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#ifndef _OSMO_BITS_H
#define _OSMO_BITS_H
#include <stdint.h>
/*! \defgroup bits soft, unpacked and packed bits
* @{
*/
/*! \file bits.h
* \brief Osmocom bit level support code
*/
typedef int8_t sbit_t; /*!< \brief soft bit (-127...127) */
typedef uint8_t ubit_t; /*!< \brief unpacked bit (0 or 1) */
typedef uint8_t pbit_t; /*!< \brief packed bis (8 bits in a byte) */
/*
NOTE on the endianess of pbit_t:
Bits in a pbit_t are ordered MSB first, i.e. 0x80 is the first bit.
Bit i in a pbit_t array is array[i/8] & (1<<(7-i%8))
*/
/*! \brief determine how many bytes we would need for \a num_bits packed bits
* \param[in] num_bits Number of packed bits
*/
static inline unsigned int osmo_pbit_bytesize(unsigned int num_bits)
{
unsigned int pbit_bytesize = num_bits / 8;
if (num_bits % 8)
pbit_bytesize++;
return pbit_bytesize;
}
int osmo_ubit2pbit(pbit_t *out, const ubit_t *in, unsigned int num_bits);
int osmo_pbit2ubit(ubit_t *out, const pbit_t *in, unsigned int num_bits);
int osmo_ubit2pbit_ext(pbit_t *out, unsigned int out_ofs,
const ubit_t *in, unsigned int in_ofs,
unsigned int num_bits, int lsb_mode);
int osmo_pbit2ubit_ext(ubit_t *out, unsigned int out_ofs,
const pbit_t *in, unsigned int in_ofs,
unsigned int num_bits, int lsb_mode);
/* BIT REVERSAL */
/*! \brief bit-reversal mode for osmo_bit_reversal() */
enum osmo_br_mode {
/*! \brief reverse all bits in a 32bit dword */
OSMO_BR_BITS_IN_DWORD = 31,
/*! \brief reverse byte order in a 32bit dword */
OSMO_BR_BYTES_IN_DWORD = 24,
/*! \brief reverse bits of each byte in a 32bit dword */
OSMO_BR_BITS_IN_BYTE = 7,
/*! \brief swap the two 16bit words in a 32bit dword */
OSMO_BR_WORD_SWAP = 16,
};
/*! \brief generic bit reversal function */
uint32_t osmo_bit_reversal(uint32_t x, enum osmo_br_mode k);
/* \brief reverse the bits within each byte of a 32bit word */
uint32_t osmo_revbytebits_32(uint32_t x);
/* \brief reverse the bits within a byte */
uint32_t osmo_revbytebits_8(uint8_t x);
/* \brief reverse the bits of each byte in a given buffer */
void osmo_revbytebits_buf(uint8_t *buf, int len);
/*! @} */
#endif /* _OSMO_BITS_H */
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