FreeCalypso > hg > freecalypso-tools
view miscutil/fc-gsm2vm.c @ 407:19e5a3e2f9c0
fcup-settime: moved time() retrieval a little closer to the output
A fundamental problem with all simple time transfer tools is that there is
always some delay between the time retrieval on the source system and that
transmitted time being set on the destination, and the resulting time
on the destination system is off by that delay amount. This delay cannot
be fully eliminated when working in a simple environment like ours,
but we should make our best effort to minimize it. In the present case,
moving the atinterf_init() call before the time() retrieval should make
a teensy-tiny improvement.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Sat, 11 Aug 2018 21:52:17 +0000 |
parents | f736f3ce8310 |
children |
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/* * This utility converts a GSM 06.10 speech recording from the format that is * commonly accepted as standard in the Unix/Linux world (libgsm format) into * a voice memo file that can be uploaded into the FFS of a FreeCalypso device * and played with the audio_vm_play_start() API or the AT@VMP command that * invokes the latter. */ #include <sys/types.h> #include <stdio.h> #include <stdlib.h> main(argc, argv) char **argv; { FILE *inf, *outf; u_char libgsm_bytes[33], tidsp_bytes[34], arm_bytes[34]; static u_char header_bytes[6] = {0x00, 0xC4, 0x00, 0x00, 0x00, 0x00}; static u_char endmarker[2] = {0xFF, 0xFB}; int cc, i, gotsome = 0; 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); } tidsp_bytes[33] = 0; for (;;) { cc = fread(libgsm_bytes, 1, 33, inf); if (cc < 33) break; if ((libgsm_bytes[0] & 0xF0) != 0xD0) { invalid: fprintf(stderr, "error: %s is not in libgsm format\n", argv[1]); exit(1); } gsm0610_libgsm_to_tidsp(libgsm_bytes, tidsp_bytes); for (i = 0; i < 34; i += 2) { arm_bytes[i] = tidsp_bytes[i+1]; arm_bytes[i+1] = tidsp_bytes[i]; } fwrite(header_bytes, 1, 6, outf); fwrite(arm_bytes, 1, 34, outf); gotsome = 1; } fwrite(endmarker, 1, 2, outf); fclose(outf); if (cc) { if (gotsome) fprintf(stderr, "warning: extra non-33 bytes at the end of %s\n", argv[1]); else goto invalid; } exit(0); }