blob: 7f3801774ae075318df53f2d7d7c89900ffba104
1 | /* |
2 | * Microsoft Screen 3 (aka Microsoft ATC Screen) decoder |
3 | * Copyright (c) 2012 Konstantin Shishkov |
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 | * Microsoft Screen 3 (aka Microsoft ATC Screen) decoder |
25 | */ |
26 | |
27 | #include "avcodec.h" |
28 | #include "bytestream.h" |
29 | #include "internal.h" |
30 | #include "mathops.h" |
31 | #include "mss34dsp.h" |
32 | |
33 | #define HEADER_SIZE 27 |
34 | |
35 | #define MODEL2_SCALE 13 |
36 | #define MODEL_SCALE 15 |
37 | #define MODEL256_SEC_SCALE 9 |
38 | |
39 | typedef struct Model2 { |
40 | int upd_val, till_rescale; |
41 | unsigned zero_freq, zero_weight; |
42 | unsigned total_freq, total_weight; |
43 | } Model2; |
44 | |
45 | typedef struct Model { |
46 | int weights[16], freqs[16]; |
47 | int num_syms; |
48 | int tot_weight; |
49 | int upd_val, max_upd_val, till_rescale; |
50 | } Model; |
51 | |
52 | typedef struct Model256 { |
53 | int weights[256], freqs[256]; |
54 | int tot_weight; |
55 | int secondary[68]; |
56 | int sec_size; |
57 | int upd_val, max_upd_val, till_rescale; |
58 | } Model256; |
59 | |
60 | #define RAC_BOTTOM 0x01000000 |
61 | typedef struct RangeCoder { |
62 | const uint8_t *src, *src_end; |
63 | |
64 | uint32_t range, low; |
65 | int got_error; |
66 | } RangeCoder; |
67 | |
68 | enum BlockType { |
69 | FILL_BLOCK = 0, |
70 | IMAGE_BLOCK, |
71 | DCT_BLOCK, |
72 | HAAR_BLOCK, |
73 | SKIP_BLOCK |
74 | }; |
75 | |
76 | typedef struct BlockTypeContext { |
77 | int last_type; |
78 | Model bt_model[5]; |
79 | } BlockTypeContext; |
80 | |
81 | typedef struct FillBlockCoder { |
82 | int fill_val; |
83 | Model coef_model; |
84 | } FillBlockCoder; |
85 | |
86 | typedef struct ImageBlockCoder { |
87 | Model256 esc_model, vec_entry_model; |
88 | Model vec_size_model; |
89 | Model vq_model[125]; |
90 | } ImageBlockCoder; |
91 | |
92 | typedef struct DCTBlockCoder { |
93 | int *prev_dc; |
94 | ptrdiff_t prev_dc_stride; |
95 | int prev_dc_height; |
96 | int quality; |
97 | uint16_t qmat[64]; |
98 | Model dc_model; |
99 | Model2 sign_model; |
100 | Model256 ac_model; |
101 | } DCTBlockCoder; |
102 | |
103 | typedef struct HaarBlockCoder { |
104 | int quality, scale; |
105 | Model256 coef_model; |
106 | Model coef_hi_model; |
107 | } HaarBlockCoder; |
108 | |
109 | typedef struct MSS3Context { |
110 | AVCodecContext *avctx; |
111 | AVFrame *pic; |
112 | |
113 | int got_error; |
114 | RangeCoder coder; |
115 | BlockTypeContext btype[3]; |
116 | FillBlockCoder fill_coder[3]; |
117 | ImageBlockCoder image_coder[3]; |
118 | DCTBlockCoder dct_coder[3]; |
119 | HaarBlockCoder haar_coder[3]; |
120 | |
121 | int dctblock[64]; |
122 | int hblock[16 * 16]; |
123 | } MSS3Context; |
124 | |
125 | |
126 | static void model2_reset(Model2 *m) |
127 | { |
128 | m->zero_weight = 1; |
129 | m->total_weight = 2; |
130 | m->zero_freq = 0x1000; |
131 | m->total_freq = 0x2000; |
132 | m->upd_val = 4; |
133 | m->till_rescale = 4; |
134 | } |
135 | |
136 | static void model2_update(Model2 *m, int bit) |
137 | { |
138 | unsigned scale; |
139 | |
140 | if (!bit) |
141 | m->zero_weight++; |
142 | m->till_rescale--; |
143 | if (m->till_rescale) |
144 | return; |
145 | |
146 | m->total_weight += m->upd_val; |
147 | if (m->total_weight > 0x2000) { |
148 | m->total_weight = (m->total_weight + 1) >> 1; |
149 | m->zero_weight = (m->zero_weight + 1) >> 1; |
150 | if (m->total_weight == m->zero_weight) |
151 | m->total_weight = m->zero_weight + 1; |
152 | } |
153 | m->upd_val = m->upd_val * 5 >> 2; |
154 | if (m->upd_val > 64) |
155 | m->upd_val = 64; |
156 | scale = 0x80000000u / m->total_weight; |
157 | m->zero_freq = m->zero_weight * scale >> 18; |
158 | m->total_freq = m->total_weight * scale >> 18; |
159 | m->till_rescale = m->upd_val; |
160 | } |
161 | |
162 | static void model_update(Model *m, int val) |
163 | { |
164 | int i, sum = 0; |
165 | unsigned scale; |
166 | |
167 | m->weights[val]++; |
168 | m->till_rescale--; |
169 | if (m->till_rescale) |
170 | return; |
171 | m->tot_weight += m->upd_val; |
172 | |
173 | if (m->tot_weight > 0x8000) { |
174 | m->tot_weight = 0; |
175 | for (i = 0; i < m->num_syms; i++) { |
176 | m->weights[i] = (m->weights[i] + 1) >> 1; |
177 | m->tot_weight += m->weights[i]; |
178 | } |
179 | } |
180 | scale = 0x80000000u / m->tot_weight; |
181 | for (i = 0; i < m->num_syms; i++) { |
182 | m->freqs[i] = sum * scale >> 16; |
183 | sum += m->weights[i]; |
184 | } |
185 | |
186 | m->upd_val = m->upd_val * 5 >> 2; |
187 | if (m->upd_val > m->max_upd_val) |
188 | m->upd_val = m->max_upd_val; |
189 | m->till_rescale = m->upd_val; |
190 | } |
191 | |
192 | static void model_reset(Model *m) |
193 | { |
194 | int i; |
195 | |
196 | m->tot_weight = 0; |
197 | for (i = 0; i < m->num_syms - 1; i++) |
198 | m->weights[i] = 1; |
199 | m->weights[m->num_syms - 1] = 0; |
200 | |
201 | m->upd_val = m->num_syms; |
202 | m->till_rescale = 1; |
203 | model_update(m, m->num_syms - 1); |
204 | m->till_rescale = |
205 | m->upd_val = (m->num_syms + 6) >> 1; |
206 | } |
207 | |
208 | static av_cold void model_init(Model *m, int num_syms) |
209 | { |
210 | m->num_syms = num_syms; |
211 | m->max_upd_val = 8 * num_syms + 48; |
212 | |
213 | model_reset(m); |
214 | } |
215 | |
216 | static void model256_update(Model256 *m, int val) |
217 | { |
218 | int i, sum = 0; |
219 | unsigned scale; |
220 | int send, sidx = 1; |
221 | |
222 | m->weights[val]++; |
223 | m->till_rescale--; |
224 | if (m->till_rescale) |
225 | return; |
226 | m->tot_weight += m->upd_val; |
227 | |
228 | if (m->tot_weight > 0x8000) { |
229 | m->tot_weight = 0; |
230 | for (i = 0; i < 256; i++) { |
231 | m->weights[i] = (m->weights[i] + 1) >> 1; |
232 | m->tot_weight += m->weights[i]; |
233 | } |
234 | } |
235 | scale = 0x80000000u / m->tot_weight; |
236 | m->secondary[0] = 0; |
237 | for (i = 0; i < 256; i++) { |
238 | m->freqs[i] = sum * scale >> 16; |
239 | sum += m->weights[i]; |
240 | send = m->freqs[i] >> MODEL256_SEC_SCALE; |
241 | while (sidx <= send) |
242 | m->secondary[sidx++] = i - 1; |
243 | } |
244 | while (sidx < m->sec_size) |
245 | m->secondary[sidx++] = 255; |
246 | |
247 | m->upd_val = m->upd_val * 5 >> 2; |
248 | if (m->upd_val > m->max_upd_val) |
249 | m->upd_val = m->max_upd_val; |
250 | m->till_rescale = m->upd_val; |
251 | } |
252 | |
253 | static void model256_reset(Model256 *m) |
254 | { |
255 | int i; |
256 | |
257 | for (i = 0; i < 255; i++) |
258 | m->weights[i] = 1; |
259 | m->weights[255] = 0; |
260 | |
261 | m->tot_weight = 0; |
262 | m->upd_val = 256; |
263 | m->till_rescale = 1; |
264 | model256_update(m, 255); |
265 | m->till_rescale = |
266 | m->upd_val = (256 + 6) >> 1; |
267 | } |
268 | |
269 | static av_cold void model256_init(Model256 *m) |
270 | { |
271 | m->max_upd_val = 8 * 256 + 48; |
272 | m->sec_size = (1 << 6) + 2; |
273 | |
274 | model256_reset(m); |
275 | } |
276 | |
277 | static void rac_init(RangeCoder *c, const uint8_t *src, int size) |
278 | { |
279 | int i; |
280 | |
281 | c->src = src; |
282 | c->src_end = src + size; |
283 | c->low = 0; |
284 | for (i = 0; i < FFMIN(size, 4); i++) |
285 | c->low = (c->low << 8) | *c->src++; |
286 | c->range = 0xFFFFFFFF; |
287 | c->got_error = 0; |
288 | } |
289 | |
290 | static void rac_normalise(RangeCoder *c) |
291 | { |
292 | for (;;) { |
293 | c->range <<= 8; |
294 | c->low <<= 8; |
295 | if (c->src < c->src_end) { |
296 | c->low |= *c->src++; |
297 | } else if (!c->low) { |
298 | c->got_error = 1; |
299 | c->low = 1; |
300 | } |
301 | if (c->range >= RAC_BOTTOM) |
302 | return; |
303 | } |
304 | } |
305 | |
306 | static int rac_get_bit(RangeCoder *c) |
307 | { |
308 | int bit; |
309 | |
310 | c->range >>= 1; |
311 | |
312 | bit = (c->range <= c->low); |
313 | if (bit) |
314 | c->low -= c->range; |
315 | |
316 | if (c->range < RAC_BOTTOM) |
317 | rac_normalise(c); |
318 | |
319 | return bit; |
320 | } |
321 | |
322 | static int rac_get_bits(RangeCoder *c, int nbits) |
323 | { |
324 | int val; |
325 | |
326 | c->range >>= nbits; |
327 | val = c->low / c->range; |
328 | c->low -= c->range * val; |
329 | |
330 | if (c->range < RAC_BOTTOM) |
331 | rac_normalise(c); |
332 | |
333 | return val; |
334 | } |
335 | |
336 | static int rac_get_model2_sym(RangeCoder *c, Model2 *m) |
337 | { |
338 | int bit, helper; |
339 | |
340 | helper = m->zero_freq * (c->range >> MODEL2_SCALE); |
341 | bit = (c->low >= helper); |
342 | if (bit) { |
343 | c->low -= helper; |
344 | c->range -= helper; |
345 | } else { |
346 | c->range = helper; |
347 | } |
348 | |
349 | if (c->range < RAC_BOTTOM) |
350 | rac_normalise(c); |
351 | |
352 | model2_update(m, bit); |
353 | |
354 | return bit; |
355 | } |
356 | |
357 | static int rac_get_model_sym(RangeCoder *c, Model *m) |
358 | { |
359 | int prob, prob2, helper, val; |
360 | int end, end2; |
361 | |
362 | prob = 0; |
363 | prob2 = c->range; |
364 | c->range >>= MODEL_SCALE; |
365 | val = 0; |
366 | end = m->num_syms >> 1; |
367 | end2 = m->num_syms; |
368 | do { |
369 | helper = m->freqs[end] * c->range; |
370 | if (helper <= c->low) { |
371 | val = end; |
372 | prob = helper; |
373 | } else { |
374 | end2 = end; |
375 | prob2 = helper; |
376 | } |
377 | end = (end2 + val) >> 1; |
378 | } while (end != val); |
379 | c->low -= prob; |
380 | c->range = prob2 - prob; |
381 | if (c->range < RAC_BOTTOM) |
382 | rac_normalise(c); |
383 | |
384 | model_update(m, val); |
385 | |
386 | return val; |
387 | } |
388 | |
389 | static int rac_get_model256_sym(RangeCoder *c, Model256 *m) |
390 | { |
391 | int prob, prob2, helper, val; |
392 | int start, end; |
393 | int ssym; |
394 | |
395 | prob2 = c->range; |
396 | c->range >>= MODEL_SCALE; |
397 | |
398 | helper = c->low / c->range; |
399 | ssym = helper >> MODEL256_SEC_SCALE; |
400 | val = m->secondary[ssym]; |
401 | |
402 | end = start = m->secondary[ssym + 1] + 1; |
403 | while (end > val + 1) { |
404 | ssym = (end + val) >> 1; |
405 | if (m->freqs[ssym] <= helper) { |
406 | end = start; |
407 | val = ssym; |
408 | } else { |
409 | end = (end + val) >> 1; |
410 | start = ssym; |
411 | } |
412 | } |
413 | prob = m->freqs[val] * c->range; |
414 | if (val != 255) |
415 | prob2 = m->freqs[val + 1] * c->range; |
416 | |
417 | c->low -= prob; |
418 | c->range = prob2 - prob; |
419 | if (c->range < RAC_BOTTOM) |
420 | rac_normalise(c); |
421 | |
422 | model256_update(m, val); |
423 | |
424 | return val; |
425 | } |
426 | |
427 | static int decode_block_type(RangeCoder *c, BlockTypeContext *bt) |
428 | { |
429 | bt->last_type = rac_get_model_sym(c, &bt->bt_model[bt->last_type]); |
430 | |
431 | return bt->last_type; |
432 | } |
433 | |
434 | static int decode_coeff(RangeCoder *c, Model *m) |
435 | { |
436 | int val, sign; |
437 | |
438 | val = rac_get_model_sym(c, m); |
439 | if (val) { |
440 | sign = rac_get_bit(c); |
441 | if (val > 1) { |
442 | val--; |
443 | val = (1 << val) + rac_get_bits(c, val); |
444 | } |
445 | if (!sign) |
446 | val = -val; |
447 | } |
448 | |
449 | return val; |
450 | } |
451 | |
452 | static void decode_fill_block(RangeCoder *c, FillBlockCoder *fc, |
453 | uint8_t *dst, ptrdiff_t stride, int block_size) |
454 | { |
455 | int i; |
456 | |
457 | fc->fill_val += decode_coeff(c, &fc->coef_model); |
458 | |
459 | for (i = 0; i < block_size; i++, dst += stride) |
460 | memset(dst, fc->fill_val, block_size); |
461 | } |
462 | |
463 | static void decode_image_block(RangeCoder *c, ImageBlockCoder *ic, |
464 | uint8_t *dst, ptrdiff_t stride, int block_size) |
465 | { |
466 | int i, j; |
467 | int vec_size; |
468 | int vec[4]; |
469 | int prev_line[16]; |
470 | int A, B, C; |
471 | |
472 | vec_size = rac_get_model_sym(c, &ic->vec_size_model) + 2; |
473 | for (i = 0; i < vec_size; i++) |
474 | vec[i] = rac_get_model256_sym(c, &ic->vec_entry_model); |
475 | for (; i < 4; i++) |
476 | vec[i] = 0; |
477 | memset(prev_line, 0, sizeof(prev_line)); |
478 | |
479 | for (j = 0; j < block_size; j++) { |
480 | A = 0; |
481 | B = 0; |
482 | for (i = 0; i < block_size; i++) { |
483 | C = B; |
484 | B = prev_line[i]; |
485 | A = rac_get_model_sym(c, &ic->vq_model[A + B * 5 + C * 25]); |
486 | |
487 | prev_line[i] = A; |
488 | if (A < 4) |
489 | dst[i] = vec[A]; |
490 | else |
491 | dst[i] = rac_get_model256_sym(c, &ic->esc_model); |
492 | } |
493 | dst += stride; |
494 | } |
495 | } |
496 | |
497 | static int decode_dct(RangeCoder *c, DCTBlockCoder *bc, int *block, |
498 | int bx, int by) |
499 | { |
500 | int skip, val, sign, pos = 1, zz_pos, dc; |
501 | int blk_pos = bx + by * bc->prev_dc_stride; |
502 | |
503 | memset(block, 0, sizeof(*block) * 64); |
504 | |
505 | dc = decode_coeff(c, &bc->dc_model); |
506 | if (by) { |
507 | if (bx) { |
508 | int l, tl, t; |
509 | |
510 | l = bc->prev_dc[blk_pos - 1]; |
511 | tl = bc->prev_dc[blk_pos - 1 - bc->prev_dc_stride]; |
512 | t = bc->prev_dc[blk_pos - bc->prev_dc_stride]; |
513 | |
514 | if (FFABS(t - tl) <= FFABS(l - tl)) |
515 | dc += l; |
516 | else |
517 | dc += t; |
518 | } else { |
519 | dc += bc->prev_dc[blk_pos - bc->prev_dc_stride]; |
520 | } |
521 | } else if (bx) { |
522 | dc += bc->prev_dc[bx - 1]; |
523 | } |
524 | bc->prev_dc[blk_pos] = dc; |
525 | block[0] = dc * bc->qmat[0]; |
526 | |
527 | while (pos < 64) { |
528 | val = rac_get_model256_sym(c, &bc->ac_model); |
529 | if (!val) |
530 | return 0; |
531 | if (val == 0xF0) { |
532 | pos += 16; |
533 | continue; |
534 | } |
535 | skip = val >> 4; |
536 | val = val & 0xF; |
537 | if (!val) |
538 | return -1; |
539 | pos += skip; |
540 | if (pos >= 64) |
541 | return -1; |
542 | |
543 | sign = rac_get_model2_sym(c, &bc->sign_model); |
544 | if (val > 1) { |
545 | val--; |
546 | val = (1 << val) + rac_get_bits(c, val); |
547 | } |
548 | if (!sign) |
549 | val = -val; |
550 | |
551 | zz_pos = ff_zigzag_direct[pos]; |
552 | block[zz_pos] = val * bc->qmat[zz_pos]; |
553 | pos++; |
554 | } |
555 | |
556 | return pos == 64 ? 0 : -1; |
557 | } |
558 | |
559 | static void decode_dct_block(RangeCoder *c, DCTBlockCoder *bc, |
560 | uint8_t *dst, ptrdiff_t stride, int block_size, |
561 | int *block, int mb_x, int mb_y) |
562 | { |
563 | int i, j; |
564 | int bx, by; |
565 | int nblocks = block_size >> 3; |
566 | |
567 | bx = mb_x * nblocks; |
568 | by = mb_y * nblocks; |
569 | |
570 | for (j = 0; j < nblocks; j++) { |
571 | for (i = 0; i < nblocks; i++) { |
572 | if (decode_dct(c, bc, block, bx + i, by + j)) { |
573 | c->got_error = 1; |
574 | return; |
575 | } |
576 | ff_mss34_dct_put(dst + i * 8, stride, block); |
577 | } |
578 | dst += 8 * stride; |
579 | } |
580 | } |
581 | |
582 | static void decode_haar_block(RangeCoder *c, HaarBlockCoder *hc, |
583 | uint8_t *dst, ptrdiff_t stride, |
584 | int block_size, int *block) |
585 | { |
586 | const int hsize = block_size >> 1; |
587 | int A, B, C, D, t1, t2, t3, t4; |
588 | int i, j; |
589 | |
590 | for (j = 0; j < block_size; j++) { |
591 | for (i = 0; i < block_size; i++) { |
592 | if (i < hsize && j < hsize) |
593 | block[i] = rac_get_model256_sym(c, &hc->coef_model); |
594 | else |
595 | block[i] = decode_coeff(c, &hc->coef_hi_model); |
596 | block[i] *= hc->scale; |
597 | } |
598 | block += block_size; |
599 | } |
600 | block -= block_size * block_size; |
601 | |
602 | for (j = 0; j < hsize; j++) { |
603 | for (i = 0; i < hsize; i++) { |
604 | A = block[i]; |
605 | B = block[i + hsize]; |
606 | C = block[i + hsize * block_size]; |
607 | D = block[i + hsize * block_size + hsize]; |
608 | |
609 | t1 = A - B; |
610 | t2 = C - D; |
611 | t3 = A + B; |
612 | t4 = C + D; |
613 | dst[i * 2] = av_clip_uint8(t1 - t2); |
614 | dst[i * 2 + stride] = av_clip_uint8(t1 + t2); |
615 | dst[i * 2 + 1] = av_clip_uint8(t3 - t4); |
616 | dst[i * 2 + 1 + stride] = av_clip_uint8(t3 + t4); |
617 | } |
618 | block += block_size; |
619 | dst += stride * 2; |
620 | } |
621 | } |
622 | |
623 | static void reset_coders(MSS3Context *ctx, int quality) |
624 | { |
625 | int i, j; |
626 | |
627 | for (i = 0; i < 3; i++) { |
628 | ctx->btype[i].last_type = SKIP_BLOCK; |
629 | for (j = 0; j < 5; j++) |
630 | model_reset(&ctx->btype[i].bt_model[j]); |
631 | ctx->fill_coder[i].fill_val = 0; |
632 | model_reset(&ctx->fill_coder[i].coef_model); |
633 | model256_reset(&ctx->image_coder[i].esc_model); |
634 | model256_reset(&ctx->image_coder[i].vec_entry_model); |
635 | model_reset(&ctx->image_coder[i].vec_size_model); |
636 | for (j = 0; j < 125; j++) |
637 | model_reset(&ctx->image_coder[i].vq_model[j]); |
638 | if (ctx->dct_coder[i].quality != quality) { |
639 | ctx->dct_coder[i].quality = quality; |
640 | ff_mss34_gen_quant_mat(ctx->dct_coder[i].qmat, quality, !i); |
641 | } |
642 | memset(ctx->dct_coder[i].prev_dc, 0, |
643 | sizeof(*ctx->dct_coder[i].prev_dc) * |
644 | ctx->dct_coder[i].prev_dc_stride * |
645 | ctx->dct_coder[i].prev_dc_height); |
646 | model_reset(&ctx->dct_coder[i].dc_model); |
647 | model2_reset(&ctx->dct_coder[i].sign_model); |
648 | model256_reset(&ctx->dct_coder[i].ac_model); |
649 | if (ctx->haar_coder[i].quality != quality) { |
650 | ctx->haar_coder[i].quality = quality; |
651 | ctx->haar_coder[i].scale = 17 - 7 * quality / 50; |
652 | } |
653 | model_reset(&ctx->haar_coder[i].coef_hi_model); |
654 | model256_reset(&ctx->haar_coder[i].coef_model); |
655 | } |
656 | } |
657 | |
658 | static av_cold void init_coders(MSS3Context *ctx) |
659 | { |
660 | int i, j; |
661 | |
662 | for (i = 0; i < 3; i++) { |
663 | for (j = 0; j < 5; j++) |
664 | model_init(&ctx->btype[i].bt_model[j], 5); |
665 | model_init(&ctx->fill_coder[i].coef_model, 12); |
666 | model256_init(&ctx->image_coder[i].esc_model); |
667 | model256_init(&ctx->image_coder[i].vec_entry_model); |
668 | model_init(&ctx->image_coder[i].vec_size_model, 3); |
669 | for (j = 0; j < 125; j++) |
670 | model_init(&ctx->image_coder[i].vq_model[j], 5); |
671 | model_init(&ctx->dct_coder[i].dc_model, 12); |
672 | model256_init(&ctx->dct_coder[i].ac_model); |
673 | model_init(&ctx->haar_coder[i].coef_hi_model, 12); |
674 | model256_init(&ctx->haar_coder[i].coef_model); |
675 | } |
676 | } |
677 | |
678 | static int mss3_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, |
679 | AVPacket *avpkt) |
680 | { |
681 | const uint8_t *buf = avpkt->data; |
682 | int buf_size = avpkt->size; |
683 | MSS3Context *c = avctx->priv_data; |
684 | RangeCoder *acoder = &c->coder; |
685 | GetByteContext gb; |
686 | uint8_t *dst[3]; |
687 | int dec_width, dec_height, dec_x, dec_y, quality, keyframe; |
688 | int x, y, i, mb_width, mb_height, blk_size, btype; |
689 | int ret; |
690 | |
691 | if (buf_size < HEADER_SIZE) { |
692 | av_log(avctx, AV_LOG_ERROR, |
693 | "Frame should have at least %d bytes, got %d instead\n", |
694 | HEADER_SIZE, buf_size); |
695 | return AVERROR_INVALIDDATA; |
696 | } |
697 | |
698 | bytestream2_init(&gb, buf, buf_size); |
699 | keyframe = bytestream2_get_be32(&gb); |
700 | if (keyframe & ~0x301) { |
701 | av_log(avctx, AV_LOG_ERROR, "Invalid frame type %X\n", keyframe); |
702 | return AVERROR_INVALIDDATA; |
703 | } |
704 | keyframe = !(keyframe & 1); |
705 | bytestream2_skip(&gb, 6); |
706 | dec_x = bytestream2_get_be16(&gb); |
707 | dec_y = bytestream2_get_be16(&gb); |
708 | dec_width = bytestream2_get_be16(&gb); |
709 | dec_height = bytestream2_get_be16(&gb); |
710 | |
711 | if (dec_x + dec_width > avctx->width || |
712 | dec_y + dec_height > avctx->height || |
713 | (dec_width | dec_height) & 0xF) { |
714 | av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d +%d,%d\n", |
715 | dec_width, dec_height, dec_x, dec_y); |
716 | return AVERROR_INVALIDDATA; |
717 | } |
718 | bytestream2_skip(&gb, 4); |
719 | quality = bytestream2_get_byte(&gb); |
720 | if (quality < 1 || quality > 100) { |
721 | av_log(avctx, AV_LOG_ERROR, "Invalid quality setting %d\n", quality); |
722 | return AVERROR_INVALIDDATA; |
723 | } |
724 | bytestream2_skip(&gb, 4); |
725 | |
726 | if (keyframe && !bytestream2_get_bytes_left(&gb)) { |
727 | av_log(avctx, AV_LOG_ERROR, "Keyframe without data found\n"); |
728 | return AVERROR_INVALIDDATA; |
729 | } |
730 | if (!keyframe && c->got_error) |
731 | return buf_size; |
732 | c->got_error = 0; |
733 | |
734 | if ((ret = ff_reget_buffer(avctx, c->pic)) < 0) |
735 | return ret; |
736 | c->pic->key_frame = keyframe; |
737 | c->pic->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P; |
738 | if (!bytestream2_get_bytes_left(&gb)) { |
739 | if ((ret = av_frame_ref(data, c->pic)) < 0) |
740 | return ret; |
741 | *got_frame = 1; |
742 | |
743 | return buf_size; |
744 | } |
745 | |
746 | reset_coders(c, quality); |
747 | |
748 | rac_init(acoder, buf + HEADER_SIZE, buf_size - HEADER_SIZE); |
749 | |
750 | mb_width = dec_width >> 4; |
751 | mb_height = dec_height >> 4; |
752 | dst[0] = c->pic->data[0] + dec_x + dec_y * c->pic->linesize[0]; |
753 | dst[1] = c->pic->data[1] + dec_x / 2 + (dec_y / 2) * c->pic->linesize[1]; |
754 | dst[2] = c->pic->data[2] + dec_x / 2 + (dec_y / 2) * c->pic->linesize[2]; |
755 | for (y = 0; y < mb_height; y++) { |
756 | for (x = 0; x < mb_width; x++) { |
757 | for (i = 0; i < 3; i++) { |
758 | blk_size = 8 << !i; |
759 | |
760 | btype = decode_block_type(acoder, c->btype + i); |
761 | switch (btype) { |
762 | case FILL_BLOCK: |
763 | decode_fill_block(acoder, c->fill_coder + i, |
764 | dst[i] + x * blk_size, |
765 | c->pic->linesize[i], blk_size); |
766 | break; |
767 | case IMAGE_BLOCK: |
768 | decode_image_block(acoder, c->image_coder + i, |
769 | dst[i] + x * blk_size, |
770 | c->pic->linesize[i], blk_size); |
771 | break; |
772 | case DCT_BLOCK: |
773 | decode_dct_block(acoder, c->dct_coder + i, |
774 | dst[i] + x * blk_size, |
775 | c->pic->linesize[i], blk_size, |
776 | c->dctblock, x, y); |
777 | break; |
778 | case HAAR_BLOCK: |
779 | decode_haar_block(acoder, c->haar_coder + i, |
780 | dst[i] + x * blk_size, |
781 | c->pic->linesize[i], blk_size, |
782 | c->hblock); |
783 | break; |
784 | } |
785 | if (c->got_error || acoder->got_error) { |
786 | av_log(avctx, AV_LOG_ERROR, "Error decoding block %d,%d\n", |
787 | x, y); |
788 | c->got_error = 1; |
789 | return AVERROR_INVALIDDATA; |
790 | } |
791 | } |
792 | } |
793 | dst[0] += c->pic->linesize[0] * 16; |
794 | dst[1] += c->pic->linesize[1] * 8; |
795 | dst[2] += c->pic->linesize[2] * 8; |
796 | } |
797 | |
798 | if ((ret = av_frame_ref(data, c->pic)) < 0) |
799 | return ret; |
800 | |
801 | *got_frame = 1; |
802 | |
803 | return buf_size; |
804 | } |
805 | |
806 | static av_cold int mss3_decode_end(AVCodecContext *avctx) |
807 | { |
808 | MSS3Context * const c = avctx->priv_data; |
809 | int i; |
810 | |
811 | av_frame_free(&c->pic); |
812 | for (i = 0; i < 3; i++) |
813 | av_freep(&c->dct_coder[i].prev_dc); |
814 | |
815 | return 0; |
816 | } |
817 | |
818 | static av_cold int mss3_decode_init(AVCodecContext *avctx) |
819 | { |
820 | MSS3Context * const c = avctx->priv_data; |
821 | int i; |
822 | |
823 | c->avctx = avctx; |
824 | |
825 | if ((avctx->width & 0xF) || (avctx->height & 0xF)) { |
826 | av_log(avctx, AV_LOG_ERROR, |
827 | "Image dimensions should be a multiple of 16.\n"); |
828 | return AVERROR_INVALIDDATA; |
829 | } |
830 | |
831 | c->got_error = 0; |
832 | for (i = 0; i < 3; i++) { |
833 | int b_width = avctx->width >> (2 + !!i); |
834 | int b_height = avctx->height >> (2 + !!i); |
835 | c->dct_coder[i].prev_dc_stride = b_width; |
836 | c->dct_coder[i].prev_dc_height = b_height; |
837 | c->dct_coder[i].prev_dc = av_malloc(sizeof(*c->dct_coder[i].prev_dc) * |
838 | b_width * b_height); |
839 | if (!c->dct_coder[i].prev_dc) { |
840 | av_log(avctx, AV_LOG_ERROR, "Cannot allocate buffer\n"); |
841 | av_frame_free(&c->pic); |
842 | while (i >= 0) { |
843 | av_freep(&c->dct_coder[i].prev_dc); |
844 | i--; |
845 | } |
846 | return AVERROR(ENOMEM); |
847 | } |
848 | } |
849 | |
850 | c->pic = av_frame_alloc(); |
851 | if (!c->pic) { |
852 | mss3_decode_end(avctx); |
853 | return AVERROR(ENOMEM); |
854 | } |
855 | |
856 | avctx->pix_fmt = AV_PIX_FMT_YUV420P; |
857 | |
858 | init_coders(c); |
859 | |
860 | return 0; |
861 | } |
862 | |
863 | AVCodec ff_msa1_decoder = { |
864 | .name = "msa1", |
865 | .long_name = NULL_IF_CONFIG_SMALL("MS ATC Screen"), |
866 | .type = AVMEDIA_TYPE_VIDEO, |
867 | .id = AV_CODEC_ID_MSA1, |
868 | .priv_data_size = sizeof(MSS3Context), |
869 | .init = mss3_decode_init, |
870 | .close = mss3_decode_end, |
871 | .decode = mss3_decode_frame, |
872 | .capabilities = AV_CODEC_CAP_DR1, |
873 | }; |
874 |