#!/usr/bin/perl -w 

die "Usage: a.pl <input> <output>\n" unless $#ARGV==1;

$in = shift;
$out = shift;
$idx=0;
$red = 0;
$blue = 0;
$green = 0;


open(INFILE, "<$in") or die "Can't open $in: $!";
open(OUTFILE, ">$out") or die "Can't open $out: $!";

while( sysread(INFILE, $byte, 1) != 0 ) {
    syswrite OUTFILE, $byte,1;
    printf("Byte\n");
    $idx++;

    $val = vec($byte, 0, 8);
    if ($idx%3==1) {
	$red = $val;
    }
    if ($idx%3==2) {
	$green = $val;
    }
    if ($idx%3==0) {
	$blue = $val;
    }
    if ( $red == 127 && $blue == 127 && $green == 127 )
    {
	$alpha = 0;
    }
    else {
	$alpha = 255;
    }

    if ($idx%3==0) {
        syswrite OUTFILE, (pack("C", $alpha)), 1;
	printf("Alpha\n");

    }
}
syswrite OUTFILE, (pack("C", 128)), 1;

close INFILE;
close OUTFILE;