FFmpeg
mss3.c
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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 "libavutil/mem.h"
28 #include "avcodec.h"
29 #include "bytestream.h"
30 #include "codec_internal.h"
31 #include "decode.h"
32 #include "mathops.h"
33 #include "mss34dsp.h"
34 
35 #define HEADER_SIZE 27
36 
37 #define MODEL2_SCALE 13
38 #define MODEL_SCALE 15
39 #define MODEL256_SEC_SCALE 9
40 
41 typedef struct Model2 {
45 } Model2;
46 
47 typedef struct Model {
48  int weights[16], freqs[16];
49  int num_syms;
52 } Model;
53 
54 typedef struct Model256 {
55  int weights[256], freqs[256];
57  int secondary[68];
58  int sec_size;
60 } Model256;
61 
62 #define RAC_BOTTOM 0x01000000
63 typedef struct RangeCoder {
64  const uint8_t *src, *src_end;
65 
66  uint32_t range, low;
67  int got_error;
68 } RangeCoder;
69 
70 enum BlockType {
76 };
77 
78 typedef struct BlockTypeContext {
79  int last_type;
82 
83 typedef struct FillBlockCoder {
84  int fill_val;
87 
88 typedef struct ImageBlockCoder {
93 
94 typedef struct DCTBlockCoder {
95  int *prev_dc;
96  ptrdiff_t prev_dc_stride;
98  int quality;
99  uint16_t qmat[64];
103 } DCTBlockCoder;
104 
105 typedef struct HaarBlockCoder {
110 
111 typedef struct MSS3Context {
114 
122 
123  int dctblock[64];
124  int hblock[16 * 16];
125 } MSS3Context;
126 
127 
128 static void model2_reset(Model2 *m)
129 {
130  m->zero_weight = 1;
131  m->total_weight = 2;
132  m->zero_freq = 0x1000;
133  m->total_freq = 0x2000;
134  m->upd_val = 4;
135  m->till_rescale = 4;
136 }
137 
138 static void model2_update(Model2 *m, int bit)
139 {
140  unsigned scale;
141 
142  if (!bit)
143  m->zero_weight++;
144  m->till_rescale--;
145  if (m->till_rescale)
146  return;
147 
148  m->total_weight += m->upd_val;
149  if (m->total_weight > 0x2000) {
150  m->total_weight = (m->total_weight + 1) >> 1;
151  m->zero_weight = (m->zero_weight + 1) >> 1;
152  if (m->total_weight == m->zero_weight)
153  m->total_weight = m->zero_weight + 1;
154  }
155  m->upd_val = m->upd_val * 5 >> 2;
156  if (m->upd_val > 64)
157  m->upd_val = 64;
158  scale = 0x80000000u / m->total_weight;
159  m->zero_freq = m->zero_weight * scale >> 18;
160  m->total_freq = m->total_weight * scale >> 18;
161  m->till_rescale = m->upd_val;
162 }
163 
164 static void model_update(Model *m, int val)
165 {
166  int i, sum = 0;
167  unsigned scale;
168 
169  m->weights[val]++;
170  m->till_rescale--;
171  if (m->till_rescale)
172  return;
173  m->tot_weight += m->upd_val;
174 
175  if (m->tot_weight > 0x8000) {
176  m->tot_weight = 0;
177  for (i = 0; i < m->num_syms; i++) {
178  m->weights[i] = (m->weights[i] + 1) >> 1;
179  m->tot_weight += m->weights[i];
180  }
181  }
182  scale = 0x80000000u / m->tot_weight;
183  for (i = 0; i < m->num_syms; i++) {
184  m->freqs[i] = sum * scale >> 16;
185  sum += m->weights[i];
186  }
187 
188  m->upd_val = m->upd_val * 5 >> 2;
189  if (m->upd_val > m->max_upd_val)
190  m->upd_val = m->max_upd_val;
191  m->till_rescale = m->upd_val;
192 }
193 
194 static void model_reset(Model *m)
195 {
196  int i;
197 
198  m->tot_weight = 0;
199  for (i = 0; i < m->num_syms - 1; i++)
200  m->weights[i] = 1;
201  m->weights[m->num_syms - 1] = 0;
202 
203  m->upd_val = m->num_syms;
204  m->till_rescale = 1;
205  model_update(m, m->num_syms - 1);
206  m->till_rescale =
207  m->upd_val = (m->num_syms + 6) >> 1;
208 }
209 
210 static av_cold void model_init(Model *m, int num_syms)
211 {
212  m->num_syms = num_syms;
213  m->max_upd_val = 8 * num_syms + 48;
214 
215  model_reset(m);
216 }
217 
218 static void model256_update(Model256 *m, int val)
219 {
220  int i, sum = 0;
221  unsigned scale;
222  int send, sidx = 1;
223 
224  m->weights[val]++;
225  m->till_rescale--;
226  if (m->till_rescale)
227  return;
228  m->tot_weight += m->upd_val;
229 
230  if (m->tot_weight > 0x8000) {
231  m->tot_weight = 0;
232  for (i = 0; i < 256; i++) {
233  m->weights[i] = (m->weights[i] + 1) >> 1;
234  m->tot_weight += m->weights[i];
235  }
236  }
237  scale = 0x80000000u / m->tot_weight;
238  m->secondary[0] = 0;
239  for (i = 0; i < 256; i++) {
240  m->freqs[i] = sum * scale >> 16;
241  sum += m->weights[i];
242  send = m->freqs[i] >> MODEL256_SEC_SCALE;
243  while (sidx <= send)
244  m->secondary[sidx++] = i - 1;
245  }
246  while (sidx < m->sec_size)
247  m->secondary[sidx++] = 255;
248 
249  m->upd_val = m->upd_val * 5 >> 2;
250  if (m->upd_val > m->max_upd_val)
251  m->upd_val = m->max_upd_val;
252  m->till_rescale = m->upd_val;
253 }
254 
255 static void model256_reset(Model256 *m)
256 {
257  int i;
258 
259  for (i = 0; i < 255; i++)
260  m->weights[i] = 1;
261  m->weights[255] = 0;
262 
263  m->tot_weight = 0;
264  m->upd_val = 256;
265  m->till_rescale = 1;
266  model256_update(m, 255);
267  m->till_rescale =
268  m->upd_val = (256 + 6) >> 1;
269 }
270 
272 {
273  m->max_upd_val = 8 * 256 + 48;
274  m->sec_size = (1 << 6) + 2;
275 
276  model256_reset(m);
277 }
278 
279 static void rac_init(RangeCoder *c, const uint8_t *src, int size)
280 {
281  int i;
282 
283  c->src = src;
284  c->src_end = src + size;
285  c->low = 0;
286  for (i = 0; i < FFMIN(size, 4); i++)
287  c->low = (c->low << 8) | *c->src++;
288  c->range = 0xFFFFFFFF;
289  c->got_error = 0;
290 }
291 
293 {
294  for (;;) {
295  c->range <<= 8;
296  c->low <<= 8;
297  if (c->src < c->src_end) {
298  c->low |= *c->src++;
299  } else if (!c->low) {
300  c->got_error = 1;
301  c->low = 1;
302  }
303  if (c->low > c->range) {
304  c->got_error = 1;
305  c->low = 1;
306  }
307  if (c->range >= RAC_BOTTOM)
308  return;
309  }
310 }
311 
313 {
314  int bit;
315 
316  c->range >>= 1;
317 
318  bit = (c->range <= c->low);
319  if (bit)
320  c->low -= c->range;
321 
322  if (c->range < RAC_BOTTOM)
323  rac_normalise(c);
324 
325  return bit;
326 }
327 
328 static int rac_get_bits(RangeCoder *c, int nbits)
329 {
330  int val;
331 
332  c->range >>= nbits;
333  val = c->low / c->range;
334  c->low -= c->range * val;
335 
336  if (c->range < RAC_BOTTOM)
337  rac_normalise(c);
338 
339  return val;
340 }
341 
343 {
344  int bit, helper;
345 
346  helper = m->zero_freq * (c->range >> MODEL2_SCALE);
347  bit = (c->low >= helper);
348  if (bit) {
349  c->low -= helper;
350  c->range -= helper;
351  } else {
352  c->range = helper;
353  }
354 
355  if (c->range < RAC_BOTTOM)
356  rac_normalise(c);
357 
358  model2_update(m, bit);
359 
360  return bit;
361 }
362 
364 {
365  int val;
366  int end, end2;
367  unsigned prob, prob2, helper;
368 
369  prob = 0;
370  prob2 = c->range;
371  c->range >>= MODEL_SCALE;
372  val = 0;
373  end = m->num_syms >> 1;
374  end2 = m->num_syms;
375  do {
376  helper = m->freqs[end] * c->range;
377  if (helper <= c->low) {
378  val = end;
379  prob = helper;
380  } else {
381  end2 = end;
382  prob2 = helper;
383  }
384  end = (end2 + val) >> 1;
385  } while (end != val);
386  c->low -= prob;
387  c->range = prob2 - prob;
388  if (c->range < RAC_BOTTOM)
389  rac_normalise(c);
390 
391  model_update(m, val);
392 
393  return val;
394 }
395 
397 {
398  int val;
399  int start, end;
400  int ssym;
401  unsigned prob, prob2, helper;
402 
403  prob2 = c->range;
404  c->range >>= MODEL_SCALE;
405 
406  helper = c->low / c->range;
407  ssym = helper >> MODEL256_SEC_SCALE;
408  val = m->secondary[ssym];
409 
410  end = start = m->secondary[ssym + 1] + 1;
411  while (end > val + 1) {
412  ssym = (end + val) >> 1;
413  if (m->freqs[ssym] <= helper) {
414  end = start;
415  val = ssym;
416  } else {
417  end = (end + val) >> 1;
418  start = ssym;
419  }
420  }
421  prob = m->freqs[val] * c->range;
422  if (val != 255)
423  prob2 = m->freqs[val + 1] * c->range;
424 
425  c->low -= prob;
426  c->range = prob2 - prob;
427  if (c->range < RAC_BOTTOM)
428  rac_normalise(c);
429 
430  model256_update(m, val);
431 
432  return val;
433 }
434 
436 {
437  bt->last_type = rac_get_model_sym(c, &bt->bt_model[bt->last_type]);
438 
439  return bt->last_type;
440 }
441 
442 static int decode_coeff(RangeCoder *c, Model *m)
443 {
444  int val, sign;
445 
446  val = rac_get_model_sym(c, m);
447  if (val) {
448  sign = rac_get_bit(c);
449  if (val > 1) {
450  val--;
451  val = (1 << val) + rac_get_bits(c, val);
452  }
453  if (!sign)
454  val = -val;
455  }
456 
457  return val;
458 }
459 
461  uint8_t *dst, ptrdiff_t stride, int block_size)
462 {
463  int i;
464 
465  fc->fill_val += decode_coeff(c, &fc->coef_model);
466 
467  for (i = 0; i < block_size; i++, dst += stride)
468  memset(dst, fc->fill_val, block_size);
469 }
470 
472  uint8_t *dst, ptrdiff_t stride, int block_size)
473 {
474  int i, j;
475  int vec_size;
476  int vec[4];
477  int prev_line[16];
478  int A, B, C;
479 
480  vec_size = rac_get_model_sym(c, &ic->vec_size_model) + 2;
481  for (i = 0; i < vec_size; i++)
482  vec[i] = rac_get_model256_sym(c, &ic->vec_entry_model);
483  for (; i < 4; i++)
484  vec[i] = 0;
485  memset(prev_line, 0, sizeof(prev_line));
486 
487  for (j = 0; j < block_size; j++) {
488  A = 0;
489  B = 0;
490  for (i = 0; i < block_size; i++) {
491  C = B;
492  B = prev_line[i];
493  A = rac_get_model_sym(c, &ic->vq_model[A + B * 5 + C * 25]);
494 
495  prev_line[i] = A;
496  if (A < 4)
497  dst[i] = vec[A];
498  else
499  dst[i] = rac_get_model256_sym(c, &ic->esc_model);
500  }
501  dst += stride;
502  }
503 }
504 
505 static int decode_dct(RangeCoder *c, DCTBlockCoder *bc, int *block,
506  int bx, int by)
507 {
508  int skip, val, sign, pos = 1, zz_pos, dc;
509  int blk_pos = bx + by * bc->prev_dc_stride;
510 
511  memset(block, 0, sizeof(*block) * 64);
512 
513  dc = decode_coeff(c, &bc->dc_model);
514  if (by) {
515  if (bx) {
516  int l, tl, t;
517 
518  l = bc->prev_dc[blk_pos - 1];
519  tl = bc->prev_dc[blk_pos - 1 - bc->prev_dc_stride];
520  t = bc->prev_dc[blk_pos - bc->prev_dc_stride];
521 
522  if (FFABS(t - tl) <= FFABS(l - tl))
523  dc += l;
524  else
525  dc += t;
526  } else {
527  dc += bc->prev_dc[blk_pos - bc->prev_dc_stride];
528  }
529  } else if (bx) {
530  dc += bc->prev_dc[bx - 1];
531  }
532  bc->prev_dc[blk_pos] = dc;
533  block[0] = dc * bc->qmat[0];
534 
535  while (pos < 64) {
537  if (!val)
538  return 0;
539  if (val == 0xF0) {
540  pos += 16;
541  continue;
542  }
543  skip = val >> 4;
544  val = val & 0xF;
545  if (!val)
546  return -1;
547  pos += skip;
548  if (pos >= 64)
549  return -1;
550 
551  sign = rac_get_model2_sym(c, &bc->sign_model);
552  if (val > 1) {
553  val--;
554  val = (1 << val) + rac_get_bits(c, val);
555  }
556  if (!sign)
557  val = -val;
558 
559  zz_pos = ff_zigzag_direct[pos];
560  block[zz_pos] = val * bc->qmat[zz_pos];
561  pos++;
562  }
563 
564  return pos == 64 ? 0 : -1;
565 }
566 
568  uint8_t *dst, ptrdiff_t stride, int block_size,
569  int *block, int mb_x, int mb_y)
570 {
571  int i, j;
572  int bx, by;
573  int nblocks = block_size >> 3;
574 
575  bx = mb_x * nblocks;
576  by = mb_y * nblocks;
577 
578  for (j = 0; j < nblocks; j++) {
579  for (i = 0; i < nblocks; i++) {
580  if (decode_dct(c, bc, block, bx + i, by + j)) {
581  c->got_error = 1;
582  return;
583  }
584  ff_mss34_dct_put(dst + i * 8, stride, block);
585  }
586  dst += 8 * stride;
587  }
588 }
589 
591  uint8_t *dst, ptrdiff_t stride,
592  int block_size, int *block)
593 {
594  const int hsize = block_size >> 1;
595  int A, B, C, D, t1, t2, t3, t4;
596  int i, j;
597 
598  for (j = 0; j < block_size; j++) {
599  for (i = 0; i < block_size; i++) {
600  if (i < hsize && j < hsize)
602  else
603  block[i] = decode_coeff(c, &hc->coef_hi_model);
604  block[i] *= hc->scale;
605  }
606  block += block_size;
607  }
608  block -= block_size * block_size;
609 
610  for (j = 0; j < hsize; j++) {
611  for (i = 0; i < hsize; i++) {
612  A = block[i];
613  B = block[i + hsize];
614  C = block[i + hsize * block_size];
615  D = block[i + hsize * block_size + hsize];
616 
617  t1 = A - B;
618  t2 = C - D;
619  t3 = A + B;
620  t4 = C + D;
621  dst[i * 2] = av_clip_uint8(t1 - t2);
622  dst[i * 2 + stride] = av_clip_uint8(t1 + t2);
623  dst[i * 2 + 1] = av_clip_uint8(t3 - t4);
624  dst[i * 2 + 1 + stride] = av_clip_uint8(t3 + t4);
625  }
626  block += block_size;
627  dst += stride * 2;
628  }
629 }
630 
632 {
633  int i, j;
634 
635  for (i = 0; i < 3; i++) {
636  ctx->btype[i].last_type = SKIP_BLOCK;
637  for (j = 0; j < 5; j++)
638  model_reset(&ctx->btype[i].bt_model[j]);
639  ctx->fill_coder[i].fill_val = 0;
640  model_reset(&ctx->fill_coder[i].coef_model);
641  model256_reset(&ctx->image_coder[i].esc_model);
642  model256_reset(&ctx->image_coder[i].vec_entry_model);
643  model_reset(&ctx->image_coder[i].vec_size_model);
644  for (j = 0; j < 125; j++)
645  model_reset(&ctx->image_coder[i].vq_model[j]);
646  if (ctx->dct_coder[i].quality != quality) {
647  ctx->dct_coder[i].quality = quality;
648  ff_mss34_gen_quant_mat(ctx->dct_coder[i].qmat, quality, !i);
649  }
650  memset(ctx->dct_coder[i].prev_dc, 0,
651  sizeof(*ctx->dct_coder[i].prev_dc) *
652  ctx->dct_coder[i].prev_dc_stride *
653  ctx->dct_coder[i].prev_dc_height);
654  model_reset(&ctx->dct_coder[i].dc_model);
655  model2_reset(&ctx->dct_coder[i].sign_model);
656  model256_reset(&ctx->dct_coder[i].ac_model);
657  if (ctx->haar_coder[i].quality != quality) {
658  ctx->haar_coder[i].quality = quality;
659  ctx->haar_coder[i].scale = 17 - 7 * quality / 50;
660  }
661  model_reset(&ctx->haar_coder[i].coef_hi_model);
662  model256_reset(&ctx->haar_coder[i].coef_model);
663  }
664 }
665 
667 {
668  int i, j;
669 
670  for (i = 0; i < 3; i++) {
671  for (j = 0; j < 5; j++)
672  model_init(&ctx->btype[i].bt_model[j], 5);
673  model_init(&ctx->fill_coder[i].coef_model, 12);
674  model256_init(&ctx->image_coder[i].esc_model);
675  model256_init(&ctx->image_coder[i].vec_entry_model);
676  model_init(&ctx->image_coder[i].vec_size_model, 3);
677  for (j = 0; j < 125; j++)
678  model_init(&ctx->image_coder[i].vq_model[j], 5);
679  model_init(&ctx->dct_coder[i].dc_model, 12);
680  model256_init(&ctx->dct_coder[i].ac_model);
681  model_init(&ctx->haar_coder[i].coef_hi_model, 12);
682  model256_init(&ctx->haar_coder[i].coef_model);
683  }
684 }
685 
686 static int mss3_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
687  int *got_frame, AVPacket *avpkt)
688 {
689  const uint8_t *buf = avpkt->data;
690  int buf_size = avpkt->size;
691  MSS3Context *c = avctx->priv_data;
692  RangeCoder *acoder = &c->coder;
693  GetByteContext gb;
694  uint8_t *dst[3];
695  int dec_width, dec_height, dec_x, dec_y, quality, keyframe;
696  int x, y, i, mb_width, mb_height, blk_size, btype;
697  int ret;
698 
699  if (buf_size < HEADER_SIZE) {
700  av_log(avctx, AV_LOG_ERROR,
701  "Frame should have at least %d bytes, got %d instead\n",
702  HEADER_SIZE, buf_size);
703  return AVERROR_INVALIDDATA;
704  }
705 
706  bytestream2_init(&gb, buf, buf_size);
707  keyframe = bytestream2_get_be32(&gb);
708  if (keyframe & ~0x301) {
709  av_log(avctx, AV_LOG_ERROR, "Invalid frame type %X\n", keyframe);
710  return AVERROR_INVALIDDATA;
711  }
712  keyframe = !(keyframe & 1);
713  bytestream2_skip(&gb, 6);
714  dec_x = bytestream2_get_be16(&gb);
715  dec_y = bytestream2_get_be16(&gb);
716  dec_width = bytestream2_get_be16(&gb);
717  dec_height = bytestream2_get_be16(&gb);
718 
719  if (dec_x + dec_width > avctx->width ||
720  dec_y + dec_height > avctx->height ||
721  (dec_width | dec_height) & 0xF) {
722  av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d +%d,%d\n",
723  dec_width, dec_height, dec_x, dec_y);
724  return AVERROR_INVALIDDATA;
725  }
726  bytestream2_skip(&gb, 4);
727  quality = bytestream2_get_byte(&gb);
728  if (quality < 1 || quality > 100) {
729  av_log(avctx, AV_LOG_ERROR, "Invalid quality setting %d\n", quality);
730  return AVERROR_INVALIDDATA;
731  }
732  bytestream2_skip(&gb, 4);
733 
734  if (keyframe && !bytestream2_get_bytes_left(&gb)) {
735  av_log(avctx, AV_LOG_ERROR, "Keyframe without data found\n");
736  return AVERROR_INVALIDDATA;
737  }
738  if (!keyframe && c->got_error)
739  return buf_size;
740  c->got_error = 0;
741 
742  if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0)
743  return ret;
744  if (keyframe)
745  c->pic->flags |= AV_FRAME_FLAG_KEY;
746  else
747  c->pic->flags &= ~AV_FRAME_FLAG_KEY;
748  c->pic->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
749  if (!bytestream2_get_bytes_left(&gb)) {
750  if ((ret = av_frame_ref(rframe, c->pic)) < 0)
751  return ret;
752  *got_frame = 1;
753 
754  return buf_size;
755  }
756 
758 
759  rac_init(acoder, buf + HEADER_SIZE, buf_size - HEADER_SIZE);
760 
761  mb_width = dec_width >> 4;
762  mb_height = dec_height >> 4;
763  dst[0] = c->pic->data[0] + dec_x + dec_y * c->pic->linesize[0];
764  dst[1] = c->pic->data[1] + dec_x / 2 + (dec_y / 2) * c->pic->linesize[1];
765  dst[2] = c->pic->data[2] + dec_x / 2 + (dec_y / 2) * c->pic->linesize[2];
766  for (y = 0; y < mb_height; y++) {
767  for (x = 0; x < mb_width; x++) {
768  for (i = 0; i < 3; i++) {
769  blk_size = 8 << !i;
770 
771  btype = decode_block_type(acoder, c->btype + i);
772  switch (btype) {
773  case FILL_BLOCK:
774  decode_fill_block(acoder, c->fill_coder + i,
775  dst[i] + x * blk_size,
776  c->pic->linesize[i], blk_size);
777  break;
778  case IMAGE_BLOCK:
779  decode_image_block(acoder, c->image_coder + i,
780  dst[i] + x * blk_size,
781  c->pic->linesize[i], blk_size);
782  break;
783  case DCT_BLOCK:
784  decode_dct_block(acoder, c->dct_coder + i,
785  dst[i] + x * blk_size,
786  c->pic->linesize[i], blk_size,
787  c->dctblock, x, y);
788  break;
789  case HAAR_BLOCK:
790  decode_haar_block(acoder, c->haar_coder + i,
791  dst[i] + x * blk_size,
792  c->pic->linesize[i], blk_size,
793  c->hblock);
794  break;
795  }
796  if (c->got_error || acoder->got_error) {
797  av_log(avctx, AV_LOG_ERROR, "Error decoding block %d,%d\n",
798  x, y);
799  c->got_error = 1;
800  return AVERROR_INVALIDDATA;
801  }
802  }
803  }
804  dst[0] += c->pic->linesize[0] * 16;
805  dst[1] += c->pic->linesize[1] * 8;
806  dst[2] += c->pic->linesize[2] * 8;
807  }
808 
809  if ((ret = av_frame_ref(rframe, c->pic)) < 0)
810  return ret;
811 
812  *got_frame = 1;
813 
814  return buf_size;
815 }
816 
818 {
819  MSS3Context * const c = avctx->priv_data;
820  int i;
821 
822  av_frame_free(&c->pic);
823  for (i = 0; i < 3; i++)
824  av_freep(&c->dct_coder[i].prev_dc);
825 
826  return 0;
827 }
828 
830 {
831  MSS3Context * const c = avctx->priv_data;
832  int i;
833 
834  c->avctx = avctx;
835 
836  if ((avctx->width & 0xF) || (avctx->height & 0xF)) {
837  av_log(avctx, AV_LOG_ERROR,
838  "Image dimensions should be a multiple of 16.\n");
839  return AVERROR_INVALIDDATA;
840  }
841 
842  c->got_error = 0;
843  for (i = 0; i < 3; i++) {
844  int b_width = avctx->width >> (2 + !!i);
845  int b_height = avctx->height >> (2 + !!i);
846  c->dct_coder[i].prev_dc_stride = b_width;
847  c->dct_coder[i].prev_dc_height = b_height;
848  c->dct_coder[i].prev_dc = av_malloc(sizeof(*c->dct_coder[i].prev_dc) *
849  b_width * b_height);
850  if (!c->dct_coder[i].prev_dc) {
851  av_log(avctx, AV_LOG_ERROR, "Cannot allocate buffer\n");
852  return AVERROR(ENOMEM);
853  }
854  }
855 
856  c->pic = av_frame_alloc();
857  if (!c->pic)
858  return AVERROR(ENOMEM);
859 
860  avctx->pix_fmt = AV_PIX_FMT_YUV420P;
861 
862  init_coders(c);
863 
864  return 0;
865 }
866 
868  .p.name = "msa1",
869  CODEC_LONG_NAME("MS ATC Screen"),
870  .p.type = AVMEDIA_TYPE_VIDEO,
871  .p.id = AV_CODEC_ID_MSA1,
872  .priv_data_size = sizeof(MSS3Context),
874  .close = mss3_decode_end,
876  .p.capabilities = AV_CODEC_CAP_DR1,
877  .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
878 };
RangeCoder::range
uint32_t range
Definition: mss3.c:66
A
#define A(x)
Definition: vpx_arith.h:28
HEADER_SIZE
#define HEADER_SIZE
Definition: mss3.c:35
ff_mss34_gen_quant_mat
void ff_mss34_gen_quant_mat(uint16_t *qmat, int quality, int luma)
Generate quantisation matrix for given quality.
Definition: mss34dsp.c:27
Model256::upd_val
int upd_val
Definition: mss3.c:59
FF_CODEC_CAP_INIT_CLEANUP
#define FF_CODEC_CAP_INIT_CLEANUP
The codec allows calling the close function for deallocation even if the init function returned a fai...
Definition: codec_internal.h:42
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
Model2
Definition: mss3.c:41
ImageBlockCoder::esc_model
Model256 esc_model
Definition: mss3.c:89
ImageBlockCoder::vq_model
Model vq_model[125]
Definition: mss3.c:91
DCTBlockCoder::prev_dc_stride
ptrdiff_t prev_dc_stride
Definition: mss3.c:96
Model256::secondary
int secondary[68]
Definition: mss3.c:57
GetByteContext
Definition: bytestream.h:33
u
#define u(width, name, range_min, range_max)
Definition: cbs_h2645.c:251
HaarBlockCoder::coef_hi_model
Model coef_hi_model
Definition: mss3.c:108
DCTBlockCoder::dc_model
Model dc_model
Definition: mss3.c:100
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:160
DCTBlockCoder::ac_model
Model256 ac_model
Definition: mss3.c:102
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:374
MSS3Context
Definition: mss3.c:111
AVPacket::data
uint8_t * data
Definition: packet.h:524
ImageBlockCoder::vec_entry_model
Model256 vec_entry_model
Definition: mss3.c:89
FillBlockCoder
Definition: mss3.c:83
MSS3Context::got_error
int got_error
Definition: mss3.c:115
BlockType
BlockType
Definition: mss3.c:70
FFCodec
Definition: codec_internal.h:126
DCTBlockCoder::qmat
uint16_t qmat[64]
Definition: mss3.c:99
DCTBlockCoder::quality
int quality
Definition: mss3.c:98
fc
#define fc(width, name, range_min, range_max)
Definition: cbs_av1.c:464
t1
#define t1
Definition: regdef.h:29
Model::weights
int16_t weights[MODEL_MAX_SYMS+1]
Definition: mss12.h:42
Model256::till_rescale
int till_rescale
Definition: mss3.c:59
MSS3Context::haar_coder
HaarBlockCoder haar_coder[3]
Definition: mss3.c:121
model2_update
static void model2_update(Model2 *m, int bit)
Definition: mss3.c:138
quality
trying all byte sequences megabyte in length and selecting the best looking sequence will yield cases to try But a word about quality
Definition: rate_distortion.txt:12
MSS3Context::avctx
AVCodecContext * avctx
Definition: mss3.c:112
D
D(D(float, sse)
Definition: rematrix_init.c:30
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:30
MODEL256_SEC_SCALE
#define MODEL256_SEC_SCALE
Definition: mss3.c:39
bit
#define bit(string, value)
Definition: cbs_mpeg2.c:56
HaarBlockCoder::quality
int quality
Definition: mss3.c:106
bytestream2_skip
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:168
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:130
MSS3Context::dct_coder
DCTBlockCoder dct_coder[3]
Definition: mss3.c:120
val
static double val(void *priv, double ch)
Definition: aeval.c:78
Model256::max_upd_val
int max_upd_val
Definition: mss3.c:59
DCTBlockCoder::prev_dc
int * prev_dc
Definition: mss3.c:95
init_coders
static av_cold void init_coders(MSS3Context *ctx)
Definition: mss3.c:666
decode_image_block
static void decode_image_block(RangeCoder *c, ImageBlockCoder *ic, uint8_t *dst, ptrdiff_t stride, int block_size)
Definition: mss3.c:471
MSS3Context::btype
BlockTypeContext btype[3]
Definition: mss3.c:117
decode_block_type
static int decode_block_type(RangeCoder *c, BlockTypeContext *bt)
Definition: mss3.c:435
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:148
C
s EdgeDetect Foobar g libavfilter vf_edgedetect c libavfilter vf_foobar c edit libavfilter and add an entry for foobar following the pattern of the other filters edit libavfilter allfilters and add an entry for foobar following the pattern of the other filters configure make j< whatever > ffmpeg ffmpeg i you should get a foobar png with Lena edge detected That s your new playground is ready Some little details about what s going which in turn will define variables for the build system and the C
Definition: writing_filters.txt:58
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
model2_reset
static void model2_reset(Model2 *m)
Definition: mss3.c:128
av_cold
#define av_cold
Definition: attributes.h:90
AV_FRAME_FLAG_KEY
#define AV_FRAME_FLAG_KEY
A flag to mark frames that are keyframes.
Definition: frame.h:625
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:286
HaarBlockCoder::scale
int scale
Definition: mss3.c:106
rac_get_model2_sym
static int rac_get_model2_sym(RangeCoder *c, Model2 *m)
Definition: mss3.c:342
rac_get_model_sym
static int rac_get_model_sym(RangeCoder *c, Model *m)
Definition: mss3.c:363
mss3_decode_init
static av_cold int mss3_decode_init(AVCodecContext *avctx)
Definition: mss3.c:829
RangeCoder::got_error
int got_error
Definition: mss3.c:67
RangeCoder::src_end
const uint8_t * src_end
Definition: mss3.c:64
B
#define B
Definition: huffyuv.h:42
MODEL_SCALE
#define MODEL_SCALE
Definition: mss3.c:38
ctx
AVFormatContext * ctx
Definition: movenc.c:49
decode.h
FillBlockCoder::fill_val
int fill_val
Definition: mss3.c:84
rac_get_bit
static int rac_get_bit(RangeCoder *c)
Definition: mss3.c:312
AV_PIX_FMT_YUV420P
@ AV_PIX_FMT_YUV420P
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:73
SKIP_BLOCK
@ SKIP_BLOCK
Definition: mss3.c:75
HAAR_BLOCK
@ HAAR_BLOCK
Definition: mss3.c:74
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:271
FFABS
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:73
decode_haar_block
static void decode_haar_block(RangeCoder *c, HaarBlockCoder *hc, uint8_t *dst, ptrdiff_t stride, int block_size, int *block)
Definition: mss3.c:590
Model2::upd_val
int upd_val
Definition: mss3.c:42
rac_get_model256_sym
static int rac_get_model256_sym(RangeCoder *c, Model256 *m)
Definition: mss3.c:396
MODEL2_SCALE
#define MODEL2_SCALE
Definition: mss3.c:37
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:279
mathops.h
Model256
Definition: mss3.c:54
mss3_decode_end
static av_cold int mss3_decode_end(AVCodecContext *avctx)
Definition: mss3.c:817
MSS3Context::hblock
int hblock[16 *16]
Definition: mss3.c:124
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
decode_coeff
static int decode_coeff(RangeCoder *c, Model *m)
Definition: mss3.c:442
Model::upd_val
int upd_val
Definition: mss3.c:51
decode_dct
static int decode_dct(RangeCoder *c, DCTBlockCoder *bc, int *block, int bx, int by)
Definition: mss3.c:505
bytestream2_get_bytes_left
static av_always_inline int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:158
FILL_BLOCK
@ FILL_BLOCK
Definition: mss3.c:71
mss34dsp.h
BlockTypeContext::last_type
int last_type
Definition: mss3.c:79
MSS3Context::fill_coder
FillBlockCoder fill_coder[3]
Definition: mss3.c:118
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts.c:366
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:525
dc
Tag MUST be and< 10hcoeff half pel interpolation filter coefficients, hcoeff[0] are the 2 middle coefficients[1] are the next outer ones and so on, resulting in a filter like:...eff[2], hcoeff[1], hcoeff[0], hcoeff[0], hcoeff[1], hcoeff[2] ... the sign of the coefficients is not explicitly stored but alternates after each coeff and coeff[0] is positive, so ...,+,-,+,-,+,+,-,+,-,+,... hcoeff[0] is not explicitly stored but found by subtracting the sum of all stored coefficients with signs from 32 hcoeff[0]=32 - hcoeff[1] - hcoeff[2] - ... a good choice for hcoeff and htaps is htaps=6 hcoeff={40,-10, 2} an alternative which requires more computations at both encoder and decoder side and may or may not be better is htaps=8 hcoeff={42,-14, 6,-2}ref_frames minimum of the number of available reference frames and max_ref_frames for example the first frame after a key frame always has ref_frames=1spatial_decomposition_type wavelet type 0 is a 9/7 symmetric compact integer wavelet 1 is a 5/3 symmetric compact integer wavelet others are reserved stored as delta from last, last is reset to 0 if always_reset||keyframeqlog quality(logarithmic quantizer scale) stored as delta from last, last is reset to 0 if always_reset||keyframemv_scale stored as delta from last, last is reset to 0 if always_reset||keyframe FIXME check that everything works fine if this changes between framesqbias dequantization bias stored as delta from last, last is reset to 0 if always_reset||keyframeblock_max_depth maximum depth of the block tree stored as delta from last, last is reset to 0 if always_reset||keyframequant_table quantization tableHighlevel bitstream structure:==============================--------------------------------------------|Header|--------------------------------------------|------------------------------------|||Block0||||split?||||yes no||||......... intra?||||:Block01 :yes no||||:Block02 :....... ..........||||:Block03 ::y DC ::ref index:||||:Block04 ::cb DC ::motion x :||||......... :cr DC ::motion y :||||....... ..........|||------------------------------------||------------------------------------|||Block1|||...|--------------------------------------------|------------ ------------ ------------|||Y subbands||Cb subbands||Cr subbands||||--- ---||--- ---||--- ---|||||LL0||HL0||||LL0||HL0||||LL0||HL0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||LH0||HH0||||LH0||HH0||||LH0||HH0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HL1||LH1||||HL1||LH1||||HL1||LH1|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HH1||HL2||||HH1||HL2||||HH1||HL2|||||...||...||...|||------------ ------------ ------------|--------------------------------------------Decoding process:=================------------|||Subbands|------------||||------------|Intra DC||||LL0 subband prediction ------------|\ Dequantization ------------------- \||Reference frames|\ IDWT|------- -------|Motion \|||Frame 0||Frame 1||Compensation . OBMC v -------|------- -------|--------------. \------> Frame n output Frame Frame<----------------------------------/|...|------------------- Range Coder:============Binary Range Coder:------------------- The implemented range coder is an adapted version based upon "Range encoding: an algorithm for removing redundancy from a digitised message." by G. N. N. Martin. The symbols encoded by the Snow range coder are bits(0|1). The associated probabilities are not fix but change depending on the symbol mix seen so far. bit seen|new state ---------+----------------------------------------------- 0|256 - state_transition_table[256 - old_state];1|state_transition_table[old_state];state_transition_table={ 0, 0, 0, 0, 0, 0, 0, 0, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 190, 191, 192, 194, 194, 195, 196, 197, 198, 199, 200, 201, 202, 202, 204, 205, 206, 207, 208, 209, 209, 210, 211, 212, 213, 215, 215, 216, 217, 218, 219, 220, 220, 222, 223, 224, 225, 226, 227, 227, 229, 229, 230, 231, 232, 234, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 248, 0, 0, 0, 0, 0, 0, 0};FIXME Range Coding of integers:------------------------- FIXME Neighboring Blocks:===================left and top are set to the respective blocks unless they are outside of the image in which case they are set to the Null block top-left is set to the top left block unless it is outside of the image in which case it is set to the left block if this block has no larger parent block or it is at the left side of its parent block and the top right block is not outside of the image then the top right block is used for top-right else the top-left block is used Null block y, cb, cr are 128 level, ref, mx and my are 0 Motion Vector Prediction:=========================1. the motion vectors of all the neighboring blocks are scaled to compensate for the difference of reference frames scaled_mv=(mv *(256 *(current_reference+1)/(mv.reference+1))+128)> the median of the scaled top and top right vectors is used as motion vector prediction the used motion vector is the sum of the predictor and(mvx_diff, mvy_diff) *mv_scale Intra DC Prediction block[y][x] dc[1]
Definition: snow.txt:400
RangeCoder::src
const uint8_t * src
Definition: mss3.c:64
av_frame_ref
int av_frame_ref(AVFrame *dst, const AVFrame *src)
Set up a new reference to the data described by the source frame.
Definition: frame.c:384
codec_internal.h
size
int size
Definition: twinvq_data.h:10344
RAC_BOTTOM
#define RAC_BOTTOM
Definition: mss3.c:62
model256_init
static av_cold void model256_init(Model256 *m)
Definition: mss3.c:271
BlockTypeContext
Definition: mss3.c:78
MSS3Context::coder
RangeCoder coder
Definition: mss3.c:116
IMAGE_BLOCK
@ IMAGE_BLOCK
Definition: mss3.c:72
HaarBlockCoder::coef_model
Model256 coef_model
Definition: mss3.c:107
rac_normalise
static void rac_normalise(RangeCoder *c)
Definition: mss3.c:292
DCTBlockCoder::prev_dc_height
int prev_dc_height
Definition: mss3.c:97
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
t4
#define t4
Definition: regdef.h:32
t3
#define t3
Definition: regdef.h:31
FillBlockCoder::coef_model
Model coef_model
Definition: mss3.c:85
Model::tot_weight
int tot_weight
Definition: mss3.c:50
Model2::total_freq
unsigned total_freq
Definition: mss3.c:44
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
Model256::freqs
int freqs[256]
Definition: mss3.c:55
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:194
MSS3Context::pic
AVFrame * pic
Definition: mss3.c:113
Model::num_syms
int num_syms
Definition: mss12.h:44
AVCodecContext::height
int height
Definition: avcodec.h:618
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:657
avcodec.h
stride
#define stride
Definition: h264pred_template.c:537
ff_zigzag_direct
const uint8_t ff_zigzag_direct[64]
Definition: mathtables.c:98
ff_msa1_decoder
const FFCodec ff_msa1_decoder
Definition: mss3.c:867
ff_reget_buffer
int ff_reget_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Identical in function to ff_get_buffer(), except it reuses the existing buffer if available.
Definition: decode.c:1684
ret
ret
Definition: filter_design.txt:187
model_reset
static void model_reset(Model *m)
Definition: mss3.c:194
prob
#define prob(name, subs,...)
Definition: cbs_vp9.c:325
pos
unsigned int pos
Definition: spdifenc.c:414
AVCodecContext
main external API structure.
Definition: avcodec.h:445
t2
#define t2
Definition: regdef.h:30
decode_dct_block
static void decode_dct_block(RangeCoder *c, DCTBlockCoder *bc, uint8_t *dst, ptrdiff_t stride, int block_size, int *block, int mb_x, int mb_y)
Definition: mss3.c:567
Model256::tot_weight
int tot_weight
Definition: mss3.c:56
DCTBlockCoder::sign_model
Model2 sign_model
Definition: mss3.c:101
DCTBlockCoder
Definition: mss3.c:94
MSS3Context::dctblock
int dctblock[64]
Definition: mss3.c:123
AV_CODEC_ID_MSA1
@ AV_CODEC_ID_MSA1
Definition: codec_id.h:215
Model::max_upd_val
int max_upd_val
Definition: mss3.c:51
av_clip_uint8
#define av_clip_uint8
Definition: common.h:105
model256_reset
static void model256_reset(Model256 *m)
Definition: mss3.c:255
AV_PICTURE_TYPE_P
@ AV_PICTURE_TYPE_P
Predicted.
Definition: avutil.h:280
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
mem.h
Model::till_rescale
int till_rescale
Definition: mss3.c:51
RangeCoder::low
uint32_t low
Definition: mss3.c:66
Model2::total_weight
unsigned total_weight
Definition: mss3.c:44
scale
static void scale(int *out, const int *in, const int w, const int h, const int shift)
Definition: intra.c:291
reset_coders
static void reset_coders(MSS3Context *ctx, int quality)
Definition: mss3.c:631
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:472
AVPacket
This structure stores compressed data.
Definition: packet.h:501
Model2::zero_freq
unsigned zero_freq
Definition: mss3.c:43
Model
Definition: mss12.h:40
Model256::sec_size
int sec_size
Definition: mss3.c:58
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
src
INIT_CLIP pixel * src
Definition: h264pred_template.c:418
HaarBlockCoder
Definition: mss3.c:105
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:618
Model2::zero_weight
unsigned zero_weight
Definition: mss3.c:43
bytestream.h
model256_update
static void model256_update(Model256 *m, int val)
Definition: mss3.c:218
Model2::till_rescale
int till_rescale
Definition: mss3.c:42
bytestream2_init
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:137
Model::freqs
int freqs[16]
Definition: mss3.c:48
block
The exact code depends on how similar the blocks are and how related they are to the block
Definition: filter_design.txt:207
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
decode_fill_block
static void decode_fill_block(RangeCoder *c, FillBlockCoder *fc, uint8_t *dst, ptrdiff_t stride, int block_size)
Definition: mss3.c:460
ImageBlockCoder::vec_size_model
Model vec_size_model
Definition: mss3.c:90
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
rac_get_bits
static int rac_get_bits(RangeCoder *c, int nbits)
Definition: mss3.c:328
RangeCoder
Definition: mss3.c:63
ImageBlockCoder
Definition: mss3.c:88
mss3_decode_frame
static int mss3_decode_frame(AVCodecContext *avctx, AVFrame *rframe, int *got_frame, AVPacket *avpkt)
Definition: mss3.c:686
DCT_BLOCK
@ DCT_BLOCK
Definition: mss3.c:73
Model256::weights
int weights[256]
Definition: mss3.c:55
ff_mss34_dct_put
void ff_mss34_dct_put(uint8_t *dst, ptrdiff_t stride, int *block)
Transform and output DCT block.
Definition: mss34dsp.c:69
MSS3Context::image_coder
ImageBlockCoder image_coder[3]
Definition: mss3.c:119
model_update
static void model_update(Model *m, int val)
Definition: mss3.c:164
skip
static void BS_FUNC() skip(BSCTX *bc, unsigned int n)
Skip n bits in the buffer.
Definition: bitstream_template.h:375
model_init
static av_cold void model_init(Model *m, int num_syms)
Definition: mss3.c:210
BlockTypeContext::bt_model
Model bt_model[5]
Definition: mss3.c:80
rac_init
static void rac_init(RangeCoder *c, const uint8_t *src, int size)
Definition: mss3.c:279