FreeCalypso > hg > gsm-net-reveng
view trau-decode/hr-guts.c @ 74:e78c6b1ecb91
trau-decode: refactor trau-hr-dump
The desire is to create a companion program that will read hex lines
representing TRAU-8k frames and then decode those frames in exactly
the same way how we currently decode frames read from binary capture
files. Hence the decoder portion of trau-hr-dump needs to be
factored out.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Sat, 08 Feb 2025 03:00:31 +0000 |
parents | trau-decode/trau-hr-dump.c@06f241846c67 |
children |
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/* * This module contains the guts of trau-hr-dump program in terms of * HRv1 frame decoding. It has been factored out to facilitate creation * of trau-hr-dump-hex version. */ #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <string.h> #include <strings.h> #include "gsmhr_unpack.h" #include "osmo_bits.h" /* * EFR TRAU parity (also used for HR) * * g(x) = x^3 + x^1 + 1 */ static const struct osmo_crc8gen_code gsm0860_efr_crc3 = { .bits = 3, .poly = 0x3, .init = 0x0, .remainder = 0x7, }; static int bit_parity(bits, nbits) ubit_t *bits; unsigned nbits; { unsigned n, sum; sum = 0; for (n = 0; n < nbits; n++) sum += bits[n]; return sum & 1; } static void bits2bytes(bits, bytes, nbytes) ubit_t *bits; uint8_t *bytes; unsigned nbytes; { unsigned n, m, acc; for (n = 0; n < nbytes; n++) { acc = 0; for (m = 0; m < 8; m++) { acc <<= 1; acc |= *bits++; } *bytes++ = acc; } } void print_gsmhr_frame(frame) ubit_t *frame; { ubit_t xc_bits[6], dbits[112]; uint8_t hr_bytes[14]; int16_t params[18]; int crc_stat; printf(" C1-C4: %u%u%u%u OP %s\n", frame[9], frame[10], frame[11], frame[12], bit_parity(frame + 9, 5) ? "good" : "bad"); bcopy(frame + 14, xc_bits, 2); bcopy(frame + 18, xc_bits + 2, 4); printf(" XC1-XC5: %u%u%u%u%u OP %s\n", xc_bits[0], xc_bits[1], xc_bits[2], xc_bits[3], xc_bits[4], bit_parity(xc_bits, 6) ? "good" : "bad"); bcopy(frame + 22, dbits, 2); bcopy(frame + 25, dbits + 2, 7); bcopy(frame + 33, dbits + 9, 7); bcopy(frame + 41, dbits + 16, 7); bcopy(frame + 49, dbits + 23, 7); bcopy(frame + 57, dbits + 30, 7); bcopy(frame + 65, dbits + 37, 7); bcopy(frame + 76, dbits + 44, 4); bcopy(frame + 81, dbits + 48, 7); bcopy(frame + 89, dbits + 55, 7); bcopy(frame + 97, dbits + 62, 7); bcopy(frame + 105, dbits + 69, 7); bcopy(frame + 113, dbits + 76, 7); bcopy(frame + 121, dbits + 83, 7); bcopy(frame + 129, dbits + 90, 7); bcopy(frame + 137, dbits + 97, 7); bcopy(frame + 145, dbits + 104, 7); dbits[111] = frame[153]; crc_stat = osmo_crc8gen_check_bits(&gsm0860_efr_crc3, dbits, 44, frame + 73); printf(" CRC %s\n", crc_stat ? "bad" : "good"); bits2bytes(dbits, hr_bytes, 14); gsmhr_unpack_ts101318(hr_bytes, params); printf(" R0=%02x LPC=%03x,%03x,%02x Int=%x Mode=%x\n", params[0], params[1], params[2], params[3], params[4], params[5]); printf(params[5] ? " s1=%02x,%03x,%02x" : " s1=%02x,%02x,%02x", params[6], params[7], params[8]); printf(params[5] ? " s2=%x,%03x,%02x" : " s2=%02x,%02x,%02x", params[9], params[10], params[11]); printf(params[5] ? " s3=%x,%03x,%02x" : " s3=%02x,%02x,%02x", params[12], params[13], params[14]); printf(params[5] ? " s4=%x,%03x,%02x\n" : " s4=%02x,%02x,%02x\n", params[15], params[16], params[17]); printf(" C6-C9: %u%u%u%u\n", frame[154], frame[155], frame[156], frame[157]); printf(" T1=%u T2=%u\n", frame[158], frame[159]); }