#!/bin/bash

##
## #############################################################################
##  Copyright (C) 2019-2021 Chrystian Huot <chrystian.huot@saubeo.solutions>
##
## This program is free software: you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
##
## 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 General Public License
## along with this program.  If not, see <http://www.gnu.org/licenses/>
## #############################################################################
##

##
## Begin of configurable values
##

audio_dir=./audio_files/air
device_id=00000001
center_freq=119.4e6
gain=38.6
sampling_rate=2400000
squelch=2e-4

## List of frequencies covered by your RTL

freqs=(118.9e6 119.1e6 119.9e6)

## Filename tempaltes for each frequencies
## See sox documentation for multiple files output

filenames=(118900000-%6n 119100000-%6n 119900000-%6n)

##
## End of configurable values
##

for i in ${!freqs[@]}; do
	mkfifo /tmp/csdr_${device_id}_${freqs[i]}_iq.fifo

	mkfifo /tmp/csdr_${device_id}_${freqs[i]}_squelch.fifo
done

trap cleanup EXIT

test -d ${audio_dir} || mkdir -p ${audio_dir} || exit 1

trap "rm -f /tmp/csdr_${device_id}_*.fifo" EXIT

for i in ${!freqs[@]}; do
	cat /tmp/csdr_${device_id}_${freqs[i]}_iq.fifo |
		csdr convert_u8_f |
		csdr shift_addition_cc $(csdr =\(${center_freq}-${freqs[i]}\)/${sampling_rate}) |
		csdr fir_decimate_cc 50 0.005 HAMMING |
		csdr squelch_and_smeter_cc --fifo /tmp/csdr_${device_id}_${freqs[i]}_squelch.fifo --outfifo /dev/null 6e-5 600 |
		csdr amdemod_cf |
		csdr agc_ff |
		csdr limit_ff |
		csdr convert_f_s16 |
		sox -c 1 -r 44100 -t s16 - "${audio_dir}/${filenames[i]}.wav" silence 1 0.50 0.1% 1 2.0 0.1% : newfile : restart &
done

for i in ${!freqs[@]}; do
	echo ${squelch} >/tmp/csdr_${device_id}_${freqs[i]}_squelch.fifo
done

server="rtl_sdr -d ${device_id} -f ${center_freq} -g ${gain} -s ${sampling_rate} -"

for i in ${!freqs[@]}; do
	if [ $i == $((${#freqs[@]} - 1)) ]; then
		server+=" > /tmp/csdr_${device_id}_${freqs[i]}_iq.fifo"
	else
		server+=" | tee /tmp/csdr_${device_id}_${freqs[i]}_iq.fifo"
	fi
done

eval ${server}