ref: f02c9bac3a569255eba7213e8eecadd149ecca4c
dir: /libcelt/entdec.c/
#ifdef HAVE_CONFIG_H #include "config.h" #endif #include <stddef.h> #include "entdec.h" #include "os_support.h" void ec_byte_readinit(ec_byte_buffer *_b,unsigned char *_buf,long _bytes){ _b->buf=_b->ptr=_buf; _b->storage=_bytes; } int ec_byte_look1(ec_byte_buffer *_b){ ptrdiff_t endbyte; endbyte=_b->ptr-_b->buf; if(endbyte>=_b->storage)return -1; else return _b->ptr[0]; } int ec_byte_look4(ec_byte_buffer *_b,ec_uint32 *_val){ ptrdiff_t endbyte; endbyte=_b->ptr-_b->buf; if(endbyte+4>_b->storage){ if(endbyte<_b->storage){ *_val=_b->ptr[0]; endbyte++; if(endbyte<_b->storage){ *_val|=(ec_uint32)_b->ptr[1]<<8; endbyte++; if(endbyte<_b->storage)*_val|=(ec_uint32)_b->ptr[2]<<16; } } return -1; } else{ *_val=_b->ptr[0]; *_val|=(ec_uint32)_b->ptr[1]<<8; *_val|=(ec_uint32)_b->ptr[2]<<16; *_val|=(ec_uint32)_b->ptr[3]<<24; } return 0; } void ec_byte_adv1(ec_byte_buffer *_b){ _b->ptr++; } void ec_byte_adv4(ec_byte_buffer *_b){ _b->ptr+=4; } int ec_byte_read1(ec_byte_buffer *_b){ ptrdiff_t endbyte; endbyte=_b->ptr-_b->buf; if(endbyte>=_b->storage)return -1; else return *(_b->ptr++); } int ec_byte_read4(ec_byte_buffer *_b,ec_uint32 *_val){ unsigned char *end; end=_b->buf+_b->storage; if(_b->ptr+4>end){ if(_b->ptr<end){ *_val=*(_b->ptr++); if(_b->ptr<end){ *_val|=(ec_uint32)*(_b->ptr++)<<8; if(_b->ptr<end)*_val|=(ec_uint32)*(_b->ptr++)<<16; } } return -1; } else{ *_val=(*_b->ptr++); *_val|=(ec_uint32)*(_b->ptr++)<<8; *_val|=(ec_uint32)*(_b->ptr++)<<16; *_val|=(ec_uint32)*(_b->ptr++)<<24; } return 0; } ec_uint32 ec_dec_bits(ec_dec *_this,int _ftb){ ec_uint32 t; unsigned s; unsigned ft; t=0; while(_ftb>EC_UNIT_BITS){ s=ec_decode_bin(_this,EC_UNIT_BITS); ec_dec_update(_this,s,s+1,EC_UNIT_MASK+1); t=t<<EC_UNIT_BITS|s; _ftb-=EC_UNIT_BITS; } ft=1U<<_ftb; s=ec_decode_bin(_this,_ftb); ec_dec_update(_this,s,s+1,ft); t=t<<_ftb|s; return t; } ec_uint64 ec_dec_bits64(ec_dec *_this,int _ftb){ ec_uint32 t; if(_ftb>32){ t=ec_dec_bits(_this,_ftb-32); _ftb=32; } else t=0; return (ec_uint64)t<<32|ec_dec_bits(_this,_ftb); } ec_uint32 ec_dec_uint(ec_dec *_this,ec_uint32 _ft){ ec_uint32 t; unsigned ft; unsigned s; int ftb; t=0; _ft--; ftb=EC_ILOG(_ft); if(ftb>EC_UNIT_BITS){ ftb-=EC_UNIT_BITS; ft=(unsigned)(_ft>>ftb)+1; s=ec_decode(_this,ft); ec_dec_update(_this,s,s+1,ft); t=t<<EC_UNIT_BITS|s; t = t<<ftb|ec_dec_bits(_this,ftb); if (t>_ft) { celt_notify("uint decode error"); t = _ft; } return t; } else { _ft++; s=ec_decode(_this,(unsigned)_ft); ec_dec_update(_this,s,s+1,(unsigned)_ft); t=t<<ftb|s; return t; } } ec_uint64 ec_dec_uint64(ec_dec *_this,ec_uint64 _ft){ ec_uint64 t; unsigned ft; unsigned s; int ftb; t=0; _ft--; ftb=EC_ILOG64(_ft); if(ftb>EC_UNIT_BITS){ ftb-=EC_UNIT_BITS; ft=(unsigned)(_ft>>ftb)+1; s=ec_decode(_this,ft); ec_dec_update(_this,s,s+1,ft); t=t<<EC_UNIT_BITS|s; t = t<<ftb|ec_dec_bits64(_this,ftb); if (t>_ft) { celt_notify("uint decode error"); t = _ft; } return t; } else { _ft++; s=ec_decode(_this,(unsigned)_ft); ec_dec_update(_this,s,s+1,(unsigned)_ft); t=t<<ftb|s; return t; } }