| 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 | }; |