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 libavcodec/golomb.h
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#include "bitstream.h"
35
36#define INVALID_VLC           0x80000000
37
38extern const uint8_t ff_golomb_vlc_len[512];
39extern const uint8_t ff_ue_golomb_vlc_code[512];
40extern const  int8_t ff_se_golomb_vlc_code[512];
41extern const uint8_t ff_ue_golomb_len[256];
42
43extern const uint8_t ff_interleaved_golomb_vlc_len[256];
44extern const uint8_t ff_interleaved_ue_golomb_vlc_code[256];
45extern const  int8_t ff_interleaved_se_golomb_vlc_code[256];
46extern const uint8_t ff_interleaved_dirac_golomb_vlc_code[256];
47
48
49 /**
50 * read unsigned exp golomb code.
51 */
52static inline int get_ue_golomb(GetBitContext *gb){
53    unsigned int buf;
54    int log;
55
56    OPEN_READER(re, gb);
57    UPDATE_CACHE(re, gb);
58    buf=GET_CACHE(re, gb);
59
60    if(buf >= (1<<27)){
61        buf >>= 32 - 9;
62        LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
63        CLOSE_READER(re, gb);
64
65        return ff_ue_golomb_vlc_code[buf];
66    }else{
67        log= 2*av_log2(buf) - 31;
68        buf>>= log;
69        buf--;
70        LAST_SKIP_BITS(re, gb, 32 - log);
71        CLOSE_READER(re, gb);
72
73        return buf;
74    }
75}
76
77 /**
78 * read unsigned exp golomb code, constraint to a max of 31.
79 * the return value is undefined if the stored value exceeds 31.
80 */
81static inline int get_ue_golomb_31(GetBitContext *gb){
82    unsigned int buf;
83
84    OPEN_READER(re, gb);
85    UPDATE_CACHE(re, gb);
86    buf=GET_CACHE(re, gb);
87
88    buf >>= 32 - 9;
89    LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
90    CLOSE_READER(re, gb);
91
92    return ff_ue_golomb_vlc_code[buf];
93}
94
95static inline int svq3_get_ue_golomb(GetBitContext *gb){
96    uint32_t buf;
97
98    OPEN_READER(re, gb);
99    UPDATE_CACHE(re, gb);
100    buf=GET_CACHE(re, gb);
101
102    if(buf&0xAA800000){
103        buf >>= 32 - 8;
104        LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
105        CLOSE_READER(re, gb);
106
107        return ff_interleaved_ue_golomb_vlc_code[buf];
108    }else{
109        int ret = 1;
110
111        while (1) {
112            buf >>= 32 - 8;
113            LAST_SKIP_BITS(re, gb, FFMIN(ff_interleaved_golomb_vlc_len[buf], 8));
114
115            if (ff_interleaved_golomb_vlc_len[buf] != 9){
116                ret <<= (ff_interleaved_golomb_vlc_len[buf] - 1) >> 1;
117                ret |= ff_interleaved_dirac_golomb_vlc_code[buf];
118                break;
119            }
120            ret = (ret << 4) | ff_interleaved_dirac_golomb_vlc_code[buf];
121            UPDATE_CACHE(re, gb);
122            buf = GET_CACHE(re, gb);
123        }
124
125        CLOSE_READER(re, gb);
126        return ret - 1;
127    }
128}
129
130/**
131 * read unsigned truncated exp golomb code.
132 */
133static inline int get_te0_golomb(GetBitContext *gb, int range){
134    assert(range >= 1);
135
136    if(range==1)      return 0;
137    else if(range==2) return get_bits1(gb)^1;
138    else              return get_ue_golomb(gb);
139}
140
141/**
142 * read unsigned truncated exp golomb code.
143 */
144static inline int get_te_golomb(GetBitContext *gb, int range){
145    assert(range >= 1);
146
147    if(range==2) return get_bits1(gb)^1;
148    else         return get_ue_golomb(gb);
149}
150
151
152/**
153 * read signed exp golomb code.
154 */
155static inline int get_se_golomb(GetBitContext *gb){
156    unsigned int buf;
157    int log;
158
159    OPEN_READER(re, gb);
160    UPDATE_CACHE(re, gb);
161    buf=GET_CACHE(re, gb);
162
163    if(buf >= (1<<27)){
164        buf >>= 32 - 9;
165        LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
166        CLOSE_READER(re, gb);
167
168        return ff_se_golomb_vlc_code[buf];
169    }else{
170        log= 2*av_log2(buf) - 31;
171        buf>>= log;
172
173        LAST_SKIP_BITS(re, gb, 32 - log);
174        CLOSE_READER(re, gb);
175
176        if(buf&1) buf= -(buf>>1);
177        else      buf=  (buf>>1);
178
179        return buf;
180    }
181}
182
183static inline int svq3_get_se_golomb(GetBitContext *gb){
184    unsigned int buf;
185    int log;
186
187    OPEN_READER(re, gb);
188    UPDATE_CACHE(re, gb);
189    buf=GET_CACHE(re, gb);
190
191    if(buf&0xAA800000){
192        buf >>= 32 - 8;
193        LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
194        CLOSE_READER(re, gb);
195
196        return ff_interleaved_se_golomb_vlc_code[buf];
197    }else{
198        LAST_SKIP_BITS(re, gb, 8);
199        UPDATE_CACHE(re, gb);
200        buf |= 1 | (GET_CACHE(re, gb) >> 8);
201
202        if((buf & 0xAAAAAAAA) == 0)
203            return INVALID_VLC;
204
205        for(log=31; (buf & 0x80000000) == 0; log--){
206            buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
207        }
208
209        LAST_SKIP_BITS(re, gb, 63 - 2*log - 8);
210        CLOSE_READER(re, gb);
211
212        return (signed) (((((buf << log) >> log) - 1) ^ -(buf & 0x1)) + 1) >> 1;
213    }
214}
215
216static inline int dirac_get_se_golomb(GetBitContext *gb){
217    uint32_t buf;
218    uint32_t ret;
219
220    ret = svq3_get_ue_golomb(gb);
221
222    if (ret) {
223        OPEN_READER(re, gb);
224        UPDATE_CACHE(re, gb);
225        buf = SHOW_SBITS(re, gb, 1);
226        LAST_SKIP_BITS(re, gb, 1);
227        ret = (ret ^ buf) - buf;
228        CLOSE_READER(re, gb);
229    }
230
231    return ret;
232}
233
234/**
235 * read unsigned golomb rice code (ffv1).
236 */
237static inline int get_ur_golomb(GetBitContext *gb, int k, int limit, int esc_len){
238    unsigned int buf;
239    int log;
240
241    OPEN_READER(re, gb);
242    UPDATE_CACHE(re, gb);
243    buf=GET_CACHE(re, gb);
244
245    log= av_log2(buf);
246
247    if(log > 31-limit){
248        buf >>= log - k;
249        buf += (30-log)<<k;
250        LAST_SKIP_BITS(re, gb, 32 + k - log);
251        CLOSE_READER(re, gb);
252
253        return buf;
254    }else{
255        buf >>= 32 - limit - esc_len;
256        LAST_SKIP_BITS(re, gb, esc_len + limit);
257        CLOSE_READER(re, gb);
258
259        return buf + limit - 1;
260    }
261}
262
263/**
264 * read unsigned golomb rice code (jpegls).
265 */
266static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit, int esc_len){
267    unsigned int buf;
268    int log;
269
270    OPEN_READER(re, gb);
271    UPDATE_CACHE(re, gb);
272    buf=GET_CACHE(re, gb);
273
274    log= av_log2(buf);
275
276    if(log - k >= 32-MIN_CACHE_BITS+(MIN_CACHE_BITS==32) && 32-log < limit){
277        buf >>= log - k;
278        buf += (30-log)<<k;
279        LAST_SKIP_BITS(re, gb, 32 + k - log);
280        CLOSE_READER(re, gb);
281
282        return buf;
283    }else{
284        int i;
285        for(i=0; SHOW_UBITS(re, gb, 1) == 0; i++){
286            LAST_SKIP_BITS(re, gb, 1);
287            UPDATE_CACHE(re, gb);
288        }
289        SKIP_BITS(re, gb, 1);
290
291        if(i < limit - 1){
292            if(k){
293                buf = SHOW_UBITS(re, gb, k);
294                LAST_SKIP_BITS(re, gb, k);
295            }else{
296                buf=0;
297            }
298
299            CLOSE_READER(re, gb);
300            return buf + (i<<k);
301        }else if(i == limit - 1){
302            buf = SHOW_UBITS(re, gb, esc_len);
303            LAST_SKIP_BITS(re, gb, esc_len);
304            CLOSE_READER(re, gb);
305
306            return buf + 1;
307        }else
308            return -1;
309    }
310}
311
312/**
313 * read signed golomb rice code (ffv1).
314 */
315static inline int get_sr_golomb(GetBitContext *gb, int k, int limit, int esc_len){
316    int v= get_ur_golomb(gb, k, limit, esc_len);
317
318    v++;
319    if (v&1) return v>>1;
320    else return -(v>>1);
321
322//    return (v>>1) ^ -(v&1);
323}
324
325/**
326 * read signed golomb rice code (flac).
327 */
328static inline int get_sr_golomb_flac(GetBitContext *gb, int k, int limit, int esc_len){
329    int v= get_ur_golomb_jpegls(gb, k, limit, esc_len);
330    return (v>>1) ^ -(v&1);
331}
332
333/**
334 * read unsigned golomb rice code (shorten).
335 */
336static inline unsigned int get_ur_golomb_shorten(GetBitContext *gb, int k){
337        return get_ur_golomb_jpegls(gb, k, INT_MAX, 0);
338}
339
340/**
341 * read signed golomb rice code (shorten).
342 */
343static inline int get_sr_golomb_shorten(GetBitContext* gb, int k)
344{
345    int uvar = get_ur_golomb_jpegls(gb, k + 1, INT_MAX, 0);
346    if (uvar & 1)
347        return ~(uvar >> 1);
348    else
349        return uvar >> 1;
350}
351
352
353
354#ifdef TRACE
355
356static inline int get_ue(GetBitContext *s, char *file, const char *func, int line){
357    int show= show_bits(s, 24);
358    int pos= get_bits_count(s);
359    int i= get_ue_golomb(s);
360    int len= get_bits_count(s) - pos;
361    int bits= show>>(24-len);
362
363    print_bin(bits, len);
364
365    av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d ue  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
366
367    return i;
368}
369
370static inline int get_se(GetBitContext *s, char *file, const char *func, int line){
371    int show= show_bits(s, 24);
372    int pos= get_bits_count(s);
373    int i= get_se_golomb(s);
374    int len= get_bits_count(s) - pos;
375    int bits= show>>(24-len);
376
377    print_bin(bits, len);
378
379    av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d se  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
380
381    return i;
382}
383
384static inline int get_te(GetBitContext *s, int r, char *file, const char *func, int line){
385    int show= show_bits(s, 24);
386    int pos= get_bits_count(s);
387    int i= get_te0_golomb(s, r);
388    int len= get_bits_count(s) - pos;
389    int bits= show>>(24-len);
390
391    print_bin(bits, len);
392
393    av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d te  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
394
395    return i;
396}
397
398#define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
399#define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
400#define get_te_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
401#define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
402
403#endif
404
405/**
406 * write unsigned exp golomb code.
407 */
408static inline void set_ue_golomb(PutBitContext *pb, int i){
409    int e;
410
411    assert(i>=0);
412
413#if 0
414    if(i=0){
415        put_bits(pb, 1, 1);
416        return;
417    }
418#endif
419    if(i<256)
420        put_bits(pb, ff_ue_golomb_len[i], i+1);
421    else{
422        e= av_log2(i+1);
423
424        put_bits(pb, 2*e+1, i+1);
425    }
426}
427
428/**
429 * write truncated unsigned exp golomb code.
430 */
431static inline void set_te_golomb(PutBitContext *pb, int i, int range){
432    assert(range >= 1);
433    assert(i<=range);
434
435    if(range==2) put_bits(pb, 1, i^1);
436    else         set_ue_golomb(pb, i);
437}
438
439/**
440 * write signed exp golomb code. 16 bits at most.
441 */
442static inline void set_se_golomb(PutBitContext *pb, int i){
443//    if (i>32767 || i<-32767)
444//        av_log(NULL,AV_LOG_ERROR,"value out of range %d\n", i);
445#if 0
446    if(i<=0) i= -2*i;
447    else     i=  2*i-1;
448#elif 1
449    i= 2*i-1;
450    if(i<0) i^= -1; //FIXME check if gcc does the right thing
451#else
452    i= 2*i-1;
453    i^= (i>>31);
454#endif
455    set_ue_golomb(pb, i);
456}
457
458/**
459 * write unsigned golomb rice code (ffv1).
460 */
461static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
462    int e;
463
464    assert(i>=0);
465
466    e= i>>k;
467    if(e<limit){
468        put_bits(pb, e + k + 1, (1<<k) + (i&((1<<k)-1)));
469    }else{
470        put_bits(pb, limit + esc_len, i - limit + 1);
471    }
472}
473
474/**
475 * write unsigned golomb rice code (jpegls).
476 */
477static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k, int limit, int esc_len){
478    int e;
479
480    assert(i>=0);
481
482    e= (i>>k) + 1;
483    if(e<limit){
484        while(e > 31) {
485            put_bits(pb, 31, 0);
486            e -= 31;
487        }
488        put_bits(pb, e, 1);
489        if(k)
490            put_sbits(pb, k, i);
491    }else{
492        while(limit > 31) {
493            put_bits(pb, 31, 0);
494            limit -= 31;
495        }
496        put_bits(pb, limit  , 1);
497        put_bits(pb, esc_len, i - 1);
498    }
499}
500
501/**
502 * write signed golomb rice code (ffv1).
503 */
504static inline void set_sr_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
505    int v;
506
507    v = -2*i-1;
508    v ^= (v>>31);
509
510    set_ur_golomb(pb, v, k, limit, esc_len);
511}
512
513/**
514 * write signed golomb rice code (flac).
515 */
516static inline void set_sr_golomb_flac(PutBitContext *pb, int i, int k, int limit, int esc_len){
517    int v;
518
519    v = -2*i-1;
520    v ^= (v>>31);
521
522    set_ur_golomb_jpegls(pb, v, k, limit, esc_len);
523}
524
525#endif /* AVCODEC_GOLOMB_H */
526