1 /*
2 * Lagarith lossless decoder
3 * Copyright (c) 2009 Nathan Caldwell <saintdev (at) gmail.com>
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 * Lagarith lossless decoder
25 * @author Nathan Caldwell
26 */
27
28 #include <inttypes.h>
29
30 #include "avcodec.h"
31 #include "get_bits.h"
32 #include "mathops.h"
33 #include "lagarithrac.h"
34 #include "lossless_videodsp.h"
35 #include "thread.h"
36
37 enum LagarithFrameType {
38 FRAME_RAW = 1, /**< uncompressed */
39 FRAME_U_RGB24 = 2, /**< unaligned RGB24 */
40 FRAME_ARITH_YUY2 = 3, /**< arithmetic coded YUY2 */
41 FRAME_ARITH_RGB24 = 4, /**< arithmetic coded RGB24 */
42 FRAME_SOLID_GRAY = 5, /**< solid grayscale color frame */
43 FRAME_SOLID_COLOR = 6, /**< solid non-grayscale color frame */
44 FRAME_OLD_ARITH_RGB = 7, /**< obsolete arithmetic coded RGB (no longer encoded by upstream since version 1.1.0) */
45 FRAME_ARITH_RGBA = 8, /**< arithmetic coded RGBA */
46 FRAME_SOLID_RGBA = 9, /**< solid RGBA color frame */
47 FRAME_ARITH_YV12 = 10, /**< arithmetic coded YV12 */
48 FRAME_REDUCED_RES = 11, /**< reduced resolution YV12 frame */
49 };
50
51 typedef struct LagarithContext {
52 AVCodecContext *avctx;
53 LLVidDSPContext llviddsp;
54 int zeros; /**< number of consecutive zero bytes encountered */
55 int zeros_rem; /**< number of zero bytes remaining to output */
56 } LagarithContext;
57
58 /**
59 * Compute the 52-bit mantissa of 1/(double)denom.
60 * This crazy format uses floats in an entropy coder and we have to match x86
61 * rounding exactly, thus ordinary floats aren't portable enough.
62 * @param denom denominator
63 * @return 52-bit mantissa
64 * @see softfloat_mul
65 */
softfloat_reciprocal(uint32_t denom)66 static uint64_t softfloat_reciprocal(uint32_t denom)
67 {
68 int shift = av_log2(denom - 1) + 1;
69 uint64_t ret = (1ULL << 52) / denom;
70 uint64_t err = (1ULL << 52) - ret * denom;
71 ret <<= shift;
72 err <<= shift;
73 err += denom / 2;
74 return ret + err / denom;
75 }
76
77 /**
78 * (uint32_t)(x*f), where f has the given mantissa, and exponent 0
79 * Used in combination with softfloat_reciprocal computes x/(double)denom.
80 * @param x 32-bit integer factor
81 * @param mantissa mantissa of f with exponent 0
82 * @return 32-bit integer value (x*f)
83 * @see softfloat_reciprocal
84 */
softfloat_mul(uint32_t x,uint64_t mantissa)85 static uint32_t softfloat_mul(uint32_t x, uint64_t mantissa)
86 {
87 uint64_t l = x * (mantissa & 0xffffffff);
88 uint64_t h = x * (mantissa >> 32);
89 h += l >> 32;
90 l &= 0xffffffff;
91 l += 1LL << av_log2(h >> 21);
92 h += l >> 32;
93 return h >> 20;
94 }
95
lag_calc_zero_run(int8_t x)96 static uint8_t lag_calc_zero_run(int8_t x)
97 {
98 return (x * 2) ^ (x >> 7);
99 }
100
lag_decode_prob(GetBitContext * gb,uint32_t * value)101 static int lag_decode_prob(GetBitContext *gb, uint32_t *value)
102 {
103 static const uint8_t series[] = { 1, 2, 3, 5, 8, 13, 21 };
104 int i;
105 int bit = 0;
106 int bits = 0;
107 int prevbit = 0;
108 unsigned val;
109
110 for (i = 0; i < 7; i++) {
111 if (prevbit && bit)
112 break;
113 prevbit = bit;
114 bit = get_bits1(gb);
115 if (bit && !prevbit)
116 bits += series[i];
117 }
118 bits--;
119 if (bits < 0 || bits > 31) {
120 *value = 0;
121 return -1;
122 } else if (bits == 0) {
123 *value = 0;
124 return 0;
125 }
126
127 val = get_bits_long(gb, bits);
128 val |= 1U << bits;
129
130 *value = val - 1;
131
132 return 0;
133 }
134
lag_read_prob_header(lag_rac * rac,GetBitContext * gb)135 static int lag_read_prob_header(lag_rac *rac, GetBitContext *gb)
136 {
137 int i, j, scale_factor;
138 unsigned prob, cumulative_target;
139 unsigned cumul_prob = 0;
140 unsigned scaled_cumul_prob = 0;
141 int nnz = 0;
142
143 rac->prob[0] = 0;
144 rac->prob[257] = UINT_MAX;
145 /* Read probabilities from bitstream */
146 for (i = 1; i < 257; i++) {
147 if (lag_decode_prob(gb, &rac->prob[i]) < 0) {
148 av_log(rac->avctx, AV_LOG_ERROR, "Invalid probability encountered.\n");
149 return -1;
150 }
151 if ((uint64_t)cumul_prob + rac->prob[i] > UINT_MAX) {
152 av_log(rac->avctx, AV_LOG_ERROR, "Integer overflow encountered in cumulative probability calculation.\n");
153 return -1;
154 }
155 cumul_prob += rac->prob[i];
156 if (!rac->prob[i]) {
157 if (lag_decode_prob(gb, &prob)) {
158 av_log(rac->avctx, AV_LOG_ERROR, "Invalid probability run encountered.\n");
159 return -1;
160 }
161 if (prob > 256 - i)
162 prob = 256 - i;
163 for (j = 0; j < prob; j++)
164 rac->prob[++i] = 0;
165 }else {
166 nnz++;
167 }
168 }
169
170 if (!cumul_prob) {
171 av_log(rac->avctx, AV_LOG_ERROR, "All probabilities are 0!\n");
172 return -1;
173 }
174
175 if (nnz == 1 && (show_bits_long(gb, 32) & 0xFFFFFF)) {
176 return AVERROR_INVALIDDATA;
177 }
178
179 /* Scale probabilities so cumulative probability is an even power of 2. */
180 scale_factor = av_log2(cumul_prob);
181
182 if (cumul_prob & (cumul_prob - 1)) {
183 uint64_t mul = softfloat_reciprocal(cumul_prob);
184 for (i = 1; i <= 128; i++) {
185 rac->prob[i] = softfloat_mul(rac->prob[i], mul);
186 scaled_cumul_prob += rac->prob[i];
187 }
188 if (scaled_cumul_prob <= 0) {
189 av_log(rac->avctx, AV_LOG_ERROR, "Scaled probabilities invalid\n");
190 return AVERROR_INVALIDDATA;
191 }
192 for (; i < 257; i++) {
193 rac->prob[i] = softfloat_mul(rac->prob[i], mul);
194 scaled_cumul_prob += rac->prob[i];
195 }
196
197 scale_factor++;
198 if (scale_factor >= 32U)
199 return AVERROR_INVALIDDATA;
200 cumulative_target = 1U << scale_factor;
201
202 if (scaled_cumul_prob > cumulative_target) {
203 av_log(rac->avctx, AV_LOG_ERROR,
204 "Scaled probabilities are larger than target!\n");
205 return -1;
206 }
207
208 scaled_cumul_prob = cumulative_target - scaled_cumul_prob;
209
210 for (i = 1; scaled_cumul_prob; i = (i & 0x7f) + 1) {
211 if (rac->prob[i]) {
212 rac->prob[i]++;
213 scaled_cumul_prob--;
214 }
215 /* Comment from reference source:
216 * if (b & 0x80 == 0) { // order of operations is 'wrong'; it has been left this way
217 * // since the compression change is negligible and fixing it
218 * // breaks backwards compatibility
219 * b =- (signed int)b;
220 * b &= 0xFF;
221 * } else {
222 * b++;
223 * b &= 0x7f;
224 * }
225 */
226 }
227 }
228
229 if (scale_factor > 23)
230 return AVERROR_INVALIDDATA;
231
232 rac->scale = scale_factor;
233
234 /* Fill probability array with cumulative probability for each symbol. */
235 for (i = 1; i < 257; i++)
236 rac->prob[i] += rac->prob[i - 1];
237
238 return 0;
239 }
240
add_lag_median_prediction(uint8_t * dst,uint8_t * src1,uint8_t * diff,int w,int * left,int * left_top)241 static void add_lag_median_prediction(uint8_t *dst, uint8_t *src1,
242 uint8_t *diff, int w, int *left,
243 int *left_top)
244 {
245 /* This is almost identical to add_hfyu_median_pred in huffyuvdsp.h.
246 * However the &0xFF on the gradient predictor yields incorrect output
247 * for lagarith.
248 */
249 int i;
250 uint8_t l, lt;
251
252 l = *left;
253 lt = *left_top;
254
255 for (i = 0; i < w; i++) {
256 l = mid_pred(l, src1[i], l + src1[i] - lt) + diff[i];
257 lt = src1[i];
258 dst[i] = l;
259 }
260
261 *left = l;
262 *left_top = lt;
263 }
264
lag_pred_line(LagarithContext * l,uint8_t * buf,int width,int stride,int line)265 static void lag_pred_line(LagarithContext *l, uint8_t *buf,
266 int width, int stride, int line)
267 {
268 int L, TL;
269
270 if (!line) {
271 /* Left prediction only for first line */
272 L = l->llviddsp.add_left_pred(buf, buf, width, 0);
273 } else {
274 /* Left pixel is actually prev_row[width] */
275 L = buf[width - stride - 1];
276
277 if (line == 1) {
278 /* Second line, left predict first pixel, the rest of the line is median predicted
279 * NOTE: In the case of RGB this pixel is top predicted */
280 TL = l->avctx->pix_fmt == AV_PIX_FMT_YUV420P ? buf[-stride] : L;
281 } else {
282 /* Top left is 2 rows back, last pixel */
283 TL = buf[width - (2 * stride) - 1];
284 }
285
286 add_lag_median_prediction(buf, buf - stride, buf,
287 width, &L, &TL);
288 }
289 }
290
lag_pred_line_yuy2(LagarithContext * l,uint8_t * buf,int width,int stride,int line,int is_luma)291 static void lag_pred_line_yuy2(LagarithContext *l, uint8_t *buf,
292 int width, int stride, int line,
293 int is_luma)
294 {
295 int L, TL;
296
297 if (!line) {
298 L= buf[0];
299 if (is_luma)
300 buf[0] = 0;
301 l->llviddsp.add_left_pred(buf, buf, width, 0);
302 if (is_luma)
303 buf[0] = L;
304 return;
305 }
306 if (line == 1) {
307 const int HEAD = is_luma ? 4 : 2;
308 int i;
309
310 L = buf[width - stride - 1];
311 TL = buf[HEAD - stride - 1];
312 for (i = 0; i < HEAD; i++) {
313 L += buf[i];
314 buf[i] = L;
315 }
316 for (; i < width; i++) {
317 L = mid_pred(L & 0xFF, buf[i - stride], (L + buf[i - stride] - TL) & 0xFF) + buf[i];
318 TL = buf[i - stride];
319 buf[i] = L;
320 }
321 } else {
322 TL = buf[width - (2 * stride) - 1];
323 L = buf[width - stride - 1];
324 l->llviddsp.add_median_pred(buf, buf - stride, buf, width, &L, &TL);
325 }
326 }
327
lag_decode_line(LagarithContext * l,lag_rac * rac,uint8_t * dst,int width,int stride,int esc_count)328 static int lag_decode_line(LagarithContext *l, lag_rac *rac,
329 uint8_t *dst, int width, int stride,
330 int esc_count)
331 {
332 int i = 0;
333 int ret = 0;
334
335 if (!esc_count)
336 esc_count = -1;
337
338 /* Output any zeros remaining from the previous run */
339 handle_zeros:
340 if (l->zeros_rem) {
341 int count = FFMIN(l->zeros_rem, width - i);
342 memset(dst + i, 0, count);
343 i += count;
344 l->zeros_rem -= count;
345 }
346
347 while (i < width) {
348 dst[i] = lag_get_rac(rac);
349 ret++;
350
351 if (dst[i])
352 l->zeros = 0;
353 else
354 l->zeros++;
355
356 i++;
357 if (l->zeros == esc_count) {
358 int index = lag_get_rac(rac);
359 ret++;
360
361 l->zeros = 0;
362
363 l->zeros_rem = lag_calc_zero_run(index);
364 goto handle_zeros;
365 }
366 }
367 return ret;
368 }
369
lag_decode_zero_run_line(LagarithContext * l,uint8_t * dst,const uint8_t * src,const uint8_t * src_end,int width,int esc_count)370 static int lag_decode_zero_run_line(LagarithContext *l, uint8_t *dst,
371 const uint8_t *src, const uint8_t *src_end,
372 int width, int esc_count)
373 {
374 int i = 0;
375 int count;
376 uint8_t zero_run = 0;
377 const uint8_t *src_start = src;
378 uint8_t mask1 = -(esc_count < 2);
379 uint8_t mask2 = -(esc_count < 3);
380 uint8_t *end = dst + (width - 2);
381
382 avpriv_request_sample(l->avctx, "zero_run_line");
383
384 memset(dst, 0, width);
385
386 output_zeros:
387 if (l->zeros_rem) {
388 count = FFMIN(l->zeros_rem, width - i);
389 if (end - dst < count) {
390 av_log(l->avctx, AV_LOG_ERROR, "Too many zeros remaining.\n");
391 return AVERROR_INVALIDDATA;
392 }
393
394 memset(dst, 0, count);
395 l->zeros_rem -= count;
396 dst += count;
397 }
398
399 while (dst < end) {
400 i = 0;
401 while (!zero_run && dst + i < end) {
402 i++;
403 if (i+2 >= src_end - src)
404 return AVERROR_INVALIDDATA;
405 zero_run =
406 !(src[i] | (src[i + 1] & mask1) | (src[i + 2] & mask2));
407 }
408 if (zero_run) {
409 zero_run = 0;
410 i += esc_count;
411 memcpy(dst, src, i);
412 dst += i;
413 l->zeros_rem = lag_calc_zero_run(src[i]);
414
415 src += i + 1;
416 goto output_zeros;
417 } else {
418 memcpy(dst, src, i);
419 src += i;
420 dst += i;
421 }
422 }
423 return src - src_start;
424 }
425
426
427
lag_decode_arith_plane(LagarithContext * l,uint8_t * dst,int width,int height,int stride,const uint8_t * src,int src_size)428 static int lag_decode_arith_plane(LagarithContext *l, uint8_t *dst,
429 int width, int height, int stride,
430 const uint8_t *src, int src_size)
431 {
432 int i = 0;
433 int read = 0;
434 uint32_t length;
435 uint32_t offset = 1;
436 int esc_count;
437 GetBitContext gb;
438 lag_rac rac;
439 const uint8_t *src_end = src + src_size;
440 int ret;
441
442 rac.avctx = l->avctx;
443 l->zeros = 0;
444
445 if(src_size < 2)
446 return AVERROR_INVALIDDATA;
447
448 esc_count = src[0];
449 if (esc_count < 4) {
450 length = width * height;
451 if(src_size < 5)
452 return AVERROR_INVALIDDATA;
453 if (esc_count && AV_RL32(src + 1) < length) {
454 length = AV_RL32(src + 1);
455 offset += 4;
456 }
457
458 if ((ret = init_get_bits8(&gb, src + offset, src_size - offset)) < 0)
459 return ret;
460
461 if (lag_read_prob_header(&rac, &gb) < 0)
462 return -1;
463
464 ff_lag_rac_init(&rac, &gb, length - stride);
465 for (i = 0; i < height; i++) {
466 if (rac.overread > MAX_OVERREAD)
467 return AVERROR_INVALIDDATA;
468 read += lag_decode_line(l, &rac, dst + (i * stride), width,
469 stride, esc_count);
470 }
471
472 if (read > length)
473 av_log(l->avctx, AV_LOG_WARNING,
474 "Output more bytes than length (%d of %"PRIu32")\n", read,
475 length);
476 } else if (esc_count < 8) {
477 esc_count -= 4;
478 src ++;
479 src_size --;
480 if (esc_count > 0) {
481 /* Zero run coding only, no range coding. */
482 for (i = 0; i < height; i++) {
483 int res = lag_decode_zero_run_line(l, dst + (i * stride), src,
484 src_end, width, esc_count);
485 if (res < 0)
486 return res;
487 src += res;
488 }
489 } else {
490 if (src_size < width * height)
491 return AVERROR_INVALIDDATA; // buffer not big enough
492 /* Plane is stored uncompressed */
493 for (i = 0; i < height; i++) {
494 memcpy(dst + (i * stride), src, width);
495 src += width;
496 }
497 }
498 } else if (esc_count == 0xff) {
499 /* Plane is a solid run of given value */
500 for (i = 0; i < height; i++)
501 memset(dst + i * stride, src[1], width);
502 /* Do not apply prediction.
503 Note: memset to 0 above, setting first value to src[1]
504 and applying prediction gives the same result. */
505 return 0;
506 } else {
507 av_log(l->avctx, AV_LOG_ERROR,
508 "Invalid zero run escape code! (%#x)\n", esc_count);
509 return -1;
510 }
511
512 if (l->avctx->pix_fmt != AV_PIX_FMT_YUV422P) {
513 for (i = 0; i < height; i++) {
514 lag_pred_line(l, dst, width, stride, i);
515 dst += stride;
516 }
517 } else {
518 for (i = 0; i < height; i++) {
519 lag_pred_line_yuy2(l, dst, width, stride, i,
520 width == l->avctx->width);
521 dst += stride;
522 }
523 }
524
525 return 0;
526 }
527
528 /**
529 * Decode a frame.
530 * @param avctx codec context
531 * @param data output AVFrame
532 * @param data_size size of output data or 0 if no picture is returned
533 * @param avpkt input packet
534 * @return number of consumed bytes on success or negative if decode fails
535 */
lag_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)536 static int lag_decode_frame(AVCodecContext *avctx,
537 void *data, int *got_frame, AVPacket *avpkt)
538 {
539 const uint8_t *buf = avpkt->data;
540 unsigned int buf_size = avpkt->size;
541 LagarithContext *l = avctx->priv_data;
542 ThreadFrame frame = { .f = data };
543 AVFrame *const p = data;
544 uint8_t frametype;
545 uint32_t offset_gu = 0, offset_bv = 0, offset_ry = 9;
546 uint32_t offs[4];
547 uint8_t *srcs[4];
548 int i, j, planes = 3;
549 int ret;
550
551 p->key_frame = 1;
552 p->pict_type = AV_PICTURE_TYPE_I;
553
554 frametype = buf[0];
555
556 offset_gu = AV_RL32(buf + 1);
557 offset_bv = AV_RL32(buf + 5);
558
559 switch (frametype) {
560 case FRAME_SOLID_RGBA:
561 avctx->pix_fmt = AV_PIX_FMT_GBRAP;
562 case FRAME_SOLID_GRAY:
563 if (frametype == FRAME_SOLID_GRAY)
564 if (avctx->bits_per_coded_sample == 24) {
565 avctx->pix_fmt = AV_PIX_FMT_GBRP;
566 } else {
567 avctx->pix_fmt = AV_PIX_FMT_GBRAP;
568 planes = 4;
569 }
570
571 if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
572 return ret;
573
574 if (frametype == FRAME_SOLID_RGBA) {
575 for (i = 0; i < avctx->height; i++) {
576 memset(p->data[0] + i * p->linesize[0], buf[2], avctx->width);
577 memset(p->data[1] + i * p->linesize[1], buf[1], avctx->width);
578 memset(p->data[2] + i * p->linesize[2], buf[3], avctx->width);
579 memset(p->data[3] + i * p->linesize[3], buf[4], avctx->width);
580 }
581 } else {
582 for (i = 0; i < avctx->height; i++) {
583 for (j = 0; j < planes; j++)
584 memset(p->data[j] + i * p->linesize[j], buf[1], avctx->width);
585 }
586 }
587 break;
588 case FRAME_SOLID_COLOR:
589 if (avctx->bits_per_coded_sample == 24) {
590 avctx->pix_fmt = AV_PIX_FMT_GBRP;
591 } else {
592 avctx->pix_fmt = AV_PIX_FMT_GBRAP;
593 }
594
595 if ((ret = ff_thread_get_buffer(avctx, &frame,0)) < 0)
596 return ret;
597
598 for (i = 0; i < avctx->height; i++) {
599 memset(p->data[0] + i * p->linesize[0], buf[2], avctx->width);
600 memset(p->data[1] + i * p->linesize[1], buf[1], avctx->width);
601 memset(p->data[2] + i * p->linesize[2], buf[3], avctx->width);
602 if (avctx->pix_fmt == AV_PIX_FMT_GBRAP)
603 memset(p->data[3] + i * p->linesize[3], 0xFFu, avctx->width);
604 }
605 break;
606 case FRAME_ARITH_RGBA:
607 avctx->pix_fmt = AV_PIX_FMT_GBRAP;
608 planes = 4;
609 offset_ry += 4;
610 offs[3] = AV_RL32(buf + 9);
611 case FRAME_ARITH_RGB24:
612 case FRAME_U_RGB24:
613 if (frametype == FRAME_ARITH_RGB24 || frametype == FRAME_U_RGB24)
614 avctx->pix_fmt = AV_PIX_FMT_GBRP;
615
616 if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
617 return ret;
618
619 offs[0] = offset_bv;
620 offs[1] = offset_gu;
621 offs[2] = offset_ry;
622
623 for (i = 0; i < planes; i++)
624 srcs[i] = p->data[i] + (avctx->height - 1) * p->linesize[i];
625 for (i = 0; i < planes; i++)
626 if (buf_size <= offs[i]) {
627 av_log(avctx, AV_LOG_ERROR,
628 "Invalid frame offsets\n");
629 return AVERROR_INVALIDDATA;
630 }
631
632 for (i = 0; i < planes; i++)
633 lag_decode_arith_plane(l, srcs[i],
634 avctx->width, avctx->height,
635 -p->linesize[i], buf + offs[i],
636 buf_size - offs[i]);
637 for (i = 0; i < avctx->height; i++) {
638 l->llviddsp.add_bytes(p->data[0] + i * p->linesize[0], p->data[1] + i * p->linesize[1], avctx->width);
639 l->llviddsp.add_bytes(p->data[2] + i * p->linesize[2], p->data[1] + i * p->linesize[1], avctx->width);
640 }
641 FFSWAP(uint8_t*, p->data[0], p->data[1]);
642 FFSWAP(int, p->linesize[0], p->linesize[1]);
643 FFSWAP(uint8_t*, p->data[2], p->data[1]);
644 FFSWAP(int, p->linesize[2], p->linesize[1]);
645 break;
646 case FRAME_ARITH_YUY2:
647 avctx->pix_fmt = AV_PIX_FMT_YUV422P;
648
649 if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
650 return ret;
651
652 if (offset_ry >= buf_size ||
653 offset_gu >= buf_size ||
654 offset_bv >= buf_size) {
655 av_log(avctx, AV_LOG_ERROR,
656 "Invalid frame offsets\n");
657 return AVERROR_INVALIDDATA;
658 }
659
660 lag_decode_arith_plane(l, p->data[0], avctx->width, avctx->height,
661 p->linesize[0], buf + offset_ry,
662 buf_size - offset_ry);
663 lag_decode_arith_plane(l, p->data[1], (avctx->width + 1) / 2,
664 avctx->height, p->linesize[1],
665 buf + offset_gu, buf_size - offset_gu);
666 lag_decode_arith_plane(l, p->data[2], (avctx->width + 1) / 2,
667 avctx->height, p->linesize[2],
668 buf + offset_bv, buf_size - offset_bv);
669 break;
670 case FRAME_ARITH_YV12:
671 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
672
673 if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
674 return ret;
675
676 if (offset_ry >= buf_size ||
677 offset_gu >= buf_size ||
678 offset_bv >= buf_size) {
679 av_log(avctx, AV_LOG_ERROR,
680 "Invalid frame offsets\n");
681 return AVERROR_INVALIDDATA;
682 }
683
684 lag_decode_arith_plane(l, p->data[0], avctx->width, avctx->height,
685 p->linesize[0], buf + offset_ry,
686 buf_size - offset_ry);
687 lag_decode_arith_plane(l, p->data[2], (avctx->width + 1) / 2,
688 (avctx->height + 1) / 2, p->linesize[2],
689 buf + offset_gu, buf_size - offset_gu);
690 lag_decode_arith_plane(l, p->data[1], (avctx->width + 1) / 2,
691 (avctx->height + 1) / 2, p->linesize[1],
692 buf + offset_bv, buf_size - offset_bv);
693 break;
694 default:
695 av_log(avctx, AV_LOG_ERROR,
696 "Unsupported Lagarith frame type: %#"PRIx8"\n", frametype);
697 return AVERROR_PATCHWELCOME;
698 }
699
700 *got_frame = 1;
701
702 return buf_size;
703 }
704
lag_decode_init(AVCodecContext * avctx)705 static av_cold int lag_decode_init(AVCodecContext *avctx)
706 {
707 LagarithContext *l = avctx->priv_data;
708 l->avctx = avctx;
709
710 ff_llviddsp_init(&l->llviddsp);
711
712 return 0;
713 }
714
715 AVCodec ff_lagarith_decoder = {
716 .name = "lagarith",
717 .long_name = NULL_IF_CONFIG_SMALL("Lagarith lossless"),
718 .type = AVMEDIA_TYPE_VIDEO,
719 .id = AV_CODEC_ID_LAGARITH,
720 .priv_data_size = sizeof(LagarithContext),
721 .init = lag_decode_init,
722 .decode = lag_decode_frame,
723 .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
724 };
725