rtl

#!/usr/bin/perl
#
# raw: rtl_fm -f 314M -M raw -s 2000000 out.raw
#
# make listening/saving data from rtl-sdr or hackrf faster
# example: rtl 315M
# example: rtl 315M test.wav
#
# by samy kamkar

use strict;
use Getopt::Std;

# hackrf or rtl?
#my $fmcmd = system("rtl_test >>/dev/null 2>>/dev/null") ? "hackrf_fm" : "rtl_fm";
my $fmcmd = "rtl_fm";

my %o;
getopts('bls:m:', \%o);

die "usage: [-s samplerate] [-l squelch] [-m modulation] [-b (baudline)] [-L (lowpass)] <frequency (hz/mhz)> [file.wav]\n" unless @ARGV == 1 || @ARGV == 2;

$o{m} ||= 'am';
$o{l} &&= "-l $o{l}";
$o{L} &&= "lowpass -2 5000";

my ($freq, $file) = @ARGV;
if ($freq =~ /wav$/ && $freq =~ /(\d+)(M|K|G)/)
{
	($freq, $file) = ($1, $freq);
	print STDERR "EXTRACTED FREQUENCY `$freq` FROM FILENAME `$file`\n\n";
}
$freq *= 1_000_000 if $freq < 1000;

my $sample = $o{s} || 2_400_000;
$sample =~ s/M/000000/;
$sample =~ s/K/000/;
my $sox_opts = "-t raw -r $sample -e signed-integer -b 16 -c 1 -V1 - $file $o{L}";
my $rtl_sdr_opts = "-f $freq -s $sample -";
my $rtl_fm = "$fmcmd -M $o{m} $o{l} $rtl_sdr_opts";
if ($fmcmd =~ /^hackrf_fm/i)
{
	$rtl_fm =~ s/-M\s+am/-M/;
	$rtl_fm =~ s/-M\s+fm//;
}

my $sys;
if ($o{b})
{
	$sys = "rtl_sdr $rtl_sdr_opts | /Applications/Audio/baudline.app/Contents/MacOS/baudline -reset -samplerate $sample -channels 2 -format u8 -quadrature -stdin";
}
else
{
	$sys = $file ?
		"$rtl_fm | sox  $sox_opts" :
		"$rtl_fm | play $sox_opts";
}

print "$sys\n";
system($sys);