#!/usr/bin/perl

# Generates a 24-bit wav file for audio ramp testing 

use strict;

use Audio::Wav;
use POSIX;

my $max = (2**24) - 1;

my $wav = new Audio::Wav;



sub ramp {
    my $file = shift;
    my $rate = shift;

    my $details = {
	'bits_sample' => 24,
	'sample_rate' => $rate,
	'channels'    => 2,
    };

    my $write = $wav->write($file, $details);

    $write->set_info('name' => 'Ramp test');

    my $left = 0;
    my $right = floor($max/2);

    for (my $i=0; $i<=$max; $i++) {
	my @samples = ($left, $right);

	# Audio::Wav can only write 16-bit samples
	$write->write_raw_samples(pack('CCCCCC',
				       @samples[0] & 0xFF,
				       (@samples[0] >> 8) & 0xFF,
				       (@samples[0] >> 16) & 0xFF,
				       @samples[1] & 0xFF,
				       (@samples[1] >> 8) & 0xFF,
				       (@samples[1] >> 16) & 0xFF,
				  ));

	if (++$left > $max) {
	    $left = 0;
	}
	if (--$right < 0) {
	    $right = $max;
	}
    }

    $write->finish();
}


ramp("ramp44100.wav", 44100);
ramp("ramp48000.wav", 48000);
ramp("ramp88200.wav", 88200);
ramp("ramp96000.wav", 96000);