jamulus/libs/celt/cc6_entdec.c

166 lines
4.5 KiB
C
Raw Normal View History

2013-02-13 18:08:47 +01:00
/* (C) 2001-2008 Timothy B. Terriberry
(C) 2008 Jean-Marc Valin */
/*
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
- Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
- Neither the name of the Xiph.org Foundation nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stddef.h>
2013-02-13 18:20:51 +01:00
#include "cc6_entdec.h"
2013-02-13 19:48:36 +01:00
#include "cc6_os_support.h"
2013-02-13 18:08:47 +01:00
#include "cc6_arch.h"
void cc6_ec_byte_readinit(cc6_ec_byte_buffer *_b,unsigned char *_buf,long _bytes){
2013-02-13 18:08:47 +01:00
_b->buf=_b->ptr=_buf;
_b->storage=_bytes;
}
int cc6_ec_byte_look1(cc6_ec_byte_buffer *_b){
2013-02-13 18:08:47 +01:00
ptrdiff_t endbyte;
endbyte=_b->ptr-_b->buf;
if(endbyte>=_b->storage)return -1;
else return _b->ptr[0];
}
int cc6_ec_byte_look4(cc6_ec_byte_buffer *_b,cc6_ec_uint32 *_val){
2013-02-13 18:08:47 +01:00
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|=(cc6_ec_uint32)_b->ptr[1]<<8;
2013-02-13 18:08:47 +01:00
endbyte++;
if(endbyte<_b->storage)*_val|=(cc6_ec_uint32)_b->ptr[2]<<16;
2013-02-13 18:08:47 +01:00
}
}
return -1;
}
else{
*_val=_b->ptr[0];
*_val|=(cc6_ec_uint32)_b->ptr[1]<<8;
*_val|=(cc6_ec_uint32)_b->ptr[2]<<16;
*_val|=(cc6_ec_uint32)_b->ptr[3]<<24;
2013-02-13 18:08:47 +01:00
}
return 0;
}
void cc6_ec_byte_adv1(cc6_ec_byte_buffer *_b){
2013-02-13 18:08:47 +01:00
_b->ptr++;
}
void cc6_ec_byte_adv4(cc6_ec_byte_buffer *_b){
2013-02-13 18:08:47 +01:00
_b->ptr+=4;
}
int cc6_ec_byte_read1(cc6_ec_byte_buffer *_b){
2013-02-13 18:08:47 +01:00
ptrdiff_t endbyte;
endbyte=_b->ptr-_b->buf;
if(endbyte>=_b->storage)return -1;
else return *(_b->ptr++);
}
int cc6_ec_byte_read4(cc6_ec_byte_buffer *_b,cc6_ec_uint32 *_val){
2013-02-13 18:08:47 +01:00
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|=(cc6_ec_uint32)*(_b->ptr++)<<8;
if(_b->ptr<end)*_val|=(cc6_ec_uint32)*(_b->ptr++)<<16;
2013-02-13 18:08:47 +01:00
}
}
return -1;
}
else{
*_val=(*_b->ptr++);
*_val|=(cc6_ec_uint32)*(_b->ptr++)<<8;
*_val|=(cc6_ec_uint32)*(_b->ptr++)<<16;
*_val|=(cc6_ec_uint32)*(_b->ptr++)<<24;
2013-02-13 18:08:47 +01:00
}
return 0;
}
cc6_ec_uint32 cc6_ec_dec_bits(cc6_ec_dec *_this,int _ftb){
cc6_ec_uint32 t;
2013-02-13 18:08:47 +01:00
unsigned s;
unsigned ft;
t=0;
while(_ftb>cc6_EC_UNIT_BITS){
s=cc6_ec_decode_bin(_this,cc6_EC_UNIT_BITS);
cc6_ec_dec_update(_this,s,s+1,cc6_EC_UNIT_MASK+1);
t=t<<cc6_EC_UNIT_BITS|s;
_ftb-=cc6_EC_UNIT_BITS;
2013-02-13 18:08:47 +01:00
}
ft=1U<<_ftb;
s=cc6_ec_decode_bin(_this,_ftb);
cc6_ec_dec_update(_this,s,s+1,ft);
2013-02-13 18:08:47 +01:00
t=t<<_ftb|s;
return t;
}
cc6_ec_uint32 cc6_ec_dec_uint(cc6_ec_dec *_this,cc6_ec_uint32 _ft){
cc6_ec_uint32 t;
2013-02-13 18:08:47 +01:00
unsigned ft;
unsigned s;
int ftb;
t=0;
/*In order to optimize cc6_EC_ILOG(), it is undefined for the value 0.*/
cc6_celt_assert(_ft>1);
2013-02-13 18:08:47 +01:00
_ft--;
ftb=cc6_EC_ILOG(_ft);
if(ftb>cc6_EC_UNIT_BITS){
ftb-=cc6_EC_UNIT_BITS;
2013-02-13 18:08:47 +01:00
ft=(unsigned)(_ft>>ftb)+1;
s=cc6_ec_decode(_this,ft);
cc6_ec_dec_update(_this,s,s+1,ft);
t=t<<cc6_EC_UNIT_BITS|s;
t = t<<ftb|cc6_ec_dec_bits(_this,ftb);
2013-02-13 18:08:47 +01:00
if (t>_ft)
{
cc6_celt_notify("uint decode error");
2013-02-13 18:08:47 +01:00
t = _ft;
}
return t;
} else {
_ft++;
s=cc6_ec_decode(_this,(unsigned)_ft);
cc6_ec_dec_update(_this,s,s+1,(unsigned)_ft);
2013-02-13 18:08:47 +01:00
t=t<<ftb|s;
return t;
}
}