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#ifndef __BITS_H__
#define __BITS_H__
typedef struct bits_struct bits_t;
struct bits_struct {
unsigned char *ptr;
int idx;
unsigned char *end;
};
static inline int bits_needbits(bits_t *b, int n_bytes)
{
if(b->ptr==NULL)return 1;
if(b->ptr + n_bytes > b->end)return 1;
return 0;
}
static inline int getbit(bits_t *b)
{
int r;
r = ((*b->ptr)>>(7-b->idx))&1;
b->idx++;
if(b->idx>=8){
b->ptr++;
b->idx = 0;
}
return r;
}
static inline unsigned int getbits(bits_t *b, int n)
{
unsigned long r = 0;
int i;
for(i=0;i<n;i++){
r <<=1;
r |= getbit(b);
}
return r;
}
static inline unsigned int peekbits(bits_t *b, int n)
{
bits_t tmp = *b;
return getbits(&tmp, n);
}
static inline int getsbits(bits_t *b, int n)
{
unsigned long r = 0;
int i;
if(n==0)return 0;
r = -getbit(b);
for(i=1;i<n;i++){
r <<=1;
r |= getbit(b);
}
return r;
}
static inline unsigned int peek_u8(bits_t *b)
{
return *b->ptr;
}
static inline unsigned int get_u8(bits_t *b)
{
return *b->ptr++;
}
static inline unsigned int get_u16(bits_t *b)
{
unsigned int r;
r = b->ptr[0] | (b->ptr[1]<<8);
b->ptr+=2;
return r;
}
static inline unsigned int get_be_u16(bits_t *b)
{
unsigned int r;
r = (b->ptr[0]<<8) | b->ptr[1];
b->ptr+=2;
return r;
}
static inline unsigned int get_u32(bits_t *b)
{
unsigned int r;
r = b->ptr[0] | (b->ptr[1]<<8) | (b->ptr[2]<<16) | (b->ptr[3]<<24);
b->ptr+=4;
return r;
}
static inline void syncbits(bits_t *b)
{
if(b->idx){
b->ptr++;
b->idx=0;
}
}
#endif
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