/*---------------------------------------------------------------------------*\ FILE........: freedv_700d_tx.c AUTHOR......: David Rowe DATE CREATED: April 2021 Demo transmit program using the FreeDV API (700D mode). usage: cd ~/codec2/build_linux cat ../raw/ve9qrp_10s.raw | ./demo/freedv_700d_tx | ./demo/freedv_700d_rx | aplay -f S16_LE Listen to the modulated Tx signal: cat ../raw/ve9qrp_10s.raw | ./demo/freedv_700d_tx | aplay -f S16_LE \*---------------------------------------------------------------------------*/ /* Copyright (C) 2021 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 . */ #include #include #include #include #include "freedv_api.h" int main(int argc, char *argv[]) { struct freedv *freedv; freedv = freedv_open(FREEDV_MODE_700D); assert(freedv != NULL); /* handy functions to set buffer sizes */ int n_speech_samples = freedv_get_n_speech_samples(freedv); short speech_in[n_speech_samples]; int n_nom_modem_samples = freedv_get_n_nom_modem_samples(freedv); short mod_out[n_nom_modem_samples]; /* OK main loop --------------------------------------- */ while(fread(speech_in, sizeof(short), n_speech_samples, stdin) == n_speech_samples) { freedv_tx(freedv, mod_out, speech_in); fwrite(mod_out, sizeof(short), n_nom_modem_samples, stdout); } freedv_close(freedv); return 0; }