159 lines
3.2 KiB
C
159 lines
3.2 KiB
C
#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <stddef.h>
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#include "entdec.h"
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void ec_byte_readinit(ec_byte_buffer *_b,unsigned char *_buf,long _bytes){
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_b->buf=_b->ptr=_buf;
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_b->storage=_bytes;
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}
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int ec_byte_look1(ec_byte_buffer *_b){
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ptrdiff_t endbyte;
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endbyte=_b->ptr-_b->buf;
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if(endbyte>=_b->storage)return -1;
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else return _b->ptr[0];
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}
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int ec_byte_look4(ec_byte_buffer *_b,ec_uint32 *_val){
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ptrdiff_t endbyte;
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endbyte=_b->ptr-_b->buf;
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if(endbyte+4>_b->storage){
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if(endbyte<_b->storage){
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*_val=_b->ptr[0];
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endbyte++;
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if(endbyte<_b->storage){
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*_val|=(ec_uint32)_b->ptr[1]<<8;
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endbyte++;
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if(endbyte<_b->storage)*_val|=(ec_uint32)_b->ptr[2]<<16;
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}
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}
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return -1;
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}
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else{
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*_val=_b->ptr[0];
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*_val|=(ec_uint32)_b->ptr[1]<<8;
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*_val|=(ec_uint32)_b->ptr[2]<<16;
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*_val|=(ec_uint32)_b->ptr[3]<<24;
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}
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return 0;
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}
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void ec_byte_adv1(ec_byte_buffer *_b){
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_b->ptr++;
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}
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void ec_byte_adv4(ec_byte_buffer *_b){
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_b->ptr+=4;
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}
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int ec_byte_read1(ec_byte_buffer *_b){
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ptrdiff_t endbyte;
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endbyte=_b->ptr-_b->buf;
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if(endbyte>=_b->storage)return -1;
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else return *(_b->ptr++);
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}
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int ec_byte_read4(ec_byte_buffer *_b,ec_uint32 *_val){
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unsigned char *end;
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end=_b->buf+_b->storage;
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if(_b->ptr+4>end){
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if(_b->ptr<end){
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*_val=*(_b->ptr++);
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if(_b->ptr<end){
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*_val|=(ec_uint32)*(_b->ptr++)<<8;
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if(_b->ptr<end)*_val|=(ec_uint32)*(_b->ptr++)<<16;
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}
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}
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return -1;
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}
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else{
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*_val=(*_b->ptr++);
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*_val|=(ec_uint32)*(_b->ptr++)<<8;
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*_val|=(ec_uint32)*(_b->ptr++)<<16;
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*_val|=(ec_uint32)*(_b->ptr++)<<24;
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}
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return 0;
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}
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ec_uint32 ec_dec_bits(ec_dec *_this,int _ftb){
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ec_uint32 t;
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unsigned s;
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unsigned ft;
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t=0;
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while(_ftb>EC_UNIT_BITS){
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s=ec_decode_bin(_this,EC_UNIT_BITS);
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ec_dec_update(_this,s,s+1,EC_UNIT_MASK+1);
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t=t<<EC_UNIT_BITS|s;
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_ftb-=EC_UNIT_BITS;
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}
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ft=1U<<_ftb;
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s=ec_decode_bin(_this,_ftb);
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ec_dec_update(_this,s,s+1,ft);
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t=t<<_ftb|s;
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return t;
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}
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ec_uint64 ec_dec_bits64(ec_dec *_this,int _ftb){
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ec_uint32 t;
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if(_ftb>32){
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t=ec_dec_bits(_this,_ftb-32);
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_ftb=32;
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}
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else t=0;
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return (ec_uint64)t<<32|ec_dec_bits(_this,_ftb);
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}
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ec_uint32 ec_dec_uint(ec_dec *_this,ec_uint32 _ft){
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ec_uint32 t;
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unsigned ft;
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unsigned s;
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int ftb;
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t=0;
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_ft--;
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ftb=EC_ILOG(_ft);
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if(ftb>EC_UNIT_BITS){
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ftb-=EC_UNIT_BITS;
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ft=(unsigned)(_ft>>ftb)+1;
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s=ec_decode(_this,ft);
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ec_dec_update(_this,s,s+1,ft);
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t=t<<EC_UNIT_BITS|s;
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return t<<ftb|ec_dec_bits(_this,ftb);
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} else {
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_ft++;
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s=ec_decode(_this,(unsigned)_ft);
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ec_dec_update(_this,s,s+1,(unsigned)_ft);
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t=t<<ftb|s;
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return t;
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}
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}
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ec_uint64 ec_dec_uint64(ec_dec *_this,ec_uint64 _ft){
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ec_uint64 t;
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unsigned ft;
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unsigned s;
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int ftb;
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t=0;
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_ft--;
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ftb=EC_ILOG64(_ft);
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if(ftb>EC_UNIT_BITS){
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ftb-=EC_UNIT_BITS;
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ft=(unsigned)(_ft>>ftb)+1;
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s=ec_decode(_this,ft);
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ec_dec_update(_this,s,s+1,ft);
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t=t<<EC_UNIT_BITS|s;
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return t<<ftb|ec_dec_bits64(_this,ftb);
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} else {
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_ft++;
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s=ec_decode(_this,(unsigned)_ft);
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ec_dec_update(_this,s,s+1,(unsigned)_ft);
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t=t<<ftb|s;
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return t;
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}
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}
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