Home-Video/encode.pl

#!/usr/bin/perl
use strict;
use warnings;

# Includes
use POSIX;
use IPC::Open3;
use File::Basename;

# Default configuration
my $FORMAT        = 'mp4';
my $AUDIO_BITRATE = 192;
my $QUALITY       = 20;
my $HD_QUALITY    = 22;
my $AUDIO_COPY    = 0;
my $STEREO_ONLY   = 0;
my $VIDEO_ONLY    = 0;
my $HEIGHT        = undef();
my $WIDTH         = undef();
my $AUDIO_EXCLUDE_REGEX =
  '\b(?:Chinese|Czech|Deutsch|Espanol|Francais|Italiano|Japanese|Korean|Magyar|Polish|Portugues|Russian|Thai|Turkish|Ukrainian)\b';
my $SUB_INCLUDE_REGEX = '\b(?:English|Unknown|Closed\s+Captions)\b';
my $FORCE_MP4         = 0;
my $OUT_DIR           = undef();
my $MIXDOWN_CODEC     = 'AAC';
my $MIXDOWN_CHANNELS  = 2.0;
my $AAC_ENCODER       = 'ffaac';
my $VIDEO_ENCODER     = 'x265';
my %ENCODER_OPTS      = (
    'x264' => [ '--encopts',        'b-adapt=2:rc-lookahead=50' ],
    'x265' => [ '--encoder-preset', 'slow' ],
);

# Applicaton configuration
my $HD_WIDTH        = 1350;
my $MIN_VIDEO_WIDTH = 100;
my $MAX_CROP_DIFF   = .1;
my $MAX_DURA_DIFF   = 5;
my $NO_CROP         = 0;
my @CODEC_ORDER     = ('DTS-HD', 'FLAC', 'DTS', 'E-AC3', 'AC3', 'PCM', 'VORBIS', $MIXDOWN_CODEC, 'OTHER');
my $HB_EXEC         = $ENV{'HOME'} . '/bin/video/HandBrakeCLI';
my $DEBUG           = 0;

# General parameters for HandBrake
my @video_params = ('--markers', '--optimize', '--detelecine', '--decomb', '--auto-anamorphic');
my @audio_params = ('--audio-copy-mask', 'dtshd,dts,eac3,ac3,aac', '--audio-fallback', 'ffac3');

# Use CoreAudio where available
my ($OS) = POSIX::uname();
if ($OS eq 'Darwin') {
    $AAC_ENCODER = 'ca_aac';
}

# Runtime debug mode
if (defined($ENV{'DEBUG'}) && $ENV{'DEBUG'}) {
    $DEBUG = 1;
}

# Shortcut config
if ($ENV{'MOBILE'}) {
    $ENV{'QUALITY'}       = 24;
    $ENV{'HEIGHT'}        = 720;
    $ENV{'WIDTH'}         = 1280;
    $ENV{'AUDIO_BITRATE'} = 128;
    $ENV{'STEREO_ONLY'}   = 1;
    $ENV{'ENCODER'}       = 'x264';
}

# Allow overrides for audio languages
if ($ENV{'AUDIO_EXCLUDE_REGEX'}) {
    $AUDIO_EXCLUDE_REGEX = $ENV{'AUDIO_EXCLUDE_REGEX'};
}

# Allow overrides for subtitle languages
if ($ENV{'SUB_INCLUDE_REGEX'}) {
    $SUB_INCLUDE_REGEX = $ENV{'SUB_INCLUDE_REGEX'};
}

# Allow copy-only audio transfers (for use in re-encoding)
if ($ENV{'AUDIO_COPY'}) {
    $AUDIO_COPY = 1;
}

# Allow AAC-only audio transfers (for use in mobile encoding)
if ($ENV{'STEREO_ONLY'}) {
    $STEREO_ONLY = 1;
}

# Allow video-only transfers
if ($ENV{'VIDEO_ONLY'}) {
    $VIDEO_ONLY = 1;
}

# Allow MP4-only output format (for use in mobile encoding)
if ($ENV{'FORCE_MP4'}) {
    $FORCE_MP4 = 1;
}

# Allow overrides for video quality
if ($ENV{'QUALITY'}) {
    if (!($ENV{'QUALITY'} =~ /^\d+$/)) {
        die($0 . ': Invalid QUALITY: ' . $ENV{'QUALITY'} . "\n");
    }
    $QUALITY    = $ENV{'QUALITY'};
    $HD_QUALITY = $ENV{'QUALITY'};
}

# Allow overrides for audio bitrate
if ($ENV{'AUDIO_BITRATE'}) {
    if (!($ENV{'AUDIO_BITRATE'} =~ /^\d+$/)) {
        die($0 . ': Invalid AUDIO_BITRATE: ' . $ENV{'AUDIO_BITRATE'} . "\n");
    }
    $AUDIO_BITRATE = $ENV{'AUDIO_BITRATE'};
}

# Use an alternate output directory, if specified
if ($ENV{'OUT_DIR'}) {
    $OUT_DIR = $ENV{'OUT_DIR'};
    $OUT_DIR =~ s/\/+$//;
    if (!-d $OUT_DIR) {
        die($0 . ': Invalid OUT_DIR: ' . $OUT_DIR . "\n");
    }
}

# Allow overrides for video height and width. The default is "same as source".
if ($ENV{'HEIGHT'}) {
    if (!($ENV{'HEIGHT'} =~ /^\d+$/)) {
        die($0 . ': Invalid HEIGHT: ' . $ENV{'HEIGHT'} . "\n");
    }
    push(@video_params, '--maxHeight', $ENV{'HEIGHT'});
}
if ($ENV{'WIDTH'}) {
    if (!($ENV{'WIDTH'} =~ /^\d+$/)) {
        die($0 . ': Invalid WIDTH: ' . $ENV{'WIDTH'} . "\n");
    }
    push(@video_params, '--maxWidth', $ENV{'WIDTH'});
}

# Allow autocrop disable
if ($ENV{'NO_CROP'}) {
    $NO_CROP = 1;
}

# Allow greyscale mode
if ($ENV{'GREYSCALE'}) {
    push(@video_params, '--grayscale');
}

# Allow selection of video encoder
if ($ENV{'ENCODER'}) {
    if (!exists($ENCODER_OPTS{ $ENV{'ENCODER'} })) {
        die($0 . ': Invalid ENCODER: ' . $ENV{'ENCODER'} . "\n");
    }
    $VIDEO_ENCODER = $ENV{'ENCODER'};
}
push(@video_params, '--encoder', $VIDEO_ENCODER, @{ $ENCODER_OPTS{$VIDEO_ENCODER} });

# Additional arguments for HandBrake, to allow options not supported directly by this script
# Split on spaces; if you need spaces you'll have to work out something else
if ($ENV{'HANDBRAKE_ARGS'}) {
    my @args = split(/\s+/, $ENV{'HANDBRAKE_ARGS'});
    push(@video_params, @args);
}

# Command-line parameters
my ($in_file, $out_file, $title) = @ARGV;
if (!defined($in_file) || length($in_file) < 1 || !-r $in_file) {
    die('Usage: ' . basename($0) . " in_file [out_file] [title]\n");
}

# Sanity checks
if ($AUDIO_COPY && $STEREO_ONLY) {
    die(basename($0) . ": AUDIO_COPY and STEREO_ONLY are mutually exclusive\n");
}
if ($VIDEO_ONLY && ($AUDIO_COPY || $STEREO_ONLY)) {
    die(basename($0) . ": VIDEO_ONLY and AUDIO_COPY or STEREO_ONLY are mutually exclusive\n");
}

# Scan for title/track info
my %titles = &scan($in_file);

# Allow external subtitles for single-title files
if (scalar(keys(%titles)) == 1) {
    my $srt_file = $in_file;
    $srt_file =~ s/\.\w{2,4}$/.srt/;
    if (!-r $srt_file) {
        $srt_file =~ s/\.\w{2,4}$/.ssa/;
    }
    if (-r $srt_file) {
        if ($DEBUG) {
            print STDERR 'Adding subtitles from: ' . $srt_file . "\n";
        }
        push(@video_params, '--srt-file', $srt_file);
    }
}

# Allow encoding of a specific title
if ($title) {
    if ($title =~ /^\d+$/ && $title > 0) {
        if (!defined($titles{$title})) {
            die(basename($0) . ': Invalid title number: ' . $title . "\n");
        }
        my $selected_title = $titles{$title};
        %titles = ();
        $titles{$title} = $selected_title;
    } elsif ($title =~ /main/i) {
        my $max_title    = 0;
        my $max_duration = 0;
        foreach my $title (keys(%titles)) {
            if (!$titles{$title}{'duration'}) {
                warn(basename($0) . ': Unknown duration for title: ' . $title . "\n");
                next;
            }
            my $new_max = 0;
            if (abs($titles{$title}{'duration'} - $max_duration) < $MAX_DURA_DIFF) {
                if ($titles{$title}{'aspect'} > $titles{$max_title}{'aspect'}) {
                    $new_max = 1;
                } elsif ($titles{$title}{'size'}[0] > $titles{$max_title}{'size'}[0]
                    || $titles{$title}{'size'}[1] > $titles{$max_title}{'size'}[1])
                {
                    $new_max = 1;
                }
            } elsif ($titles{$title}{'duration'} > $max_duration) {
                $new_max = 1;
            }
            if ($new_max) {
                $max_duration = $titles{$title}{'duration'};
                $max_title    = $title;
            }
        }
        my $selected_title = $titles{$max_title};
        %titles = ();
        $titles{$max_title} = $selected_title;
    }
}

# Ensure we have an output file name
# Force MKV output if the output file name is provided and ends in .MKV
if (!defined($out_file) || length($out_file) < 1) {
    $out_file = $in_file;
} else {
    my ($force_format) = $out_file =~ /\.(\w{2,4})$/;
    if (defined($force_format) && lc($force_format) eq 'mkv') {
        $FORMAT = 'mkv';
    }
}

# Override the output directory, if requested
if ($OUT_DIR) {
    $out_file = $OUT_DIR . '/' . basename($out_file);
}

# Keep copies of our defaults so we can reset between tracks
my $format_default = $FORMAT;

# Encode each title
foreach my $title (keys(%titles)) {
    if ($DEBUG) {
        print STDERR 'Setting options for title: ' . $title . "\n";
    }

    # Reset
    $FORMAT = $format_default;

    # Select a title
    my $scan = $titles{$title};

    # Skip tracks that have no video
    if (scalar(@{ $scan->{'size'} }) < 2 || $scan->{'size'}[0] < $MIN_VIDEO_WIDTH) {
        print STDERR basename($0) . ': No video detected in: ' . $in_file . ':' . $title . ". Skipping title...\n";
        next;
    }

    # Parse subtitle tracks
    my @subs = &subOptions($scan);

    # Parse audio tracks, unless we're in VIDEO_ONLY mode
    my @audio = ();
    if (!$VIDEO_ONLY) {
        @audio = &audioOptions($scan);

        # Skip tracks that have no audio
        if (scalar(@{ $scan->{'audio'} }) < 1 || scalar(@audio) < 1) {
            print STDERR basename($0) . ': No audio detected in: ' . $in_file . ':' . $title . ". Skipping title...\n";
            next;
        }

        # Set the bitrate for transcoded audio tracks
        push(@audio, '--ab', $AUDIO_BITRATE);
    }

    # Set the video quality, using $HD_QUALITY for images larger than $HD_WIDTH (to allow lower quality on HD streams)
    my $title_quality = $QUALITY;
    if ($scan->{'size'}[0] > $HD_WIDTH) {
        $title_quality = $HD_QUALITY;
    }

    # Detect unlikely autocrop values
    my $bad_crop = 0;
    if (   abs($scan->{'crop'}[0] - $scan->{'crop'}[1]) > $scan->{'size'}[0] * $MAX_CROP_DIFF
        || abs($scan->{'crop'}[2] - $scan->{'crop'}[3]) > $scan->{'size'}[0] * $MAX_CROP_DIFF)
    {
        print STDERR basename($0)
          . ': Overriding unlikely autocrop values: '
          . join(':', @{ $scan->{'crop'} }) . ': '
          . $in_file . "\n";
        $bad_crop = 1;
    }

    # Disable cropping (if no crop argument is passed, HB will autocrop, so set 0:0:0:0 explictly)
    if ($NO_CROP || $bad_crop) {
        my @crop = (0, 0, 0, 0);
        $scan->{'crop'} = \@crop;
    }

    # Force MKV muxing if the output contains PGS subtitles (there's no support in the MP4 muxer)
    foreach my $track (values(%{ $scan->{'subtitle_selected'} })) {
        if ($track->{'type'} eq 'PGS') {
            $FORMAT = 'mkv';
            last;
        }
    }

    # Force MKV muxing if the output contains DTS audio (technically MP4 supports it but QuickTime hates it)
    foreach my $track (values(%{ $scan->{'audio_selected'} })) {
        if ($track->{'codec'} =~ /DTS/i) {
            $FORMAT = 'mkv';
            last;
        }
    }

    # Select a file name extension that matches the format
    my $title_out_file = $out_file;
    $title_out_file =~ s/\.(?:\w{2,4}|dvdmedia)$//i;
    if ($FORMAT eq 'mkv') {
        $title_out_file .= '.mkv';
    } else {
        $title_out_file .= '.m4v';
    }

    # Force the title number into the output file name if there are multiple titles to be encoded
    if (scalar(keys(%titles)) > 1) {
        my $title_text = sprintf('%02d', $title);
        $title_out_file =~ s/(\.\w{2,4})$/\-${title_text}${1}/;
    }

    # Output file
    if (uc($title_out_file) eq uc($in_file)) {
        $title_out_file =~ s/(\.\w{2,4})$/-recode${1}/;
    }

    # Build the arugment list
    my @args = ($HB_EXEC);
    push(@args, '--title',   $title);
    push(@args, '--input',   $in_file);
    push(@args, '--output',  $title_out_file);
    push(@args, '--format',  $FORMAT);
    push(@args, '--quality', $title_quality);
    push(@args, '--crop',    join(':', @{ $scan->{'crop'} }));
    push(@args, @video_params);

    # Include subtitles if available
    if (scalar(@subs)) {
        push(@args, @subs);
    }

    # Include audio unless specifically excluded
    if (!$VIDEO_ONLY) {
        push(@args, @audio_params);
        push(@args, @audio);
    }

    if ($DEBUG) {
        print STDERR "\n" . join(' ', @args) . "\n\n";
    }

    # Sanity check
    if (-e $title_out_file) {
        print STDERR basename($0) . ': Output file exists: ' . $title_out_file . ". Skipping...\n";
        next;
    }

    # Run it
    my $child_out = '';
    my $child_in  = '';
    my $pid       = open3($child_in, $child_out, $child_out, @args);
    close($child_in);
    while (<$child_out>) {
        if ($DEBUG) {
            print STDERR $_;
        }
    }
    waitpid($pid, 0);
    close($child_out);

    # Provide the new file name if requested
    if ($ENV{'RECODE_OUTFILE'}) {
        print $title_out_file;
    }
}

# Cleanup
exit(0);

sub subOptions($) {
    my ($scan) = @_;

    my %tracks = ();
    foreach my $track (@{ $scan->{'subtitle'} }) {
        my ($language, $note, $iso, $text, $type) = $track->{'description'} =~
          /^([^\(]+)(?:\s+\(([^\)]+)\))?\s+\(iso(\d+\-\d+)\:\s+\w\w\w\)\s+\((Text|Bitmap)\)\((CC|VOBSUB|PGS|SSA|TX3G|UTF\-\d+)\)/i;
        if (!defined($iso)) {
            print STDERR 'Could not parse subtitle description: ' . $track->{'description'} . "\n";
            next;
        }

        # Map text/bitmap into a boolean
        if ($text =~ /TEXT/i) {
            $text = 1;
        } else {
            $text = 0;
        }

        # Standardize the codes
        $iso  = uc($iso);
        $type = uc($type);

        # Push all parsed data into an array
        my %data = ('language' => $language, 'note' => $note, 'iso' => $iso, 'text' => $text, 'type' => $type);
        $tracks{ $track->{'index'} } = \%data;

        # Print what we found
        if ($DEBUG) {
            print STDERR 'Found subtitle track: ';
            printHash(\%data);
        }
    }

    # Push the parsed data back up the chain
    $scan->{'subtitle_parsed'} = \%tracks;

    # Select the subtitle tracks we want to keep
    my @keep = ();
    foreach my $index (keys(%tracks)) {

        # Skip PGS tracks when we're forcing MP4 output (they're not allowed by the muxer)
        if ($FORCE_MP4 && $tracks{$index}->{'type'} eq 'PGS') {
            next;
        }

        # Keep tracks in our prefered language, and all text-based subtitles (they're small)
        if (isValidSubLanguage($tracks{$index}->{'language'}, $tracks{$index}->{'iso'})) {
            push(@keep, $index);
        } elsif ($tracks{$index}->{'text'}) {
            push(@keep, $index);
        } else {
            if ($DEBUG) {
                print STDERR 'Skipping subtitle ' . $index . ' due to language: ' . $tracks{$index}->{'language'} . "\n";
            }
        }
    }

    # Push the selected tracks back up the chain
    my %tmp = ();
    foreach my $num (@keep) {
        $tmp{$num} = $tracks{$num};
    }
    $scan->{'subtitle_selected'} = \%tmp;

    # Send back the argument string (if any)
    if (scalar(@keep) < 1) {
        return '';
    }
    return ('--subtitle', join(',', @keep));
}

sub audioOptions($) {
    my ($scan) = @_;
    my @retval = ();

    # Type the audio tracks
    my %tracks = ();
    foreach my $track (@{ $scan->{'audio'} }) {
        my ($language, $codec, $note, $channels, $iso, $specs) = $track->{'description'} =~
/^([^\(]+)\s+\(([^\)]+)\)\s+(?:\(([^\)]*Commentary[^\)]*)\)\s+)?\((\d+\.\d+\s+ch|Dolby\s+Surround)\)(?:\s+\(iso(\d+\-\d+)\:\s+\w\w\w\))?(?:,\s+(.*))?/;
        if (!defined($channels)) {
            print STDERR 'Could not parse audio description: ' . $track->{'description'} . "\n";
            next;
        }

        # Decode the channels string to a number
        if ($channels =~ /(\d+\.\d+)\s+ch/i) {
            $channels = $1;
        } elsif ($channels =~ /Dolby\s+Surround/i) {
            $channels = 3.1;
        }

        # Standardize the codec
        foreach my $code (@CODEC_ORDER) {
            my $metacode = quotemeta($code);
            if ($codec =~ /${metacode}/i) {
                $codec = $code;
                last;
            } elsif ($code eq 'OTHER') {
                if ($codec =~ /MP3/i || $codec =~ /MPEG/i || $codec =~ /MP2/i) {
                    $codec = $code;
                } elsif ($codec eq 'dca') {
                    print STDERR 'Found incompatible audio (' . $track->{'description'} . ')  in track ' . $track->{'index'} . "\n";
                    $codec = undef();
                } else {
                    print STDERR 'Found unknown audio (' . $track->{'description'} . ') in track ' . $track->{'index'} . "\n";
                    $codec = $code;
                }
            }
        }

        # Standardize the specs
        my $bitrate    = 0;
        my $samplerate = 0;
        if (!$specs) {
            $specs = '';
        }
        if ($specs =~ /(\d+)bps/) {
            $bitrate = $1 / 1000;
        } elsif ($specs =~ /(\d+)\s*kb\/s/) {
            $bitrate = $1;
        }
        if ($specs =~ /(\d+)Hz/) {
            $samplerate = $1;
        }

        # Push all parsed data into the array
        my %data = (
            'language'   => $language,
            'codec'      => $codec,
            'channels'   => $channels,
            'iso'        => $iso,
            'note'       => $note,
            'bitrate'    => $bitrate,
            'samplerate' => $samplerate,
        );
        $tracks{ $track->{'index'} } = \%data;

        # Print what we found
        if ($DEBUG) {
            print STDERR 'Found audio track: ';
            printHash(\%data);
        }
    }

    # Push the parsed data back up the chain
    $scan->{'audio_parsed'} = \%tracks;

    # Find the track with the most channels for each codec, and the highest number of channels among all types of tracks
    # Then choose the most desired codec among the set of codecs that contain the highest number of channels
    # This chooses the track with the most channels for the mixdown, and resolves ties using CODEC_ORDER
    my $mixdown      = undef();
    my %bestByCodec  = ();
    my $bestCodec    = undef();
    my $mostChannels = 0;

    # Loop point, in case we need to run the selector more than once
  SELECT_AUDIO:
    foreach my $codec (@CODEC_ORDER) {
        $bestByCodec{$codec} = findBestAudioTrack(\%tracks, $codec);
        if (defined($bestByCodec{$codec})
            && (!defined($bestCodec) || $mostChannels < $tracks{ $bestByCodec{$codec} }->{'channels'}))
        {
            $bestCodec    = $codec;
            $mostChannels = $tracks{ $bestByCodec{$codec} }->{'channels'};
        }
    }
    foreach my $codec (@CODEC_ORDER) {
        if (defined($bestByCodec{$codec}) && $tracks{ $bestByCodec{$codec} }->{'channels'} == $mostChannels) {
            $mixdown = $bestByCodec{$codec};
            last;
        }
    }

    # Sanity check
    if (!defined($mixdown) || $mixdown < 1) {

        # If we applied an exclude filter, remove it and try again
        if ($AUDIO_EXCLUDE_REGEX ne 'ACCEPT_ALL') {
            $AUDIO_EXCLUDE_REGEX = 'ACCEPT_ALL';
            print STDERR "No usable audio tracks found in title. Removing exclude filter...\n";
            goto SELECT_AUDIO;
        }

        # If we got no audio, give up -- this file is not valid
        print STDERR basename($0) . ": No usable audio tracks in title\n";
        return;
    }

    # Clear the mixdown selection if we're copying audio
    if ($AUDIO_COPY) {
        $mixdown = undef();
    }

    # Mixdown track first
    my @audio_tracks = ();
    if (defined($mixdown) && $mixdown > 0) {
        if ($DEBUG) {
            print STDERR 'Using track ' . $mixdown . " as default AAC audio\n";
            if ($tracks{$mixdown}->{'channels'} > 2) {
                push(@retval, '--mixdown', 'dpl2');
                print STDERR "\tMixing down with Dolby Pro Logic II encoding\n";
            }
        }
        my %track = ('index' => $mixdown, 'encoder' => $AAC_ENCODER);
        push(@audio_tracks, \%track);
    }

    # Keep all other audio tracks, unless STEREO_ONLY is set
    if (!$STEREO_ONLY) {

        # Passthru DTS-MA, DTS, AC3, and AAC
        # Keep other audio tracks, but recode to AAC (using Handbrake's audio-copy-mask/audio-fallback feature)
        foreach my $index (keys(%tracks)) {
            if (defined($mixdown) && $mixdown == $index && $tracks{$index}->{'channels'} <= $MIXDOWN_CHANNELS) {
                if ($DEBUG) {
                    print STDERR 'Skipping passthru of track '
                      . $index
                      . ' since it is already used as the mixdown track and contains only '
                      . $tracks{$index}->{'channels'}
                      . " channels\n";
                }
                next;
            } elsif (!$tracks{$index}->{'codec'}) {
                if ($DEBUG) {
                    print STDERR 'Skipping track ' . $index . " due to invalid codec\n";
                }
                next;
            } elsif (!isValidAudioLanguage($tracks{$index}->{'language'}, $tracks{$index}->{'iso'})) {
                if ($DEBUG) {
                    print STDERR 'Skipping track ' . $index . ' due to language: ' . $tracks{$index}->{'language'} . "\n";
                }
                next;
            } elsif ($FORCE_MP4 && $tracks{$index}->{'codec'} =~ /DTS/i) {
                if ($DEBUG) {
                    print STDERR 'Skipping track ' . $index . " due to DTS codec and FORCE_MP4 flag\n";
                }
                next;
            } else {
                my %track = ('index' => $index, 'encoder' => 'copy');
                push(@audio_tracks, \%track);
            }
        }
    }

    # Push the selected tracks back up the chain
    my %sel = ();
    foreach my $track (@audio_tracks) {

        # Copy the data, rather than just point to it -- we sometimes need modifications
        my $index = $track->{'index'};
        my %tmp   = %{ $tracks{$index} };

        # The mixdown track needs special handling -- it appears twice, and with different settings
        if ($track->{'encoder'} ne 'copy' && defined($mixdown) && $mixdown > 0 && $track->{'index'} == $mixdown) {
            $index .= '_mixdown';
            $tmp{'codec'}    = $MIXDOWN_CODEC;
            $tmp{'channels'} = $MIXDOWN_CHANNELS;
        }

        # Collect our (possibly modified) hash
        $sel{$index} = \%tmp;
    }
    $scan->{'audio_selected'} = \%sel;

    # Consolidate from the hashes
    my @output_tracks   = ();
    my @output_encoders = ();
    foreach my $track (@audio_tracks) {
        push(@output_tracks,   $track->{'index'});
        push(@output_encoders, $track->{'encoder'});
    }

    # Send back the argument strings
    push(@retval, '--audio',    join(',', @output_tracks));
    push(@retval, '--aencoder', join(',', @output_encoders));
    return (@retval);
}

sub scan($) {
    my ($in_file) = @_;

    # Fork to scan the file
    my $child_out = '';
    my $pid = open3('<&STDIN', $child_out, $child_out, $HB_EXEC, '--previews', '30', '--title', '0', '--input', $in_file);

    # Loop through the output
    my $scan;
    my %titles  = ();
    my $inTitle = 0;
    my $zone    = '';
    while (<$child_out>) {

        if (!$inTitle && m/scan thread found (\d+) valid title/i) {
            if ($DEBUG) {
                print STDERR 'Found ' . $1 . " titles in source\n";
            }
        } elsif (m/^\s+Stream \#0\.(\d+)\(\w+\)\:\s+(.*)/) {
            my $stream = $1;
            my $desc   = $2;
        } elsif (m/^\s*\+\s+title\s+(\d+)\:/) {

            # Save the current title (if any)
            if ($inTitle) {
                $titles{$inTitle} = $scan;
            }

            # Grab the new title number
            $inTitle = $1;

            # Init the data collectors
            my @audio    = ();
            my @crop     = ();
            my @subtitle = ();
            my @size     = ();
            my %tmp      = (
                'audio'    => \@audio,
                'crop'     => \@crop,
                'subtitle' => \@subtitle,
                'size'     => \@size,
                'duration' => 0,
                'aspect'   => 0
            );
            $scan = \%tmp;

            if ($DEBUG) {
                print STDERR 'Found data for title ' . $1 . "\n";
            }
        } elsif ($inTitle) {
            if (/^\s*\+\s+size: (\d+)x(\d+)/) {
                push(@{ $scan->{'size'} }, $1, $2);
                if ($DEBUG) {
                    print STDERR 'Size: ' . join('x', @{ $scan->{'size'} }) . "\n";
                }
                if (/\s+display aspect\: (\d*\.\d+)/) {
                    $scan->{'aspect'} = $1;
                    if ($DEBUG) {
                        print STDERR 'Aspect: ' . $scan->{'aspect'} . "\n";
                    }
                }
            } elsif (/^\s*\+\s+duration\:\s+(\d+)\:(\d+)\:(\d+)/) {
                $scan->{'duration'} = ($1 * 3600) + ($2 * 60) + $3;
                if ($DEBUG) {
                    print STDERR 'Duration: ' . $scan->{'duration'} . "\n";
                }
            } elsif (/^\s*\+\s+autocrop\:\s+(\d+)\/(\d+)\/(\d+)\/(\d+)/) {
                push(@{ $scan->{'crop'} }, $1, $2, $3, $4);
                if ($DEBUG) {
                    print STDERR 'Crop: ' . join('/', @{ $scan->{'crop'} }) . "\n";
                }
            } elsif ($zone ne 'audio' && /^\s*\+\s+audio\s+tracks\:\s*$/) {
                $zone = 'audio';
            } elsif ($zone eq 'audio' && /^\s*\+\s+(\d+)\,\s+(.*)/) {
                my %track = ('index' => $1, 'description' => $2);
                push(@{ $scan->{'audio'} }, \%track);
                if ($DEBUG) {
                    print STDERR 'Audio Track #' . $track{'index'} . ': ' . $track{'description'} . "\n";
                }
            } elsif ($zone ne 'subtitle' && /^\s*\+\s+subtitle\s+tracks\:\s*$/) {
                $zone = 'subtitle';
            } elsif ($zone eq 'subtitle' && m/^\s*\+\s+(\d+)\,\s+(.*)$/) {
                my %track = ('index' => $1, 'description' => $2);
                push(@{ $scan->{'subtitle'} }, \%track);
                if ($DEBUG) {
                    print STDERR 'Subtitle Track #' . $track{'index'} . ': ' . $track{'description'} . "\n";
                }
            }
        }
    }

    # Save the last title (if any)
    if ($inTitle) {
        $titles{$inTitle} = $scan;
    }

    # Cleanup the scan process
    waitpid($pid, 0);
    close($child_out);

    # Sanity check
    if (scalar(keys(%titles)) < 1) {
        die(basename($0) . ': Did not find any titles in file: ' . $in_file . "\n");
    }

    # Return
    return %titles;
}

sub findBestAudioTrack($$) {
    my ($tracks, $codec) = @_;
    my $best      = undef();
    my @available = ();

    # Find available tracks
    for my $index (keys(%{$tracks})) {
        my $track = $tracks->{$index};

        # Skip tracks not in the specified codec
        if (!$track->{'codec'} || $track->{'codec'} ne $codec) {
            next;
        }

        # Skip foreign language tracks
        if (!isValidAudioLanguage($track->{'language'}, $track->{'iso'})) {
            next;
        }

        push(@available, $index);
    }
    if (scalar(@available) < 1) {
        return $best;
    }

    # Find the tracks with the most channels
    {
        my @most     = ();
        my $channels = 0;
        foreach my $index (@available) {
            my $track = $tracks->{$index};
            if ($track->{'channels'} > $channels) {
                @most     = ($index);
                $channels = $track->{'channels'};
            } elsif ($track->{'channels'} == $channels) {
                push(@most, $index);
            }
        }
        @available = @most;
    }
    if (scalar(@available) < 1) {
        return $best;
    }

    # Find the tracks with the highest bitrate
    {
        my @highest = ();
        my $bitrate = 0;
        foreach my $index (@available) {
            my $track = $tracks->{$index};
            if ($track->{'bitrate'} > $bitrate) {
                @highest = ($index);
                $bitrate = $track->{'bitrate'};
            } elsif ($track->{'bitrate'} == $bitrate) {
                push(@highest, $index);
            }
        }
        @available = @highest;
    }
    if (scalar(@available) < 1) {
        return $best;
    }

    # Find the track if the lowest index
    foreach my $index (@available) {
        if (!defined($best) || $index < $best) {
            $best = $index;
        }
    }
    return $best;
}

sub isValidSubLanguage($) {
    my ($lang, $iso) = @_;

    if ($SUB_INCLUDE_REGEX && $lang =~ /${SUB_INCLUDE_REGEX}/i) {
        return 1;
    }

    return 0;
}

sub isValidAudioLanguage($) {
    my ($lang, $iso) = @_;

    if ($AUDIO_EXCLUDE_REGEX && $lang =~ /${AUDIO_EXCLUDE_REGEX}/i) {
        return 0;
    }

    return 1;
}

sub printHash($) {
    my ($data) = @_;

    my $first = 1;
    foreach my $key (keys(%{$data})) {
        if (defined($data->{$key})) {
            if ($first) {
                $first = 0;
            } else {
                print STDERR ', ';
            }
            print STDERR $key . ' => ' . $data->{$key};
        }
    }
    print STDERR "\n";
}