#!/usr/bin/perl

# dumps "interesting" data about tv channels

use Video::Capture::V4l;
use Video::Capture::VBI qw/:DEFAULT %VPS_CNI %VT_NI/;

$vbi = new Video::Capture::V4l::VBI or die;

# the next line is optional (it enables buffering)
$vbi->backlog(25); # max. 1 second backlog (~900kB)

$inp_fd = fileno STDIN;
$vbi_fd = $vbi->fileno;

print "VBI capturing started.\n\n";
print <<EOF;
You can enter the following commands, ended by <return>

q   quit
c   clear

EOF

sub init {
   %fea = ();
   print "\n";
}

sub fea {
   $fea{$_[0]} = $_[1];
}

my($last_cni, $last_ni);

for(;;) {
   my $r="";
   vec($r,$inp_fd,1)=1;
   #vec($r,$vbi_fd,1)=1;
   select $r,undef,undef,0.2;
   while ($vbi->queued) {
      $fields++;
      my $vbi_alloc;
      for (decode_field $vbi->field, VBI_VT|VBI_VPS|VBI_OTHER|VBI_EMPTY) {
         if ($_->[0] == VBI_VPS) {
            init if $last_cni != $_->[3]; $last_cni = $_->[3];
            if (ord($_->[1]) > 127 or length $name_ >= 12) {
               $name = $name_; $name_ = "";
            }
            $name_ .= $_->[1] & "\x7f";
            fea('VPS',sprintf "%04x=%s|$name",$_->[3],$VPS_CNI{$_->[3] & 0x0fff});
            $vps++;
            $vbi_alloc .= "V";
         } elsif ($_->[0] == VBI_VT) {
            if ($_->[2] == 0) {
               if ($_->[4] == 0x1df) {
                  fea('EPG');
               } else {
                  fea('VT');
               }
            } elsif ($_->[2] == 30) {
               if (($_->[3]>>1) == 0) {
                  init if $last_ni != $_->[6]; $last_ni = $_->[6];
                  fea("NI30/1",sprintf "%04x=%s", $_->[6], $VT_NI{$_->[6]}[0]);
               } elsif (($_->[3]>>1) == 8) {
                  fea('PDC');
               } else {
                  fea("30","$_->[3]");
               }
            } elsif ($_->[2] == 31) {
               if ($_->[4] == 0x500) {
                  fea("$_->[1]/IC");
               } else {
                  fea(sprintf "$_->[1]/31[%x]",$_->[4]);
               }
            }
            $vt++;
            $vbi_alloc .= "T";
         } elsif ($_->[0] == VBI_OTHER) {
            $vbi_alloc .= $_->[1] == 1 ? "c" : "O";
         } elsif ($_->[0] == VBI_EMPTY) {
            $vbi_alloc .= ".";
         } else {
            $others++;
         }
      }
      fea("alloc","$vbi_alloc");
   }
   if (vec($r,$inp_fd,1)) {
      $_ = <STDIN>;
      if (/^q/) {
         last;
      } elsif (/^c/) {
         init;
      }
   }
   printf "%5d|F %5d|VPS %6d|VT %5d|O", $fields, $vps,$vt,$others;
   while (my($k, $v) = each(%fea)) {
      print " $k";
      print "[$v]" if $v;
   }
   $|=1;
   print " < \r";
   $|=0;
}