#!/usr/bin/perl
# Author: Alan J. Pippin
# Description: For the given srcpath, merge all the videos that were taken on the same day into a single mkv file

use File::Copy;
use File::Basename;
use Getopt::Std;
use File::stat;
use Time::localtime;

# Early command line options processing
getopts("qrh:tvs:");
my $srcpathname = $opt_s;

####################################################################################################
# Configuration parameters - CHANGE THESE TO SUITE YOUR NEEDS
my $compute_host = "pippin.pippins.net"; # I need this since this script is run from a virtual machine 
my $use_compute_host = 1; # Set to 1 to use a remote compute host to run the mkvmerge command. Set to 0 to use the local host to run it.
my $make_mkv = "/naspool/videos/bin/make_mkv"; # Update this to be the path to the make_mkv script
my $requantize_input_video=1; # This will dramatically decrease the size of the video with minimal compute processing requirements.
my $owner = "ajp"; # The owner of the files after they are moved
my $group = "pip"; # The group of the files after they are moved
my $mode = "664"; # The mode to set on each file after they are moved
my $video_suffix = "000"; # What number to start with when adding an incrementing suffix to the end of the video clip to avoid name collisons
my $video_title_prefix = "HomeVideos:"; # What text to put on the front of the title for the merged video being created
my $find_cmd = "find \"$srcpathname/\" -iregex \".*\.mov\" -o -iregex \".*\.3gp\" -o -iregex \".*\.mp4\" -o -iregex \".*\.mts\"";
my $handbrake='HandBrakeCLI';
my $interlaced_requantize_quality=0.85;
my $progressive_requantize_quality=0.7;
####################################################################################################

sub usage {
    print "usage: $0 [-tvrh] -s <srcpath>\n";
    print "   -s <srcpath>          specify the path to search for videos to merge under\n";
    print "   -h <compute host>     specify the remote compute host to submit the mkvmerge job to\n";
    print "   -v                    verbose mode; print extra information about what is being found/merged\n";
    print "   -t                    test mode; print what will happen, but don't do anything\n";
    print "   -r                    remove merged video clips; after a merge, remove the individual video files that were merged\n";
    print "   -q                    Requantize MTS input videos to decrease output video size (requires HandBrakeCLI)\n";
    return 1;
}
if(defined $opt_h) { usage(); exit 1; }

# Sanity checks
if(defined $opt_q && !$use_compute_host) { die "-E- Unable to find required program: handbrake\n"; }
if(! -d $srcpathname) { &usage; print "-E- Can't find srcpath: $srcpathname\n"; exit 1; }
if(defined $opt_h) { $compute_host = $opt_h; }

my %monthname2month = (
		       "Jan" => "01",
		       "Feb" => "02",
		       "Mar" => "03",
		       "Apr" => "04",
		       "May" => "05",
		       "Jun" => "06",
		       "Jul" => "07",
		       "Aug" => "08",
		       "Sep" => "09",
		       "Oct" => "10",
		       "Nov" => "11",
		       "Dec" => "12"
		       );

my %month2monthname = (
		       "01" => "Jan",
		       "02" => "Feb",
		       "03" => "Mar",
		       "04" => "Apr",
		       "05" => "May",
		       "06" => "Jun",
		       "07" => "Jul",
		       "08" => "Aug",
		       "09" => "Sep",
		       "10" => "Oct",
		       "11" => "Nov",
		       "12" => "Dec"
		       );

# Change directories to the srcpath to search for videos to merge
print "-> Finding all videos under '$srcpathname' to merge by day\n";
my %videos;
chdir "$srcpathname";
print "$find_cmd\n" if($opt_v);
foreach $file (sort `$find_cmd`) {

    chomp($file);
    $srcdir = dirname($file);
    $file = basename($file);
    $srcfile = $file;
    $srcext = "";
    if($srcfile =~ /\.(\w+)$/) { $srcext = $1; }
    $ext = "mkv";
    
    print "Found movie: srcdir: $srcdir srcfile: $srcfile srcext: $srcext dstext: $ext\n" if($opt_v);

    # Throw out files not in the current srcpath
    if((! -f "$srcfile") && (! -f "$srcdir/$srcfile")) { next; }
            
    # Make a note of the month, year, and day this video was taken (from the modification time of the file)
    $date_taken = ctime(stat("$srcdir/$srcfile")->mtime);

    # Get the date taken from the filename
    if($srcfile =~ /^(\d+)-(\d+)-(\d+)/) {
	$year = $1;
	$month = $2;
	$day = sprintf("%02d",$3);
	$monthnum = $month;
	$monthname = lc($month2monthname{$month});
    }
    # Get the date taken from the modification time
    elsif($date_taken =~ /\S+\s+(\S+)\s+(\d+)\s+\S+\s+(\d+)/) {
	$year = $3;
	$month = $1;
	$day = sprintf("%02d",$2);
	$monthnum = $monthname2month{$month};
	$monthname = lc($month2monthname{$month});
    } else {
	print "-E- Unable to parse year and month from this file: $srcdir/$srcfile\n";
	next;
    }

    # We are ready to pick a destination folder to put the merged video in
    $dstdir = $srcdir;
    $dstfile = $dstdir . "/" . $year . "-" . $monthnum . "-" . $day;

    # Check for duplicate filenames at the destination
    $newfile = $dstfile . "." . $video_suffix;
    if(-e "$newfile.$ext") {
	foreach $i ($video_suffix+1 .. '999') {
	    $newfile = $dstfile . "." . sprintf("%03d",$i);
	    if(! -e "$newfile.$ext") { last; }
	}
	$dstfile = $newfile;
    }

    # Set the name of our unique destination file
    $dstfile = "$newfile.$ext";

    # You can only merge videos into a single destination that have the same extension/type
    push(@{$videos{"$srcext"}{"$dstfile"}}, "\"$srcdir/$srcfile\"");
}

# For single videos, with the re-quantize option given, rename the destination file to mp4
foreach $ext (sort keys %videos) {
    foreach $video (sort keys %{$videos{$ext}}) {	
	# Get a count of the number of videos for this date
	# If we only have a single video, its extension will actually be mp4 if opt_q is specified
	my $num_videos = $#{$videos{$ext}{$video}} + 1;
	if((defined $opt_q) && ($num_videos <= 1)) {
	    if($video =~ /(.*?)\.(\d+)\.(\w+)$/) {
		$dstfile = $1;
		$dstnum = $2;
		$new_dstvideo = "$1.$2.mp4";
		$videos{$ext}{$new_dstvideo} = $videos{$ext}{$video}; # make a new dst video entry with the src video being the same
		delete $videos{$ext}{$video}; # delete the old destination video from the hash
	    }
	}
    }
}

# Check for duplicate filenames in the dstfiles being created for other exts
foreach $ext (sort keys %videos) {
    foreach $video (sort keys %{$videos{$ext}}) {	
	# Make sure this video name is not in use as a destination for any other ext
	foreach $checkext (sort keys %videos) {
	    if($checkext eq $ext) { next; }
	    foreach $checkvideo (sort keys %{$videos{$checkext}}) {
	     	if("$video" eq "$checkvideo") {
		    if($video =~ /(.*?)\.(\d+)\.(\w+)$/) {
			$dstfile = $1;
			$dstnum = $2;
			$dstext = $3;
		    }
		    foreach $i ($dstnum .. '999') {
			$newfile = $dstfile . "." . sprintf("%03d",$i);
			if("$video" ne "$newfile.$dstext") { last; }
		    }
		    $videos{$ext}{"$newfile.$dstext"} = $videos{$ext}{$video};
		    delete $videos{$ext}{$video};
		}
	    }
	}
    }
}

# Only merge the videos if there is more than 1 video to merge on a given day for a given ext
# If there is only 1 video for a given day for a given ext, re-quantize it here if that option was given
foreach $ext (sort keys %videos) {
    foreach $video (sort keys %{$videos{$ext}}) {
	
	# Get a count of the number of videos for this date
	my $num_videos = $#{$videos{$ext}{$video}} + 1;

	# Process any single videos now
	if($num_videos <= 1) {

	    # Store the srcvideo name
	    my $srcvideo = $videos{$ext}{$video}[0];
	    my $pwd = `pwd`; chomp($pwd);

	    # Make a note if this video is interlaced or not
	    my $ffmpeg_cmd = "";
	    if($use_compute_host) { $ffmpeg_cmd .= "ssh $compute_host 'cd \"$pwd\";"; }
	    $ffmpeg_cmd .= "$ffmpeg -i $srcvideo 2>&1 | grep -q \"frame rate differs\"";
	    if($use_compute_host) { $ffmpeg_cmd .= "'"; }
	    my $progressive = system('$ffmpeg_cmd');
	    if(!$progressive) { print "   Detected interlaced video content: $srcvideo\n"; }
	    
	    # Re-quantize the input video to reduce the resulting output filesize
	    # This also gives us a chance to deinterlace the video as well
	    # Only do this for .MTS videos
	    if((defined $opt_q) && ($ext =~ /mts/i)) {
		
		# Set our requantize factor accordingly
		my $requantize_option = "";
		if(!$progressive) { $requantize_option = "-q $interlaced_requantize_quality"; }
		else { $requantize_option = "-q $progressive_requantize_quality"; }
		
		# Set our de-interlace option accordingly
		my $deinterlace_option = "";
		if(!$progressive) { $deinterlace_option = "-d"; }
		
		# Use HandBrake to requantize/deinterlace the input video
		print "   Re-quantizing input video content: $video\n";
		my $handbrake_cmd = "";
		if($use_compute_host) { $handbrake_cmd .= "ssh $compute_host 'cd \"$pwd\";"; }
		$handbrake_cmd .= "$handbrake $deinterlace_option $requantize_option -E ac3 -i $srcvideo -o \"$video\" > /dev/null 2>&1";
		if($use_compute_host) { $handbrake_cmd .= "'"; }
		if(! defined $opt_t) { 
		    my $errno = system("$handbrake_cmd");
		    $errno = $errno >> 8;
		    if($errno > 1) {
			unlink "$video";
			die "-E- handbrake encountered some errors with exit code $errno\n";
		    } else {
			# Remove the original srcvideo since we created a new version of it that we are going to keep instead
			if(defined $opt_r) { 
			    system("rm -f $srcvideo\n");
			}
		    }
		}
	    }

	    # Remove the video from the array since we already processed it above
	    delete $videos{$ext}{$video};
	    next;
	}
    }
}

# Tell the user which videos we are going to merge
foreach $ext (sort keys %videos) {
    foreach $video (sort keys %{$videos{$ext}}) {
	foreach $srcfile (@{$videos{$ext}{$video}}) { 
	    print "   merging \"$srcfile\" into \"$video\"\n";
	}
    }
}

# Now actually do the merging
print "\n";
foreach $ext (sort keys %videos) {
    foreach $video (sort keys %{$videos{$ext}}) {

	my $videos = join(',', @{$videos{$ext}{$video}});
	
	if($video =~ /(\d+)-(\d+)-(\d+)/) {
	    $year = $1;
	    $month = $2;
	    $day = sprintf("%02d",$3);
	}
	
	my $pwd = `pwd`; chomp($pwd);
	my $cmd = "";
	if($use_compute_host) { $cmd .= "ssh $compute_host 'cd \"$pwd\";"; }
	$cmd .= "$make_mkv -t \"$video_title_prefix $year-$month-$day\" -o \"$video\" -i $videos";
	if($requantize_input_video) { $cmd .= ' -q'; }
	if($use_compute_host) { $cmd .= "'"; }
	if(defined $opt_t) {
	    print "\n-> Creating \"$video\"\n";
	    print "$cmd\n";
	    if(defined $opt_r) { 
		foreach $video (@{$videos{$ext}{$video}}) {
		    print("rm -f $video\n");
		}
	    }
	} else {
	    # Create the merged video
	    my $errno = system("$cmd");
	    $errno = $errno >> 8;
	    if($errno) { die "-E- make_mkv encountered some errors with exit code $errno\n"; }
	    # Fix the permissions
	    system("chown $owner \"$video\"");
	    system("chgrp $group \"$video\"");
	    system("chmod $mode \"$video\"");
	    # Remove the individual video files
	    if(defined $opt_r) { 
		foreach $video (@{$videos{$ext}{$video}}) {
		    system("rm -f $video");
		}
	    }
	}
    }
}