/* * exp golomb vlc stuff * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at> * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ /** * @file golomb.h * @brief * exp golomb vlc stuff * @author Michael Niedermayer <michaelni@gmx.at> */ extern const uint8_t ff_golomb_vlc_len[512]; extern const uint8_t ff_ue_golomb_vlc_code[512]; extern const int8_t ff_se_golomb_vlc_code[512]; extern const uint8_t ff_ue_golomb_len[256]; /** * read unsigned exp golomb code. */ static inline int get_ue_golomb(GetBitContext *gb){ unsigned int buf; int log; OPEN_READER(re, gb); UPDATE_CACHE(re, gb); buf=GET_CACHE(re, gb); if(buf >= (1<<27)){ buf >>= 32 - 9; LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]); CLOSE_READER(re, gb); return ff_ue_golomb_vlc_code[buf]; }else{ log= 2*av_log2(buf) - 31; buf>>= log; buf--; LAST_SKIP_BITS(re, gb, 32 - log); CLOSE_READER(re, gb); return buf; } } /** * read unsigned truncated exp golomb code. */ static inline int get_te0_golomb(GetBitContext *gb, int range){ assert(range >= 1); if(range==1) return 0; else if(range==2) return get_bits1(gb)^1; else return get_ue_golomb(gb); } /** * read unsigned truncated exp golomb code. */ static inline int get_te_golomb(GetBitContext *gb, int range){ assert(range >= 1); if(range==2) return get_bits1(gb)^1; else return get_ue_golomb(gb); } /** * read signed exp golomb code. */ static inline int get_se_golomb(GetBitContext *gb){ unsigned int buf; int log; OPEN_READER(re, gb); UPDATE_CACHE(re, gb); buf=GET_CACHE(re, gb); if(buf >= (1<<27)){ buf >>= 32 - 9; LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]); CLOSE_READER(re, gb); return ff_se_golomb_vlc_code[buf]; }else{ log= 2*av_log2(buf) - 31; buf>>= log; LAST_SKIP_BITS(re, gb, 32 - log); CLOSE_READER(re, gb); if(buf&1) buf= -(buf>>1); else buf= (buf>>1); return buf; } } #ifdef TRACE static inline int get_ue(GetBitContext *s, char *file, char *func, int line){ int show= show_bits(s, 24); int pos= get_bits_count(s); int i= get_ue_golomb(s); int len= get_bits_count(s) - pos; int bits= show>>(24-len); print_bin(bits, len); printf("%5d %2d %3d ue @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line); return i; } static inline int get_se(GetBitContext *s, char *file, char *func, int line){ int show= show_bits(s, 24); int pos= get_bits_count(s); int i= get_se_golomb(s); int len= get_bits_count(s) - pos; int bits= show>>(24-len); print_bin(bits, len); printf("%5d %2d %3d se @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line); return i; } static inline int get_te(GetBitContext *s, int r, char *file, char *func, int line){ int show= show_bits(s, 24); int pos= get_bits_count(s); int i= get_te0_golomb(s, r); int len= get_bits_count(s) - pos; int bits= show>>(24-len); print_bin(bits, len); printf("%5d %2d %3d te @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line); return i; } #define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__) #define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__) #define get_te_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__) #define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__) #endif /** * write unsigned exp golomb code. */ static inline void set_ue_golomb(PutBitContext *pb, int i){ int e; assert(i>=0); #if 0 if(i=0){ put_bits(pb, 1, 1); return; } #endif if(i<256) put_bits(pb, ff_ue_golomb_len[i], i+1); else{ e= av_log2(i+1); put_bits(pb, 2*e+1, i+1); } } /** * write truncated unsigned exp golomb code. */ static inline void set_te_golomb(PutBitContext *pb, int i, int range){ assert(range >= 1); assert(i<=range); if(range==2) put_bits(pb, 1, i^1); else set_ue_golomb(pb, i); } /** * write signed exp golomb code. */ static inline void set_se_golomb(PutBitContext *pb, int i){ #if 0 if(i<=0) i= -2*i; else i= 2*i-1; #elif 1 i= 2*i-1; if(i<0) i^= -1; //FIXME check if gcc does the right thing #else i= 2*i-1; i^= (i>>31); #endif set_ue_golomb(pb, i); }