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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(NULL, 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), sign;
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  sign = -(buf & 1);
209  buf = ((buf >> 1) ^ sign) - sign;
210 
211  return buf;
212  }
213 }
214 
215 static inline int get_se_golomb_long(GetBitContext *gb)
216 {
217  unsigned int buf = get_ue_golomb_long(gb);
218  int sign;
219 
220  sign = (buf & 1) - 1;
221  return ((buf >> 1) ^ sign) + 1;
222 }
223 
224 static inline int svq3_get_se_golomb(GetBitContext *gb)
225 {
226  unsigned int buf;
227 
228  OPEN_READER(re, gb);
229  UPDATE_CACHE(re, gb);
230  buf = GET_CACHE(re, gb);
231 
232  if (buf & 0xAA800000) {
233  buf >>= 32 - 8;
234  LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
235  CLOSE_READER(re, gb);
236 
237  return ff_interleaved_se_golomb_vlc_code[buf];
238  } else {
239  int log;
240  LAST_SKIP_BITS(re, gb, 8);
241  UPDATE_CACHE(re, gb);
242  buf |= 1 | (GET_CACHE(re, gb) >> 8);
243 
244  if ((buf & 0xAAAAAAAA) == 0)
245  return INVALID_VLC;
246 
247  for (log = 31; (buf & 0x80000000) == 0; log--)
248  buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
249 
250  LAST_SKIP_BITS(re, gb, 63 - 2 * log - 8);
251  CLOSE_READER(re, gb);
252 
253  return (signed) (((((buf << log) >> log) - 1) ^ -(buf & 0x1)) + 1) >> 1;
254  }
255 }
256 
257 static inline int dirac_get_se_golomb(GetBitContext *gb)
258 {
259  uint32_t ret = svq3_get_ue_golomb(gb);
260 
261  if (ret) {
262  int sign;
263  sign = -get_bits1(gb);
264  ret = (ret ^ sign) - sign;
265  }
266 
267  return ret;
268 }
269 
270 /**
271  * read unsigned golomb rice code (ffv1).
272  */
273 static inline int get_ur_golomb(GetBitContext *gb, int k, int limit,
274  int esc_len)
275 {
276  unsigned int buf;
277  int log;
278 
279  OPEN_READER(re, gb);
280  UPDATE_CACHE(re, gb);
281  buf = GET_CACHE(re, gb);
282 
283  log = av_log2(buf);
284 
285  if (log > 31 - limit) {
286  buf >>= log - k;
287  buf += (30 - log) << k;
288  LAST_SKIP_BITS(re, gb, 32 + k - log);
289  CLOSE_READER(re, gb);
290 
291  return buf;
292  } else {
293  LAST_SKIP_BITS(re, gb, limit);
294  UPDATE_CACHE(re, gb);
295 
296  buf = SHOW_UBITS(re, gb, esc_len);
297 
298  LAST_SKIP_BITS(re, gb, esc_len);
299  CLOSE_READER(re, gb);
300 
301  return buf + limit - 1;
302  }
303 }
304 
305 /**
306  * read unsigned golomb rice code (jpegls).
307  */
308 static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit,
309  int esc_len)
310 {
311  unsigned int buf;
312  int log;
313 
314  OPEN_READER(re, gb);
315  UPDATE_CACHE(re, gb);
316  buf = GET_CACHE(re, gb);
317 
318  log = av_log2(buf);
319 
320  if (log - k >= 32 - MIN_CACHE_BITS + (MIN_CACHE_BITS == 32) &&
321  32 - log < limit) {
322  buf >>= log - k;
323  buf += (30 - log) << k;
324  LAST_SKIP_BITS(re, gb, 32 + k - log);
325  CLOSE_READER(re, gb);
326 
327  return buf;
328  } else {
329  int i;
330  for (i = 0; i < limit && SHOW_UBITS(re, gb, 1) == 0; i++) {
331  if (gb->size_in_bits <= re_index)
332  return -1;
333  LAST_SKIP_BITS(re, gb, 1);
334  UPDATE_CACHE(re, gb);
335  }
336  SKIP_BITS(re, gb, 1);
337 
338  if (i < limit - 1) {
339  if (k) {
340  buf = SHOW_UBITS(re, gb, k);
341  LAST_SKIP_BITS(re, gb, k);
342  } else {
343  buf = 0;
344  }
345 
346  CLOSE_READER(re, gb);
347  return buf + (i << k);
348  } else if (i == limit - 1) {
349  buf = SHOW_UBITS(re, gb, esc_len);
350  LAST_SKIP_BITS(re, gb, esc_len);
351  CLOSE_READER(re, gb);
352 
353  return buf + 1;
354  } else
355  return -1;
356  }
357 }
358 
359 /**
360  * read signed golomb rice code (ffv1).
361  */
362 static inline int get_sr_golomb(GetBitContext *gb, int k, int limit,
363  int esc_len)
364 {
365  int v = get_ur_golomb(gb, k, limit, esc_len);
366  int sign;
367 
368  v++;
369  sign = (v & 1) - 1;
370  return ((v >> 1) ^ sign) - sign;
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  return (uvar >> 1) ^ -(uvar & 1);
398 }
399 
400 #ifdef TRACE
401 
402 static inline int get_ue(GetBitContext *s, const char *file, const char *func,
403  int line)
404 {
405  int show = show_bits(s, 24);
406  int pos = get_bits_count(s);
407  int i = get_ue_golomb(s);
408  int len = get_bits_count(s) - pos;
409  int bits = show >> (24 - len);
410 
411  print_bin(bits, len);
412 
413  av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d ue @%5d in %s %s:%d\n",
414  bits, len, i, pos, file, func, line);
415 
416  return i;
417 }
418 
419 static inline int get_se(GetBitContext *s, const char *file, const char *func,
420  int line)
421 {
422  int show = show_bits(s, 24);
423  int pos = get_bits_count(s);
424  int i = get_se_golomb(s);
425  int len = get_bits_count(s) - pos;
426  int bits = show >> (24 - len);
427 
428  print_bin(bits, len);
429 
430  av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d se @%5d in %s %s:%d\n",
431  bits, len, i, pos, file, func, line);
432 
433  return i;
434 }
435 
436 static inline int get_te(GetBitContext *s, int r, char *file, const char *func,
437  int line)
438 {
439  int show = show_bits(s, 24);
440  int pos = get_bits_count(s);
441  int i = get_te0_golomb(s, r);
442  int len = get_bits_count(s) - pos;
443  int bits = show >> (24 - len);
444 
445  print_bin(bits, len);
446 
447  av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d te @%5d in %s %s:%d\n",
448  bits, len, i, pos, file, func, line);
449 
450  return i;
451 }
452 
453 #define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
454 #define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
455 #define get_te_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
456 #define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
457 
458 #endif /* TRACE */
459 
460 /**
461  * write unsigned exp golomb code.
462  */
463 static inline void set_ue_golomb(PutBitContext *pb, int i)
464 {
465  av_assert2(i >= 0);
466 
467 #if 0
468  if (i = 0) {
469  put_bits(pb, 1, 1);
470  return;
471  }
472 #endif
473  if (i < 256)
474  put_bits(pb, ff_ue_golomb_len[i], i + 1);
475  else {
476  int e = av_log2(i + 1);
477  put_bits(pb, 2 * e + 1, i + 1);
478  }
479 }
480 
481 /**
482  * write truncated unsigned exp golomb code.
483  */
484 static inline void set_te_golomb(PutBitContext *pb, int i, int range)
485 {
486  av_assert2(range >= 1);
487  av_assert2(i <= range);
488 
489  if (range == 2)
490  put_bits(pb, 1, i ^ 1);
491  else
492  set_ue_golomb(pb, i);
493 }
494 
495 /**
496  * write signed exp golomb code. 16 bits at most.
497  */
498 static inline void set_se_golomb(PutBitContext *pb, int i)
499 {
500 #if 0
501  if (i <= 0)
502  i = -2 * i;
503  else
504  i = 2 * i - 1;
505 #elif 1
506  i = 2 * i - 1;
507  if (i < 0)
508  i ^= -1; //FIXME check if gcc does the right thing
509 #else
510  i = 2 * i - 1;
511  i ^= (i >> 31);
512 #endif
513  set_ue_golomb(pb, i);
514 }
515 
516 /**
517  * write unsigned golomb rice code (ffv1).
518  */
519 static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit,
520  int esc_len)
521 {
522  int e;
523 
524  av_assert2(i >= 0);
525 
526  e = i >> k;
527  if (e < limit)
528  put_bits(pb, e + k + 1, (1 << k) + (i & ((1 << k) - 1)));
529  else
530  put_bits(pb, limit + esc_len, i - limit + 1);
531 }
532 
533 /**
534  * write unsigned golomb rice code (jpegls).
535  */
536 static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k,
537  int limit, int esc_len)
538 {
539  int e;
540 
541  av_assert2(i >= 0);
542 
543  e = (i >> k) + 1;
544  if (e < limit) {
545  while (e > 31) {
546  put_bits(pb, 31, 0);
547  e -= 31;
548  }
549  put_bits(pb, e, 1);
550  if (k)
551  put_sbits(pb, k, i);
552  } else {
553  while (limit > 31) {
554  put_bits(pb, 31, 0);
555  limit -= 31;
556  }
557  put_bits(pb, limit, 1);
558  put_bits(pb, esc_len, i - 1);
559  }
560 }
561 
562 /**
563  * write signed golomb rice code (ffv1).
564  */
565 static inline void set_sr_golomb(PutBitContext *pb, int i, int k, int limit,
566  int esc_len)
567 {
568  int v;
569 
570  v = -2 * i - 1;
571  v ^= (v >> 31);
572 
573  set_ur_golomb(pb, v, k, limit, esc_len);
574 }
575 
576 /**
577  * write signed golomb rice code (flac).
578  */
579 static inline void set_sr_golomb_flac(PutBitContext *pb, int i, int k,
580  int limit, int esc_len)
581 {
582  int v;
583 
584  v = -2 * i - 1;
585  v ^= (v >> 31);
586 
587  set_ur_golomb_jpegls(pb, v, k, limit, esc_len);
588 }
589 
590 #endif /* AVCODEC_GOLOMB_H */
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