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281 lines
6.9 KiB
281 lines
6.9 KiB
/* |
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* exp golomb vlc stuff |
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* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at> |
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* |
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* This library is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2 of the License, or (at your option) any later version. |
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* |
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* This library is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with this library; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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* |
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*/ |
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/** |
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* @file golomb.h |
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* @brief |
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* exp golomb vlc stuff |
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* @author Michael Niedermayer <michaelni@gmx.at> |
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*/ |
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#define INVALID_VLC 0x80000000 |
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extern const uint8_t ff_golomb_vlc_len[512]; |
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extern const uint8_t ff_ue_golomb_vlc_code[512]; |
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extern const int8_t ff_se_golomb_vlc_code[512]; |
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extern const uint8_t ff_ue_golomb_len[256]; |
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extern const uint8_t ff_interleaved_golomb_vlc_len[256]; |
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extern const uint8_t ff_interleaved_ue_golomb_vlc_code[256]; |
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extern const int8_t ff_interleaved_se_golomb_vlc_code[256]; |
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/** |
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* read unsigned exp golomb code. |
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*/ |
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static inline int get_ue_golomb(GetBitContext *gb){ |
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unsigned int buf; |
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int log; |
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OPEN_READER(re, gb); |
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UPDATE_CACHE(re, gb); |
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buf=GET_CACHE(re, gb); |
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if(buf >= (1<<27)){ |
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buf >>= 32 - 9; |
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LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]); |
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CLOSE_READER(re, gb); |
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return ff_ue_golomb_vlc_code[buf]; |
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}else{ |
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log= 2*av_log2(buf) - 31; |
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buf>>= log; |
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buf--; |
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LAST_SKIP_BITS(re, gb, 32 - log); |
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CLOSE_READER(re, gb); |
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return buf; |
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} |
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} |
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static inline int svq3_get_ue_golomb(GetBitContext *gb){ |
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uint32_t buf; |
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int log; |
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OPEN_READER(re, gb); |
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UPDATE_CACHE(re, gb); |
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buf=GET_CACHE(re, gb); |
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if(buf&0xAA800000){ |
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buf >>= 32 - 8; |
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LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]); |
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CLOSE_READER(re, gb); |
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return ff_interleaved_ue_golomb_vlc_code[buf]; |
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}else{ |
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buf|=1; |
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if((buf & 0xAAAAAAAA) == 0) |
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return INVALID_VLC; |
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for(log=31; (buf & 0x80000000) == 0; log--){ |
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buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30); |
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} |
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LAST_SKIP_BITS(re, gb, 63 - 2*log); |
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CLOSE_READER(re, gb); |
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return ((buf << log) >> log) - 1; |
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} |
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} |
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/** |
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* read unsigned truncated exp golomb code. |
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*/ |
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static inline int get_te0_golomb(GetBitContext *gb, int range){ |
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assert(range >= 1); |
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if(range==1) return 0; |
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else if(range==2) return get_bits1(gb)^1; |
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else return get_ue_golomb(gb); |
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} |
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/** |
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* read unsigned truncated exp golomb code. |
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*/ |
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static inline int get_te_golomb(GetBitContext *gb, int range){ |
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assert(range >= 1); |
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if(range==2) return get_bits1(gb)^1; |
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else return get_ue_golomb(gb); |
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} |
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/** |
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* read signed exp golomb code. |
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*/ |
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static inline int get_se_golomb(GetBitContext *gb){ |
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unsigned int buf; |
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int log; |
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OPEN_READER(re, gb); |
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UPDATE_CACHE(re, gb); |
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buf=GET_CACHE(re, gb); |
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if(buf >= (1<<27)){ |
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buf >>= 32 - 9; |
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LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]); |
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CLOSE_READER(re, gb); |
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return ff_se_golomb_vlc_code[buf]; |
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}else{ |
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log= 2*av_log2(buf) - 31; |
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buf>>= log; |
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LAST_SKIP_BITS(re, gb, 32 - log); |
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CLOSE_READER(re, gb); |
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if(buf&1) buf= -(buf>>1); |
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else buf= (buf>>1); |
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return buf; |
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} |
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} |
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static inline int svq3_get_se_golomb(GetBitContext *gb){ |
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unsigned int buf; |
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int log; |
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OPEN_READER(re, gb); |
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UPDATE_CACHE(re, gb); |
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buf=GET_CACHE(re, gb); |
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if(buf&0xAA800000){ |
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buf >>= 32 - 8; |
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LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]); |
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CLOSE_READER(re, gb); |
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return ff_interleaved_se_golomb_vlc_code[buf]; |
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}else{ |
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buf |=1; |
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if((buf & 0xAAAAAAAA) == 0) |
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return INVALID_VLC; |
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for(log=31; (buf & 0x80000000) == 0; log--){ |
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buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30); |
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} |
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LAST_SKIP_BITS(re, gb, 63 - 2*log); |
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CLOSE_READER(re, gb); |
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return (signed) (((((buf << log) >> log) - 1) ^ -(buf & 0x1)) + 1) >> 1; |
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} |
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} |
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#ifdef TRACE |
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static inline int get_ue(GetBitContext *s, char *file, char *func, int line){ |
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int show= show_bits(s, 24); |
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int pos= get_bits_count(s); |
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int i= get_ue_golomb(s); |
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int len= get_bits_count(s) - pos; |
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int bits= show>>(24-len); |
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print_bin(bits, len); |
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printf("%5d %2d %3d ue @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line); |
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return i; |
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} |
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static inline int get_se(GetBitContext *s, char *file, char *func, int line){ |
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int show= show_bits(s, 24); |
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int pos= get_bits_count(s); |
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int i= get_se_golomb(s); |
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int len= get_bits_count(s) - pos; |
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int bits= show>>(24-len); |
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print_bin(bits, len); |
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printf("%5d %2d %3d se @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line); |
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return i; |
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} |
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static inline int get_te(GetBitContext *s, int r, char *file, char *func, int line){ |
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int show= show_bits(s, 24); |
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int pos= get_bits_count(s); |
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int i= get_te0_golomb(s, r); |
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int len= get_bits_count(s) - pos; |
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int bits= show>>(24-len); |
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print_bin(bits, len); |
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printf("%5d %2d %3d te @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line); |
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return i; |
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} |
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#define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__) |
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#define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__) |
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#define get_te_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__) |
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#define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__) |
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#endif |
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/** |
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* write unsigned exp golomb code. |
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*/ |
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static inline void set_ue_golomb(PutBitContext *pb, int i){ |
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int e; |
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assert(i>=0); |
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#if 0 |
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if(i=0){ |
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put_bits(pb, 1, 1); |
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return; |
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} |
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#endif |
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if(i<256) |
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put_bits(pb, ff_ue_golomb_len[i], i+1); |
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else{ |
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e= av_log2(i+1); |
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put_bits(pb, 2*e+1, i+1); |
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} |
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} |
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/** |
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* write truncated unsigned exp golomb code. |
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*/ |
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static inline void set_te_golomb(PutBitContext *pb, int i, int range){ |
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assert(range >= 1); |
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assert(i<=range); |
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if(range==2) put_bits(pb, 1, i^1); |
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else set_ue_golomb(pb, i); |
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} |
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/** |
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* write signed exp golomb code. |
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*/ |
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static inline void set_se_golomb(PutBitContext *pb, int i){ |
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#if 0 |
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if(i<=0) i= -2*i; |
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else i= 2*i-1; |
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#elif 1 |
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i= 2*i-1; |
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if(i<0) i^= -1; //FIXME check if gcc does the right thing |
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#else |
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i= 2*i-1; |
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i^= (i>>31); |
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#endif |
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set_ue_golomb(pb, i); |
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}
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