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#include "get_bits.h"
35#include "put_bits.h"
36
37#define INVALID_VLC           0x80000000
38
39extern const uint8_t ff_golomb_vlc_len[512];
40extern const uint8_t ff_ue_golomb_vlc_code[512];
41extern const  int8_t ff_se_golomb_vlc_code[512];
42extern const uint8_t ff_ue_golomb_len[256];
43
44extern const uint8_t ff_interleaved_golomb_vlc_len[256];
45extern const uint8_t ff_interleaved_ue_golomb_vlc_code[256];
46extern const  int8_t ff_interleaved_se_golomb_vlc_code[256];
47extern const uint8_t ff_interleaved_dirac_golomb_vlc_code[256];
48
49
50 /**
51 * read unsigned exp golomb code.
52 */
53static inline int get_ue_golomb(GetBitContext *gb){
54    unsigned int buf;
55    int log;
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        log= 2*av_log2(buf) - 31;
69        buf>>= log;
70        buf--;
71        LAST_SKIP_BITS(re, gb, 32 - log);
72        CLOSE_READER(re, gb);
73
74        return buf;
75    }
76}
77
78 /**
79 * read unsigned exp golomb code, constraint to a max of 31.
80 * the return value is undefined if the stored value exceeds 31.
81 */
82static inline int get_ue_golomb_31(GetBitContext *gb){
83    unsigned int buf;
84
85    OPEN_READER(re, gb);
86    UPDATE_CACHE(re, gb);
87    buf=GET_CACHE(re, gb);
88
89    buf >>= 32 - 9;
90    LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
91    CLOSE_READER(re, gb);
92
93    return ff_ue_golomb_vlc_code[buf];
94}
95
96static inline int svq3_get_ue_golomb(GetBitContext *gb){
97    uint32_t buf;
98
99    OPEN_READER(re, gb);
100    UPDATE_CACHE(re, gb);
101    buf=GET_CACHE(re, gb);
102
103    if(buf&0xAA800000){
104        buf >>= 32 - 8;
105        LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
106        CLOSE_READER(re, gb);
107
108        return ff_interleaved_ue_golomb_vlc_code[buf];
109    }else{
110        int ret = 1;
111
112        while (1) {
113            buf >>= 32 - 8;
114            LAST_SKIP_BITS(re, gb, FFMIN(ff_interleaved_golomb_vlc_len[buf], 8));
115
116            if (ff_interleaved_golomb_vlc_len[buf] != 9){
117                ret <<= (ff_interleaved_golomb_vlc_len[buf] - 1) >> 1;
118                ret |= ff_interleaved_dirac_golomb_vlc_code[buf];
119                break;
120            }
121            ret = (ret << 4) | ff_interleaved_dirac_golomb_vlc_code[buf];
122            UPDATE_CACHE(re, gb);
123            buf = GET_CACHE(re, gb);
124        }
125
126        CLOSE_READER(re, gb);
127        return ret - 1;
128    }
129}
130
131/**
132 * read unsigned truncated exp golomb code.
133 */
134static inline int get_te0_golomb(GetBitContext *gb, int range){
135    assert(range >= 1);
136
137    if(range==1)      return 0;
138    else if(range==2) return get_bits1(gb)^1;
139    else              return get_ue_golomb(gb);
140}
141
142/**
143 * read unsigned truncated exp golomb code.
144 */
145static inline int get_te_golomb(GetBitContext *gb, int range){
146    assert(range >= 1);
147
148    if(range==2) return get_bits1(gb)^1;
149    else         return get_ue_golomb(gb);
150}
151
152
153/**
154 * read signed exp golomb code.
155 */
156static inline int get_se_golomb(GetBitContext *gb){
157    unsigned int buf;
158    int log;
159
160    OPEN_READER(re, gb);
161    UPDATE_CACHE(re, gb);
162    buf=GET_CACHE(re, gb);
163
164    if(buf >= (1<<27)){
165        buf >>= 32 - 9;
166        LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
167        CLOSE_READER(re, gb);
168
169        return ff_se_golomb_vlc_code[buf];
170    }else{
171        log= 2*av_log2(buf) - 31;
172        buf>>= log;
173
174        LAST_SKIP_BITS(re, gb, 32 - log);
175        CLOSE_READER(re, gb);
176
177        if(buf&1) buf= -(buf>>1);
178        else      buf=  (buf>>1);
179
180        return buf;
181    }
182}
183
184static inline int svq3_get_se_golomb(GetBitContext *gb){
185    unsigned int buf;
186    int log;
187
188    OPEN_READER(re, gb);
189    UPDATE_CACHE(re, gb);
190    buf=GET_CACHE(re, gb);
191
192    if(buf&0xAA800000){
193        buf >>= 32 - 8;
194        LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
195        CLOSE_READER(re, gb);
196
197        return ff_interleaved_se_golomb_vlc_code[buf];
198    }else{
199        LAST_SKIP_BITS(re, gb, 8);
200        UPDATE_CACHE(re, gb);
201        buf |= 1 | (GET_CACHE(re, gb) >> 8);
202
203        if((buf & 0xAAAAAAAA) == 0)
204            return INVALID_VLC;
205
206        for(log=31; (buf & 0x80000000) == 0; log--){
207            buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
208        }
209
210        LAST_SKIP_BITS(re, gb, 63 - 2*log - 8);
211        CLOSE_READER(re, gb);
212
213        return (signed) (((((buf << log) >> log) - 1) ^ -(buf & 0x1)) + 1) >> 1;
214    }
215}
216
217static inline int dirac_get_se_golomb(GetBitContext *gb){
218    uint32_t buf;
219    uint32_t ret;
220
221    ret = svq3_get_ue_golomb(gb);
222
223    if (ret) {
224        OPEN_READER(re, gb);
225        UPDATE_CACHE(re, gb);
226        buf = SHOW_SBITS(re, gb, 1);
227        LAST_SKIP_BITS(re, gb, 1);
228        ret = (ret ^ buf) - buf;
229        CLOSE_READER(re, gb);
230    }
231
232    return ret;
233}
234
235/**
236 * read unsigned golomb rice code (ffv1).
237 */
238static inline int get_ur_golomb(GetBitContext *gb, int k, int limit, int esc_len){
239    unsigned int buf;
240    int log;
241
242    OPEN_READER(re, gb);
243    UPDATE_CACHE(re, gb);
244    buf=GET_CACHE(re, gb);
245
246    log= av_log2(buf);
247
248    if(log > 31-limit){
249        buf >>= log - k;
250        buf += (30-log)<<k;
251        LAST_SKIP_BITS(re, gb, 32 + k - log);
252        CLOSE_READER(re, gb);
253
254        return buf;
255    }else{
256        LAST_SKIP_BITS(re, gb, limit);
257        UPDATE_CACHE(re, gb);
258
259        buf = SHOW_UBITS(re, gb, esc_len);
260
261        LAST_SKIP_BITS(re, gb, esc_len);
262        CLOSE_READER(re, gb);
263
264        return buf + limit - 1;
265    }
266}
267
268/**
269 * read unsigned golomb rice code (jpegls).
270 */
271static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit, int esc_len){
272    unsigned int buf;
273    int log;
274
275    OPEN_READER(re, gb);
276    UPDATE_CACHE(re, gb);
277    buf=GET_CACHE(re, gb);
278
279    log= av_log2(buf);
280
281    if(log - k >= 32-MIN_CACHE_BITS+(MIN_CACHE_BITS==32) && 32-log < limit){
282        buf >>= log - k;
283        buf += (30-log)<<k;
284        LAST_SKIP_BITS(re, gb, 32 + k - log);
285        CLOSE_READER(re, gb);
286
287        return buf;
288    }else{
289        int i;
290        for(i=0; SHOW_UBITS(re, gb, 1) == 0; i++){
291            LAST_SKIP_BITS(re, gb, 1);
292            UPDATE_CACHE(re, gb);
293        }
294        SKIP_BITS(re, gb, 1);
295
296        if(i < limit - 1){
297            if(k){
298                buf = SHOW_UBITS(re, gb, k);
299                LAST_SKIP_BITS(re, gb, k);
300            }else{
301                buf=0;
302            }
303
304            CLOSE_READER(re, gb);
305            return buf + (i<<k);
306        }else if(i == limit - 1){
307            buf = SHOW_UBITS(re, gb, esc_len);
308            LAST_SKIP_BITS(re, gb, esc_len);
309            CLOSE_READER(re, gb);
310
311            return buf + 1;
312        }else
313            return -1;
314    }
315}
316
317/**
318 * read signed golomb rice code (ffv1).
319 */
320static inline int get_sr_golomb(GetBitContext *gb, int k, int limit, int esc_len){
321    int v= get_ur_golomb(gb, k, limit, esc_len);
322
323    v++;
324    if (v&1) return v>>1;
325    else return -(v>>1);
326
327//    return (v>>1) ^ -(v&1);
328}
329
330/**
331 * read signed golomb rice code (flac).
332 */
333static inline int get_sr_golomb_flac(GetBitContext *gb, int k, int limit, int esc_len){
334    int v= get_ur_golomb_jpegls(gb, k, limit, esc_len);
335    return (v>>1) ^ -(v&1);
336}
337
338/**
339 * read unsigned golomb rice code (shorten).
340 */
341static inline unsigned int get_ur_golomb_shorten(GetBitContext *gb, int k){
342        return get_ur_golomb_jpegls(gb, k, INT_MAX, 0);
343}
344
345/**
346 * read signed golomb rice code (shorten).
347 */
348static inline int get_sr_golomb_shorten(GetBitContext* gb, int k)
349{
350    int uvar = get_ur_golomb_jpegls(gb, k + 1, INT_MAX, 0);
351    if (uvar & 1)
352        return ~(uvar >> 1);
353    else
354        return uvar >> 1;
355}
356
357
358
359#ifdef TRACE
360
361static inline int get_ue(GetBitContext *s, char *file, const char *func, int line){
362    int show= show_bits(s, 24);
363    int pos= get_bits_count(s);
364    int i= get_ue_golomb(s);
365    int len= get_bits_count(s) - pos;
366    int bits= show>>(24-len);
367
368    print_bin(bits, len);
369
370    av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d ue  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
371
372    return i;
373}
374
375static inline int get_se(GetBitContext *s, char *file, const char *func, int line){
376    int show= show_bits(s, 24);
377    int pos= get_bits_count(s);
378    int i= get_se_golomb(s);
379    int len= get_bits_count(s) - pos;
380    int bits= show>>(24-len);
381
382    print_bin(bits, len);
383
384    av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d se  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
385
386    return i;
387}
388
389static inline int get_te(GetBitContext *s, int r, char *file, const char *func, int line){
390    int show= show_bits(s, 24);
391    int pos= get_bits_count(s);
392    int i= get_te0_golomb(s, r);
393    int len= get_bits_count(s) - pos;
394    int bits= show>>(24-len);
395
396    print_bin(bits, len);
397
398    av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d te  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
399
400    return i;
401}
402
403#define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
404#define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
405#define get_te_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
406#define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
407
408#endif
409
410/**
411 * write unsigned exp golomb code.
412 */
413static inline void set_ue_golomb(PutBitContext *pb, int i){
414    int e;
415
416    assert(i>=0);
417
418#if 0
419    if(i=0){
420        put_bits(pb, 1, 1);
421        return;
422    }
423#endif
424    if(i<256)
425        put_bits(pb, ff_ue_golomb_len[i], i+1);
426    else{
427        e= av_log2(i+1);
428
429        put_bits(pb, 2*e+1, i+1);
430    }
431}
432
433/**
434 * write truncated unsigned exp golomb code.
435 */
436static inline void set_te_golomb(PutBitContext *pb, int i, int range){
437    assert(range >= 1);
438    assert(i<=range);
439
440    if(range==2) put_bits(pb, 1, i^1);
441    else         set_ue_golomb(pb, i);
442}
443
444/**
445 * write signed exp golomb code. 16 bits at most.
446 */
447static inline void set_se_golomb(PutBitContext *pb, int i){
448//    if (i>32767 || i<-32767)
449//        av_log(NULL,AV_LOG_ERROR,"value out of range %d\n", i);
450#if 0
451    if(i<=0) i= -2*i;
452    else     i=  2*i-1;
453#elif 1
454    i= 2*i-1;
455    if(i<0) i^= -1; //FIXME check if gcc does the right thing
456#else
457    i= 2*i-1;
458    i^= (i>>31);
459#endif
460    set_ue_golomb(pb, i);
461}
462
463/**
464 * write unsigned golomb rice code (ffv1).
465 */
466static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
467    int e;
468
469    assert(i>=0);
470
471    e= i>>k;
472    if(e<limit){
473        put_bits(pb, e + k + 1, (1<<k) + (i&((1<<k)-1)));
474    }else{
475        put_bits(pb, limit + esc_len, i - limit + 1);
476    }
477}
478
479/**
480 * write unsigned golomb rice code (jpegls).
481 */
482static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k, int limit, int esc_len){
483    int e;
484
485    assert(i>=0);
486
487    e= (i>>k) + 1;
488    if(e<limit){
489        while(e > 31) {
490            put_bits(pb, 31, 0);
491            e -= 31;
492        }
493        put_bits(pb, e, 1);
494        if(k)
495            put_sbits(pb, k, i);
496    }else{
497        while(limit > 31) {
498            put_bits(pb, 31, 0);
499            limit -= 31;
500        }
501        put_bits(pb, limit  , 1);
502        put_bits(pb, esc_len, i - 1);
503    }
504}
505
506/**
507 * write signed golomb rice code (ffv1).
508 */
509static inline void set_sr_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
510    int v;
511
512    v = -2*i-1;
513    v ^= (v>>31);
514
515    set_ur_golomb(pb, v, k, limit, esc_len);
516}
517
518/**
519 * write signed golomb rice code (flac).
520 */
521static inline void set_sr_golomb_flac(PutBitContext *pb, int i, int k, int limit, int esc_len){
522    int v;
523
524    v = -2*i-1;
525    v ^= (v>>31);
526
527    set_ur_golomb_jpegls(pb, v, k, limit, esc_len);
528}
529
530#endif /* AVCODEC_GOLOMB_H */
531