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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 && BITS_AVAILABLE(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 get_se_golomb_long(GetBitContext *gb)
218 {
219  unsigned int buf = get_ue_golomb_long(gb);
220 
221  if (buf & 1)
222  buf = (buf + 1) >> 1;
223  else
224  buf = -(buf >> 1);
225 
226  return buf;
227 }
228 
229 static inline int svq3_get_se_golomb(GetBitContext *gb)
230 {
231  unsigned int buf;
232 
233  OPEN_READER(re, gb);
234  UPDATE_CACHE(re, gb);
235  buf = GET_CACHE(re, gb);
236 
237  if (buf & 0xAA800000) {
238  buf >>= 32 - 8;
239  LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
240  CLOSE_READER(re, gb);
241 
242  return ff_interleaved_se_golomb_vlc_code[buf];
243  } else {
244  int log;
245  LAST_SKIP_BITS(re, gb, 8);
246  UPDATE_CACHE(re, gb);
247  buf |= 1 | (GET_CACHE(re, gb) >> 8);
248 
249  if ((buf & 0xAAAAAAAA) == 0)
250  return INVALID_VLC;
251 
252  for (log = 31; (buf & 0x80000000) == 0; log--)
253  buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
254 
255  LAST_SKIP_BITS(re, gb, 63 - 2 * log - 8);
256  CLOSE_READER(re, gb);
257 
258  return (signed) (((((buf << log) >> log) - 1) ^ -(buf & 0x1)) + 1) >> 1;
259  }
260 }
261 
262 static inline int dirac_get_se_golomb(GetBitContext *gb)
263 {
264  uint32_t ret = svq3_get_ue_golomb(gb);
265 
266  if (ret) {
267  uint32_t buf;
268  OPEN_READER(re, gb);
269  UPDATE_CACHE(re, gb);
270  buf = SHOW_SBITS(re, gb, 1);
271  LAST_SKIP_BITS(re, gb, 1);
272  ret = (ret ^ buf) - buf;
273  CLOSE_READER(re, gb);
274  }
275 
276  return ret;
277 }
278 
279 /**
280  * read unsigned golomb rice code (ffv1).
281  */
282 static inline int get_ur_golomb(GetBitContext *gb, int k, int limit,
283  int esc_len)
284 {
285  unsigned int buf;
286  int log;
287 
288  OPEN_READER(re, gb);
289  UPDATE_CACHE(re, gb);
290  buf = GET_CACHE(re, gb);
291 
292  log = av_log2(buf);
293 
294  if (log > 31 - limit) {
295  buf >>= log - k;
296  buf += (30 - log) << k;
297  LAST_SKIP_BITS(re, gb, 32 + k - log);
298  CLOSE_READER(re, gb);
299 
300  return buf;
301  } else {
302  LAST_SKIP_BITS(re, gb, limit);
303  UPDATE_CACHE(re, gb);
304 
305  buf = SHOW_UBITS(re, gb, esc_len);
306 
307  LAST_SKIP_BITS(re, gb, esc_len);
308  CLOSE_READER(re, gb);
309 
310  return buf + limit - 1;
311  }
312 }
313 
314 /**
315  * read unsigned golomb rice code (jpegls).
316  */
317 static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit,
318  int esc_len)
319 {
320  unsigned int buf;
321  int log;
322 
323  OPEN_READER(re, gb);
324  UPDATE_CACHE(re, gb);
325  buf = GET_CACHE(re, gb);
326 
327  log = av_log2(buf);
328 
329  if (log - k >= 32 - MIN_CACHE_BITS + (MIN_CACHE_BITS == 32) &&
330  32 - log < limit) {
331  buf >>= log - k;
332  buf += (30 - log) << k;
333  LAST_SKIP_BITS(re, gb, 32 + k - log);
334  CLOSE_READER(re, gb);
335 
336  return buf;
337  } else {
338  int i;
339  for (i = 0; i < limit && SHOW_UBITS(re, gb, 1) == 0; i++) {
340  if (gb->size_in_bits <= re_index)
341  return -1;
342  LAST_SKIP_BITS(re, gb, 1);
343  UPDATE_CACHE(re, gb);
344  }
345  SKIP_BITS(re, gb, 1);
346 
347  if (i < limit - 1) {
348  if (k) {
349  buf = SHOW_UBITS(re, gb, k);
350  LAST_SKIP_BITS(re, gb, k);
351  } else {
352  buf = 0;
353  }
354 
355  CLOSE_READER(re, gb);
356  return buf + (i << k);
357  } else if (i == limit - 1) {
358  buf = SHOW_UBITS(re, gb, esc_len);
359  LAST_SKIP_BITS(re, gb, esc_len);
360  CLOSE_READER(re, gb);
361 
362  return buf + 1;
363  } else
364  return -1;
365  }
366 }
367 
368 /**
369  * read signed golomb rice code (ffv1).
370  */
371 static inline int get_sr_golomb(GetBitContext *gb, int k, int limit,
372  int esc_len)
373 {
374  int v = get_ur_golomb(gb, k, limit, esc_len);
375 
376  v++;
377  if (v & 1)
378  return v >> 1;
379  else
380  return -(v >> 1);
381 
382 // return (v>>1) ^ -(v&1);
383 }
384 
385 /**
386  * read signed golomb rice code (flac).
387  */
388 static inline int get_sr_golomb_flac(GetBitContext *gb, int k, int limit,
389  int esc_len)
390 {
391  int v = get_ur_golomb_jpegls(gb, k, limit, esc_len);
392  return (v >> 1) ^ -(v & 1);
393 }
394 
395 /**
396  * read unsigned golomb rice code (shorten).
397  */
398 static inline unsigned int get_ur_golomb_shorten(GetBitContext *gb, int k)
399 {
400  return get_ur_golomb_jpegls(gb, k, INT_MAX, 0);
401 }
402 
403 /**
404  * read signed golomb rice code (shorten).
405  */
406 static inline int get_sr_golomb_shorten(GetBitContext *gb, int k)
407 {
408  int uvar = get_ur_golomb_jpegls(gb, k + 1, INT_MAX, 0);
409  if (uvar & 1)
410  return ~(uvar >> 1);
411  else
412  return uvar >> 1;
413 }
414 
415 #ifdef TRACE
416 
417 static inline int get_ue(GetBitContext *s, const char *file, const char *func,
418  int line)
419 {
420  int show = show_bits(s, 24);
421  int pos = get_bits_count(s);
422  int i = get_ue_golomb(s);
423  int len = get_bits_count(s) - pos;
424  int bits = show >> (24 - len);
425 
426  print_bin(bits, len);
427 
428  av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d ue @%5d in %s %s:%d\n",
429  bits, len, i, pos, file, func, line);
430 
431  return i;
432 }
433 
434 static inline int get_se(GetBitContext *s, const char *file, const char *func,
435  int line)
436 {
437  int show = show_bits(s, 24);
438  int pos = get_bits_count(s);
439  int i = get_se_golomb(s);
440  int len = get_bits_count(s) - pos;
441  int bits = show >> (24 - len);
442 
443  print_bin(bits, len);
444 
445  av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d se @%5d in %s %s:%d\n",
446  bits, len, i, pos, file, func, line);
447 
448  return i;
449 }
450 
451 static inline int get_te(GetBitContext *s, int r, char *file, const char *func,
452  int line)
453 {
454  int show = show_bits(s, 24);
455  int pos = get_bits_count(s);
456  int i = get_te0_golomb(s, r);
457  int len = get_bits_count(s) - pos;
458  int bits = show >> (24 - len);
459 
460  print_bin(bits, len);
461 
462  av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d te @%5d in %s %s:%d\n",
463  bits, len, i, pos, file, func, line);
464 
465  return i;
466 }
467 
468 #define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
469 #define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
470 #define get_te_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
471 #define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
472 
473 #endif /* TRACE */
474 
475 /**
476  * write unsigned exp golomb code.
477  */
478 static inline void set_ue_golomb(PutBitContext *pb, int i)
479 {
480  av_assert2(i >= 0);
481 
482 #if 0
483  if (i = 0) {
484  put_bits(pb, 1, 1);
485  return;
486  }
487 #endif
488  if (i < 256)
489  put_bits(pb, ff_ue_golomb_len[i], i + 1);
490  else {
491  int e = av_log2(i + 1);
492  put_bits(pb, 2 * e + 1, i + 1);
493  }
494 }
495 
496 /**
497  * write truncated unsigned exp golomb code.
498  */
499 static inline void set_te_golomb(PutBitContext *pb, int i, int range)
500 {
501  av_assert2(range >= 1);
502  av_assert2(i <= range);
503 
504  if (range == 2)
505  put_bits(pb, 1, i ^ 1);
506  else
507  set_ue_golomb(pb, i);
508 }
509 
510 /**
511  * write signed exp golomb code. 16 bits at most.
512  */
513 static inline void set_se_golomb(PutBitContext *pb, int i)
514 {
515 #if 0
516  if (i <= 0)
517  i = -2 * i;
518  else
519  i = 2 * i - 1;
520 #elif 1
521  i = 2 * i - 1;
522  if (i < 0)
523  i ^= -1; //FIXME check if gcc does the right thing
524 #else
525  i = 2 * i - 1;
526  i ^= (i >> 31);
527 #endif
528  set_ue_golomb(pb, i);
529 }
530 
531 /**
532  * write unsigned golomb rice code (ffv1).
533  */
534 static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit,
535  int esc_len)
536 {
537  int e;
538 
539  av_assert2(i >= 0);
540 
541  e = i >> k;
542  if (e < limit)
543  put_bits(pb, e + k + 1, (1 << k) + (i & ((1 << k) - 1)));
544  else
545  put_bits(pb, limit + esc_len, i - limit + 1);
546 }
547 
548 /**
549  * write unsigned golomb rice code (jpegls).
550  */
551 static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k,
552  int limit, int esc_len)
553 {
554  int e;
555 
556  av_assert2(i >= 0);
557 
558  e = (i >> k) + 1;
559  if (e < limit) {
560  while (e > 31) {
561  put_bits(pb, 31, 0);
562  e -= 31;
563  }
564  put_bits(pb, e, 1);
565  if (k)
566  put_sbits(pb, k, i);
567  } else {
568  while (limit > 31) {
569  put_bits(pb, 31, 0);
570  limit -= 31;
571  }
572  put_bits(pb, limit, 1);
573  put_bits(pb, esc_len, i - 1);
574  }
575 }
576 
577 /**
578  * write signed golomb rice code (ffv1).
579  */
580 static inline void set_sr_golomb(PutBitContext *pb, int i, int k, int limit,
581  int esc_len)
582 {
583  int v;
584 
585  v = -2 * i - 1;
586  v ^= (v >> 31);
587 
588  set_ur_golomb(pb, v, k, limit, esc_len);
589 }
590 
591 /**
592  * write signed golomb rice code (flac).
593  */
594 static inline void set_sr_golomb_flac(PutBitContext *pb, int i, int k,
595  int limit, int esc_len)
596 {
597  int v;
598 
599  v = -2 * i - 1;
600  v ^= (v >> 31);
601 
602  set_ur_golomb_jpegls(pb, v, k, limit, esc_len);
603 }
604 
605 #endif /* AVCODEC_GOLOMB_H */
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