FFmpeg: libavcodec/golomb.h Source File

00001 /*
00002  * exp golomb vlc stuff
00003  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
00004  * Copyright (c) 2004 Alex Beregszaszi
00005  *
00006  * This file is part of FFmpeg.
00007  *
00008  * FFmpeg is free software; you can redistribute it and/or
00009  * modify it under the terms of the GNU Lesser General Public
00010  * License as published by the Free Software Foundation; either
00011  * version 2.1 of the License, or (at your option) any later version.
00012  *
00013  * FFmpeg is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016  * Lesser General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU Lesser General Public
00019  * License along with FFmpeg; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00021  */
00022 
00030 #ifndef AVCODEC_GOLOMB_H
00031 #define AVCODEC_GOLOMB_H
00032 
00033 #include <stdint.h>
00034 #include "get_bits.h"
00035 #include "put_bits.h"
00036 
00037 #define INVALID_VLC           0x80000000
00038 
00039 extern const uint8_t ff_golomb_vlc_len[512];
00040 extern const uint8_t ff_ue_golomb_vlc_code[512];
00041 extern const  int8_t ff_se_golomb_vlc_code[512];
00042 extern const uint8_t ff_ue_golomb_len[256];
00043 
00044 extern const uint8_t ff_interleaved_golomb_vlc_len[256];
00045 extern const uint8_t ff_interleaved_ue_golomb_vlc_code[256];
00046 extern const  int8_t ff_interleaved_se_golomb_vlc_code[256];
00047 extern const uint8_t ff_interleaved_dirac_golomb_vlc_code[256];
00048 
00049 
00053 static inline int get_ue_golomb(GetBitContext *gb){
00054     unsigned int buf;
00055     int log;
00056 
00057     OPEN_READER(re, gb);
00058     UPDATE_CACHE(re, gb);
00059     buf=GET_CACHE(re, gb);
00060 
00061     if(buf >= (1<<27)){
00062         buf >>= 32 - 9;
00063         LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
00064         CLOSE_READER(re, gb);
00065 
00066         return ff_ue_golomb_vlc_code[buf];
00067     }else{
00068         log= 2*av_log2(buf) - 31;
00069         buf>>= log;
00070         buf--;
00071         LAST_SKIP_BITS(re, gb, 32 - log);
00072         CLOSE_READER(re, gb);
00073 
00074         return buf;
00075     }
00076 }
00077 
00082 static inline int get_ue_golomb_31(GetBitContext *gb){
00083     unsigned int buf;
00084 
00085     OPEN_READER(re, gb);
00086     UPDATE_CACHE(re, gb);
00087     buf=GET_CACHE(re, gb);
00088 
00089     buf >>= 32 - 9;
00090     LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
00091     CLOSE_READER(re, gb);
00092 
00093     return ff_ue_golomb_vlc_code[buf];
00094 }
00095 
00096 static inline int svq3_get_ue_golomb(GetBitContext *gb){
00097     uint32_t buf;
00098 
00099     OPEN_READER(re, gb);
00100     UPDATE_CACHE(re, gb);
00101     buf=GET_CACHE(re, gb);
00102 
00103     if(buf&0xAA800000){
00104         buf >>= 32 - 8;
00105         LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
00106         CLOSE_READER(re, gb);
00107 
00108         return ff_interleaved_ue_golomb_vlc_code[buf];
00109     }else{
00110         int ret = 1;
00111 
00112         while (1) {
00113             buf >>= 32 - 8;
00114             LAST_SKIP_BITS(re, gb, FFMIN(ff_interleaved_golomb_vlc_len[buf], 8));
00115 
00116             if (ff_interleaved_golomb_vlc_len[buf] != 9){
00117                 ret <<= (ff_interleaved_golomb_vlc_len[buf] - 1) >> 1;
00118                 ret |= ff_interleaved_dirac_golomb_vlc_code[buf];
00119                 break;
00120             }
00121             ret = (ret << 4) | ff_interleaved_dirac_golomb_vlc_code[buf];
00122             UPDATE_CACHE(re, gb);
00123             buf = GET_CACHE(re, gb);
00124         }
00125 
00126         CLOSE_READER(re, gb);
00127         return ret - 1;
00128     }
00129 }
00130 
00134 static inline int get_te0_golomb(GetBitContext *gb, int range){
00135     assert(range >= 1);
00136 
00137     if(range==1)      return 0;
00138     else if(range==2) return get_bits1(gb)^1;
00139     else              return get_ue_golomb(gb);
00140 }
00141 
00145 static inline int get_te_golomb(GetBitContext *gb, int range){
00146     assert(range >= 1);
00147 
00148     if(range==2) return get_bits1(gb)^1;
00149     else         return get_ue_golomb(gb);
00150 }
00151 
00152 
00156 static inline int get_se_golomb(GetBitContext *gb){
00157     unsigned int buf;
00158     int log;
00159 
00160     OPEN_READER(re, gb);
00161     UPDATE_CACHE(re, gb);
00162     buf=GET_CACHE(re, gb);
00163 
00164     if(buf >= (1<<27)){
00165         buf >>= 32 - 9;
00166         LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
00167         CLOSE_READER(re, gb);
00168 
00169         return ff_se_golomb_vlc_code[buf];
00170     }else{
00171         log= 2*av_log2(buf) - 31;
00172         buf>>= log;
00173 
00174         LAST_SKIP_BITS(re, gb, 32 - log);
00175         CLOSE_READER(re, gb);
00176 
00177         if(buf&1) buf= -(buf>>1);
00178         else      buf=  (buf>>1);
00179 
00180         return buf;
00181     }
00182 }
00183 
00184 static inline int svq3_get_se_golomb(GetBitContext *gb){
00185     unsigned int buf;
00186     int log;
00187 
00188     OPEN_READER(re, gb);
00189     UPDATE_CACHE(re, gb);
00190     buf=GET_CACHE(re, gb);
00191 
00192     if(buf&0xAA800000){
00193         buf >>= 32 - 8;
00194         LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
00195         CLOSE_READER(re, gb);
00196 
00197         return ff_interleaved_se_golomb_vlc_code[buf];
00198     }else{
00199         LAST_SKIP_BITS(re, gb, 8);
00200         UPDATE_CACHE(re, gb);
00201         buf |= 1 | (GET_CACHE(re, gb) >> 8);
00202 
00203         if((buf & 0xAAAAAAAA) == 0)
00204             return INVALID_VLC;
00205 
00206         for(log=31; (buf & 0x80000000) == 0; log--){
00207             buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
00208         }
00209 
00210         LAST_SKIP_BITS(re, gb, 63 - 2*log - 8);
00211         CLOSE_READER(re, gb);
00212 
00213         return (signed) (((((buf << log) >> log) - 1) ^ -(buf & 0x1)) + 1) >> 1;
00214     }
00215 }
00216 
00217 static inline int dirac_get_se_golomb(GetBitContext *gb){
00218     uint32_t buf;
00219     uint32_t ret;
00220 
00221     ret = svq3_get_ue_golomb(gb);
00222 
00223     if (ret) {
00224         OPEN_READER(re, gb);
00225         UPDATE_CACHE(re, gb);
00226         buf = SHOW_SBITS(re, gb, 1);
00227         LAST_SKIP_BITS(re, gb, 1);
00228         ret = (ret ^ buf) - buf;
00229         CLOSE_READER(re, gb);
00230     }
00231 
00232     return ret;
00233 }
00234 
00238 static inline int get_ur_golomb(GetBitContext *gb, int k, int limit, int esc_len){
00239     unsigned int buf;
00240     int log;
00241 
00242     OPEN_READER(re, gb);
00243     UPDATE_CACHE(re, gb);
00244     buf=GET_CACHE(re, gb);
00245 
00246     log= av_log2(buf);
00247 
00248     if(log > 31-limit){
00249         buf >>= log - k;
00250         buf += (30-log)<<k;
00251         LAST_SKIP_BITS(re, gb, 32 + k - log);
00252         CLOSE_READER(re, gb);
00253 
00254         return buf;
00255     }else{
00256         LAST_SKIP_BITS(re, gb, limit);
00257         UPDATE_CACHE(re, gb);
00258 
00259         buf = SHOW_UBITS(re, gb, esc_len);
00260 
00261         LAST_SKIP_BITS(re, gb, esc_len);
00262         CLOSE_READER(re, gb);
00263 
00264         return buf + limit - 1;
00265     }
00266 }
00267 
00271 static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit, int esc_len){
00272     unsigned int buf;
00273     int log;
00274 
00275     OPEN_READER(re, gb);
00276     UPDATE_CACHE(re, gb);
00277     buf=GET_CACHE(re, gb);
00278 
00279     log= av_log2(buf);
00280 
00281     if(log - k >= 32-MIN_CACHE_BITS+(MIN_CACHE_BITS==32) && 32-log < limit){
00282         buf >>= log - k;
00283         buf += (30-log)<<k;
00284         LAST_SKIP_BITS(re, gb, 32 + k - log);
00285         CLOSE_READER(re, gb);
00286 
00287         return buf;
00288     }else{
00289         int i;
00290         for(i=0; SHOW_UBITS(re, gb, 1) == 0; i++){
00291             LAST_SKIP_BITS(re, gb, 1);
00292             UPDATE_CACHE(re, gb);
00293         }
00294         SKIP_BITS(re, gb, 1);
00295 
00296         if(i < limit - 1){
00297             if(k){
00298                 buf = SHOW_UBITS(re, gb, k);
00299                 LAST_SKIP_BITS(re, gb, k);
00300             }else{
00301                 buf=0;
00302             }
00303 
00304             CLOSE_READER(re, gb);
00305             return buf + (i<<k);
00306         }else if(i == limit - 1){
00307             buf = SHOW_UBITS(re, gb, esc_len);
00308             LAST_SKIP_BITS(re, gb, esc_len);
00309             CLOSE_READER(re, gb);
00310 
00311             return buf + 1;
00312         }else
00313             return -1;
00314     }
00315 }
00316 
00320 static inline int get_sr_golomb(GetBitContext *gb, int k, int limit, int esc_len){
00321     int v= get_ur_golomb(gb, k, limit, esc_len);
00322 
00323     v++;
00324     if (v&1) return v>>1;
00325     else return -(v>>1);
00326 
00327 //    return (v>>1) ^ -(v&1);
00328 }
00329 
00333 static inline int get_sr_golomb_flac(GetBitContext *gb, int k, int limit, int esc_len){
00334     int v= get_ur_golomb_jpegls(gb, k, limit, esc_len);
00335     return (v>>1) ^ -(v&1);
00336 }
00337 
00341 static inline unsigned int get_ur_golomb_shorten(GetBitContext *gb, int k){
00342         return get_ur_golomb_jpegls(gb, k, INT_MAX, 0);
00343 }
00344 
00348 static inline int get_sr_golomb_shorten(GetBitContext* gb, int k)
00349 {
00350     int uvar = get_ur_golomb_jpegls(gb, k + 1, INT_MAX, 0);
00351     if (uvar & 1)
00352         return ~(uvar >> 1);
00353     else
00354         return uvar >> 1;
00355 }
00356 
00357 
00358 
00359 #ifdef TRACE
00360 
00361 static inline int get_ue(GetBitContext *s, char *file, const char *func, int line){
00362     int show= show_bits(s, 24);
00363     int pos= get_bits_count(s);
00364     int i= get_ue_golomb(s);
00365     int len= get_bits_count(s) - pos;
00366     int bits= show>>(24-len);
00367 
00368     print_bin(bits, len);
00369 
00370     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d ue  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
00371 
00372     return i;
00373 }
00374 
00375 static inline int get_se(GetBitContext *s, char *file, const char *func, int line){
00376     int show= show_bits(s, 24);
00377     int pos= get_bits_count(s);
00378     int i= get_se_golomb(s);
00379     int len= get_bits_count(s) - pos;
00380     int bits= show>>(24-len);
00381 
00382     print_bin(bits, len);
00383 
00384     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d se  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
00385 
00386     return i;
00387 }
00388 
00389 static inline int get_te(GetBitContext *s, int r, char *file, const char *func, int line){
00390     int show= show_bits(s, 24);
00391     int pos= get_bits_count(s);
00392     int i= get_te0_golomb(s, r);
00393     int len= get_bits_count(s) - pos;
00394     int bits= show>>(24-len);
00395 
00396     print_bin(bits, len);
00397 
00398     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d te  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
00399 
00400     return i;
00401 }
00402 
00403 #define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
00404 #define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
00405 #define get_te_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
00406 #define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
00407 
00408 #endif
00409 
00413 static inline void set_ue_golomb(PutBitContext *pb, int i){
00414     int e;
00415 
00416     assert(i>=0);
00417 
00418 #if 0
00419     if(i=0){
00420         put_bits(pb, 1, 1);
00421         return;
00422     }
00423 #endif
00424     if(i<256)
00425         put_bits(pb, ff_ue_golomb_len[i], i+1);
00426     else{
00427         e= av_log2(i+1);
00428 
00429         put_bits(pb, 2*e+1, i+1);
00430     }
00431 }
00432 
00436 static inline void set_te_golomb(PutBitContext *pb, int i, int range){
00437     assert(range >= 1);
00438     assert(i<=range);
00439 
00440     if(range==2) put_bits(pb, 1, i^1);
00441     else         set_ue_golomb(pb, i);
00442 }
00443 
00447 static inline void set_se_golomb(PutBitContext *pb, int i){
00448 //    if (i>32767 || i<-32767)
00449 //        av_log(NULL,AV_LOG_ERROR,"value out of range %d\n", i);
00450 #if 0
00451     if(i<=0) i= -2*i;
00452     else     i=  2*i-1;
00453 #elif 1
00454     i= 2*i-1;
00455     if(i<0) i^= -1; //FIXME check if gcc does the right thing
00456 #else
00457     i= 2*i-1;
00458     i^= (i>>31);
00459 #endif
00460     set_ue_golomb(pb, i);
00461 }
00462 
00466 static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
00467     int e;
00468 
00469     assert(i>=0);
00470 
00471     e= i>>k;
00472     if(e<limit){
00473         put_bits(pb, e + k + 1, (1<<k) + (i&((1<<k)-1)));
00474     }else{
00475         put_bits(pb, limit + esc_len, i - limit + 1);
00476     }
00477 }
00478 
00482 static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k, int limit, int esc_len){
00483     int e;
00484 
00485     assert(i>=0);
00486 
00487     e= (i>>k) + 1;
00488     if(e<limit){
00489         while(e > 31) {
00490             put_bits(pb, 31, 0);
00491             e -= 31;
00492         }
00493         put_bits(pb, e, 1);
00494         if(k)
00495             put_sbits(pb, k, i);
00496     }else{
00497         while(limit > 31) {
00498             put_bits(pb, 31, 0);
00499             limit -= 31;
00500         }
00501         put_bits(pb, limit  , 1);
00502         put_bits(pb, esc_len, i - 1);
00503     }
00504 }
00505 
00509 static inline void set_sr_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
00510     int v;
00511 
00512     v = -2*i-1;
00513     v ^= (v>>31);
00514 
00515     set_ur_golomb(pb, v, k, limit, esc_len);
00516 }
00517 
00521 static inline void set_sr_golomb_flac(PutBitContext *pb, int i, int k, int limit, int esc_len){
00522     int v;
00523 
00524     v = -2*i-1;
00525     v ^= (v>>31);
00526 
00527     set_ur_golomb_jpegls(pb, v, k, limit, esc_len);
00528 }
00529 
00530 #endif /* AVCODEC_GOLOMB_H */