FreeCalypso > hg > gsm-codec-lib
view frtest/cvt-dlcap.c @ 137:b7ea278390eb
gsmfr-cvt-dlcap: support new FC TCH DL recording format
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Tue, 13 Dec 2022 04:37:45 +0000 |
parents | 7960744ba19c |
children | be57e06bed84 |
line wrap: on
line source
/* * This program reads a TCH downlink capture produced with FreeCalypso tools * (fw version with TCH downlink sniffing feature and fc-shell tch record) * and converts it into our extended-libgsm binary format, to be further * fed to gsmfr-decode. */ #include <sys/types.h> #include <ctype.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <strings.h> static decode_hex_digit(ch) { if (isdigit(ch)) return(ch - '0'); else if (isupper(ch)) return(ch - 'A' + 10); else return(ch - 'a' + 10); } static parse_classic_part(line, status_words, tidsp_bytes) char *line; u_short *status_words; u_char *tidsp_bytes; { char *cp; int i; /* grok DSP status words */ cp = line; for (i = 0; i < 3; i++) { if (!isxdigit(cp[0]) || !isxdigit(cp[1]) || !isxdigit(cp[2]) || !isxdigit(cp[3])) return -1; status_words[i] = (decode_hex_digit(cp[0]) << 12) | (decode_hex_digit(cp[1]) << 8) | (decode_hex_digit(cp[2]) << 4) | decode_hex_digit(cp[3]); cp += 4; if (*cp++ != ' ') return -1; } /* read the frame bits */ for (i = 0; i < 33; i++) { if (!isxdigit(cp[0]) || !isxdigit(cp[1])) return -1; tidsp_bytes[i] = (decode_hex_digit(cp[0]) << 4) | decode_hex_digit(cp[1]); cp += 2; } return 0; } main(argc, argv) char **argv; { FILE *inf, *outf; char linebuf[128]; int lineno, rc; u_short status_words[3]; u_char tidsp_bytes[33], libgsm_bytes[33], bfi[2]; unsigned fn_mod_104; if (argc != 3) { fprintf(stderr, "usage: %s infile outfile\n", argv[0]); exit(1); } inf = fopen(argv[1], "r"); if (!inf) { perror(argv[1]); exit(1); } outf = fopen(argv[2], "w"); if (!outf) { perror(argv[2]); exit(1); } for (lineno = 1; fgets(linebuf, sizeof linebuf, inf); lineno++) { /* support both old and new formats */ if (isxdigit(linebuf[0]) && isxdigit(linebuf[1]) && isxdigit(linebuf[2]) && isxdigit(linebuf[3])) { rc = parse_classic_part(linebuf, status_words, tidsp_bytes); if (rc < 0) { invalid: fprintf(stderr, "error: %s is not in the expected format\n", argv[1]); exit(1); } fn_mod_104 = 0; /* won't have TAF */ } else if (!strncmp(linebuf, "FR ", 3)) { rc = parse_classic_part(linebuf + 3, status_words, tidsp_bytes); if (rc < 0) goto invalid; if (linebuf[84] != ' ') goto invalid; if (!isdigit(linebuf[85])) goto invalid; fn_mod_104 = strtoul(linebuf + 85, 0, 10); } else goto invalid; /* * Bit 15 of status word 0 is buffer validity flag, * bit 2 is BFI. */ if (!(status_words[0] & 0x8000) || (status_words[0] & 0x0004)) { bfi[0] = 0xBF; bfi[1] = fn_mod_104 == 60; fwrite(bfi, 1, 2, outf); } else { gsm0610_tidsp_to_libgsm(tidsp_bytes, libgsm_bytes); fwrite(libgsm_bytes, 1, 33, outf); } } exit(0); }