X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=blobdiff_plain;f=src%2Fcore%2Fao_fec.h;h=618756c1ce7ea3984959334a7852213c1b6db462;hp=db5523a36c94c61299e1939087638a4f38aae957;hb=bb9fdef607728cc326a82aa632e59724f272e53b;hpb=75e4521ec42a368cebc67a07f8713d7a854ea265 diff --git a/src/core/ao_fec.h b/src/core/ao_fec.h index db5523a3..618756c1 100644 --- a/src/core/ao_fec.h +++ b/src/core/ao_fec.h @@ -24,37 +24,61 @@ #define AO_FEC_TRELLIS_TERMINATOR 0x0b #define AO_FEC_PREPARE_EXTRA 4 +extern const uint8_t ao_fec_whiten_table[]; + +#if AO_FEC_DEBUG void -ao_fec_dump_bytes(uint8_t *bytes, uint8_t len, char *name); +ao_fec_dump_bytes(const uint8_t *bytes, uint16_t len, const char *name); +#endif + +static inline uint16_t +ao_fec_crc_byte(uint8_t byte, uint16_t crc) +{ + uint8_t bit; + + for (bit = 0; bit < 8; bit++) { + if (((crc & 0x8000) >> 8) ^ (byte & 0x80)) + crc = (crc << 1) ^ 0x8005; + else + crc = (crc << 1); + byte <<= 1; + } + return crc; +} uint16_t -ao_fec_crc(uint8_t *bytes, uint8_t len); +ao_fec_crc(const uint8_t *bytes, uint8_t len); /* - * Append CRC and terminator bytes, returns resulting length. - * 'out' must be at least len + AO_FEC_PREPARE_EXTRA bytes long + * 'len' is the length of the original data; 'bytes' + * must be four bytes longer than that, and the first + * two after 'len' must be the received crc */ uint8_t -ao_fec_prepare(uint8_t *in, uint8_t len, uint8_t *out); +ao_fec_check_crc(const uint8_t *bytes, uint8_t len); /* - * Whiten data using the cc1111 PN9 sequence. 'out' - * must be 'len' bytes long. 'out' and 'in' can be - * the same array + * Compute CRC, whiten, convolve and interleave data. 'out' must be (len + 4) * 2 bytes long */ uint8_t -ao_fec_whiten(uint8_t *in, uint8_t len, uint8_t *out); +ao_fec_encode(const uint8_t *in, uint8_t len, uint8_t *out); /* - * Encode data. 'out' must be len*2 bytes long + * Decode data. 'in' is one byte per bit, soft decision + * 'out' must be len/8 bytes long */ + +#define AO_FEC_DECODE_BLOCK (32) /* callback must return multiples of this many bits */ + +#define AO_FEC_DECODE_CRC_OK 0x80 /* stored in out[out_len-1] */ + uint8_t -ao_fec_encode(uint8_t *in, uint8_t len, uint8_t *out); +ao_fec_decode(const uint8_t *in, uint16_t in_len, uint8_t *out, uint8_t out_len, uint16_t (*callback)(void)); /* - * Interleave data. 'out' must be 'len' bytes long + * Interleave data packed in bytes. 'out' must be 'len' bytes long. */ -uint8_t -ao_fec_interleave(uint8_t *in, uint8_t len, uint8_t *out); +uint16_t +ao_fec_interleave_bytes(uint8_t *in, uint16_t len, uint8_t *out); #endif /* _AO_FEC_H_ */