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 
00081 static inline unsigned get_ue_golomb_long(GetBitContext *gb)
00082 {
00083     unsigned buf, log;
00084 
00085     buf = show_bits_long(gb, 32);
00086     log = 31 - av_log2(buf);
00087     skip_bits_long(gb, log);
00088 
00089     return get_bits_long(gb, log + 1) - 1;
00090 }
00091 
00096 static inline int get_ue_golomb_31(GetBitContext *gb){
00097     unsigned int buf;
00098 
00099     OPEN_READER(re, gb);
00100     UPDATE_CACHE(re, gb);
00101     buf=GET_CACHE(re, gb);
00102 
00103     buf >>= 32 - 9;
00104     LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
00105     CLOSE_READER(re, gb);
00106 
00107     return ff_ue_golomb_vlc_code[buf];
00108 }
00109 
00110 static inline int svq3_get_ue_golomb(GetBitContext *gb){
00111     uint32_t buf;
00112 
00113     OPEN_READER(re, gb);
00114     UPDATE_CACHE(re, gb);
00115     buf=GET_CACHE(re, gb);
00116 
00117     if(buf&0xAA800000){
00118         buf >>= 32 - 8;
00119         LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
00120         CLOSE_READER(re, gb);
00121 
00122         return ff_interleaved_ue_golomb_vlc_code[buf];
00123     }else{
00124         int ret = 1;
00125 
00126         do {
00127             buf >>= 32 - 8;
00128             LAST_SKIP_BITS(re, gb, FFMIN(ff_interleaved_golomb_vlc_len[buf], 8));
00129 
00130             if (ff_interleaved_golomb_vlc_len[buf] != 9){
00131                 ret <<= (ff_interleaved_golomb_vlc_len[buf] - 1) >> 1;
00132                 ret |= ff_interleaved_dirac_golomb_vlc_code[buf];
00133                 break;
00134             }
00135             ret = (ret << 4) | ff_interleaved_dirac_golomb_vlc_code[buf];
00136             UPDATE_CACHE(re, gb);
00137             buf = GET_CACHE(re, gb);
00138         } while (ret<0x8000000U && HAVE_BITS_REMAINING(re, gb));
00139 
00140         CLOSE_READER(re, gb);
00141         return ret - 1;
00142     }
00143 }
00144 
00148 static inline int get_te0_golomb(GetBitContext *gb, int range){
00149     av_assert2(range >= 1);
00150 
00151     if(range==1)      return 0;
00152     else if(range==2) return get_bits1(gb)^1;
00153     else              return get_ue_golomb(gb);
00154 }
00155 
00159 static inline int get_te_golomb(GetBitContext *gb, int range){
00160     av_assert2(range >= 1);
00161 
00162     if(range==2) return get_bits1(gb)^1;
00163     else         return get_ue_golomb(gb);
00164 }
00165 
00166 
00170 static inline int get_se_golomb(GetBitContext *gb){
00171     unsigned int buf;
00172     int log;
00173 
00174     OPEN_READER(re, gb);
00175     UPDATE_CACHE(re, gb);
00176     buf=GET_CACHE(re, gb);
00177 
00178     if(buf >= (1<<27)){
00179         buf >>= 32 - 9;
00180         LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
00181         CLOSE_READER(re, gb);
00182 
00183         return ff_se_golomb_vlc_code[buf];
00184     }else{
00185         log= 2*av_log2(buf) - 31;
00186         buf>>= log;
00187 
00188         LAST_SKIP_BITS(re, gb, 32 - log);
00189         CLOSE_READER(re, gb);
00190 
00191         if(buf&1) buf= -(buf>>1);
00192         else      buf=  (buf>>1);
00193 
00194         return buf;
00195     }
00196 }
00197 
00198 static inline int svq3_get_se_golomb(GetBitContext *gb){
00199     unsigned int buf;
00200     int log;
00201 
00202     OPEN_READER(re, gb);
00203     UPDATE_CACHE(re, gb);
00204     buf=GET_CACHE(re, gb);
00205 
00206     if(buf&0xAA800000){
00207         buf >>= 32 - 8;
00208         LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
00209         CLOSE_READER(re, gb);
00210 
00211         return ff_interleaved_se_golomb_vlc_code[buf];
00212     }else{
00213         LAST_SKIP_BITS(re, gb, 8);
00214         UPDATE_CACHE(re, gb);
00215         buf |= 1 | (GET_CACHE(re, gb) >> 8);
00216 
00217         if((buf & 0xAAAAAAAA) == 0)
00218             return INVALID_VLC;
00219 
00220         for(log=31; (buf & 0x80000000) == 0; log--){
00221             buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
00222         }
00223 
00224         LAST_SKIP_BITS(re, gb, 63 - 2*log - 8);
00225         CLOSE_READER(re, gb);
00226 
00227         return (signed) (((((buf << log) >> log) - 1) ^ -(buf & 0x1)) + 1) >> 1;
00228     }
00229 }
00230 
00231 static inline int dirac_get_se_golomb(GetBitContext *gb){
00232     uint32_t buf;
00233     uint32_t ret;
00234 
00235     ret = svq3_get_ue_golomb(gb);
00236 
00237     if (ret) {
00238         OPEN_READER(re, gb);
00239         UPDATE_CACHE(re, gb);
00240         buf = SHOW_SBITS(re, gb, 1);
00241         LAST_SKIP_BITS(re, gb, 1);
00242         ret = (ret ^ buf) - buf;
00243         CLOSE_READER(re, gb);
00244     }
00245 
00246     return ret;
00247 }
00248 
00252 static inline int get_ur_golomb(GetBitContext *gb, int k, int limit, int esc_len){
00253     unsigned int buf;
00254     int log;
00255 
00256     OPEN_READER(re, gb);
00257     UPDATE_CACHE(re, gb);
00258     buf=GET_CACHE(re, gb);
00259 
00260     log= av_log2(buf);
00261 
00262     if(log > 31-limit){
00263         buf >>= log - k;
00264         buf += (30-log)<<k;
00265         LAST_SKIP_BITS(re, gb, 32 + k - log);
00266         CLOSE_READER(re, gb);
00267 
00268         return buf;
00269     }else{
00270         LAST_SKIP_BITS(re, gb, limit);
00271         UPDATE_CACHE(re, gb);
00272 
00273         buf = SHOW_UBITS(re, gb, esc_len);
00274 
00275         LAST_SKIP_BITS(re, gb, esc_len);
00276         CLOSE_READER(re, gb);
00277 
00278         return buf + limit - 1;
00279     }
00280 }
00281 
00285 static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit, int esc_len){
00286     unsigned int buf;
00287     int log;
00288 
00289     OPEN_READER(re, gb);
00290     UPDATE_CACHE(re, gb);
00291     buf=GET_CACHE(re, gb);
00292 
00293     log= av_log2(buf);
00294 
00295     if(log - k >= 32-MIN_CACHE_BITS+(MIN_CACHE_BITS==32) && 32-log < limit){
00296         buf >>= log - k;
00297         buf += (30-log)<<k;
00298         LAST_SKIP_BITS(re, gb, 32 + k - log);
00299         CLOSE_READER(re, gb);
00300 
00301         return buf;
00302     }else{
00303         int i;
00304         for (i = 0; i < limit && SHOW_UBITS(re, gb, 1) == 0; i++) {
00305             if (gb->size_in_bits <= re_index)
00306                 return -1;
00307             LAST_SKIP_BITS(re, gb, 1);
00308             UPDATE_CACHE(re, gb);
00309         }
00310         SKIP_BITS(re, gb, 1);
00311 
00312         if(i < limit - 1){
00313             if(k){
00314                 buf = SHOW_UBITS(re, gb, k);
00315                 LAST_SKIP_BITS(re, gb, k);
00316             }else{
00317                 buf=0;
00318             }
00319 
00320             CLOSE_READER(re, gb);
00321             return buf + (i<<k);
00322         }else if(i == limit - 1){
00323             buf = SHOW_UBITS(re, gb, esc_len);
00324             LAST_SKIP_BITS(re, gb, esc_len);
00325             CLOSE_READER(re, gb);
00326 
00327             return buf + 1;
00328         }else
00329             return -1;
00330     }
00331 }
00332 
00336 static inline int get_sr_golomb(GetBitContext *gb, int k, int limit, int esc_len){
00337     int v= get_ur_golomb(gb, k, limit, esc_len);
00338 
00339     v++;
00340     if (v&1) return v>>1;
00341     else return -(v>>1);
00342 
00343 //    return (v>>1) ^ -(v&1);
00344 }
00345 
00349 static inline int get_sr_golomb_flac(GetBitContext *gb, int k, int limit, int esc_len){
00350     int v= get_ur_golomb_jpegls(gb, k, limit, esc_len);
00351     return (v>>1) ^ -(v&1);
00352 }
00353 
00357 static inline unsigned int get_ur_golomb_shorten(GetBitContext *gb, int k){
00358         return get_ur_golomb_jpegls(gb, k, INT_MAX, 0);
00359 }
00360 
00364 static inline int get_sr_golomb_shorten(GetBitContext* gb, int k)
00365 {
00366     int uvar = get_ur_golomb_jpegls(gb, k + 1, INT_MAX, 0);
00367     if (uvar & 1)
00368         return ~(uvar >> 1);
00369     else
00370         return uvar >> 1;
00371 }
00372 
00373 
00374 
00375 #ifdef TRACE
00376 
00377 static inline int get_ue(GetBitContext *s, char *file, const char *func, int line){
00378     int show= show_bits(s, 24);
00379     int pos= get_bits_count(s);
00380     int i= get_ue_golomb(s);
00381     int len= get_bits_count(s) - pos;
00382     int bits= show>>(24-len);
00383 
00384     print_bin(bits, len);
00385 
00386     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d ue  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
00387 
00388     return i;
00389 }
00390 
00391 static inline int get_se(GetBitContext *s, char *file, const char *func, int line){
00392     int show= show_bits(s, 24);
00393     int pos= get_bits_count(s);
00394     int i= get_se_golomb(s);
00395     int len= get_bits_count(s) - pos;
00396     int bits= show>>(24-len);
00397 
00398     print_bin(bits, len);
00399 
00400     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d se  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
00401 
00402     return i;
00403 }
00404 
00405 static inline int get_te(GetBitContext *s, int r, char *file, const char *func, int line){
00406     int show= show_bits(s, 24);
00407     int pos= get_bits_count(s);
00408     int i= get_te0_golomb(s, r);
00409     int len= get_bits_count(s) - pos;
00410     int bits= show>>(24-len);
00411 
00412     print_bin(bits, len);
00413 
00414     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d te  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
00415 
00416     return i;
00417 }
00418 
00419 #define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
00420 #define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
00421 #define get_te_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
00422 #define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
00423 
00424 #endif
00425 
00429 static inline void set_ue_golomb(PutBitContext *pb, int i){
00430     int e;
00431 
00432     av_assert2(i>=0);
00433 
00434 #if 0
00435     if(i=0){
00436         put_bits(pb, 1, 1);
00437         return;
00438     }
00439 #endif
00440     if(i<256)
00441         put_bits(pb, ff_ue_golomb_len[i], i+1);
00442     else{
00443         e= av_log2(i+1);
00444 
00445         put_bits(pb, 2*e+1, i+1);
00446     }
00447 }
00448 
00452 static inline void set_te_golomb(PutBitContext *pb, int i, int range){
00453     av_assert2(range >= 1);
00454     av_assert2(i<=range);
00455 
00456     if(range==2) put_bits(pb, 1, i^1);
00457     else         set_ue_golomb(pb, i);
00458 }
00459 
00463 static inline void set_se_golomb(PutBitContext *pb, int i){
00464 //    if (i>32767 || i<-32767)
00465 //        av_log(NULL,AV_LOG_ERROR,"value out of range %d\n", i);
00466 #if 0
00467     if(i<=0) i= -2*i;
00468     else     i=  2*i-1;
00469 #elif 1
00470     i= 2*i-1;
00471     if(i<0) i^= -1; //FIXME check if gcc does the right thing
00472 #else
00473     i= 2*i-1;
00474     i^= (i>>31);
00475 #endif
00476     set_ue_golomb(pb, i);
00477 }
00478 
00482 static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
00483     int e;
00484 
00485     av_assert2(i>=0);
00486 
00487     e= i>>k;
00488     if(e<limit){
00489         put_bits(pb, e + k + 1, (1<<k) + (i&((1<<k)-1)));
00490     }else{
00491         put_bits(pb, limit + esc_len, i - limit + 1);
00492     }
00493 }
00494 
00498 static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k, int limit, int esc_len){
00499     int e;
00500 
00501     av_assert2(i>=0);
00502 
00503     e= (i>>k) + 1;
00504     if(e<limit){
00505         while(e > 31) {
00506             put_bits(pb, 31, 0);
00507             e -= 31;
00508         }
00509         put_bits(pb, e, 1);
00510         if(k)
00511             put_sbits(pb, k, i);
00512     }else{
00513         while(limit > 31) {
00514             put_bits(pb, 31, 0);
00515             limit -= 31;
00516         }
00517         put_bits(pb, limit  , 1);
00518         put_bits(pb, esc_len, i - 1);
00519     }
00520 }
00521 
00525 static inline void set_sr_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
00526     int v;
00527 
00528     v = -2*i-1;
00529     v ^= (v>>31);
00530 
00531     set_ur_golomb(pb, v, k, limit, esc_len);
00532 }
00533 
00537 static inline void set_sr_golomb_flac(PutBitContext *pb, int i, int k, int limit, int esc_len){
00538     int v;
00539 
00540     v = -2*i-1;
00541     v ^= (v>>31);
00542 
00543     set_ur_golomb_jpegls(pb, v, k, limit, esc_len);
00544 }
00545 
00546 #endif /* AVCODEC_GOLOMB_H */