FreeCalypso > hg > gsm-net-reveng
view trau-decode/parse-efr.c @ 28:9bcdb091c24d default tip
trau-decode: new program trau-hr-dump
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Sun, 18 Aug 2024 08:37:02 +0000 |
parents | bf5c9fb431b8 |
children |
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/* * This module implements the EFR decoding part of trau-parse. */ #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <string.h> #include <strings.h> #include <gsm_efr.h> #include "osmo_bits.h" /* * EFR TRAU parity * * g(x) = x^3 + x^1 + 1 */ static const struct osmo_crc8gen_code gsm0860_efr_crc3 = { .bits = 3, .poly = 0x3, .init = 0x0, .remainder = 0x7, }; /* re-combine EFR parity bits */ static inline void efr_parity_bits_1(ubit_t *check_bits, const ubit_t *d_bits) { memcpy(check_bits + 0 , d_bits + 0, 22); memcpy(check_bits + 22 , d_bits + 24, 3); check_bits[25] = d_bits[28]; } static inline void efr_parity_bits_2(ubit_t *check_bits, const ubit_t *d_bits) { memcpy(check_bits + 0 , d_bits + 42, 10); memcpy(check_bits + 10 , d_bits + 90, 2); } static inline void efr_parity_bits_3(ubit_t *check_bits, const ubit_t *d_bits) { memcpy(check_bits + 0 , d_bits + 98, 5); check_bits[5] = d_bits[104]; memcpy(check_bits + 6 , d_bits + 143, 2); } static inline void efr_parity_bits_4(ubit_t *check_bits, const ubit_t *d_bits) { memcpy(check_bits + 0 , d_bits + 151, 10); memcpy(check_bits + 10 , d_bits + 199, 2); } static inline void efr_parity_bits_5(ubit_t *check_bits, const ubit_t *d_bits) { memcpy(check_bits + 0 , d_bits + 207, 5); check_bits[5] = d_bits[213]; memcpy(check_bits + 6 , d_bits + 252, 2); } void check_efr_crc(d_bits) ubit_t *d_bits; { ubit_t check_bits[26]; int rc1, rc2, rc3, rc4, rc5; efr_parity_bits_1(check_bits, d_bits); rc1 = osmo_crc8gen_check_bits(&gsm0860_efr_crc3, check_bits, 26, d_bits + 39); efr_parity_bits_2(check_bits, d_bits); rc2 = osmo_crc8gen_check_bits(&gsm0860_efr_crc3, check_bits, 12, d_bits + 95); efr_parity_bits_3(check_bits, d_bits); rc3 = osmo_crc8gen_check_bits(&gsm0860_efr_crc3, check_bits, 8, d_bits + 148); efr_parity_bits_4(check_bits, d_bits); rc4 = osmo_crc8gen_check_bits(&gsm0860_efr_crc3, check_bits, 12, d_bits + 204); efr_parity_bits_5(check_bits, d_bits); rc5 = osmo_crc8gen_check_bits(&gsm0860_efr_crc3, check_bits, 8, d_bits + 257); printf(" D1=%u CRC: %s %s %s %s %s\n", d_bits[0], rc1 ? "bad" : "good", rc2 ? "bad" : "good", rc3 ? "bad" : "good", rc4 ? "bad" : "good", rc5 ? "bad" : "good"); } static void dbits_to_frame(d_bits, frame) ubit_t *d_bits; uint8_t *frame; { ubit_t intermed[248], *ip; uint8_t *op, mask; unsigned nb; intermed[0] = 1; intermed[1] = 1; intermed[2] = 0; intermed[3] = 0; bcopy(d_bits + 1, intermed + 4, 38); bcopy(d_bits + 42, intermed + 42, 53); bcopy(d_bits + 98, intermed + 95, 50); bcopy(d_bits + 151, intermed + 145, 53); bcopy(d_bits + 207, intermed + 198, 50); ip = intermed; op = frame; for (nb = 0; nb < EFR_RTP_FRAME_LEN; nb++) { *op = 0; for (mask = 0x80; mask; mask >>= 1) { if (*ip) *op |= mask; ip++; } op++; } } void print_efr_frame(d_bits) ubit_t *d_bits; { uint8_t frame[EFR_RTP_FRAME_LEN]; int16_t params[EFR_NUM_PARAMS]; int i, j, n, sid; dbits_to_frame(d_bits, frame); EFR_frame2params(frame, params); fputs(" EFR frame:\n LPC", stdout); n = 0; for (i = 0; i < 5; i++) printf(" %d", params[n++]); putchar('\n'); for (i = 0; i < 4; i++) { fputs(" ", stdout); for (j = 0; j < 13; j++) printf(" %d", params[n++]); putchar('\n'); } sid = EFR_sid_classify(frame); printf(" SID recompute: %d\n", sid); if (!bcmp(frame, EFR_decoder_homing_frame, EFR_RTP_FRAME_LEN)) puts(" Matches DHF"); }