FreeCalypso > hg > gsm-codec-lib
view libtest/parse_dlcap.c @ 285:cfa3006a66da
gsmfr-decode-r: convert to libgsmfr2
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Sun, 14 Apr 2024 06:04:32 +0000 |
parents | be57e06bed84 |
children |
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/* * All TCH/F downlink capture files produced by fc-shell tch record * (both FR and EFR, both old and new formats) include the same * 81-character block in each line: 3 DSP status words followed by * 33 bytes of frame data. Here we are factoring out the function * for parsing this common part. */ #include <ctype.h> #include <stdint.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); } parse_dlcap_common(line, status_words, tidsp_bytes) char *line; uint16_t *status_words; uint8_t *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; }