#!/usr/bin/perl

use Time::HiRes qw ( usleep getitimer setitimer ITIMER_REAL time );
use Video::Frequencies;
use Video::ivtv;

#furioustv script arguments
$device  = $ARGV[0];
$channel = $ARGV[1];
$seconds = $ARGV[2];
$file    = $ARGV[3];


#find an unused filename to write to
#should produce the same result as the bash code in the ftv examples
$ind = 1;
if (-e $file) {
  while (-e ($file . "-" . $ind)) {
   ++$ind;
  }
  $file = $file . "-" . $ind;
}


#perl is quirky
$device = "<" . $device;
$file   = ">" . $file;

#frequency voodoo
$freq = $CHANLIST{'ntsc-cable'}->{$channel};
my $driverf = ($freq * 16)/1000;

#we use the ivtv interface because it works and
#for some reason v4lctl does not work for me
open(my $tuner, $device)
  or die "unable to open: $!";
my $tunerFD = fileno($tuner);
my $ivtvObj = Video::ivtv->new();

if (!$ivtvObj->setFrequency($tunerFD, 0, $driverf))
{
  die "Error:  setFrequency($driverf) failed!\n";
}
close($tuner);


#copy straight from the pvr device to the file
#in binary mode of course, no re-encoding
open(VIDEODEV, $device);
open(FILE, $file);
binmode VIDEODEV;
binmode FILE;


#close files and exit after time elapses
$SIG{VTALRM} = sub {  close(VIDEODEV); close(FILE); exit(); };
setitimer(ITIMER_REAL, $seconds);

#read up to 64k at a time and don't use all the cpu time
while (1) { 
 while ( read (VIDEODEV, $buffer, 65536) and print FILE $buffer ) {};
 usleep(100);
}