FreeCalypso > hg > gsm-codec-lib
view efrtest/dlcap-sync.c @ 480:332397bc80aa
doc/AMR-library-API: document public const data items
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Sun, 19 May 2024 23:18:17 +0000 |
parents | d80ccb3c3970 |
children |
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/* * This program reads a TCH/EFS downlink capture file from a FreeCalypso GSM MS * that was produced in a session in which seqsync PCMA or PCMU input was fed * into the test call from IP-PSTN side. It looks for EFR DHF followed by * specific frame patterns indicating how the seqsync input was transcoded * by the alien GSM network, and reports its findings. */ #include <ctype.h> #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <string.h> #include <strings.h> #include "../libgsmefr/gsm_efr.h" static const uint8_t mr122_dhf[31] = { 0xC0,0x85,0x4D,0xB9,0x6A,0xAA,0xD6,0x00,0x00,0x00,0x00,0x01,0xB5,0x87,0xF6,0x68, 0x37,0x94,0x09,0x00,0x41,0x58,0x54,0xF1,0x0F,0x6B,0x02,0x40,0x3C,0x7E,0xA0, }; extern const uint8_t sync_from_pcma[320*31]; extern const uint8_t sync_from_pcmu[320*31]; static int check_for_match(input, table) const uint8_t *input, *table; { unsigned n; for (n = 0; n < 320; n++) { if (!bcmp(input, table + n * 31, 31)) return n; } return -1; } main(argc, argv) char **argv; { FILE *inf; char linebuf[128]; int lineno, rc; uint16_t status_words[3]; uint8_t tidsp_bytes[33], efr_bytes[31]; const uint8_t *match_table; int dhf_state; char *dhf_name; if (argc != 3) { usage: fprintf(stderr, "usage: %s dlcap-file alaw|ulaw\n", argv[0]); exit(1); } inf = fopen(argv[1], "r"); if (!inf) { perror(argv[1]); exit(1); } if (!strcmp(argv[2], "alaw")) match_table = sync_from_pcma; else if (!strcmp(argv[2], "ulaw")) match_table = sync_from_pcmu; else goto usage; dhf_state = 0; 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_dlcap_common(linebuf, status_words, tidsp_bytes); if (rc < 0) { invalid: fprintf(stderr, "error: %s is not in the expected format\n", argv[1]); exit(1); } } else if (!strncmp(linebuf, "EFR ", 4)) { rc = parse_dlcap_common(linebuf + 4, status_words, tidsp_bytes); if (rc < 0) goto invalid; if (linebuf[85] != ' ') goto invalid; if (!isdigit(linebuf[86])) goto invalid; } else goto invalid; if ((status_words[0] & 0xC204) != 0xC000) { dhf_state = 0; continue; } efr_tidsp_to_std(tidsp_bytes, efr_bytes); if (!bcmp(efr_bytes, EFR_decoder_homing_frame, 31)) { dhf_state = 1; continue; } if (!bcmp(efr_bytes, mr122_dhf, 31)) { dhf_state = 2; continue; } if (!dhf_state) continue; rc = check_for_match(efr_bytes, match_table); if (rc >= 0 && rc <= 159) { printf( "line %d: match to standard EFR with offset %d\n", lineno, rc); if (dhf_state == 2) printf("... but preceded by MR122 DHF!\n"); } else if (rc >= 160 && rc <= 279) { printf("line %d: match to AMR-EFR with offset %d\n", lineno, rc - 160); if (dhf_state == 2) printf("... but preceded by MR122 DHF!\n"); } else if (rc >= 280 && rc <= 319) { printf("line %d: match to AMR-EFR with offset %d\n", lineno, rc - 160); switch (dhf_state) { case 1: dhf_name = "EFR"; break; case 2: dhf_name = "MR122"; break; default: dhf_name = "???"; } printf("previous frame was %s DHF\n", dhf_name); } dhf_state = 0; } exit(0); }