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70 lines
1.8 KiB
C
70 lines
1.8 KiB
C
/*
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* copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg 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 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg 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 FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef AVCODEC_UNARY_H
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#define AVCODEC_UNARY_H
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#include "get_bits.h"
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/**
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* Get unary code of limited length
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* @param gb GetBitContext
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* @param[in] stop The bitstop value (unary code of 1's or 0's)
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* @param[in] len Maximum length
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* @return unary 0 based code index. This is also the length in bits of the
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* code excluding the stop bit.
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* (in case len=1)
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* 1 0
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* 0 1
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* (in case len=2)
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* 1 0
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* 01 1
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* 00 2
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* (in case len=3)
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* 1 0
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* 01 1
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* 001 2
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* 000 3
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*/
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static inline int get_unary(GetBitContext *gb, int stop, int len)
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{
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int i;
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for(i = 0; i < len && get_bits1(gb) != stop; i++);
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return i;
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}
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/**
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* Get unary code terminated by a 0 with a maximum length of 33
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* @param gb GetBitContext
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* @return Unary length/index
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*/
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static inline int get_unary_0_33(GetBitContext *gb)
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{
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return get_unary(gb, 0, 33);
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}
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static inline int get_unary_0_9(GetBitContext *gb)
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{
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return get_unary(gb, 0, 9);
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}
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#endif /* AVCODEC_UNARY_H */
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