#!/usr/bin/perl

$bpp=6;
$width=80*4;
$height=60*4;
$bits = (2**$bpp)-1;
$invert=(2**$bpp);

print "BPP: $bpp; Width: $width; Height: $height; bits: $bits; invert: $invert\n";

open(FILE, "minicom.cap") || die "Unable to open capture file: $!";
binmode FILE;
open(OUT, ">qcam.ppm") || die "Unable to open output file: $!";
binmode OUT;
print OUT "P5\n$width $height\n$bits\n";
$state=0; # for 6bpp.
do {
    $c = ord(getc(FILE));
    $b1 = ($c & 0xf0)>>4;
    $b2 = $c & 0xf;
    if ($bpp==4) {
	print "Alert: corrupt data.\n" if ($b1>16);
	$b1=16 if ($b1==0);
	print OUT chr($invert-$b1);
	print "Alert: corrupt data.\n" if ($b2>16);
	$b2=16 if ($b2==0);
	print OUT chr($invert-$b2);
    } else {
	$bytesthisline++;
	if ($state==0) {
	    $t1 = ($b1<<2) | (($b2&0x0c)>>2);
	    $save = ($b2 & 0x3) << 4;
	    # replaced the next line, but haven't tested it yet. -- 2/11/2000
	    $t1++ if ($t1 == 0);
	    print OUT chr($invert-$t1);
	    $state = 1;
	} elsif ($state==1) {
	    $t1 = ($save | $b1);
	    # replaced the next line, but haven't tested it yet. -- 2/11/2000
	    $t1++ if ($t1 == 0);
	    print OUT chr($invert-$t1);
	    $save = $b2 << 2;
	    $state = 2;
	} else {
	    $t1 = $save | ($b1 >> 2);
	    print OUT chr($invert-$t1);
	    $t2 = (($b1 & 0x3) << 4) | $b2;
	    # replaced the next two lines, but haven't tested yet. -- 2/11/2000
	    $t1++ if ($t1 == 0);
	    $t2++ if ($t2 == 0);
	    print OUT chr($invert-$t2);
	    $state = 0;
	}
# According to the code I've read, the line should prematurely end and the
# state should return to 0 if there are fewer bits on the line than the read-
# length lets us get (the remaining bits, and possibly extra bytes, don't
# exist). This code doesn't exactly work, and if my math is correct, really 
# isn't necessary anyway. All scan widths are divisible by 3 and 4, so we
# should be good.
#	if (($bytesthisline * 12) >= $width) {
#	    $bytesthisline=0;
#	    $state=0;
#	}
    }
} while (!eof(FILE));
close FILE;

close OUT;