FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/mss3.c
Date: 2021-09-26 18:22:30
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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->low > c->range) {
302 ✗ c->got_error = 1;
303 ✗ c->low = 1;
304 }
305 ✗ if (c->range >= RAC_BOTTOM)
306 ✗ return;
307 }
308 }
309
310 ✗ static int rac_get_bit(RangeCoder *c)
311 {
312 int bit;
313
314 ✗ c->range >>= 1;
315
316 ✗ bit = (c->range <= c->low);
317 ✗ if (bit)
318 ✗ c->low -= c->range;
319
320 ✗ if (c->range < RAC_BOTTOM)
321 ✗ rac_normalise(c);
322
323 ✗ return bit;
324 }
325
326 ✗ static int rac_get_bits(RangeCoder *c, int nbits)
327 {
328 int val;
329
330 ✗ c->range >>= nbits;
331 ✗ val = c->low / c->range;
332 ✗ c->low -= c->range * val;
333
334 ✗ if (c->range < RAC_BOTTOM)
335 ✗ rac_normalise(c);
336
337 ✗ return val;
338 }
339
340 ✗ static int rac_get_model2_sym(RangeCoder *c, Model2 *m)
341 {
342 int bit, helper;
343
344 ✗ helper = m->zero_freq * (c->range >> MODEL2_SCALE);
345 ✗ bit = (c->low >= helper);
346 ✗ if (bit) {
347 ✗ c->low -= helper;
348 ✗ c->range -= helper;
349 } else {
350 ✗ c->range = helper;
351 }
352
353 ✗ if (c->range < RAC_BOTTOM)
354 ✗ rac_normalise(c);
355
356 ✗ model2_update(m, bit);
357
358 ✗ return bit;
359 }
360
361 ✗ static int rac_get_model_sym(RangeCoder *c, Model *m)
362 {
363 int val;
364 int end, end2;
365 unsigned prob, prob2, helper;
366
367 ✗ prob = 0;
368 ✗ prob2 = c->range;
369 ✗ c->range >>= MODEL_SCALE;
370 ✗ val = 0;
371 ✗ end = m->num_syms >> 1;
372 ✗ end2 = m->num_syms;
373 do {
374 ✗ helper = m->freqs[end] * c->range;
375 ✗ if (helper <= c->low) {
376 ✗ val = end;
377 ✗ prob = helper;
378 } else {
379 ✗ end2 = end;
380 ✗ prob2 = helper;
381 }
382 ✗ end = (end2 + val) >> 1;
383 ✗ } while (end != val);
384 ✗ c->low -= prob;
385 ✗ c->range = prob2 - prob;
386 ✗ if (c->range < RAC_BOTTOM)
387 ✗ rac_normalise(c);
388
389 ✗ model_update(m, val);
390
391 ✗ return val;
392 }
393
394 ✗ static int rac_get_model256_sym(RangeCoder *c, Model256 *m)
395 {
396 int val;
397 int start, end;
398 int ssym;
399 unsigned prob, prob2, helper;
400
401 ✗ prob2 = c->range;
402 ✗ c->range >>= MODEL_SCALE;
403
404 ✗ helper = c->low / c->range;
405 ✗ ssym = helper >> MODEL256_SEC_SCALE;
406 ✗ val = m->secondary[ssym];
407
408 ✗ end = start = m->secondary[ssym + 1] + 1;
409 ✗ while (end > val + 1) {
410 ✗ ssym = (end + val) >> 1;
411 ✗ if (m->freqs[ssym] <= helper) {
412 ✗ end = start;
413 ✗ val = ssym;
414 } else {
415 ✗ end = (end + val) >> 1;
416 ✗ start = ssym;
417 }
418 }
419 ✗ prob = m->freqs[val] * c->range;
420 ✗ if (val != 255)
421 ✗ prob2 = m->freqs[val + 1] * c->range;
422
423 ✗ c->low -= prob;
424 ✗ c->range = prob2 - prob;
425 ✗ if (c->range < RAC_BOTTOM)
426 ✗ rac_normalise(c);
427
428 ✗ model256_update(m, val);
429
430 ✗ return val;
431 }
432
433 ✗ static int decode_block_type(RangeCoder *c, BlockTypeContext *bt)
434 {
435 ✗ bt->last_type = rac_get_model_sym(c, &bt->bt_model[bt->last_type]);
436
437 ✗ return bt->last_type;
438 }
439
440 ✗ static int decode_coeff(RangeCoder *c, Model *m)
441 {
442 int val, sign;
443
444 ✗ val = rac_get_model_sym(c, m);
445 ✗ if (val) {
446 ✗ sign = rac_get_bit(c);
447 ✗ if (val > 1) {
448 ✗ val--;
449 ✗ val = (1 << val) + rac_get_bits(c, val);
450 }
451 ✗ if (!sign)
452 ✗ val = -val;
453 }
454
455 ✗ return val;
456 }
457
458 ✗ static void decode_fill_block(RangeCoder *c, FillBlockCoder *fc,
459 uint8_t *dst, ptrdiff_t stride, int block_size)
460 {
461 int i;
462
463 ✗ fc->fill_val += decode_coeff(c, &fc->coef_model);
464
465 ✗ for (i = 0; i < block_size; i++, dst += stride)
466 ✗ memset(dst, fc->fill_val, block_size);
467 }
468
469 ✗ static void decode_image_block(RangeCoder *c, ImageBlockCoder *ic,
470 uint8_t *dst, ptrdiff_t stride, int block_size)
471 {
472 int i, j;
473 int vec_size;
474 int vec[4];
475 int prev_line[16];
476 int A, B, C;
477
478 ✗ vec_size = rac_get_model_sym(c, &ic->vec_size_model) + 2;
479 ✗ for (i = 0; i < vec_size; i++)
480 ✗ vec[i] = rac_get_model256_sym(c, &ic->vec_entry_model);
481 ✗ for (; i < 4; i++)
482 ✗ vec[i] = 0;
483 ✗ memset(prev_line, 0, sizeof(prev_line));
484
485 ✗ for (j = 0; j < block_size; j++) {
486 ✗ A = 0;
487 ✗ B = 0;
488 ✗ for (i = 0; i < block_size; i++) {
489 ✗ C = B;
490 ✗ B = prev_line[i];
491 ✗ A = rac_get_model_sym(c, &ic->vq_model[A + B * 5 + C * 25]);
492
493 ✗ prev_line[i] = A;
494 ✗ if (A < 4)
495 ✗ dst[i] = vec[A];
496 else
497 ✗ dst[i] = rac_get_model256_sym(c, &ic->esc_model);
498 }
499 ✗ dst += stride;
500 }
501 }
502
503 ✗ static int decode_dct(RangeCoder *c, DCTBlockCoder *bc, int *block,
504 int bx, int by)
505 {
506 ✗ int skip, val, sign, pos = 1, zz_pos, dc;
507 ✗ int blk_pos = bx + by * bc->prev_dc_stride;
508
509 ✗ memset(block, 0, sizeof(*block) * 64);
510
511 ✗ dc = decode_coeff(c, &bc->dc_model);
512 ✗ if (by) {
513 ✗ if (bx) {
514 int l, tl, t;
515
516 ✗ l = bc->prev_dc[blk_pos - 1];
517 ✗ tl = bc->prev_dc[blk_pos - 1 - bc->prev_dc_stride];
518 ✗ t = bc->prev_dc[blk_pos - bc->prev_dc_stride];
519
520 ✗ if (FFABS(t - tl) <= FFABS(l - tl))
521 ✗ dc += l;
522 else
523 ✗ dc += t;
524 } else {
525 ✗ dc += bc->prev_dc[blk_pos - bc->prev_dc_stride];
526 }
527 ✗ } else if (bx) {
528 ✗ dc += bc->prev_dc[bx - 1];
529 }
530 ✗ bc->prev_dc[blk_pos] = dc;
531 ✗ block[0] = dc * bc->qmat[0];
532
533 ✗ while (pos < 64) {
534 ✗ val = rac_get_model256_sym(c, &bc->ac_model);
535 ✗ if (!val)
536 ✗ return 0;
537 ✗ if (val == 0xF0) {
538 ✗ pos += 16;
539 ✗ continue;
540 }
541 ✗ skip = val >> 4;
542 ✗ val = val & 0xF;
543 ✗ if (!val)
544 ✗ return -1;
545 ✗ pos += skip;
546 ✗ if (pos >= 64)
547 ✗ return -1;
548
549 ✗ sign = rac_get_model2_sym(c, &bc->sign_model);
550 ✗ if (val > 1) {
551 ✗ val--;
552 ✗ val = (1 << val) + rac_get_bits(c, val);
553 }
554 ✗ if (!sign)
555 ✗ val = -val;
556
557 ✗ zz_pos = ff_zigzag_direct[pos];
558 ✗ block[zz_pos] = val * bc->qmat[zz_pos];
559 ✗ pos++;
560 }
561
562 ✗ return pos == 64 ? 0 : -1;
563 }
564
565 ✗ static void decode_dct_block(RangeCoder *c, DCTBlockCoder *bc,
566 uint8_t *dst, ptrdiff_t stride, int block_size,
567 int *block, int mb_x, int mb_y)
568 {
569 int i, j;
570 int bx, by;
571 ✗ int nblocks = block_size >> 3;
572
573 ✗ bx = mb_x * nblocks;
574 ✗ by = mb_y * nblocks;
575
576 ✗ for (j = 0; j < nblocks; j++) {
577 ✗ for (i = 0; i < nblocks; i++) {
578 ✗ if (decode_dct(c, bc, block, bx + i, by + j)) {
579 ✗ c->got_error = 1;
580 ✗ return;
581 }
582 ✗ ff_mss34_dct_put(dst + i * 8, stride, block);
583 }
584 ✗ dst += 8 * stride;
585 }
586 }
587
588 ✗ static void decode_haar_block(RangeCoder *c, HaarBlockCoder *hc,
589 uint8_t *dst, ptrdiff_t stride,
590 int block_size, int *block)
591 {
592 ✗ const int hsize = block_size >> 1;
593 int A, B, C, D, t1, t2, t3, t4;
594 int i, j;
595
596 ✗ for (j = 0; j < block_size; j++) {
597 ✗ for (i = 0; i < block_size; i++) {
598 ✗ if (i < hsize && j < hsize)
599 ✗ block[i] = rac_get_model256_sym(c, &hc->coef_model);
600 else
601 ✗ block[i] = decode_coeff(c, &hc->coef_hi_model);
602 ✗ block[i] *= hc->scale;
603 }
604 ✗ block += block_size;
605 }
606 ✗ block -= block_size * block_size;
607
608 ✗ for (j = 0; j < hsize; j++) {
609 ✗ for (i = 0; i < hsize; i++) {
610 ✗ A = block[i];
611 ✗ B = block[i + hsize];
612 ✗ C = block[i + hsize * block_size];
613 ✗ D = block[i + hsize * block_size + hsize];
614
615 ✗ t1 = A - B;
616 ✗ t2 = C - D;
617 ✗ t3 = A + B;
618 ✗ t4 = C + D;
619 ✗ dst[i * 2] = av_clip_uint8(t1 - t2);
620 ✗ dst[i * 2 + stride] = av_clip_uint8(t1 + t2);
621 ✗ dst[i * 2 + 1] = av_clip_uint8(t3 - t4);
622 ✗ dst[i * 2 + 1 + stride] = av_clip_uint8(t3 + t4);
623 }
624 ✗ block += block_size;
625 ✗ dst += stride * 2;
626 }
627 }
628
629 ✗ static void reset_coders(MSS3Context *ctx, int quality)
630 {
631 int i, j;
632
633 ✗ for (i = 0; i < 3; i++) {
634 ✗ ctx->btype[i].last_type = SKIP_BLOCK;
635 ✗ for (j = 0; j < 5; j++)
636 ✗ model_reset(&ctx->btype[i].bt_model[j]);
637 ✗ ctx->fill_coder[i].fill_val = 0;
638 ✗ model_reset(&ctx->fill_coder[i].coef_model);
639 ✗ model256_reset(&ctx->image_coder[i].esc_model);
640 ✗ model256_reset(&ctx->image_coder[i].vec_entry_model);
641 ✗ model_reset(&ctx->image_coder[i].vec_size_model);
642 ✗ for (j = 0; j < 125; j++)
643 ✗ model_reset(&ctx->image_coder[i].vq_model[j]);
644 ✗ if (ctx->dct_coder[i].quality != quality) {
645 ✗ ctx->dct_coder[i].quality = quality;
646 ✗ ff_mss34_gen_quant_mat(ctx->dct_coder[i].qmat, quality, !i);
647 }
648 ✗ memset(ctx->dct_coder[i].prev_dc, 0,
649 sizeof(*ctx->dct_coder[i].prev_dc) *
650 ✗ ctx->dct_coder[i].prev_dc_stride *
651 ✗ ctx->dct_coder[i].prev_dc_height);
652 ✗ model_reset(&ctx->dct_coder[i].dc_model);
653 ✗ model2_reset(&ctx->dct_coder[i].sign_model);
654 ✗ model256_reset(&ctx->dct_coder[i].ac_model);
655 ✗ if (ctx->haar_coder[i].quality != quality) {
656 ✗ ctx->haar_coder[i].quality = quality;
657 ✗ ctx->haar_coder[i].scale = 17 - 7 * quality / 50;
658 }
659 ✗ model_reset(&ctx->haar_coder[i].coef_hi_model);
660 ✗ model256_reset(&ctx->haar_coder[i].coef_model);
661 }
662 }
663
664 ✗ static av_cold void init_coders(MSS3Context *ctx)
665 {
666 int i, j;
667
668 ✗ for (i = 0; i < 3; i++) {
669 ✗ for (j = 0; j < 5; j++)
670 ✗ model_init(&ctx->btype[i].bt_model[j], 5);
671 ✗ model_init(&ctx->fill_coder[i].coef_model, 12);
672 ✗ model256_init(&ctx->image_coder[i].esc_model);
673 ✗ model256_init(&ctx->image_coder[i].vec_entry_model);
674 ✗ model_init(&ctx->image_coder[i].vec_size_model, 3);
675 ✗ for (j = 0; j < 125; j++)
676 ✗ model_init(&ctx->image_coder[i].vq_model[j], 5);
677 ✗ model_init(&ctx->dct_coder[i].dc_model, 12);
678 ✗ model256_init(&ctx->dct_coder[i].ac_model);
679 ✗ model_init(&ctx->haar_coder[i].coef_hi_model, 12);
680 ✗ model256_init(&ctx->haar_coder[i].coef_model);
681 }
682 }
683
684 ✗ static int mss3_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
685 AVPacket *avpkt)
686 {
687 ✗ const uint8_t *buf = avpkt->data;
688 ✗ int buf_size = avpkt->size;
689 ✗ MSS3Context *c = avctx->priv_data;
690 ✗ RangeCoder *acoder = &c->coder;
691 GetByteContext gb;
692 uint8_t *dst[3];
693 int dec_width, dec_height, dec_x, dec_y, quality, keyframe;
694 int x, y, i, mb_width, mb_height, blk_size, btype;
695 int ret;
696
697 ✗ if (buf_size < HEADER_SIZE) {
698 ✗ av_log(avctx, AV_LOG_ERROR,
699 "Frame should have at least %d bytes, got %d instead\n",
700 HEADER_SIZE, buf_size);
701 ✗ return AVERROR_INVALIDDATA;
702 }
703
704 ✗ bytestream2_init(&gb, buf, buf_size);
705 ✗ keyframe = bytestream2_get_be32(&gb);
706 ✗ if (keyframe & ~0x301) {
707 ✗ av_log(avctx, AV_LOG_ERROR, "Invalid frame type %X\n", keyframe);
708 ✗ return AVERROR_INVALIDDATA;
709 }
710 ✗ keyframe = !(keyframe & 1);
711 ✗ bytestream2_skip(&gb, 6);
712 ✗ dec_x = bytestream2_get_be16(&gb);
713 ✗ dec_y = bytestream2_get_be16(&gb);
714 ✗ dec_width = bytestream2_get_be16(&gb);
715 ✗ dec_height = bytestream2_get_be16(&gb);
716
717 ✗ if (dec_x + dec_width > avctx->width ||
718 ✗ dec_y + dec_height > avctx->height ||
719 ✗ (dec_width | dec_height) & 0xF) {
720 ✗ av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d +%d,%d\n",
721 dec_width, dec_height, dec_x, dec_y);
722 ✗ return AVERROR_INVALIDDATA;
723 }
724 ✗ bytestream2_skip(&gb, 4);
725 ✗ quality = bytestream2_get_byte(&gb);
726 ✗ if (quality < 1 || quality > 100) {
727 ✗ av_log(avctx, AV_LOG_ERROR, "Invalid quality setting %d\n", quality);
728 ✗ return AVERROR_INVALIDDATA;
729 }
730 ✗ bytestream2_skip(&gb, 4);
731
732 ✗ if (keyframe && !bytestream2_get_bytes_left(&gb)) {
733 ✗ av_log(avctx, AV_LOG_ERROR, "Keyframe without data found\n");
734 ✗ return AVERROR_INVALIDDATA;
735 }
736 ✗ if (!keyframe && c->got_error)
737 ✗ return buf_size;
738 ✗ c->got_error = 0;
739
740 ✗ if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0)
741 ✗ return ret;
742 ✗ c->pic->key_frame = keyframe;
743 ✗ c->pic->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
744 ✗ if (!bytestream2_get_bytes_left(&gb)) {
745 ✗ if ((ret = av_frame_ref(data, c->pic)) < 0)
746 ✗ return ret;
747 ✗ *got_frame = 1;
748
749 ✗ return buf_size;
750 }
751
752 ✗ reset_coders(c, quality);
753
754 ✗ rac_init(acoder, buf + HEADER_SIZE, buf_size - HEADER_SIZE);
755
756 ✗ mb_width = dec_width >> 4;
757 ✗ mb_height = dec_height >> 4;
758 ✗ dst[0] = c->pic->data[0] + dec_x + dec_y * c->pic->linesize[0];
759 ✗ dst[1] = c->pic->data[1] + dec_x / 2 + (dec_y / 2) * c->pic->linesize[1];
760 ✗ dst[2] = c->pic->data[2] + dec_x / 2 + (dec_y / 2) * c->pic->linesize[2];
761 ✗ for (y = 0; y < mb_height; y++) {
762 ✗ for (x = 0; x < mb_width; x++) {
763 ✗ for (i = 0; i < 3; i++) {
764 ✗ blk_size = 8 << !i;
765
766 ✗ btype = decode_block_type(acoder, c->btype + i);
767 ✗ switch (btype) {
768 ✗ case FILL_BLOCK:
769 ✗ decode_fill_block(acoder, c->fill_coder + i,
770 ✗ dst[i] + x * blk_size,
771 ✗ c->pic->linesize[i], blk_size);
772 ✗ break;
773 ✗ case IMAGE_BLOCK:
774 ✗ decode_image_block(acoder, c->image_coder + i,
775 ✗ dst[i] + x * blk_size,
776 ✗ c->pic->linesize[i], blk_size);
777 ✗ break;
778 ✗ case DCT_BLOCK:
779 ✗ decode_dct_block(acoder, c->dct_coder + i,
780 ✗ dst[i] + x * blk_size,
781 ✗ c->pic->linesize[i], blk_size,
782 ✗ c->dctblock, x, y);
783 ✗ break;
784 ✗ case HAAR_BLOCK:
785 ✗ decode_haar_block(acoder, c->haar_coder + i,
786 ✗ dst[i] + x * blk_size,
787 ✗ c->pic->linesize[i], blk_size,
788 ✗ c->hblock);
789 ✗ break;
790 }
791 ✗ if (c->got_error || acoder->got_error) {
792 ✗ av_log(avctx, AV_LOG_ERROR, "Error decoding block %d,%d\n",
793 x, y);
794 ✗ c->got_error = 1;
795 ✗ return AVERROR_INVALIDDATA;
796 }
797 }
798 }
799 ✗ dst[0] += c->pic->linesize[0] * 16;
800 ✗ dst[1] += c->pic->linesize[1] * 8;
801 ✗ dst[2] += c->pic->linesize[2] * 8;
802 }
803
804 ✗ if ((ret = av_frame_ref(data, c->pic)) < 0)
805 ✗ return ret;
806
807 ✗ *got_frame = 1;
808
809 ✗ return buf_size;
810 }
811
812 ✗ static av_cold int mss3_decode_end(AVCodecContext *avctx)
813 {
814 ✗ MSS3Context * const c = avctx->priv_data;
815 int i;
816
817 ✗ av_frame_free(&c->pic);
818 ✗ for (i = 0; i < 3; i++)
819 ✗ av_freep(&c->dct_coder[i].prev_dc);
820
821 ✗ return 0;
822 }
823
824 ✗ static av_cold int mss3_decode_init(AVCodecContext *avctx)
825 {
826 ✗ MSS3Context * const c = avctx->priv_data;
827 int i;
828
829 ✗ c->avctx = avctx;
830
831 ✗ if ((avctx->width & 0xF) || (avctx->height & 0xF)) {
832 ✗ av_log(avctx, AV_LOG_ERROR,
833 "Image dimensions should be a multiple of 16.\n");
834 ✗ return AVERROR_INVALIDDATA;
835 }
836
837 ✗ c->got_error = 0;
838 ✗ for (i = 0; i < 3; i++) {
839 ✗ int b_width = avctx->width >> (2 + !!i);
840 ✗ int b_height = avctx->height >> (2 + !!i);
841 ✗ c->dct_coder[i].prev_dc_stride = b_width;
842 ✗ c->dct_coder[i].prev_dc_height = b_height;
843 ✗ c->dct_coder[i].prev_dc = av_malloc(sizeof(*c->dct_coder[i].prev_dc) *
844 ✗ b_width * b_height);
845 ✗ if (!c->dct_coder[i].prev_dc) {
846 ✗ av_log(avctx, AV_LOG_ERROR, "Cannot allocate buffer\n");
847 ✗ return AVERROR(ENOMEM);
848 }
849 }
850
851 ✗ c->pic = av_frame_alloc();
852 ✗ if (!c->pic)
853 ✗ return AVERROR(ENOMEM);
854
855 ✗ avctx->pix_fmt = AV_PIX_FMT_YUV420P;
856
857 ✗ init_coders(c);
858
859 ✗ return 0;
860 }
861
862 const AVCodec ff_msa1_decoder = {
863 .name = "msa1",
864 .long_name = NULL_IF_CONFIG_SMALL("MS ATC Screen"),
865 .type = AVMEDIA_TYPE_VIDEO,
866 .id = AV_CODEC_ID_MSA1,
867 .priv_data_size = sizeof(MSS3Context),
868 .init = mss3_decode_init,
869 .close = mss3_decode_end,
870 .decode = mss3_decode_frame,
871 .capabilities = AV_CODEC_CAP_DR1,
872 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
873 };
874