Line data Source code
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 :
38 : #define BITSTREAM_READER_LE
39 : #include "avcodec.h"
40 : #include "bytestream.h"
41 : #include "get_bits.h"
42 : #include "internal.h"
43 :
44 : #define RUNTIME_GAMMA 0
45 :
46 : #define VGA__TAG MKTAG('V', 'G', 'A', ' ')
47 : #define PALT_TAG MKTAG('P', 'A', 'L', 'T')
48 : #define SHOT_TAG MKTAG('S', 'H', 'O', 'T')
49 : #define PALETTE_COUNT 256
50 : #define PALETTE_SIZE (PALETTE_COUNT * 3)
51 : #define PALETTES_MAX 256
52 :
53 : typedef struct XanContext {
54 :
55 : AVCodecContext *avctx;
56 : AVFrame *last_frame;
57 :
58 : const uint8_t *buf;
59 : int size;
60 :
61 : /* scratch space */
62 : uint8_t *buffer1;
63 : int buffer1_size;
64 : uint8_t *buffer2;
65 : int buffer2_size;
66 :
67 : unsigned *palettes;
68 : int palettes_count;
69 : int cur_palette;
70 :
71 : int frame_size;
72 :
73 : } XanContext;
74 :
75 2 : static av_cold int xan_decode_end(AVCodecContext *avctx)
76 : {
77 2 : XanContext *s = avctx->priv_data;
78 :
79 2 : av_frame_free(&s->last_frame);
80 :
81 2 : av_freep(&s->buffer1);
82 2 : av_freep(&s->buffer2);
83 2 : av_freep(&s->palettes);
84 :
85 2 : return 0;
86 : }
87 :
88 2 : static av_cold int xan_decode_init(AVCodecContext *avctx)
89 : {
90 2 : XanContext *s = avctx->priv_data;
91 :
92 2 : s->avctx = avctx;
93 2 : s->frame_size = 0;
94 :
95 2 : avctx->pix_fmt = AV_PIX_FMT_PAL8;
96 :
97 2 : s->buffer1_size = avctx->width * avctx->height;
98 2 : s->buffer1 = av_malloc(s->buffer1_size);
99 2 : if (!s->buffer1)
100 0 : return AVERROR(ENOMEM);
101 2 : s->buffer2_size = avctx->width * avctx->height;
102 2 : s->buffer2 = av_malloc(s->buffer2_size + 130);
103 2 : if (!s->buffer2) {
104 0 : av_freep(&s->buffer1);
105 0 : return AVERROR(ENOMEM);
106 : }
107 :
108 2 : s->last_frame = av_frame_alloc();
109 2 : if (!s->last_frame) {
110 0 : xan_decode_end(avctx);
111 0 : return AVERROR(ENOMEM);
112 : }
113 :
114 2 : return 0;
115 : }
116 :
117 35 : static int xan_huffman_decode(uint8_t *dest, int dest_len,
118 : const uint8_t *src, int src_len)
119 : {
120 35 : uint8_t byte = *src++;
121 35 : uint8_t ival = byte + 0x16;
122 35 : const uint8_t * ptr = src + byte*2;
123 35 : int ptr_len = src_len - 1 - byte*2;
124 35 : uint8_t val = ival;
125 35 : uint8_t *dest_end = dest + dest_len;
126 35 : uint8_t *dest_start = dest;
127 : int ret;
128 : GetBitContext gb;
129 :
130 35 : if ((ret = init_get_bits8(&gb, ptr, ptr_len)) < 0)
131 0 : return ret;
132 :
133 568526 : while (val != 0x16) {
134 : unsigned idx;
135 568456 : if (get_bits_left(&gb) < 1)
136 0 : return AVERROR_INVALIDDATA;
137 568456 : idx = val - 0x17 + get_bits1(&gb) * byte;
138 568456 : if (idx >= 2 * byte)
139 0 : return AVERROR_INVALIDDATA;
140 568456 : val = src[idx];
141 :
142 568456 : if (val < 0x16) {
143 170624 : if (dest >= dest_end)
144 0 : return dest_len;
145 170624 : *dest++ = val;
146 170624 : val = ival;
147 : }
148 : }
149 :
150 35 : return dest - dest_start;
151 : }
152 :
153 : /**
154 : * unpack simple compression
155 : *
156 : * @param dest destination buffer of dest_len, must be padded with at least 130 bytes
157 : */
158 21 : static void xan_unpack(uint8_t *dest, int dest_len,
159 : const uint8_t *src, int src_len)
160 : {
161 : uint8_t opcode;
162 : int size;
163 21 : uint8_t *dest_org = dest;
164 21 : uint8_t *dest_end = dest + dest_len;
165 : GetByteContext ctx;
166 :
167 21 : bytestream2_init(&ctx, src, src_len);
168 21 : while (dest < dest_end && bytestream2_get_bytes_left(&ctx)) {
169 29043 : opcode = bytestream2_get_byte(&ctx);
170 :
171 29043 : if (opcode < 0xe0) {
172 : int size2, back;
173 22017 : if ((opcode & 0x80) == 0) {
174 17508 : size = opcode & 3;
175 :
176 17508 : back = ((opcode & 0x60) << 3) + bytestream2_get_byte(&ctx) + 1;
177 17508 : size2 = ((opcode & 0x1c) >> 2) + 3;
178 4509 : } else if ((opcode & 0x40) == 0) {
179 4241 : size = bytestream2_peek_byte(&ctx) >> 6;
180 :
181 4241 : back = (bytestream2_get_be16(&ctx) & 0x3fff) + 1;
182 4241 : size2 = (opcode & 0x3f) + 4;
183 : } else {
184 268 : size = opcode & 3;
185 :
186 268 : back = ((opcode & 0x10) << 12) + bytestream2_get_be16(&ctx) + 1;
187 268 : size2 = ((opcode & 0x0c) << 6) + bytestream2_get_byte(&ctx) + 5;
188 : }
189 :
190 44034 : if (dest_end - dest < size + size2 ||
191 44034 : dest + size - dest_org < back ||
192 22017 : bytestream2_get_bytes_left(&ctx) < size)
193 20 : return;
194 22017 : bytestream2_get_buffer(&ctx, dest, size);
195 22017 : dest += size;
196 22017 : av_memcpy_backptr(dest, back, size2);
197 22017 : dest += size2;
198 : } else {
199 7026 : int finish = opcode >= 0xfc;
200 7026 : size = finish ? opcode & 3 : ((opcode & 0x1f) << 2) + 4;
201 :
202 7026 : if (dest_end - dest < size || bytestream2_get_bytes_left(&ctx) < size)
203 0 : return;
204 7026 : bytestream2_get_buffer(&ctx, dest, size);
205 7026 : dest += size;
206 7026 : if (finish)
207 20 : return;
208 : }
209 : }
210 : }
211 :
212 50368 : static inline void xan_wc3_output_pixel_run(XanContext *s, AVFrame *frame,
213 : const uint8_t *pixel_buffer, int x, int y, int pixel_count)
214 : {
215 : int stride;
216 : int line_inc;
217 : int index;
218 : int current_x;
219 50368 : int width = s->avctx->width;
220 : uint8_t *palette_plane;
221 :
222 50368 : palette_plane = frame->data[0];
223 50368 : stride = frame->linesize[0];
224 50368 : line_inc = stride - width;
225 50368 : index = y * stride + x;
226 50368 : current_x = x;
227 151305 : while (pixel_count && index < s->frame_size) {
228 50569 : int count = FFMIN(pixel_count, width - current_x);
229 50569 : memcpy(palette_plane + index, pixel_buffer, count);
230 50569 : pixel_count -= count;
231 50569 : index += count;
232 50569 : pixel_buffer += count;
233 50569 : current_x += count;
234 :
235 50569 : if (current_x >= width) {
236 1828 : index += line_inc;
237 1828 : current_x = 0;
238 : }
239 : }
240 50368 : }
241 :
242 111283 : static inline void xan_wc3_copy_pixel_run(XanContext *s, AVFrame *frame,
243 : int x, int y,
244 : int pixel_count, int motion_x,
245 : int motion_y)
246 : {
247 : int stride;
248 : int line_inc;
249 : int curframe_index, prevframe_index;
250 : int curframe_x, prevframe_x;
251 111283 : int width = s->avctx->width;
252 : uint8_t *palette_plane, *prev_palette_plane;
253 :
254 222566 : if (y + motion_y < 0 || y + motion_y >= s->avctx->height ||
255 222566 : x + motion_x < 0 || x + motion_x >= s->avctx->width)
256 0 : return;
257 :
258 111283 : palette_plane = frame->data[0];
259 111283 : prev_palette_plane = s->last_frame->data[0];
260 111283 : if (!prev_palette_plane)
261 0 : prev_palette_plane = palette_plane;
262 111283 : stride = frame->linesize[0];
263 111283 : line_inc = stride - width;
264 111283 : curframe_index = y * stride + x;
265 111283 : curframe_x = x;
266 111283 : prevframe_index = (y + motion_y) * stride + x + motion_x;
267 111283 : prevframe_x = x + motion_x;
268 :
269 111283 : if (prev_palette_plane == palette_plane && FFABS(motion_x + width*motion_y) < pixel_count) {
270 0 : avpriv_request_sample(s->avctx, "Overlapping copy");
271 0 : return ;
272 : }
273 :
274 451912 : while (pixel_count &&
275 229346 : curframe_index < s->frame_size &&
276 114673 : prevframe_index < s->frame_size) {
277 114673 : int count = FFMIN3(pixel_count, width - curframe_x,
278 : width - prevframe_x);
279 :
280 229346 : memcpy(palette_plane + curframe_index,
281 114673 : prev_palette_plane + prevframe_index, count);
282 114673 : pixel_count -= count;
283 114673 : curframe_index += count;
284 114673 : prevframe_index += count;
285 114673 : curframe_x += count;
286 114673 : prevframe_x += count;
287 :
288 114673 : if (curframe_x >= width) {
289 3947 : curframe_index += line_inc;
290 3947 : curframe_x = 0;
291 : }
292 :
293 114673 : if (prevframe_x >= width) {
294 3892 : prevframe_index += line_inc;
295 3892 : prevframe_x = 0;
296 : }
297 : }
298 : }
299 :
300 35 : static int xan_wc3_decode_frame(XanContext *s, AVFrame *frame)
301 : {
302 :
303 35 : int width = s->avctx->width;
304 35 : int height = s->avctx->height;
305 35 : int total_pixels = width * height;
306 : uint8_t opcode;
307 35 : uint8_t flag = 0;
308 35 : int size = 0;
309 : int motion_x, motion_y;
310 : int x, y, ret;
311 :
312 35 : uint8_t *opcode_buffer = s->buffer1;
313 35 : uint8_t *opcode_buffer_end = s->buffer1 + s->buffer1_size;
314 35 : int opcode_buffer_size = s->buffer1_size;
315 35 : const uint8_t *imagedata_buffer = s->buffer2;
316 :
317 : /* pointers to segments inside the compressed chunk */
318 : const uint8_t *huffman_segment;
319 : GetByteContext size_segment;
320 : GetByteContext vector_segment;
321 : const uint8_t *imagedata_segment;
322 : int huffman_offset, size_offset, vector_offset, imagedata_offset,
323 : imagedata_size;
324 :
325 35 : if (s->size < 8)
326 0 : return AVERROR_INVALIDDATA;
327 :
328 35 : huffman_offset = AV_RL16(&s->buf[0]);
329 35 : size_offset = AV_RL16(&s->buf[2]);
330 35 : vector_offset = AV_RL16(&s->buf[4]);
331 35 : imagedata_offset = AV_RL16(&s->buf[6]);
332 :
333 70 : if (huffman_offset >= s->size ||
334 70 : size_offset >= s->size ||
335 70 : vector_offset >= s->size ||
336 35 : imagedata_offset >= s->size)
337 0 : return AVERROR_INVALIDDATA;
338 :
339 35 : huffman_segment = s->buf + huffman_offset;
340 35 : bytestream2_init(&size_segment, s->buf + size_offset, s->size - size_offset);
341 35 : bytestream2_init(&vector_segment, s->buf + vector_offset, s->size - vector_offset);
342 35 : imagedata_segment = s->buf + imagedata_offset;
343 :
344 35 : if ((ret = xan_huffman_decode(opcode_buffer, opcode_buffer_size,
345 35 : huffman_segment, s->size - huffman_offset)) < 0)
346 0 : return AVERROR_INVALIDDATA;
347 35 : opcode_buffer_end = opcode_buffer + ret;
348 :
349 35 : if (imagedata_segment[0] == 2) {
350 21 : xan_unpack(s->buffer2, s->buffer2_size,
351 21 : &imagedata_segment[1], s->size - imagedata_offset - 1);
352 21 : imagedata_size = s->buffer2_size;
353 : } else {
354 14 : imagedata_size = s->size - imagedata_offset - 1;
355 14 : imagedata_buffer = &imagedata_segment[1];
356 : }
357 :
358 : /* use the decoded data segments to build the frame */
359 35 : x = y = 0;
360 170690 : while (total_pixels && opcode_buffer < opcode_buffer_end) {
361 :
362 170620 : opcode = *opcode_buffer++;
363 170620 : size = 0;
364 :
365 170620 : switch (opcode) {
366 :
367 8969 : case 0:
368 8969 : flag ^= 1;
369 8969 : continue;
370 :
371 91913 : case 1:
372 : case 2:
373 : case 3:
374 : case 4:
375 : case 5:
376 : case 6:
377 : case 7:
378 : case 8:
379 91913 : size = opcode;
380 91913 : break;
381 :
382 48168 : case 12:
383 : case 13:
384 : case 14:
385 : case 15:
386 : case 16:
387 : case 17:
388 : case 18:
389 48168 : size += (opcode - 10);
390 48168 : break;
391 :
392 20805 : case 9:
393 : case 19:
394 20805 : if (bytestream2_get_bytes_left(&size_segment) < 1) {
395 0 : av_log(s->avctx, AV_LOG_ERROR, "size_segment overread\n");
396 0 : return AVERROR_INVALIDDATA;
397 : }
398 20805 : size = bytestream2_get_byte(&size_segment);
399 20805 : break;
400 :
401 765 : case 10:
402 : case 20:
403 765 : if (bytestream2_get_bytes_left(&size_segment) < 2) {
404 0 : av_log(s->avctx, AV_LOG_ERROR, "size_segment overread\n");
405 0 : return AVERROR_INVALIDDATA;
406 : }
407 765 : size = bytestream2_get_be16(&size_segment);
408 765 : break;
409 :
410 0 : case 11:
411 : case 21:
412 0 : if (bytestream2_get_bytes_left(&size_segment) < 3) {
413 0 : av_log(s->avctx, AV_LOG_ERROR, "size_segment overread\n");
414 0 : return AVERROR_INVALIDDATA;
415 : }
416 0 : size = bytestream2_get_be24(&size_segment);
417 0 : break;
418 : }
419 :
420 161651 : if (size > total_pixels)
421 0 : break;
422 :
423 161651 : if (opcode < 12) {
424 112748 : flag ^= 1;
425 112748 : if (flag) {
426 : /* run of (size) pixels is unchanged from last frame */
427 62380 : xan_wc3_copy_pixel_run(s, frame, x, y, size, 0, 0);
428 : } else {
429 : /* output a run of pixels from imagedata_buffer */
430 50368 : if (imagedata_size < size)
431 0 : break;
432 50368 : xan_wc3_output_pixel_run(s, frame, imagedata_buffer, x, y, size);
433 50368 : imagedata_buffer += size;
434 50368 : imagedata_size -= size;
435 : }
436 : } else {
437 : uint8_t vector;
438 48903 : if (bytestream2_get_bytes_left(&vector_segment) <= 0) {
439 0 : av_log(s->avctx, AV_LOG_ERROR, "vector_segment overread\n");
440 0 : return AVERROR_INVALIDDATA;
441 : }
442 : /* run-based motion compensation from last frame */
443 48903 : vector = bytestream2_get_byte(&vector_segment);
444 48903 : motion_x = sign_extend(vector >> 4, 4);
445 48903 : motion_y = sign_extend(vector & 0xF, 4);
446 :
447 : /* copy a run of pixels from the previous frame */
448 48903 : xan_wc3_copy_pixel_run(s, frame, x, y, size, motion_x, motion_y);
449 :
450 48903 : flag = 0;
451 : }
452 :
453 : /* coordinate accounting */
454 161651 : total_pixels -= size;
455 161651 : y += (x + size) / width;
456 161651 : x = (x + size) % width;
457 : }
458 35 : return 0;
459 : }
460 :
461 : #if RUNTIME_GAMMA
462 : static inline unsigned mul(unsigned a, unsigned b)
463 : {
464 : return (a * b) >> 16;
465 : }
466 :
467 : static inline unsigned pow4(unsigned a)
468 : {
469 : unsigned square = mul(a, a);
470 : return mul(square, square);
471 : }
472 :
473 : static inline unsigned pow5(unsigned a)
474 : {
475 : return mul(pow4(a), a);
476 : }
477 :
478 : static uint8_t gamma_corr(uint8_t in) {
479 : unsigned lo, hi = 0xff40, target;
480 : int i = 15;
481 : in = (in << 2) | (in >> 6);
482 : /* equivalent float code:
483 : if (in >= 252)
484 : return 253;
485 : return round(pow(in / 256.0, 0.8) * 256);
486 : */
487 : lo = target = in << 8;
488 : do {
489 : unsigned mid = (lo + hi) >> 1;
490 : unsigned pow = pow5(mid);
491 : if (pow > target) hi = mid;
492 : else lo = mid;
493 : } while (--i);
494 : return (pow4((lo + hi) >> 1) + 0x80) >> 8;
495 : }
496 : #else
497 : /**
498 : * This is a gamma correction that xan3 applies to all palette entries.
499 : *
500 : * There is a peculiarity, namely that the values are clamped to 253 -
501 : * it seems likely that this table was calculated by a buggy fixed-point
502 : * implementation, the one above under RUNTIME_GAMMA behaves like this for
503 : * example.
504 : * The exponent value of 0.8 can be explained by this as well, since 0.8 = 4/5
505 : * and thus pow(x, 0.8) is still easy to calculate.
506 : * Also, the input values are first rotated to the left by 2.
507 : */
508 : static const uint8_t gamma_lookup[256] = {
509 : 0x00, 0x09, 0x10, 0x16, 0x1C, 0x21, 0x27, 0x2C,
510 : 0x31, 0x35, 0x3A, 0x3F, 0x43, 0x48, 0x4C, 0x50,
511 : 0x54, 0x59, 0x5D, 0x61, 0x65, 0x69, 0x6D, 0x71,
512 : 0x75, 0x79, 0x7D, 0x80, 0x84, 0x88, 0x8C, 0x8F,
513 : 0x93, 0x97, 0x9A, 0x9E, 0xA2, 0xA5, 0xA9, 0xAC,
514 : 0xB0, 0xB3, 0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8,
515 : 0xCB, 0xCF, 0xD2, 0xD5, 0xD9, 0xDC, 0xDF, 0xE3,
516 : 0xE6, 0xE9, 0xED, 0xF0, 0xF3, 0xF6, 0xFA, 0xFD,
517 : 0x03, 0x0B, 0x12, 0x18, 0x1D, 0x23, 0x28, 0x2D,
518 : 0x32, 0x36, 0x3B, 0x40, 0x44, 0x49, 0x4D, 0x51,
519 : 0x56, 0x5A, 0x5E, 0x62, 0x66, 0x6A, 0x6E, 0x72,
520 : 0x76, 0x7A, 0x7D, 0x81, 0x85, 0x89, 0x8D, 0x90,
521 : 0x94, 0x98, 0x9B, 0x9F, 0xA2, 0xA6, 0xAA, 0xAD,
522 : 0xB1, 0xB4, 0xB8, 0xBB, 0xBF, 0xC2, 0xC5, 0xC9,
523 : 0xCC, 0xD0, 0xD3, 0xD6, 0xDA, 0xDD, 0xE0, 0xE4,
524 : 0xE7, 0xEA, 0xED, 0xF1, 0xF4, 0xF7, 0xFA, 0xFD,
525 : 0x05, 0x0D, 0x13, 0x19, 0x1F, 0x24, 0x29, 0x2E,
526 : 0x33, 0x38, 0x3C, 0x41, 0x45, 0x4A, 0x4E, 0x52,
527 : 0x57, 0x5B, 0x5F, 0x63, 0x67, 0x6B, 0x6F, 0x73,
528 : 0x77, 0x7B, 0x7E, 0x82, 0x86, 0x8A, 0x8D, 0x91,
529 : 0x95, 0x99, 0x9C, 0xA0, 0xA3, 0xA7, 0xAA, 0xAE,
530 : 0xB2, 0xB5, 0xB9, 0xBC, 0xBF, 0xC3, 0xC6, 0xCA,
531 : 0xCD, 0xD0, 0xD4, 0xD7, 0xDA, 0xDE, 0xE1, 0xE4,
532 : 0xE8, 0xEB, 0xEE, 0xF1, 0xF5, 0xF8, 0xFB, 0xFD,
533 : 0x07, 0x0E, 0x15, 0x1A, 0x20, 0x25, 0x2A, 0x2F,
534 : 0x34, 0x39, 0x3D, 0x42, 0x46, 0x4B, 0x4F, 0x53,
535 : 0x58, 0x5C, 0x60, 0x64, 0x68, 0x6C, 0x70, 0x74,
536 : 0x78, 0x7C, 0x7F, 0x83, 0x87, 0x8B, 0x8E, 0x92,
537 : 0x96, 0x99, 0x9D, 0xA1, 0xA4, 0xA8, 0xAB, 0xAF,
538 : 0xB2, 0xB6, 0xB9, 0xBD, 0xC0, 0xC4, 0xC7, 0xCB,
539 : 0xCE, 0xD1, 0xD5, 0xD8, 0xDB, 0xDF, 0xE2, 0xE5,
540 : 0xE9, 0xEC, 0xEF, 0xF2, 0xF6, 0xF9, 0xFC, 0xFD
541 : };
542 : #endif
543 :
544 35 : static int xan_decode_frame(AVCodecContext *avctx,
545 : void *data, int *got_frame,
546 : AVPacket *avpkt)
547 : {
548 35 : AVFrame *frame = data;
549 35 : const uint8_t *buf = avpkt->data;
550 35 : int ret, buf_size = avpkt->size;
551 35 : XanContext *s = avctx->priv_data;
552 : GetByteContext ctx;
553 35 : int tag = 0;
554 :
555 35 : bytestream2_init(&ctx, buf, buf_size);
556 130 : while (bytestream2_get_bytes_left(&ctx) > 8 && tag != VGA__TAG) {
557 : unsigned *tmpptr;
558 : uint32_t new_pal;
559 : int size;
560 : int i;
561 60 : tag = bytestream2_get_le32(&ctx);
562 60 : size = bytestream2_get_be32(&ctx);
563 60 : if (size < 0) {
564 0 : av_log(avctx, AV_LOG_ERROR, "Invalid tag size %d\n", size);
565 0 : return AVERROR_INVALIDDATA;
566 : }
567 60 : size = FFMIN(size, bytestream2_get_bytes_left(&ctx));
568 60 : switch (tag) {
569 24 : case PALT_TAG:
570 24 : if (size < PALETTE_SIZE)
571 0 : return AVERROR_INVALIDDATA;
572 24 : if (s->palettes_count >= PALETTES_MAX)
573 0 : return AVERROR_INVALIDDATA;
574 24 : tmpptr = av_realloc_array(s->palettes,
575 24 : s->palettes_count + 1, AVPALETTE_SIZE);
576 24 : if (!tmpptr)
577 0 : return AVERROR(ENOMEM);
578 24 : s->palettes = tmpptr;
579 24 : tmpptr += s->palettes_count * AVPALETTE_COUNT;
580 6168 : for (i = 0; i < PALETTE_COUNT; i++) {
581 : #if RUNTIME_GAMMA
582 : int r = gamma_corr(bytestream2_get_byteu(&ctx));
583 : int g = gamma_corr(bytestream2_get_byteu(&ctx));
584 : int b = gamma_corr(bytestream2_get_byteu(&ctx));
585 : #else
586 6144 : int r = gamma_lookup[bytestream2_get_byteu(&ctx)];
587 6144 : int g = gamma_lookup[bytestream2_get_byteu(&ctx)];
588 6144 : int b = gamma_lookup[bytestream2_get_byteu(&ctx)];
589 : #endif
590 6144 : *tmpptr++ = (0xFFU << 24) | (r << 16) | (g << 8) | b;
591 : }
592 24 : s->palettes_count++;
593 24 : break;
594 1 : case SHOT_TAG:
595 1 : if (size < 4)
596 0 : return AVERROR_INVALIDDATA;
597 1 : new_pal = bytestream2_get_le32(&ctx);
598 1 : if (new_pal < s->palettes_count) {
599 1 : s->cur_palette = new_pal;
600 : } else
601 0 : av_log(avctx, AV_LOG_ERROR, "Invalid palette selected\n");
602 1 : break;
603 35 : case VGA__TAG:
604 35 : break;
605 0 : default:
606 0 : bytestream2_skip(&ctx, size);
607 0 : break;
608 : }
609 : }
610 35 : buf_size = bytestream2_get_bytes_left(&ctx);
611 :
612 35 : if (s->palettes_count <= 0) {
613 0 : av_log(s->avctx, AV_LOG_ERROR, "No palette found\n");
614 0 : return AVERROR_INVALIDDATA;
615 : }
616 :
617 35 : if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
618 0 : return ret;
619 :
620 35 : if (!s->frame_size)
621 1 : s->frame_size = frame->linesize[0] * s->avctx->height;
622 :
623 70 : memcpy(frame->data[1],
624 70 : s->palettes + s->cur_palette * AVPALETTE_COUNT, AVPALETTE_SIZE);
625 :
626 35 : s->buf = ctx.buffer;
627 35 : s->size = buf_size;
628 :
629 35 : if (xan_wc3_decode_frame(s, frame) < 0)
630 0 : return AVERROR_INVALIDDATA;
631 :
632 35 : av_frame_unref(s->last_frame);
633 35 : if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
634 0 : return ret;
635 :
636 35 : *got_frame = 1;
637 :
638 : /* always report that the buffer was completely consumed */
639 35 : return buf_size;
640 : }
641 :
642 : AVCodec ff_xan_wc3_decoder = {
643 : .name = "xan_wc3",
644 : .long_name = NULL_IF_CONFIG_SMALL("Wing Commander III / Xan"),
645 : .type = AVMEDIA_TYPE_VIDEO,
646 : .id = AV_CODEC_ID_XAN_WC3,
647 : .priv_data_size = sizeof(XanContext),
648 : .init = xan_decode_init,
649 : .close = xan_decode_end,
650 : .decode = xan_decode_frame,
651 : .capabilities = AV_CODEC_CAP_DR1,
652 : };
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