Home-Video/encode.pl

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

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

# Default configuration
my $FORMAT        = 'av_mkv';
my $QUALITY       = 20;
my $HD_QUALITY    = 22;
my $NO_MIXDOWN    = 1;
my $AUDIO_COPY    = 0;
my $STEREO_ONLY   = 0;
my $VIDEO_ONLY    = 0;
my $AUDIO_BITRATE = undef();
my $HEIGHT        = undef();
my $WIDTH         = undef();
my $AUDIO_EXCLUDE_REGEX =
'\b(?:Chinese|Czech|Deutsch|Espanol|español|Francais|Italiano|Japanese|Korean|Magyar|Polish|Portugues|Russian|Thai|Turkish|Ukrainian)\b';
my %AUDIO_EXCLUDE_ISO = (
	'THA' => 1
);
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  = 5.1;
my $VIDEO_ENCODER     = 'x265';
my %ENCODER_OPTS      = (
	'x264' => [ '--encopts',        'b-adapt=2:rc-lookahead=50' ],
	'x265' => [ '--encoder-preset', 'medium' ],
);

# Applicaton configuration
my $X265_MAX_WIDTH = 1080 * (16 / 9) * 1.1;
my $HD_WIDTH       = 720 *  (16 / 9) * 1.1;
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', 'TRUEHD', 'AAC', 'PCM', 'DTS', 'E-AC3', 'AC3', 'VORBIS', 'OTHER');
my $HB_EXEC         = $ENV{'HOME'} . '/bin/video/HandBrakeCLI';
my $DEBUG           = 0;

# General parameters for HandBrake
# Someday we will also --use-opencl, but not today
my @video_params = ('--markers', '--optimize', '--detelecine', '--decomb', '--auto-anamorphic');
# HD Audio: 'dtshd,dts,truehd,eac3,ac3,aac'
my @audio_params = ('--audio-copy-mask', 'aac,dts,eac3,ac3', '--audio-fallback', 'aac');

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

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

# Shortcut config
if ($ENV{'MOBILE'}) {
	$ENV{'QUALITY'}       = 25;
	$ENV{'HEIGHT'}        = 720;
	$ENV{'WIDTH'}         = 1280;
	$ENV{'AUDIO_BITRATE'} = 128;
	if (! $VIDEO_ONLY) {
		$ENV{'STEREO_ONLY'}   = 1;
	}
	$ENV{'ENCODER'}       = 'x264';
	$ENV{'FORCE_MP4'}     = 1;
}

# 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;
	$MIXDOWN_CHANNELS = 2.0;
}

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

# Allow mixdown if requested
if ($STEREO_ONLY || (defined($ENV{'NO_MIXDOWN'}) && !$ENV{'NO_MIXDOWN'})) {
	$NO_MIXDOWN = 0;
}

# 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");
	}
	$HEIGHT = $ENV{'HEIGHT'};
	push(@video_params, '--maxHeight', $HEIGHT);
}
if ($ENV{'WIDTH'}) {
	if (!($ENV{'WIDTH'} =~ /^\d+$/)) {
		die($0 . ': Invalid WIDTH: ' . $ENV{'WIDTH'} . "\n");
	}
	$WIDTH = $ENV{'WIDTH'};
	push(@video_params, '--maxWidth', $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'};
}

# 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 with a reasonable extension
# Force the output format by file name or flag
# Default to MKV if neither is specified
if (!defined($out_file) || length($out_file) < 1) {
	$out_file = $in_file;
} else {
	my ($format) = $out_file =~ /\.(\w{2,4})$/;
	if (defined($format)) {
		$FORMAT = 'av_' . lc($format);
	}
}
if ($FORCE_MP4) {
	$FORMAT = 'av_mp4';
}
if (!$FORMAT) {
	$FORMAT = 'av_mkv';
}

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

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

	# 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 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;
	}

	# Fall back to x264 if the video is larger than $X265_MAX_WIDTH
	# Even x86 systems have trouble with x265 @ 4k and hardware support is (as of 2017) rare
	my $encoder = $VIDEO_ENCODER;
	if ($scan->{'size'}[0] > $X265_MAX_WIDTH && (!defined($WIDTH) || $WIDTH > $X265_MAX_WIDTH)) {
		$encoder = 'x264';
	}

	# 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)
	my $format = $FORMAT;
	foreach my $track (values(%{ $scan->{'subtitle_selected'} })) {
		if ($track->{'type'} eq 'PGS') {
			$format = 'av_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 = 'av_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 'av_mp4') {
		$title_out_file .= '.m4v';
	} else {
		$title_out_file .= '.mkv';
	}

	# 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, '--encoder', $encoder, @{ $ENCODER_OPTS{$encoder} });
	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;
		}

		# Normalize 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;
		}

		# Normalize the codes
		$iso  = defined($iso) ? uc($iso) : '';
		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' || scalar(keys(%AUDIO_EXCLUDE_ISO))) {
			$AUDIO_EXCLUDE_REGEX = 'ACCEPT_ALL';
			%AUDIO_EXCLUDE_ISO = ();
			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 track if not required
	if ($AUDIO_COPY || $NO_MIXDOWN) {
		$mixdown = undef();
	}

	# Mixdown track first
	my @audio_tracks = ();
	if (defined($mixdown) && $mixdown > 0) {
		if ($DEBUG) {
			print STDERR 'Using track ' . $mixdown . " as mixdown audio (" . $MIXDOWN_CODEC . ")\n";
		}
		my %track = ('index' => $mixdown, 'encoder' => codecToEncoder($MIXDOWN_CODEC));
		push(@audio_tracks, \%track);

		# Include mixdown params for this track
		push(@retval, mixdownParams($tracks{$mixdown}->{'channels'}));
	}

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

		# Passthru DTS, AC3, and AAC
		# Keep other audio tracks, but recode to the mixdown codec (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 (sort(@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', '100:0', '--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 codecToEncoder($) {
	my ($codec) = @_;
	my $encoder = undef();

	if ($codec eq 'AAC') {
		# Use CoreAudio where available
		my ($OS) = POSIX::uname();
		$encoder = ($OS eq 'Darwin') ? 'ca_aac' : 'ffaac';
	} else {
		my $t = lc($codec);
		$t =~ s/[\w]//g;
		$encoder = $t;
	}

	return $encoder;
}

sub mixdownParams() {
	my ($channels) = @_;
	my $mixdown = '7point1';
	my $bitrate = 512;

	# Don't encode more than we need
	if ($MIXDOWN_CHANNELS < $channels) {
		$channels = $MIXDOWN_CHANNELS;
	}

	# Pick mixdown models and appropriate bitrates (for AAC)
	if ($channels <= 2.0) {
		$mixdown = 'dpl12';
		$bitrate = 128;
	} elsif ($channels <= 5.1) {
		$mixdown = '5point1';
		$bitrate = 384;
	} elsif ($channels <= 6.1) {
		$mixdown = '6point1';
		$bitrate = 448;
	}

	# Allow user override of the bitrate
	if ($AUDIO_BITRATE) {
		$bitrate = $AUDIO_BITRATE;
	}

	if ($DEBUG) {
		print STDERR "\tMixdown to " . $MIXDOWN_CHANNELS . " channels at " . $bitrate .
			" kbps with " . $mixdown . " encoding\n";
	}
	return ('--mixdown', $mixdown, '--ab', $bitrate);
}

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;
	}

	if ($AUDIO_EXCLUDE_ISO{$iso}) {
		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";
}