#!/usr/bin/env perl
use warnings FATAL => 'all';
use strict;
use 5.010;

use MP4::Info 'get_mp4tag';
my %func = (
external => sub {
    my $file=shift;
    return `AtomicParsley "$file" -T 1 2>/dev/null`=~/hdvd/i;
},
scan => sub {
    my $file=shift;
    my $BUFN = 1024; $BUFN *= 4096;
    my $SIG = '68 64 76 64 00 00 00 11 64 61 74 61 00 00 00 15'
        .'00 00 00 00 02 00 00 00';
    $SIG =~ tr[ ][]d;
    $SIG = pack 'H*', $SIG;
    open my $in, '<:raw', $file or die $!;
    my( $offset, $buffer ) = ( 0, '' );
    while( sysread( $in, $buffer, $BUFN, length $buffer ) ) {
        my $pos = 1+index( $buffer, $SIG );
        if( $pos ) {
            return 1;
        }
        $offset += length( $buffer ) - length( $SIG );
        $buffer = substr $buffer, - length $SIG;
    }
    close $in;
    return;
},
mp4info => sub {
    my $file=shift;
    my $tag = get_mp4tag($file) or return;
    return !!$tag->{HDVD};
},
);

die "Usage: $0 ".join('|',sort keys %func)." PATH\n"
    unless @ARGV==2 && exists $func{$ARGV[0]} && -d $ARGV[1];
my $FUNC = $ARGV[0];
my $PATH = $ARGV[1];

use File::Find 'find';
my ($yes,$no,$size) = (0,0,0);
find({ wanted=>sub {
    return unless -f && /\.(mp4|m4[apvb])$/i;
    $size+=-s;
    if ($func{$FUNC}->($_))
        { $yes++; say "YES $_"; }
    else
        { $no++; say " no $_"; }
}}, $PATH);
say "yes=$yes, no=$no, size=$size";
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