#! perl
#
# copyright P KENT SEPTEMBER 2000
# version 1.4 public release - only outputs mode 4 files
#
# written as a service to the QL community
# no responsibility will be assumed for anything this program does
# use at your own risk
#
# converts to QL video dump from raw format
# Note: QL video is encoded as 2-byte chunks
# msb->lsb (Green Red)
# mode 4: GGGGGGGG RRRRRRRR
# R+G=White
#
# input file must be called ql4.raw
# now performs internal diffusion/stochastic dithering

if (! -e "ql4.raw" ) { print("\nNO INPUT\n");exit(0); }
else { print("\n\nNEW RUN\n"); }

open(RAW,"ql4.raw");
open(CNV,"> img_ql4");

$line=0;
$thresh=254.99;
while ( $line < 256 ) {

  print("$line\n");
  $px=0;
  while ( $px < 64 ) {
    read RAW,$n,24;
    @twpix = split(//,$n);
 
   $ga = ((ord $twpix[1]) > rand($thresh) ) * 128;
    $gb = ((ord $twpix[4]) > rand($thresh) ) * 64;
    $gc = ((ord $twpix[7]) > rand($thresh) ) * 32;
    $gd = ((ord $twpix[10]) > rand($thresh) ) * 16;
    $ge = ((ord $twpix[13]) > rand($thresh) ) * 8;
    $gf = ((ord $twpix[16]) > rand($thresh) ) * 4;
    $gg = ((ord $twpix[19]) > rand($thresh) ) * 2;
    $gh = ((ord $twpix[22]) > rand($thresh) ) * 1;

    $ra = ((ord $twpix[0]) > rand($thresh) ) * 128;
    $rb = ((ord $twpix[3]) > rand($thresh) ) * 64;
    $rc = ((ord $twpix[6]) > rand($thresh) ) * 32;
    $rd = ((ord $twpix[9]) > rand($thresh) ) * 16;
    $re = ((ord $twpix[12]) > rand($thresh) ) * 8;
    $rf = ((ord $twpix[15]) > rand($thresh) ) * 4;
    $rg = ((ord $twpix[18]) > rand($thresh) ) * 2;
    $rh = ((ord $twpix[21]) > rand($thresh) ) * 1;

    $byteone = chr($ga + $gb + $gc + $gd + $ge + $gf + $gg + $gh);
    $bytetwo = chr($ra + $rb + $rc + $rd + $re + $rf + $rg + $rh);

    print(CNV "$byteone$bytetwo");
    $px++;
  }
$line++;
}

close(RAW);
close(CNV);
exit(0);