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Diffstat (limited to 'src/fsk_mod.c')
| -rw-r--r-- | src/fsk_mod.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/src/fsk_mod.c b/src/fsk_mod.c new file mode 100644 index 0000000..f0bd06f --- /dev/null +++ b/src/fsk_mod.c @@ -0,0 +1,142 @@ +/*---------------------------------------------------------------------------*\ + + FILE........: fsk_mod.c + AUTHOR......: Brady O'Brien and David Rowe + DATE CREATED: 8 January 2016 + + Command line FSK modulator. Reads in bits, writes FSK modulated output. + +\*---------------------------------------------------------------------------*/ + +/* + Copyright (C) 2016 David Rowe + + All rights reserved. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License version 2.1, as + published by the Free Software Foundation. This program is + distributed in the hope that it will be useful, but WITHOUT ANY + WARRANTY; without even the implied warranty of MERCHANTABILITY or + FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public + License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with this program; if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdio.h> +#include <string.h> +#include <getopt.h> +#include "fsk.h" +#include "codec2_fdmdv.h" + +int main(int argc,char *argv[]){ + struct FSK *fsk; + int Fs,Rs,f1,fs,M; + int i; + int p, user_p = 0; + FILE *fin,*fout; + int complex = 0; + int bytes_per_sample = 2; + float amp = FDMDV_SCALE; + int test_mode = 0; + + char usage[] = "usage: %s [-p P] [-c] [-a Amplitude] [-t] Mode SampleFreq SymbolFreq TxFreq1 TxFreqSpace InputOneBitPerCharFile OutputModRawFile\n" + " -c complex signed 16 bit output format\n" + " -a Amplitude Amplitude of signal\n" + " -t test mode unmodulated carrier, useful for setting levels\n"; + + int opt; + while ((opt = getopt(argc, argv, "a:p:ct")) != -1) { + switch (opt) { + case 'a': + amp = atof(optarg)/2.0; /* fsk_mod amplitude is +/-2 */ + break; + case 'c': + complex = 1; bytes_per_sample = 4; + break; + case 't': + test_mode = 1; + break; + case 'p': + p = atoi(optarg); + user_p = 1; + break; + default: + fprintf(stderr, usage, argv[0]); + exit(1); + } + } + + if (argc<8){ + fprintf(stderr, usage, argv[0]); + exit(1); + } + + /* Extract parameters */ + M = atoi(argv[optind++]); + Fs = atoi(argv[optind++]); + Rs = atoi(argv[optind++]); + f1 = atoi(argv[optind++]); + fs = atoi(argv[optind++]); + + if(strcmp(argv[optind],"-")==0){ + fin = stdin; + }else{ + fin = fopen(argv[optind],"r"); + } + optind++; + + if(strcmp(argv[optind],"-")==0){ + fout = stdout; + }else{ + fout = fopen(argv[optind],"w"); + } + + /* p is not actually used for the modulator, but we need to set it for fsk_create() to be happy */ + if (!user_p) + p = Fs/Rs; + + /* set up FSK */ + fsk = fsk_create_hbr(Fs,Rs,M,p,FSK_DEFAULT_NSYM,f1,fs); + + if(fin==NULL || fout==NULL || fsk==NULL){ + fprintf(stderr,"Couldn't open files\n"); + exit(1); + } + + /* Mote we use the same buffer sizes as demod (fsk->Nbits, fsk->N) + for convenience, but other sizes are possible for the + FSK modulator. */ + uint8_t bitbuf[fsk->Nbits]; + + while( fread(bitbuf,sizeof(uint8_t),fsk->Nbits,fin) == fsk->Nbits ){ + if (test_mode) memset(bitbuf,0,fsk->Nbits); + if (complex == 0) { + float modbuf[fsk->N]; + int16_t rawbuf[fsk->N]; + /* 16 bit signed short real output */ + fsk_mod(fsk,modbuf,bitbuf,fsk->Nbits); + for(i=0; i<fsk->N; i++) + rawbuf[i] = (int16_t)(modbuf[i]*amp); + fwrite(rawbuf,bytes_per_sample,fsk->N,fout); + } else { + /* 16 bit signed char complex output */ + COMP modbuf[fsk->N]; + int16_t rawbuf[2*fsk->N]; + fsk_mod_c(fsk,(COMP*)modbuf,bitbuf,fsk->Nbits); + for(i=0; i<fsk->N; i++) { + rawbuf[2*i] = (int16_t)(modbuf[i].real*amp); + rawbuf[2*i+1] = (int16_t)(modbuf[i].imag*amp); + } + fwrite(rawbuf,bytes_per_sample,fsk->N,fout); + } + + if(fout == stdin){ + fflush(fout); + } + } + + fsk_destroy(fsk); +} |