From ac7c48b4dee99d4c772f133d70d8d1b38262fcd2 Mon Sep 17 00:00:00 2001 From: Author Name Date: Fri, 7 Jul 2023 12:20:59 +0930 Subject: shallow zip-file copy from codec2 e9d726bf20 --- src/fdmdv_mod.c | 162 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 162 insertions(+) create mode 100644 src/fdmdv_mod.c (limited to 'src/fdmdv_mod.c') diff --git a/src/fdmdv_mod.c b/src/fdmdv_mod.c new file mode 100644 index 0000000..b47c543 --- /dev/null +++ b/src/fdmdv_mod.c @@ -0,0 +1,162 @@ +/*---------------------------------------------------------------------------*\ + + FILE........: fdmdv_mod.c + AUTHOR......: David Rowe + DATE CREATED: April 28 2012 + + Given an input file of bits outputs a raw file (8kHz, 16 bit shorts) + of FDMDV modem samples ready to send over a HF radio channel. The + input file is assumed to be arranged as codec frames of 56 bits (7 + bytes) which we send as two 28 bit modem frames. + +\*---------------------------------------------------------------------------*/ + + +/* + Copyright (C) 2012 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 +#include + +#include "codec2_fdmdv.h" + +int main(int argc, char *argv[]) +{ + FILE *fin, *fout; + struct FDMDV *fdmdv; + char *packed_bits; + int *tx_bits; + COMP tx_fdm[2*FDMDV_NOM_SAMPLES_PER_FRAME]; + short tx_fdm_scaled[2*FDMDV_NOM_SAMPLES_PER_FRAME]; + int frames; + int i, bit, byte; + int sync_bit; + int bits_per_fdmdv_frame; + int bits_per_codec_frame; + int bytes_per_codec_frame; + int Nc; +#ifdef CHANNEL_SIM + COMP foff_phase_rect; + float foff; +#endif + + if (argc < 3) { + printf("usage: %s InputBitFile OutputModemRawFile [Nc]\n", argv[0]); + printf("e.g %s hts1a.c2 hts1a_fdmdv.raw\n", argv[0]); + exit(1); + } + + if (strcmp(argv[1], "-") == 0) fin = stdin; + else if ( (fin = fopen(argv[1],"rb")) == NULL ) { + fprintf(stderr, "Error opening input bit file: %s: %s.\n", + argv[1], strerror(errno)); + exit(1); + } + + if (strcmp(argv[2], "-") == 0) fout = stdout; + else if ( (fout = fopen(argv[2],"wb")) == NULL ) { + fprintf(stderr, "Error opening output modem sample file: %s: %s.\n", + argv[2], strerror(errno)); + exit(1); + } + + if (argc == 4) { + Nc = atoi(argv[3]); + + if ((Nc < 2) || (Nc > FDMDV_NC_MAX) ) { + fprintf(stderr, "Error number of carriers must be between 2 and %d\n", FDMDV_NC_MAX); + exit(1); + } + } + else + Nc = FDMDV_NC; + + fdmdv = fdmdv_create(Nc); + + bits_per_fdmdv_frame = fdmdv_bits_per_frame(fdmdv); + bits_per_codec_frame = 2*fdmdv_bits_per_frame(fdmdv); + bytes_per_codec_frame = (bits_per_codec_frame+7)/8; + + packed_bits = (char*)malloc(bytes_per_codec_frame); + assert(packed_bits != NULL); + tx_bits = (int*)malloc(sizeof(int)*bits_per_codec_frame); + assert(tx_bits != NULL); + +#ifdef CHANNEL_SIM + foff = -100; + foff_phase_rect.real = 1.0; foff_phase_rect.imag = 0.0; +#endif + + frames = 0; + + while(fread(packed_bits, sizeof(char), bytes_per_codec_frame, fin) == bytes_per_codec_frame) { + frames++; + + /* unpack bits, MSB first */ + + bit = 7; byte = 0; + for(i=0; i> bit) & 0x1; + bit--; + if (bit < 0) { + bit = 7; + byte++; + } + } + + /* modulate even and odd frames */ + + fdmdv_mod(fdmdv, tx_fdm, tx_bits, &sync_bit); + assert(sync_bit == 1); + + fdmdv_mod(fdmdv, &tx_fdm[FDMDV_NOM_SAMPLES_PER_FRAME], &tx_bits[bits_per_fdmdv_frame], &sync_bit); + assert(sync_bit == 0); + + #ifdef CHANNEL_SIM + /* optional freq shift and channel simulation */ + + fdmdv_freq_shift(tx_fdm, tx_fdm, foff, &foff_phase_rect, 2*FDMDV_NOM_SAMPLES_PER_FRAME); + fdmdv_simulate_channel(&sig_pwr_av, tx_fdm, 2*FDMDV_NOM_SAMPLES_PER_FRAME, 10.0); + #endif + + /* scale and save to disk as shorts */ + + for(i=0; i<2*FDMDV_NOM_SAMPLES_PER_FRAME; i++) + tx_fdm_scaled[i] = FDMDV_SCALE * tx_fdm[i].real; + + fwrite(tx_fdm_scaled, sizeof(short), 2*FDMDV_NOM_SAMPLES_PER_FRAME, fout); + + /* if this is in a pipeline, we probably don't want the usual + buffering to occur */ + + if (fout == stdout) fflush(stdout); + } + + //fdmdv_dump_osc_mags(fdmdv); + + free(tx_bits); + free(packed_bits); + fclose(fin); + fclose(fout); + fdmdv_destroy(fdmdv); + + return 0; +} -- cgit v1.2.3