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ffmpeg / libavcodec / golomb.h @ d4f2a625

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/*
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 * exp golomb vlc stuff
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 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
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 * Copyright (c) 2004 Alex Beregszaszi
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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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/**
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 * @file libavcodec/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> and Alex Beregszaszi
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 */
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#ifndef AVCODEC_GOLOMB_H
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#define AVCODEC_GOLOMB_H
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#include <stdint.h>
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#include "bitstream.h"
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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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extern const uint8_t ff_interleaved_dirac_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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 /**
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 * read unsigned exp golomb code, constraint to a max of 31.
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 * the return value is undefined if the stored value exceeds 31.
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 */
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static inline int get_ue_golomb_31(GetBitContext *gb){
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    unsigned int buf;
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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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    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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}
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static inline int svq3_get_ue_golomb(GetBitContext *gb){
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    uint32_t buf;
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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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        int ret = 1;
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        while (1) {
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            buf >>= 32 - 8;
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            LAST_SKIP_BITS(re, gb, FFMIN(ff_interleaved_golomb_vlc_len[buf], 8));
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            if (ff_interleaved_golomb_vlc_len[buf] != 9){
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                ret <<= (ff_interleaved_golomb_vlc_len[buf] - 1) >> 1;
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                ret |= ff_interleaved_dirac_golomb_vlc_code[buf];
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                break;
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            }
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            ret = (ret << 4) | ff_interleaved_dirac_golomb_vlc_code[buf];
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            UPDATE_CACHE(re, gb);
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            buf = GET_CACHE(re, gb);
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        }
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        CLOSE_READER(re, gb);
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        return ret - 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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        LAST_SKIP_BITS(re, gb, 8);
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        UPDATE_CACHE(re, gb);
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        buf |= 1 | (GET_CACHE(re, gb) >> 8);
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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 - 8);
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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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static inline int dirac_get_se_golomb(GetBitContext *gb){
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    uint32_t buf;
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    uint32_t ret;
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    ret = svq3_get_ue_golomb(gb);
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    if (ret) {
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        OPEN_READER(re, gb);
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        UPDATE_CACHE(re, gb);
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        buf = SHOW_SBITS(re, gb, 1);
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        LAST_SKIP_BITS(re, gb, 1);
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        ret = (ret ^ buf) - buf;
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        CLOSE_READER(re, gb);
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    }
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    return ret;
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}
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/**
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 * read unsigned golomb rice code (ffv1).
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 */
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static inline int get_ur_golomb(GetBitContext *gb, int k, int limit, int esc_len){
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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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    log= av_log2(buf);
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    if(log > 31-limit){
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        buf >>= log - k;
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        buf += (30-log)<<k;
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        LAST_SKIP_BITS(re, gb, 32 + k - log);
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        CLOSE_READER(re, gb);
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        return buf;
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    }else{
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        buf >>= 32 - limit - esc_len;
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        LAST_SKIP_BITS(re, gb, esc_len + limit);
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        CLOSE_READER(re, gb);
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        return buf + limit - 1;
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    }
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}
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/**
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 * read unsigned golomb rice code (jpegls).
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 */
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static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit, int esc_len){
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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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    log= av_log2(buf);
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    if(log - k >= 32-MIN_CACHE_BITS+(MIN_CACHE_BITS==32) && 32-log < limit){
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        buf >>= log - k;
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        buf += (30-log)<<k;
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        LAST_SKIP_BITS(re, gb, 32 + k - log);
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        CLOSE_READER(re, gb);
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282
        return buf;
283
    }else{
284
        int i;
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        for(i=0; SHOW_UBITS(re, gb, 1) == 0; i++){
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            LAST_SKIP_BITS(re, gb, 1);
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            UPDATE_CACHE(re, gb);
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        }
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        SKIP_BITS(re, gb, 1);
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        if(i < limit - 1){
292
            if(k){
293
                buf = SHOW_UBITS(re, gb, k);
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                LAST_SKIP_BITS(re, gb, k);
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            }else{
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                buf=0;
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            }
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            CLOSE_READER(re, gb);
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            return buf + (i<<k);
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        }else if(i == limit - 1){
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            buf = SHOW_UBITS(re, gb, esc_len);
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            LAST_SKIP_BITS(re, gb, esc_len);
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            CLOSE_READER(re, gb);
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            return buf + 1;
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        }else
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            return -1;
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    }
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}
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/**
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 * read signed golomb rice code (ffv1).
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 */
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static inline int get_sr_golomb(GetBitContext *gb, int k, int limit, int esc_len){
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    int v= get_ur_golomb(gb, k, limit, esc_len);
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    v++;
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    if (v&1) return v>>1;
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    else return -(v>>1);
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//    return (v>>1) ^ -(v&1);
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}
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/**
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 * read signed golomb rice code (flac).
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 */
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static inline int get_sr_golomb_flac(GetBitContext *gb, int k, int limit, int esc_len){
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    int v= get_ur_golomb_jpegls(gb, k, limit, esc_len);
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    return (v>>1) ^ -(v&1);
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}
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/**
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 * read unsigned golomb rice code (shorten).
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 */
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static inline unsigned int get_ur_golomb_shorten(GetBitContext *gb, int k){
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        return get_ur_golomb_jpegls(gb, k, INT_MAX, 0);
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}
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/**
341
 * read signed golomb rice code (shorten).
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 */
343
static inline int get_sr_golomb_shorten(GetBitContext* gb, int k)
344
{
345
    int uvar = get_ur_golomb_jpegls(gb, k + 1, INT_MAX, 0);
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    if (uvar & 1)
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        return ~(uvar >> 1);
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    else
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        return uvar >> 1;
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}
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#ifdef TRACE
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static inline int get_ue(GetBitContext *s, char *file, const 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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    av_log(NULL, AV_LOG_DEBUG, "%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, const 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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    av_log(NULL, AV_LOG_DEBUG, "%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, const 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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391
    print_bin(bits, len);
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    av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d te  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
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395
    return i;
396
}
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#define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
399
#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__)
401
#define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
402

    
403
#endif
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/**
406
 * write unsigned exp golomb code.
407
 */
408
static inline void set_ue_golomb(PutBitContext *pb, int i){
409
    int e;
410

    
411
    assert(i>=0);
412

    
413
#if 0
414
    if(i=0){
415
        put_bits(pb, 1, 1);
416
        return;
417
    }
418
#endif
419
    if(i<256)
420
        put_bits(pb, ff_ue_golomb_len[i], i+1);
421
    else{
422
        e= av_log2(i+1);
423

    
424
        put_bits(pb, 2*e+1, i+1);
425
    }
426
}
427

    
428
/**
429
 * write truncated unsigned exp golomb code.
430
 */
431
static inline void set_te_golomb(PutBitContext *pb, int i, int range){
432
    assert(range >= 1);
433
    assert(i<=range);
434

    
435
    if(range==2) put_bits(pb, 1, i^1);
436
    else         set_ue_golomb(pb, i);
437
}
438

    
439
/**
440
 * write signed exp golomb code. 16 bits at most.
441
 */
442
static inline void set_se_golomb(PutBitContext *pb, int i){
443
//    if (i>32767 || i<-32767)
444
//        av_log(NULL,AV_LOG_ERROR,"value out of range %d\n", i);
445
#if 0
446
    if(i<=0) i= -2*i;
447
    else     i=  2*i-1;
448
#elif 1
449
    i= 2*i-1;
450
    if(i<0) i^= -1; //FIXME check if gcc does the right thing
451
#else
452
    i= 2*i-1;
453
    i^= (i>>31);
454
#endif
455
    set_ue_golomb(pb, i);
456
}
457

    
458
/**
459
 * write unsigned golomb rice code (ffv1).
460
 */
461
static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
462
    int e;
463

    
464
    assert(i>=0);
465

    
466
    e= i>>k;
467
    if(e<limit){
468
        put_bits(pb, e + k + 1, (1<<k) + (i&((1<<k)-1)));
469
    }else{
470
        put_bits(pb, limit + esc_len, i - limit + 1);
471
    }
472
}
473

    
474
/**
475
 * write unsigned golomb rice code (jpegls).
476
 */
477
static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k, int limit, int esc_len){
478
    int e;
479

    
480
    assert(i>=0);
481

    
482
    e= (i>>k) + 1;
483
    if(e<limit){
484
        while(e > 31) {
485
            put_bits(pb, 31, 0);
486
            e -= 31;
487
        }
488
        put_bits(pb, e, 1);
489
        if(k)
490
            put_sbits(pb, k, i);
491
    }else{
492
        while(limit > 31) {
493
            put_bits(pb, 31, 0);
494
            limit -= 31;
495
        }
496
        put_bits(pb, limit  , 1);
497
        put_bits(pb, esc_len, i - 1);
498
    }
499
}
500

    
501
/**
502
 * write signed golomb rice code (ffv1).
503
 */
504
static inline void set_sr_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
505
    int v;
506

    
507
    v = -2*i-1;
508
    v ^= (v>>31);
509

    
510
    set_ur_golomb(pb, v, k, limit, esc_len);
511
}
512

    
513
/**
514
 * write signed golomb rice code (flac).
515
 */
516
static inline void set_sr_golomb_flac(PutBitContext *pb, int i, int k, int limit, int esc_len){
517
    int v;
518

    
519
    v = -2*i-1;
520
    v ^= (v>>31);
521

    
522
    set_ur_golomb_jpegls(pb, v, k, limit, esc_len);
523
}
524

    
525
#endif /* AVCODEC_GOLOMB_H */