#!/usr/bin/perl

use Video::Capture::V4l;
use Time::HiRes 'time';

$grab = new Video::Capture::V4l;

my $channel = $grab->channel (0);
my $tuner = $grab->tuner (0);
$tuner->mode(MODE_PAL); $tuner->set;
$channel->norm(MODE_PAL); $channel->set;

$grab->picture->brightness(32768);
$grab->picture->contrast(40000);
$grab->picture->hue(32768);
$grab->picture->colour(32768);
$grab->picture->set;

#$RTL2 = 855250;
$RTL2 = 154250;
print $grab->freq ($RTL2),"\n";

$|=1;

open DB,"<sailormoon.db" or die;
read(DB,$w,8) == 8 or die "no header(?)";
($w,$h)=unpack("N*",$w);
print "$w $h\n";
my $db = do { local $/; <DB> };

my $frame=0;
my $fr=$grab->capture ($frame,$w<<4,$h<<4);

my $fps = 25; # glorious PAL
my @reg;
my ($expect_frame,$expect_count);

my $start = time;
my $next_frame = 0;
my $this_frame;
my $locked;
my $minb1 = 10;

for(;;) {
   my $nfr = $grab->capture (1-$frame,$w<<4,$h<<4);
   $this_frame = $next_frame; $next_frame = int((time-$start)*$fps);
   $grab->sync($frame) or die "unable to sync";

   Video::Capture::V4l::reduce2($fr,$w<<4);
   Video::Capture::V4l::reduce2($fr,$w<<3);
   Video::Capture::V4l::reduce2($fr,$w<<2);
   Video::Capture::V4l::reduce2($fr,$w<<1);
   Video::Capture::V4l::normalize($fr);
   ($fr,$diff) = Video::Capture::V4l::findmin ($db, $fr, $expect_frame, $expect_count);

   if ($diff < 400*400) {
     push(@reg,$this_frame,$fr);
     if (@reg > $fps*2) {
        shift @reg; shift @reg;
        my ($a,$b,$r2) = Video::Capture::V4l::linreg(\@reg);
        if ($frame_zero) {
           $expect_frame = $this_frame + $frame_zero + 1;
           $expect_count = 25;
        } else {
           $expect_frame = $expect_count = 0;
        }
        printf "%9.2f + %7.2f * %6d =~ %4d (@%9.2f) EXPECT %6d - %4d ($minb1)",$a,$b,$this_frame,$fr,$r2,$frame_zero,$expect_frame;
        my $b1 = abs($b-1);
        if ($r2<100 && $b1<0.01) {
           $found++;
           print " LOCKED LOCKED LOCKED ($locked, $frame_zero)";
        }
        if ($b1<$minb1) {
           $frame_zero=-$a;
           $minb1 = $b1;
        }
        print "\n";
     }
     $jitter=0;
   } else {
     $jitter++;
     if ($jitter > 5) {
        $expect_frame=$expect_count=$frame_zero=0;
     }
   }
   if ($found && $this_frame>$frame_zero+2000) {
      print "KICKOFFKICKOFFKICKOFFKICKOFFKICKOFFKICKOFFKICKOFFKICKOFFKICKOFFKICKOFFKICKOFFKICKOFFKICKOFFKICKOFF\n";
      die;
   }

   $count++;

   $frame = 1-$frame;
   $fr = $nfr;
}