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#ifndef _OSMO_BITS_H
#define _OSMO_BITS_H
#include <stdint.h>
/*! \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;
}
/*! \brief convert unpacked bits to packed bits, return length in bytes
* \param[out] out output buffer of packed bits
* \param[in] in input buffer of unpacked bits
* \param[in] num_bits number of bits
*/
int osmo_ubit2pbit(pbit_t *out, const ubit_t *in, unsigned int num_bits);
/*! \brief convert packed bits to unpacked bits, return length in bytes
* \param[out] out output buffer of unpacked bits
* \param[in] in input buffer of packed bits
* \param[in] num_bits number of bits
*/
int osmo_pbit2ubit(ubit_t *out, const pbit_t *in, unsigned int num_bits);
/*! \brief convert unpacked bits to packed bits (extended options)
* \param[out] out output buffer of packed bits
* \param[in] out_ofs offset into output buffer
* \param[in] in input buffer of unpacked bits
* \param[in] in_ofs offset into input buffer
* \param[in] num_bits number of bits
* \param[in] lsb_mode Encode bits in LSB orde instead of MSB
* \returns length in bytes (max written offset of output buffer + 1)
*/
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);
/*! \brief convert packed bits to unpacked bits (extended options)
* \param[out] out output buffer of unpacked bits
* \param[in] out_ofs offset into output buffer
* \param[in] in input buffer of packed bits
* \param[in] in_ofs offset into input buffer
* \param[in] num_bits number of bits
* \param[in] lsb_mode Encode bits in LSB orde instead of MSB
* \returns length in bytes (max written offset of output buffer + 1)
*/
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);
#endif
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