment; | |
318 | int huffman_offset, size_offset, vector_offset, imagedata_offset, | |
319 | imagedata_size; | |
320 | ||
321 | if (s->size < 8) | |
322 | return AVERROR_INVALIDDATA; | |
323 | ||
324 | huffman_offset = AV_RL16(&s->buf[0]); | |
325 | size_offset = AV_RL16(&s->buf[2]); | |
326 | vector_offset = AV_RL16(&s->buf[4]); | |
327 | imagedata_offset = AV_RL16(&s->buf[6]); | |
328 | ||
329 | if (huffman_offset >= s->size || | |
330 | size_offset >= s->size || | |
331 | vector_offset >= s->size || | |
332 | imagedata_offset >= s->size) | |
333 | return AVERROR_INVALIDDATA; | |
334 | ||
335 | huffman_segment = s->buf + huffman_offset; | |
336 | bytestream2_init(&size_segment, s->buf + size_offset, s->size - size_offset); | |
337 | bytestream2_init(&vector_segment, s->buf + vector_offset, s->size - vector_offset); | |
338 | imagedata_segment = s->buf + imagedata_offset; | |
339 | ||
340 | if ((ret = xan_huffman_decode(opcode_buffer, opcode_buffer_size, | |
341 | huffman_segment, s->size - huffman_offset)) < 0) | |
342 | return AVERROR_INVALIDDATA; | |
343 | opcode_buffer_end = opcode_buffer + ret; | |
344 | ||
345 | if (imagedata_segment[0] == 2) { | |
346 | xan_unpack(s->buffer2, s->buffer2_size, | |
347 | &imagedata_segment[1], s->size - imagedata_offset - 1); | |
348 | imagedata_size = s->buffer2_size; | |
349 | } else { | |
350 | imagedata_size = s->size - imagedata_offset - 1; | |
351 | imagedata_buffer = &imagedata_segment[1]; | |
352 | } | |
353 | ||
354 | /* use the decoded data segments to build the frame */ | |
355 | x = y = 0; | |
356 | while (total_pixels && opcode_buffer < opcode_buffer_end) { | |
357 | ||
358 | opcode = *opcode_buffer++; | |
359 | size = 0; | |
360 | ||
361 | switch (opcode) { | |
362 | ||
363 | case 0: | |
364 | flag ^= 1; | |
365 | continue; | |
366 | ||
367 | case 1: | |
368 | case 2: | |
369 | case 3: | |
370 | case 4: | |
371 | case 5: | |
372 | case 6: | |
373 | case 7: | |
374 | case 8: | |
375 | size = opcode; | |
376 | break; | |
377 | ||
378 | case 12: | |
379 | case 13: | |
380 | case 14: | |
381 | case 15: | |
382 | case 16: | |
383 | case 17: | |
384 | case 18: | |
385 | size += (opcode - 10); | |
386 | break; | |
387 | ||
388 | case 9: | |
389 | case 19: | |
390 | if (bytestream2_get_bytes_left(&size_segment) < 1) { | |
391 | av_log(s->avctx, AV_LOG_ERROR, "size_segment overread\n"); | |
392 | return AVERROR_INVALIDDATA; | |
393 | } | |
394 | size = bytestream2_get_byte(&size_segment); | |
395 | break; | |
396 | ||
397 | case 10: | |
398 | case 20: | |
399 | if (bytestream2_get_bytes_left(&size_segment) < 2) { | |
400 | av_log(s->avctx, AV_LOG_ERROR, "size_segment overread\n"); | |
401 | return AVERROR_INVALIDDATA; | |
402 | } | |
403 | size = bytestream2_get_be16(&size_segment); | |
404 | break; | |
405 | ||
406 | case 11: | |
407 | case 21: | |
408 | if (bytestream2_get_bytes_left(&size_segment) < 3) { | |
409 | av_log(s->avctx, AV_LOG_ERROR, "size_segment overread\n"); | |
410 | return AVERROR_INVALIDDATA; | |
411 | } | |
412 | size = bytestream2_get_be24(&size_segment); | |
413 | break; | |
414 | } | |
415 | ||
416 | if (size > total_pixels) | |
417 | break; | |
418 | ||
419 | if (opcode < 12) { | |
420 | flag ^= 1; | |
421 | if (flag) { | |
422 | /* run of (size) pixels is unchanged from last frame */ | |
423 | xan_wc3_copy_pixel_run(s, frame, x, y, size, 0, 0); | |
424 | } else { | |
425 | /* output a run of pixels from imagedata_buffer */ | |
426 | if (imagedata_size < size) | |
427 | break; | |
428 | xan_wc3_output_pixel_run(s, frame, imagedata_buffer, x, y, size); | |
429 | imagedata_buffer += size; | |
430 | imagedata_size -= size; | |
431 | } | |
432 | } else { | |
433 | uint8_t vector; | |
434 | if (bytestream2_get_bytes_left(&vector_segment) <= 0) { | |
435 | av_log(s->avctx, AV_LOG_ERROR, "vector_segment overread\n"); | |
436 | return AVERROR_INVALIDDATA; | |
437 | } | |
438 | /* run-based motion compensation from last frame */ | |
439 | vector = bytestream2_get_byte(&vector_segment); | |
440 | motion_x = sign_extend(vector >> 4, 4); | |
441 | motion_y = sign_extend(vector & 0xF, 4); | |
442 | ||
443 | /* copy a run of pixels from the previous frame */ | |
444 | xan_wc3_copy_pixel_run(s, frame, x, y, size, motion_x, motion_y); | |
445 | ||
446 | flag = 0; | |
447 | } | |
448 | ||
449 | /* coordinate accounting */ | |
450 | total_pixels -= size; | |
451 | y += (x + size) / width; | |
452 | x = (x + size) % width; | |
453 | } | |
454 | return 0; | |
455 | } | |
456 | ||
457 | #if RUNTIME_GAMMA | |
458 | static inline unsigned mul(unsigned a, unsigned b) | |
459 | { | |
460 | return (a * b) >> 16; | |
461 | } | |
462 | ||
463 | static inline unsigned pow4(unsigned a) | |
464 | { | |
465 | unsigned square = mul(a, a); | |
466 | return mul(square, square); | |
467 | } | |
468 | ||
469 | static inline unsigned pow5(unsigned a) | |
470 | { | |
471 | return mul(pow4(a), a); | |
472 | } | |
473 | ||
474 | static uint8_t gamma_corr(uint8_t in) { | |
475 | unsigned lo, hi = 0xff40, target; | |
476 | int i = 15; | |
477 | in = (in << 2) | (in >> 6); | |
478 | /* equivalent float code: | |
479 | if (in >= 252) | |
480 | return 253; | |
481 | return round(pow(in / 256.0, 0.8) * 256); | |
482 | */ | |
483 | lo = target = in << 8; | |
484 | do { | |
485 | unsigned mid = (lo + hi) >> 1; | |
486 | unsigned pow = pow5(mid); | |
487 | if (pow > target) hi = mid; | |
488 | else lo = mid; | |
489 | } while (--i); | |
490 | return (pow4((lo + hi) >> 1) + 0x80) >> 8; | |
491 | } | |
492 | #else | |
493 | /** | |
494 | * This is a gamma correction that xan3 applies to all palette entries. | |
495 | * | |
496 | * There is a peculiarity, namely that the values are clamped to 253 - | |
497 | * it seems likely that this table was calculated by a buggy fixed-point | |
498 | * implementation, the one above under RUNTIME_GAMMA behaves like this for | |
499 | * example. | |
500 | * The exponent value of 0.8 can be explained by this as well, since 0.8 = 4/5 | |
501 | * and thus pow(x, 0.8) is still easy to calculate. | |
502 | * Also, the input values are first rotated to the left by 2. | |
503 | */ | |
504 | static const uint8_t gamma_lookup[256] = { | |
505 | 0x00, 0x09, 0x10, 0x16, 0x1C, 0x21, 0x27, 0x2C, | |
506 | 0x31, 0x35, 0x3A, 0x3F, 0x43, 0x48, 0x4C, 0x50, | |
507 | 0x54, 0x59, 0x5D, 0x61, 0x65, 0x69, 0x6D, 0x71, | |
508 | 0x75, 0x79, 0x7D, 0x80, 0x84, 0x88, 0x8C, 0x8F, | |
509 | 0x93, 0x97, 0x9A, 0x9E, 0xA2, 0xA5, 0xA9, 0xAC, | |
510 | 0xB0, 0xB3, 0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8, | |
511 | 0xCB, 0xCF, 0xD2, 0xD5, 0xD9, 0xDC, 0xDF, 0xE3, | |
512 | 0xE6, 0xE9, 0xED, 0xF0, 0xF3, 0xF6, 0xFA, 0xFD, | |
513 | 0x03, 0x0B, 0x12, 0x18, 0x1D, 0x23, 0x28, 0x2D, | |
514 | 0x32, 0x36, 0x3B, 0x40, 0x44, 0x49, 0x4D, 0x51, | |
515 | 0x56, 0x5A, 0x5E, 0x62, 0x66, 0x6A, 0x6E, 0x72, | |
516 | 0x76, 0x7A, 0x7D, 0x81, 0x85, 0x89, 0x8D, 0x90, | |
517 | 0x94, 0x98, 0x9B, 0x9F, 0xA2, 0xA6, 0xAA, 0xAD, | |
518 | 0xB1, 0xB4, 0xB8, 0xBB, 0xBF, 0xC2, 0xC5, 0xC9, | |
519 | 0xCC, 0xD0, 0xD3, 0xD6, 0xDA, 0xDD, 0xE0, 0xE4, | |
520 | 0xE7, 0xEA, 0xED, 0xF1, 0xF4, 0xF7, 0xFA, 0xFD, | |
521 | 0x05, 0x0D, 0x13, 0x19, 0x1F, 0x24, 0x29, 0x2E, | |
522 | 0x33, 0x38, 0x3C, 0x41, 0x45, 0x4A, 0x4E, 0x52, | |
523 | 0x57, 0x5B, 0x5F, 0x63, 0x67, 0x6B, 0x6F, 0x73, | |
524 | 0x77, 0x7B, 0x7E, 0x82, 0x86, 0x8A, 0x8D, 0x91, | |
525 | 0x95, 0x99, 0x9C, 0xA0, 0xA3, 0xA7, 0xAA, 0xAE, | |
526 | 0xB2, 0xB5, 0xB9, 0xBC, 0xBF, 0xC3, 0xC6, 0xCA, | |
527 | 0xCD, 0xD0, 0xD4, 0xD7, 0xDA, 0xDE, 0xE1, 0xE4, | |
528 | 0xE8, 0xEB, 0xEE, 0xF1, 0xF5, 0xF8, 0xFB, 0xFD, | |
529 | 0x07, 0x0E, 0x15, 0x1A, 0x20, 0x25, 0x2A, 0x2F, | |
530 | 0x34, 0x39, 0x3D, 0x42, 0x46, 0x4B, 0x4F, 0x53, | |
531 | 0x58, 0x5C, 0x60, 0x64, 0x68, 0x6C, 0x70, 0x74, | |
532 | 0x78, 0x7C, 0x7F, 0x83, 0x87, 0x8B, 0x8E, 0x92, | |
533 | 0x96, 0x99, 0x9D, 0xA1, 0xA4, 0xA8, 0xAB, 0xAF, | |
534 | 0xB2, 0xB6, 0xB9, 0xBD, 0xC0, 0xC4, 0xC7, 0xCB, | |
535 | 0xCE, 0xD1, 0xD5, 0xD8, 0xDB, 0xDF, 0xE2, 0xE5, | |
536 | 0xE9, 0xEC, 0xEF, 0xF2, 0xF6, 0xF9, 0xFC, 0xFD | |
537 | }; | |
538 | #endif | |
539 | ||
540 | static int xan_decode_frame(AVCodecContext *avctx, | |
541 | void *data, int *got_frame, | |
542 | AVPacket *avpkt) | |
543 | { | |
544 | AVFrame *frame = data; | |
545 | const uint8_t *buf = avpkt->data; | |
546 | int ret, buf_size = avpkt->size; | |
547 | XanContext *s = avctx->priv_data; | |
548 | GetByteContext ctx; | |
549 | int tag = 0; | |
550 | ||
551 | bytestream2_init(&ctx, buf, buf_size); | |
552 | while (bytestream2_get_bytes_left(&ctx) > 8 && tag != VGA__TAG) { | |
553 | unsigned *tmpptr; | |
554 | uint32_t new_pal; | |
555 | int size; | |
556 | int i; | |
557 | tag = bytestream2_get_le32(&ctx); | |
558 | size = bytestream2_get_be32(&ctx); | |
559 | if (size < 0) { | |
560 | av_log(avctx, AV_LOG_ERROR, "Invalid tag size %d\n", size); | |
561 | return AVERROR_INVALIDDATA; | |
562 | } | |
563 | size = FFMIN(size, bytestream2_get_bytes_left(&ctx)); | |
564 | switch (tag) { | |
565 | case PALT_TAG: | |
566 | if (size < PALETTE_SIZE) | |
567 | return AVERROR_INVALIDDATA; | |
568 | if (s->palettes_count >= PALETTES_MAX) | |
569 | return AVERROR_INVALIDDATA; | |
570 | tmpptr = av_realloc(s->palettes, | |
571 | (s->palettes_count + 1) * AVPALETTE_SIZE); | |
572 | if (!tmpptr) | |
573 | return AVERROR(ENOMEM); | |
574 | s->palettes = tmpptr; | |
575 | tmpptr += s->palettes_count * AVPALETTE_COUNT; | |
576 | for (i = 0; i < PALETTE_COUNT; i++) { | |
577 | #if RUNTIME_GAMMA | |
578 | int r = gamma_corr(bytestream2_get_byteu(&ctx)); | |
579 | int g = gamma_corr(bytestream2_get_byteu(&ctx)); | |
580 | int b = gamma_corr(bytestream2_get_byteu(&ctx)); | |
581 | #else | |
582 | int r = gamma_lookup[bytestream2_get_byteu(&ctx)]; | |
583 | int g = gamma_lookup[bytestream2_get_byteu(&ctx)]; | |
584 | int b = gamma_lookup[bytestream2_get_byteu(&ctx)]; | |
585 | #endif | |
586 | *tmpptr++ = (0xFFU << 24) | (r << 16) | (g << 8) | b; | |
587 | } | |
588 | s->palettes_count++; | |
589 | break; | |
590 | case SHOT_TAG: | |
591 | if (size < 4) | |
592 | return AVERROR_INVALIDDATA; | |
593 | new_pal = bytestream2_get_le32(&ctx); | |
594 | if (new_pal < s->palettes_count) { | |
595 | s->cur_palette = new_pal; | |
596 | } else | |
597 | av_log(avctx, AV_LOG_ERROR, "Invalid palette selected\n"); | |
598 | break; | |
599 | case VGA__TAG: | |
600 | break; | |
601 | default: | |
602 | bytestream2_skip(&ctx, size); | |
603 | break; | |
604 | } | |
605 | } | |
606 | buf_size = bytestream2_get_bytes_left(&ctx); | |
607 | ||
608 | if (s->palettes_count <= 0) { | |
609 | av_log(s->avctx, AV_LOG_ERROR, "No palette found\n"); | |
610 | return AVERROR_INVALIDDATA; | |
611 | } | |
612 | ||
613 | if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) | |
614 | return ret; | |
615 | ||
616 | if (!s->frame_size) | |
617 | s->frame_size = frame->linesize[0] * s->avctx->height; | |
618 | ||
619 | memcpy(frame->data[1], | |
620 | s->palettes + s->cur_palette * AVPALETTE_COUNT, AVPALETTE_SIZE); | |
621 | ||
622 | s->buf = ctx.buffer; | |
623 | s->size = buf_size; | |
624 | ||
625 | if (xan_wc3_decode_frame(s, frame) < 0) | |
626 | return AVERROR_INVALIDDATA; | |
627 | ||
628 | av_frame_unref(s->last_frame); | |
629 | if ((ret = av_frame_ref(s->last_frame, frame)) < 0) | |
630 | return ret; | |
631 | ||
632 | *got_frame = 1; | |
633 | ||
634 | /* always report that the buffer was completely consumed */ | |
635 | return buf_size; | |
636 | } | |
637 | ||
638 | AVCodec ff_xan_wc3_decoder = { | |
639 | .name = "xan_wc3", | |
640 | .long_name = NULL_IF_CONFIG_SMALL("Wing Commander III / Xan"), | |
641 | .type = AVMEDIA_TYPE_VIDEO, | |
642 | .id = AV_CODEC_ID_XAN_WC3, | |
643 | .priv_data_size = sizeof(XanContext), | |
644 | .init = xan_decode_init, | |
645 | .close = xan_decode_end, | |
646 | .decode = xan_decode_frame, | |
647 | .capabilities = CODEC_CAP_DR1, | |
648 | }; |