**diff options**

Diffstat (limited to 'include/osmocom/core/bits.h')

-rw-r--r-- | include/osmocom/core/bits.h | 45 |

1 files changed, 45 insertions, 0 deletions

diff --git a/include/osmocom/core/bits.h b/include/osmocom/core/bits.h new file mode 100644 index 00000000..8d4a0789 --- /dev/null +++ b/include/osmocom/core/bits.h @@ -0,0 +1,45 @@ +#ifndef _OSMO_BITS_H +#define _OSMO_BITS_H + +#include <stdint.h> + +typedef uint8_t sbit_t; /* soft bit (-127...127) */ +typedef uint8_t ubit_t; /* unpacked bit (0 or 1) */ +typedef uint8_t pbit_t; /* 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)) +*/ + +/* determine how many bytes we would need for 'num_bits' 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; +} + +/* convert unpacked bits to packed bits, return length in bytes */ +int osmo_ubit2pbit(pbit_t *out, const ubit_t *in, unsigned int num_bits); + +/* convert packed bits to unpacked bits, return length in bytes */ +int osmo_pbit2ubit(ubit_t *out, const pbit_t *in, unsigned int num_bits); + +/* convert unpacked bits to packed bits (extended options but slower), + * return length in bytes (max written ofs 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); + +/* convert packed bits to unpacked bits (extended options but slower), + * return length in bytes (max written ofs 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 |