Statistics
| Branch: | Revision:

ffmpeg / libavcodec / golomb.h @ e40f5d3c

History | View | Annotate | Download (9.35 KB)

1
/*
2
 * exp golomb vlc stuff
3
 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
4
 *
5
 * This library is free software; you can redistribute it and/or
6
 * modify it under the terms of the GNU Lesser General Public
7
 * License as published by the Free Software Foundation; either
8
 * version 2 of the License, or (at your option) any later version.
9
 *
10
 * This library is distributed in the hope that it will be useful,
11
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13
 * Lesser General Public License for more details.
14
 *
15
 * You should have received a copy of the GNU Lesser General Public
16
 * License along with this library; if not, write to the Free Software
17
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18
 *
19
 */
20
 
21
/**
22
 * @file golomb.h
23
 * @brief 
24
 *     exp golomb vlc stuff
25
 * @author Michael Niedermayer <michaelni@gmx.at>
26
 */
27

    
28
#define INVALID_VLC           0x80000000
29

    
30
extern const uint8_t ff_golomb_vlc_len[512];
31
extern const uint8_t ff_ue_golomb_vlc_code[512];
32
extern const  int8_t ff_se_golomb_vlc_code[512];
33
extern const uint8_t ff_ue_golomb_len[256];
34

    
35
extern const uint8_t ff_interleaved_golomb_vlc_len[256];
36
extern const uint8_t ff_interleaved_ue_golomb_vlc_code[256];
37
extern const  int8_t ff_interleaved_se_golomb_vlc_code[256];
38

    
39
 
40
 /**
41
 * read unsigned exp golomb code.
42
 */
43
static inline int get_ue_golomb(GetBitContext *gb){
44
    unsigned int buf;
45
    int log;
46
    
47
    OPEN_READER(re, gb);
48
    UPDATE_CACHE(re, gb);
49
    buf=GET_CACHE(re, gb);
50
    
51
    if(buf >= (1<<27)){
52
        buf >>= 32 - 9;
53
        LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
54
        CLOSE_READER(re, gb);
55
    
56
        return ff_ue_golomb_vlc_code[buf];
57
    }else{
58
        log= 2*av_log2(buf) - 31;
59
        buf>>= log;
60
        buf--;
61
        LAST_SKIP_BITS(re, gb, 32 - log);
62
        CLOSE_READER(re, gb);
63
    
64
        return buf;
65
    }
66
}
67

    
68
static inline int svq3_get_ue_golomb(GetBitContext *gb){
69
    uint32_t buf;
70
    int log;
71

    
72
    OPEN_READER(re, gb);
73
    UPDATE_CACHE(re, gb);
74
    buf=GET_CACHE(re, gb);
75
    
76
    if(buf&0xAA800000){
77
        buf >>= 32 - 8;
78
        LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
79
        CLOSE_READER(re, gb);
80
        
81
        return ff_interleaved_ue_golomb_vlc_code[buf];
82
    }else{
83
        buf|=1;
84
        if((buf & 0xAAAAAAAA) == 0)
85
            return INVALID_VLC;
86

    
87
        for(log=31; (buf & 0x80000000) == 0; log--){
88
            buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
89
        }
90

    
91
        LAST_SKIP_BITS(re, gb, 63 - 2*log);
92
        CLOSE_READER(re, gb);
93

    
94
        return ((buf << log) >> log) - 1;
95
    }
96
}
97

    
98
/**
99
 * read unsigned truncated exp golomb code.
100
 */
101
static inline int get_te0_golomb(GetBitContext *gb, int range){
102
    assert(range >= 1);
103
    
104
    if(range==1)      return 0;
105
    else if(range==2) return get_bits1(gb)^1;
106
    else              return get_ue_golomb(gb);
107
}
108

    
109
/**
110
 * read unsigned truncated exp golomb code.
111
 */
112
static inline int get_te_golomb(GetBitContext *gb, int range){
113
    assert(range >= 1);
114
    
115
    if(range==2) return get_bits1(gb)^1;
116
    else         return get_ue_golomb(gb);
117
}
118

    
119

    
120
/**
121
 * read signed exp golomb code.
122
 */
123
static inline int get_se_golomb(GetBitContext *gb){
124
    unsigned int buf;
125
    int log;
126
    
127
    OPEN_READER(re, gb);
128
    UPDATE_CACHE(re, gb);
129
    buf=GET_CACHE(re, gb);
130
    
131
    if(buf >= (1<<27)){
132
        buf >>= 32 - 9;
133
        LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
134
        CLOSE_READER(re, gb);
135
    
136
        return ff_se_golomb_vlc_code[buf];
137
    }else{
138
        log= 2*av_log2(buf) - 31;
139
        buf>>= log;
140
        
141
        LAST_SKIP_BITS(re, gb, 32 - log);
142
        CLOSE_READER(re, gb);
143
    
144
        if(buf&1) buf= -(buf>>1);
145
        else      buf=  (buf>>1);
146

    
147
        return buf;
148
    }
149
}
150

    
151
static inline int svq3_get_se_golomb(GetBitContext *gb){
152
    unsigned int buf;
153
    int log;
154

    
155
    OPEN_READER(re, gb);
156
    UPDATE_CACHE(re, gb);
157
    buf=GET_CACHE(re, gb);
158

    
159
    if(buf&0xAA800000){
160
        buf >>= 32 - 8;
161
        LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
162
        CLOSE_READER(re, gb);
163
        
164
        return ff_interleaved_se_golomb_vlc_code[buf];
165
    }else{
166
        buf |=1;
167
        if((buf & 0xAAAAAAAA) == 0)
168
            return INVALID_VLC;
169

    
170
        for(log=31; (buf & 0x80000000) == 0; log--){
171
            buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
172
        }
173

    
174
        LAST_SKIP_BITS(re, gb, 63 - 2*log);
175
        CLOSE_READER(re, gb);
176

    
177
        return (signed) (((((buf << log) >> log) - 1) ^ -(buf & 0x1)) + 1) >> 1;
178
    }
179
}
180

    
181
/**
182
 * read unsigned golomb rice code (ffv1).
183
 */
184
static inline int get_ur_golomb(GetBitContext *gb, int k, int limit, int esc_len){
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
    log= av_log2(buf);
193

    
194
    if(log > 31-limit){
195
        buf >>= log - k;
196
        buf += (30-log)<<k;
197
        LAST_SKIP_BITS(re, gb, 32 + k - log);
198
        CLOSE_READER(re, gb);
199
    
200
        return buf;
201
    }else{
202
        buf >>= 32 - limit - esc_len;
203
        LAST_SKIP_BITS(re, gb, esc_len + limit);
204
        CLOSE_READER(re, gb);
205
    
206
        return buf + limit - 1;
207
    }
208
}
209

    
210
/**
211
 * read unsigned golomb rice code (jpegls).
212
 */
213
static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit, int esc_len){
214
    unsigned int buf;
215
    int log;
216
    
217
    OPEN_READER(re, gb);
218
    UPDATE_CACHE(re, gb);
219
    buf=GET_CACHE(re, gb);
220

    
221
    log= av_log2(buf);
222
    
223
    if(log > 31-11){
224
        buf >>= log - k;
225
        buf += (30-log)<<k;
226
        LAST_SKIP_BITS(re, gb, 32 + k - log);
227
        CLOSE_READER(re, gb);
228
    
229
        return buf;
230
    }else{
231
        int i;
232
        for(i=0; SHOW_UBITS(re, gb, 1) == 0; i++){
233
            LAST_SKIP_BITS(re, gb, 1);
234
            UPDATE_CACHE(re, gb);
235
        }
236
        SKIP_BITS(re, gb, 1);
237

    
238
        if(i < limit - 1){
239
            if(k){
240
                buf = SHOW_UBITS(re, gb, k);
241
                LAST_SKIP_BITS(re, gb, k);
242
            }else{
243
                buf=0;
244
            }
245

    
246
            CLOSE_READER(re, gb);
247
            return buf + (i<<k);
248
        }else if(i == limit - 1){
249
            buf = SHOW_UBITS(re, gb, esc_len);
250
            LAST_SKIP_BITS(re, gb, esc_len);
251
            CLOSE_READER(re, gb);
252
    
253
            return buf + 1;
254
        }else
255
            return -1;
256
    }
257
}
258

    
259
#ifdef TRACE
260

    
261
static inline int get_ue(GetBitContext *s, char *file, char *func, int line){
262
    int show= show_bits(s, 24);
263
    int pos= get_bits_count(s);
264
    int i= get_ue_golomb(s);
265
    int len= get_bits_count(s) - pos;
266
    int bits= show>>(24-len);
267
    
268
    print_bin(bits, len);
269
    
270
    printf("%5d %2d %3d ue  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
271
    
272
    return i;
273
}
274

    
275
static inline int get_se(GetBitContext *s, char *file, char *func, int line){
276
    int show= show_bits(s, 24);
277
    int pos= get_bits_count(s);
278
    int i= get_se_golomb(s);
279
    int len= get_bits_count(s) - pos;
280
    int bits= show>>(24-len);
281
    
282
    print_bin(bits, len);
283
    
284
    printf("%5d %2d %3d se  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
285
    
286
    return i;
287
}
288

    
289
static inline int get_te(GetBitContext *s, int r, char *file, char *func, int line){
290
    int show= show_bits(s, 24);
291
    int pos= get_bits_count(s);
292
    int i= get_te0_golomb(s, r);
293
    int len= get_bits_count(s) - pos;
294
    int bits= show>>(24-len);
295
    
296
    print_bin(bits, len);
297
    
298
    printf("%5d %2d %3d te  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
299
    
300
    return i;
301
}
302

    
303
#define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
304
#define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
305
#define get_te_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
306
#define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
307

    
308
#endif
309

    
310
/**
311
 * write unsigned exp golomb code.
312
 */
313
static inline void set_ue_golomb(PutBitContext *pb, int i){
314
    int e;
315
    
316
    assert(i>=0);
317

    
318
#if 0
319
    if(i=0){
320
        put_bits(pb, 1, 1);
321
        return;
322
    }
323
#endif
324
    if(i<256)
325
        put_bits(pb, ff_ue_golomb_len[i], i+1);
326
    else{
327
        e= av_log2(i+1);
328
    
329
        put_bits(pb, 2*e+1, i+1);
330
    }
331
}
332

    
333
/**
334
 * write truncated unsigned exp golomb code.
335
 */
336
static inline void set_te_golomb(PutBitContext *pb, int i, int range){
337
    assert(range >= 1);
338
    assert(i<=range);
339

    
340
    if(range==2) put_bits(pb, 1, i^1);
341
    else         set_ue_golomb(pb, i);
342
}
343

    
344
/**
345
 * write signed exp golomb code.
346
 */
347
static inline void set_se_golomb(PutBitContext *pb, int i){
348
#if 0 
349
    if(i<=0) i= -2*i;
350
    else     i=  2*i-1;
351
#elif 1
352
    i= 2*i-1;
353
    if(i<0) i^= -1; //FIXME check if gcc does the right thing
354
#else
355
    i= 2*i-1;
356
    i^= (i>>31);
357
#endif
358
    set_ue_golomb(pb, i);
359
}
360

    
361
/**
362
 * write unsigned golomb rice code (ffv1).
363
 */
364
static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
365
    int e;
366
    
367
    assert(i>=0);
368
    
369
    e= i>>k;
370
    if(e<limit){
371
        put_bits(pb, e + k + 1, (1<<k) + (i&((1<<k)-1)));
372
    }else{
373
        put_bits(pb, limit + esc_len, i - limit + 1);
374
    }
375
}
376

    
377
/**
378
 * write unsigned golomb rice code (jpegls).
379
 */
380
static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k, int limit, int esc_len){
381
    int e;
382
    
383
    assert(i>=0);
384
    
385
    e= (i>>k) + 1;
386
    if(e<limit){
387
        put_bits(pb, e, 1);
388
        if(k)
389
            put_bits(pb, k, i&((1<<k)-1));
390
    }else{
391
        put_bits(pb, limit  , 1);
392
        put_bits(pb, esc_len, i - 1);
393
    }
394
}