mid_converter processing loop

mid_converter.pl

while (1) {
	my @alsa_event = MIDI::ALSA::input();

	# last event -> exit
	last if ($alsa_event[0] == SND_SEQ_EVENT_PORT_UNSUBSCRIBED());

	# midi event to midi score event
	my @score_event = MIDI::ALSA::alsa2scoreevent( @alsa_event );

    # filter out empty events
	next unless (@score_event && defined $score_event[0] && defined $score_event[4]);

	# accept only note events
	next unless ('note' eq $score_event[0]);

	print Dumper \@score_event;

	# accept only events on specified channel
	next unless (scalar @ARGV == 0 || grep { $_ == $score_event[3] } @ARGV );

	# calculate the pitch and duration
	# some offset since Arduino can't play notes lower than 31 Hz
        my $note = int($notes[($score_event[4] % 96) + 32]);

	# my $dur = int( $score_event[2]/1000 - 0.5);
	my $dur = 160;

	my $send = $port->write(slip_send($note, $dur));
	while (!$port->write_drain) {}


	my ($count_in, $string_in) = $port->read(5);
	print "Sent: [$note/$dur] Recv [$count_in]: " . unpack "H*", $string_in;
	print "\n";
}