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golomb.h
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1 /*
2  * exp golomb vlc stuff
3  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
4  * Copyright (c) 2004 Alex Beregszaszi
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /**
24  * @file
25  * @brief
26  * exp golomb vlc stuff
27  * @author Michael Niedermayer <michaelni@gmx.at> and Alex Beregszaszi
28  */
29 
30 #ifndef AVCODEC_GOLOMB_H
31 #define AVCODEC_GOLOMB_H
32 
33 #include <stdint.h>
34 
35 #include "get_bits.h"
36 #include "put_bits.h"
37 
38 #define INVALID_VLC 0x80000000
39 
40 extern const uint8_t ff_golomb_vlc_len[512];
41 extern const uint8_t ff_ue_golomb_vlc_code[512];
42 extern const int8_t ff_se_golomb_vlc_code[512];
43 extern const uint8_t ff_ue_golomb_len[256];
44 
45 extern const uint8_t ff_interleaved_golomb_vlc_len[256];
46 extern const uint8_t ff_interleaved_ue_golomb_vlc_code[256];
47 extern const int8_t ff_interleaved_se_golomb_vlc_code[256];
48 extern const uint8_t ff_interleaved_dirac_golomb_vlc_code[256];
49 
50 /**
51  * read unsigned exp golomb code.
52  */
53 static inline int get_ue_golomb(GetBitContext *gb)
54 {
55  unsigned int buf;
56 
57  OPEN_READER(re, gb);
58  UPDATE_CACHE(re, gb);
59  buf = GET_CACHE(re, gb);
60 
61  if (buf >= (1 << 27)) {
62  buf >>= 32 - 9;
63  LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
64  CLOSE_READER(re, gb);
65 
66  return ff_ue_golomb_vlc_code[buf];
67  } else {
68  int log = 2 * av_log2(buf) - 31;
69  LAST_SKIP_BITS(re, gb, 32 - log);
70  CLOSE_READER(re, gb);
71  if (CONFIG_FTRAPV && log < 0) {
72  av_log(0, AV_LOG_ERROR, "Invalid UE golomb code\n");
73  return AVERROR_INVALIDDATA;
74  }
75  buf >>= log;
76  buf--;
77 
78  return buf;
79  }
80 }
81 
82 /**
83  * Read an unsigned Exp-Golomb code in the range 0 to UINT32_MAX-1.
84  */
85 static inline unsigned get_ue_golomb_long(GetBitContext *gb)
86 {
87  unsigned buf, log;
88 
89  buf = show_bits_long(gb, 32);
90  log = 31 - av_log2(buf);
91  skip_bits_long(gb, log);
92 
93  return get_bits_long(gb, log + 1) - 1;
94 }
95 
96 /**
97  * read unsigned exp golomb code, constraint to a max of 31.
98  * the return value is undefined if the stored value exceeds 31.
99  */
100 static inline int get_ue_golomb_31(GetBitContext *gb)
101 {
102  unsigned int buf;
103 
104  OPEN_READER(re, gb);
105  UPDATE_CACHE(re, gb);
106  buf = GET_CACHE(re, gb);
107 
108  buf >>= 32 - 9;
109  LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
110  CLOSE_READER(re, gb);
111 
112  return ff_ue_golomb_vlc_code[buf];
113 }
114 
115 static inline unsigned svq3_get_ue_golomb(GetBitContext *gb)
116 {
117  uint32_t buf;
118 
119  OPEN_READER(re, gb);
120  UPDATE_CACHE(re, gb);
121  buf = GET_CACHE(re, gb);
122 
123  if (buf & 0xAA800000) {
124  buf >>= 32 - 8;
125  LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
126  CLOSE_READER(re, gb);
127 
128  return ff_interleaved_ue_golomb_vlc_code[buf];
129  } else {
130  unsigned ret = 1;
131 
132  do {
133  buf >>= 32 - 8;
134  LAST_SKIP_BITS(re, gb,
135  FFMIN(ff_interleaved_golomb_vlc_len[buf], 8));
136 
137  if (ff_interleaved_golomb_vlc_len[buf] != 9) {
138  ret <<= (ff_interleaved_golomb_vlc_len[buf] - 1) >> 1;
139  ret |= ff_interleaved_dirac_golomb_vlc_code[buf];
140  break;
141  }
142  ret = (ret << 4) | ff_interleaved_dirac_golomb_vlc_code[buf];
143  UPDATE_CACHE(re, gb);
144  buf = GET_CACHE(re, gb);
145  } while (ret<0x8000000U && HAVE_BITS_REMAINING(re, gb));
146 
147  CLOSE_READER(re, gb);
148  return ret - 1;
149  }
150 }
151 
152 /**
153  * read unsigned truncated exp golomb code.
154  */
155 static inline int get_te0_golomb(GetBitContext *gb, int range)
156 {
157  av_assert2(range >= 1);
158 
159  if (range == 1)
160  return 0;
161  else if (range == 2)
162  return get_bits1(gb) ^ 1;
163  else
164  return get_ue_golomb(gb);
165 }
166 
167 /**
168  * read unsigned truncated exp golomb code.
169  */
170 static inline int get_te_golomb(GetBitContext *gb, int range)
171 {
172  av_assert2(range >= 1);
173 
174  if (range == 2)
175  return get_bits1(gb) ^ 1;
176  else
177  return get_ue_golomb(gb);
178 }
179 
180 /**
181  * read signed exp golomb code.
182  */
183 static inline int get_se_golomb(GetBitContext *gb)
184 {
185  unsigned int buf;
186 
187  OPEN_READER(re, gb);
188  UPDATE_CACHE(re, gb);
189  buf = GET_CACHE(re, gb);
190 
191  if (buf >= (1 << 27)) {
192  buf >>= 32 - 9;
193  LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
194  CLOSE_READER(re, gb);
195 
196  return ff_se_golomb_vlc_code[buf];
197  } else {
198  int log = av_log2(buf);
199  LAST_SKIP_BITS(re, gb, 31 - log);
200  UPDATE_CACHE(re, gb);
201  buf = GET_CACHE(re, gb);
202 
203  buf >>= log;
204 
205  LAST_SKIP_BITS(re, gb, 32 - log);
206  CLOSE_READER(re, gb);
207 
208  if (buf & 1)
209  buf = -(buf >> 1);
210  else
211  buf = (buf >> 1);
212 
213  return buf;
214  }
215 }
216 
217 static inline int svq3_get_se_golomb(GetBitContext *gb)
218 {
219  unsigned int buf;
220 
221  OPEN_READER(re, gb);
222  UPDATE_CACHE(re, gb);
223  buf = GET_CACHE(re, gb);
224 
225  if (buf & 0xAA800000) {
226  buf >>= 32 - 8;
227  LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
228  CLOSE_READER(re, gb);
229 
230  return ff_interleaved_se_golomb_vlc_code[buf];
231  } else {
232  int log;
233  LAST_SKIP_BITS(re, gb, 8);
234  UPDATE_CACHE(re, gb);
235  buf |= 1 | (GET_CACHE(re, gb) >> 8);
236 
237  if ((buf & 0xAAAAAAAA) == 0)
238  return INVALID_VLC;
239 
240  for (log = 31; (buf & 0x80000000) == 0; log--)
241  buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
242 
243  LAST_SKIP_BITS(re, gb, 63 - 2 * log - 8);
244  CLOSE_READER(re, gb);
245 
246  return (signed) (((((buf << log) >> log) - 1) ^ -(buf & 0x1)) + 1) >> 1;
247  }
248 }
249 
250 static inline int dirac_get_se_golomb(GetBitContext *gb)
251 {
252  uint32_t ret = svq3_get_ue_golomb(gb);
253 
254  if (ret) {
255  uint32_t buf;
256  OPEN_READER(re, gb);
257  UPDATE_CACHE(re, gb);
258  buf = SHOW_SBITS(re, gb, 1);
259  LAST_SKIP_BITS(re, gb, 1);
260  ret = (ret ^ buf) - buf;
261  CLOSE_READER(re, gb);
262  }
263 
264  return ret;
265 }
266 
267 /**
268  * read unsigned golomb rice code (ffv1).
269  */
270 static inline int get_ur_golomb(GetBitContext *gb, int k, int limit,
271  int esc_len)
272 {
273  unsigned int buf;
274  int log;
275 
276  OPEN_READER(re, gb);
277  UPDATE_CACHE(re, gb);
278  buf = GET_CACHE(re, gb);
279 
280  log = av_log2(buf);
281 
282  if (log > 31 - limit) {
283  buf >>= log - k;
284  buf += (30 - log) << k;
285  LAST_SKIP_BITS(re, gb, 32 + k - log);
286  CLOSE_READER(re, gb);
287 
288  return buf;
289  } else {
290  LAST_SKIP_BITS(re, gb, limit);
291  UPDATE_CACHE(re, gb);
292 
293  buf = SHOW_UBITS(re, gb, esc_len);
294 
295  LAST_SKIP_BITS(re, gb, esc_len);
296  CLOSE_READER(re, gb);
297 
298  return buf + limit - 1;
299  }
300 }
301 
302 /**
303  * read unsigned golomb rice code (jpegls).
304  */
305 static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit,
306  int esc_len)
307 {
308  unsigned int buf;
309  int log;
310 
311  OPEN_READER(re, gb);
312  UPDATE_CACHE(re, gb);
313  buf = GET_CACHE(re, gb);
314 
315  log = av_log2(buf);
316 
317  if (log - k >= 32 - MIN_CACHE_BITS + (MIN_CACHE_BITS == 32) &&
318  32 - log < limit) {
319  buf >>= log - k;
320  buf += (30 - log) << k;
321  LAST_SKIP_BITS(re, gb, 32 + k - log);
322  CLOSE_READER(re, gb);
323 
324  return buf;
325  } else {
326  int i;
327  for (i = 0; i < limit && SHOW_UBITS(re, gb, 1) == 0; i++) {
328  if (gb->size_in_bits <= re_index)
329  return -1;
330  LAST_SKIP_BITS(re, gb, 1);
331  UPDATE_CACHE(re, gb);
332  }
333  SKIP_BITS(re, gb, 1);
334 
335  if (i < limit - 1) {
336  if (k) {
337  buf = SHOW_UBITS(re, gb, k);
338  LAST_SKIP_BITS(re, gb, k);
339  } else {
340  buf = 0;
341  }
342 
343  CLOSE_READER(re, gb);
344  return buf + (i << k);
345  } else if (i == limit - 1) {
346  buf = SHOW_UBITS(re, gb, esc_len);
347  LAST_SKIP_BITS(re, gb, esc_len);
348  CLOSE_READER(re, gb);
349 
350  return buf + 1;
351  } else
352  return -1;
353  }
354 }
355 
356 /**
357  * read signed golomb rice code (ffv1).
358  */
359 static inline int get_sr_golomb(GetBitContext *gb, int k, int limit,
360  int esc_len)
361 {
362  int v = get_ur_golomb(gb, k, limit, esc_len);
363 
364  v++;
365  if (v & 1)
366  return v >> 1;
367  else
368  return -(v >> 1);
369 
370 // return (v>>1) ^ -(v&1);
371 }
372 
373 /**
374  * read signed golomb rice code (flac).
375  */
376 static inline int get_sr_golomb_flac(GetBitContext *gb, int k, int limit,
377  int esc_len)
378 {
379  int v = get_ur_golomb_jpegls(gb, k, limit, esc_len);
380  return (v >> 1) ^ -(v & 1);
381 }
382 
383 /**
384  * read unsigned golomb rice code (shorten).
385  */
386 static inline unsigned int get_ur_golomb_shorten(GetBitContext *gb, int k)
387 {
388  return get_ur_golomb_jpegls(gb, k, INT_MAX, 0);
389 }
390 
391 /**
392  * read signed golomb rice code (shorten).
393  */
394 static inline int get_sr_golomb_shorten(GetBitContext *gb, int k)
395 {
396  int uvar = get_ur_golomb_jpegls(gb, k + 1, INT_MAX, 0);
397  if (uvar & 1)
398  return ~(uvar >> 1);
399  else
400  return uvar >> 1;
401 }
402 
403 #ifdef TRACE
404 
405 static inline int get_ue(GetBitContext *s, const char *file, const char *func,
406  int line)
407 {
408  int show = show_bits(s, 24);
409  int pos = get_bits_count(s);
410  int i = get_ue_golomb(s);
411  int len = get_bits_count(s) - pos;
412  int bits = show >> (24 - len);
413 
414  print_bin(bits, len);
415 
416  av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d ue @%5d in %s %s:%d\n",
417  bits, len, i, pos, file, func, line);
418 
419  return i;
420 }
421 
422 static inline int get_se(GetBitContext *s, const char *file, const char *func,
423  int line)
424 {
425  int show = show_bits(s, 24);
426  int pos = get_bits_count(s);
427  int i = get_se_golomb(s);
428  int len = get_bits_count(s) - pos;
429  int bits = show >> (24 - len);
430 
431  print_bin(bits, len);
432 
433  av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d se @%5d in %s %s:%d\n",
434  bits, len, i, pos, file, func, line);
435 
436  return i;
437 }
438 
439 static inline int get_te(GetBitContext *s, int r, char *file, const char *func,
440  int line)
441 {
442  int show = show_bits(s, 24);
443  int pos = get_bits_count(s);
444  int i = get_te0_golomb(s, r);
445  int len = get_bits_count(s) - pos;
446  int bits = show >> (24 - len);
447 
448  print_bin(bits, len);
449 
450  av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d te @%5d in %s %s:%d\n",
451  bits, len, i, pos, file, func, line);
452 
453  return i;
454 }
455 
456 #define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
457 #define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
458 #define get_te_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
459 #define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
460 
461 #endif /* TRACE */
462 
463 /**
464  * write unsigned exp golomb code.
465  */
466 static inline void set_ue_golomb(PutBitContext *pb, int i)
467 {
468  av_assert2(i >= 0);
469 
470 #if 0
471  if (i = 0) {
472  put_bits(pb, 1, 1);
473  return;
474  }
475 #endif
476  if (i < 256)
477  put_bits(pb, ff_ue_golomb_len[i], i + 1);
478  else {
479  int e = av_log2(i + 1);
480  put_bits(pb, 2 * e + 1, i + 1);
481  }
482 }
483 
484 /**
485  * write truncated unsigned exp golomb code.
486  */
487 static inline void set_te_golomb(PutBitContext *pb, int i, int range)
488 {
489  av_assert2(range >= 1);
490  av_assert2(i <= range);
491 
492  if (range == 2)
493  put_bits(pb, 1, i ^ 1);
494  else
495  set_ue_golomb(pb, i);
496 }
497 
498 /**
499  * write signed exp golomb code. 16 bits at most.
500  */
501 static inline void set_se_golomb(PutBitContext *pb, int i)
502 {
503 #if 0
504  if (i <= 0)
505  i = -2 * i;
506  else
507  i = 2 * i - 1;
508 #elif 1
509  i = 2 * i - 1;
510  if (i < 0)
511  i ^= -1; //FIXME check if gcc does the right thing
512 #else
513  i = 2 * i - 1;
514  i ^= (i >> 31);
515 #endif
516  set_ue_golomb(pb, i);
517 }
518 
519 /**
520  * write unsigned golomb rice code (ffv1).
521  */
522 static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit,
523  int esc_len)
524 {
525  int e;
526 
527  av_assert2(i >= 0);
528 
529  e = i >> k;
530  if (e < limit)
531  put_bits(pb, e + k + 1, (1 << k) + (i & ((1 << k) - 1)));
532  else
533  put_bits(pb, limit + esc_len, i - limit + 1);
534 }
535 
536 /**
537  * write unsigned golomb rice code (jpegls).
538  */
539 static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k,
540  int limit, int esc_len)
541 {
542  int e;
543 
544  av_assert2(i >= 0);
545 
546  e = (i >> k) + 1;
547  if (e < limit) {
548  while (e > 31) {
549  put_bits(pb, 31, 0);
550  e -= 31;
551  }
552  put_bits(pb, e, 1);
553  if (k)
554  put_sbits(pb, k, i);
555  } else {
556  while (limit > 31) {
557  put_bits(pb, 31, 0);
558  limit -= 31;
559  }
560  put_bits(pb, limit, 1);
561  put_bits(pb, esc_len, i - 1);
562  }
563 }
564 
565 /**
566  * write signed golomb rice code (ffv1).
567  */
568 static inline void set_sr_golomb(PutBitContext *pb, int i, int k, int limit,
569  int esc_len)
570 {
571  int v;
572 
573  v = -2 * i - 1;
574  v ^= (v >> 31);
575 
576  set_ur_golomb(pb, v, k, limit, esc_len);
577 }
578 
579 /**
580  * write signed golomb rice code (flac).
581  */
582 static inline void set_sr_golomb_flac(PutBitContext *pb, int i, int k,
583  int limit, int esc_len)
584 {
585  int v;
586 
587  v = -2 * i - 1;
588  v ^= (v >> 31);
589 
590  set_ur_golomb_jpegls(pb, v, k, limit, esc_len);
591 }
592 
593 #endif /* AVCODEC_GOLOMB_H */
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