Category Archives: ninja

Perl function that returns info about a video (uses FFMPEG)

This program contains a Perl function I wrote to extract data about a given video.

It also shows how to parse information from program output and organize it usefully.

This has been used a few times in production systems.

If you use this, please drop a comment! It would be fun to know.

Share and enjoy!

#!/usr/bin/perl -w
# get_video_info.pl
# by Andrew Ault, www.andrewault.net
# Please drop me a note it you use this.

use strict;
use warnings;

use IPC::Open3;

# example
my $filename  = "yourvideoFilenameHere.mp4";
my %videoInfo = videoInfo($filename);
print "duration: " . $videoInfo{'duration'} . "\n";
print "durationsecs: " . $videoInfo{'durationsecs'} . "\n";
print "bitrate: " . $videoInfo{'bitrate'} . "\n";
print "vcodec: " . $videoInfo{'vcodec'} . "\n";
print "vformat: " . $videoInfo{'vformat'} . "\n";
print "acodec: " . $videoInfo{'acodec'} . "\n";
print "asamplerate: " . $videoInfo{'asamplerate'} . "\n";
print "achannels: " . $videoInfo{'achannels'} . "\n";

#
# returns media information in a hash
sub videoInfo {
	# ffmpeg command
	my $ffmpeg = '/usr/local/bin/ffmpeg';

	my %finfo = (
				  'duration'     => "00:00:00.00",
				  'durationsecs' => "0",
				  'bitrate'      => "0",
				  'vcodec'       => "",
				  'vformat'      => "",
				  'acodec'       => "",
				  'asamplerate'   => "0",
				  'achannels'       => "0", 
	);

	my $file = shift;

	# escaping characters
	$file =~ s/(\W)/\\$1/g;

	open3( "/dev/null", \*ERPH, "$ffmpeg -i $file" ) or die "can't run $ffmpeg\n";
	my @res = ;

	# parse ffmpeg output
	foreach (@res) {

		# duration
		if (m!Duration: ([0-9][0-9]:[0-9][0-9]:[0-9][0-9].[0-9][0-9])!) {
			$finfo{'duration'} = $1;
		}

		# bitrate
		if (m!bitrate: (\d*) kb/s!) {
			$finfo{'bitrate'} = $1;
		}

		# vcodec and vformat
		if (/Video: (\w*), (\w*),/) {
			$finfo{'vcodec'}  = $1;
			$finfo{'vformat'} = $2;
		}

        # Stream #0.1(und): Audio: aac, 48000 Hz, 1 channels, s16, 64 kb/s

		# acodec, samplerate, stereo and audiorate
		if (m!Audio: (\w*), (\d*) Hz, (\d*)!) {
			$finfo{'acodec'}     = $1;
			$finfo{'asamplerate'} = $2;
			$finfo{'achannels'}     = $3;
		}
	}

	my $tenths  = substr( $finfo{'duration'}, 9, 2 );
	my $seconds = substr( $finfo{'duration'}, 6, 2 );
	my $minutes = substr( $finfo{'duration'}, 3, 2 );
	my $hours   = substr( $finfo{'duration'}, 0, 2 );
	$finfo{'durationsecs'} = ( $tenths * .01 ) + $seconds + ( $minutes * 60 ) + ( $hours * 360 );

	return %finfo;
}

Create a test pattern video with Perl

I wanted a test pattern video to test a transcoding daemon I wrote for an iPhone application. I wanted to use the classic RCA test pattern image and a tone.

Simply edit the program header with the path to an image you want to use and the name of the output file you’d like to create.

You’ll need FFMPEG installed, of course.

You can change the audio tone if you’d like to.

If you use this script, please let me know.

Share and enjoy.

#!/usr/bin/perl -w
# create_test_pattern_video.pl
# by Andrew Ault, www.andrewault.net
#
# This produces a test pattern video from an image you supply with a tone that you specify.
#
use strict;
use warnings;

use File::Temp qw/ :mktemp tempdir /;
use File::Path;
use File::Spec;
use Audio::Wav;

# still image to create video from
my $fileImage = "/path/imageInputFilename.jpeg";

# output file - name of the file to output to
my $fileOutput = "/path/videoOutputFilename.mp4";

# video parameters
my $vFrameRate      = 25;
my $vBitRate        = "200k";
my $durationSeconds = 10;

# audio parameters - set up the tone to produce and use in the resulting video
my $hertz      = 400;
my $sampleRate = 44100;
my $sampleBits = 16;

#
my $dirTemp = tempdir("tmp-hax-XXXXXXXX");
$dirTemp = File::Spec->rel2abs($dirTemp) . "/";
my $numFrames = $vFrameRate * $durationSeconds;
my $cmd;
my $fileTmpAnimationVideo = $dirTemp . "animation.mp4";
my $fileTmpAudio          = $dirTemp . "sound.wav";

chdir $dirTemp;

# create a sequence of image files
print "creating image sequence\n";
for ( my $i = 1 ; $i <= $numFrames ; $i++ ) {
	my $seq = sprintf( "%08d", $i );
	$cmd = "cp $fileImage " . $seq . ".jpeg";
	print "$cmd\n";
	`$cmd`;
}

# create .mp4 from the image sequence
print "creating animation video\n";
$cmd = "ffmpeg -r $vFrameRate -b $vBitRate -i " . $dirTemp . "%08d.jpeg $fileTmpAnimationVideo";
print "$cmd\n";
`$cmd`;

# create the audio tone .wav
my $wav = Audio::Wav->new;
my $details = {
	'bits_sample' => $sampleBits,
	'sample_rate' => $sampleRate,
	'channels'    => 1,
};
my $write = $wav->write( $fileTmpAudio, $details );
&add_sine( $hertz, $durationSeconds );
$write->finish();

# combine the video and audio files to output
print "creating final output video file\n";
$cmd = "ffmpeg -y -i $fileTmpAnimationVideo -i $fileTmpAudio -acodec libfaac -ab 128k -ar 48000 $fileOutput";
print "$cmd\n";
`$cmd`;

# wrap it up
print "done\n";
rmtree($dirTemp);
exit(0);

sub add_sine {
	my $hz     = shift;
	my $length = shift;
	my $pi     = ( 22 / 7 ) * 2;
	$length *= $sampleRate;
	my $max_no = ( 2**$sampleBits ) / 2;
	for my $pos ( 0 .. $length ) {
		my $time = $pos / $sampleRate;
		$time *= $hz;
		my $val  = sin $pi * $time;
		my $samp = $val * $max_no;
		$write->write($samp);
	}
	return;
}

My remote MySQL backup script in Perl – rtar_mysql.pl

Before you can use this script, you need to set up SSH so your local cron can access the remote servers without a password.

One thing to note about this script is that it automatically rotates the archived dump files; keeping a fie for the 1st of the week on a month, 1st of the month and 1st of the year.

see: Using Public/Private Key Pairs with SSH

Then, just modify the script for your database/servers (the block @ line 22).

This will create a series of files over time with daily/weekly/monthly MySQL dump backups.

#!/usr/bin/perl -w
# rtar_mysql.pl
#
# No arguments. The program is to be modified to include each database to be archived.
#
# Saves a tar of a remote mysql dump in a rotating file.
#
# This is used on Andrew's workstation to automatically grab a sql dump tar of each database daily.
#
use strict;
use warnings;

use DateTime;

my $fileError;
my $jobError  = 0;
my $jobErrors = "";
my $result;

# Specify a data block for each remote database to be archived.
my %dumpJobs = (
				 'db1' => {
							'remoteServer' => 'server_1',
							'database'     => 'database_name_1',
							'dbUser'       => 'database_username_1',
							'dbPassword'   => 'database_password_1',
							'dumpFilename' => 'server_1-database_name_1.dump.sql',
							'mysqlDumpCmd' => '/usr/bin/mysqldump',
							'tarCmd'       => '/bin/tar',
				 },
				 'db2' => {
							'remoteServer' => 'server_2',
							'database'     => 'database_name_2',
							'dbUser'       => 'database_username_1',
							'dbPassword'   => 'database_password_2',
							'dumpFilename' => 'server_2-database_name_2.dump.sql',
							'mysqlDumpCmd' => '/usr/bin/mysqldump',
							'tarCmd'       => '/bin/tar',
				 },
);

# Process each specified database dump/archive job.
for my $dumpJob ( sort keys %dumpJobs ) {
	$fileError = 0;
	my $tarballFilename = "$dumpJobs{$dumpJob}{'dumpFilename'}-" . tarDateSegment() . ".tgz";
	my $mysqlDumpCmd    = $dumpJobs{$dumpJob}{'mysqlDumpCmd'};
	my $tarCmd          = $dumpJobs{$dumpJob}{'tarCmd'};
	print "$dumpJob\n";

	my $dumpCommand = "ssh $dumpJobs{$dumpJob}{'remoteServer'} '$mysqlDumpCmd ";
	$dumpCommand .= "--user=$dumpJobs{$dumpJob}{'dbUser'} --password=$dumpJobs{$dumpJob}{'dbPassword'} ";
	$dumpCommand .= "$dumpJobs{$dumpJob}{'database'} > $dumpJobs{$dumpJob}{'dumpFilename'}'";
	print $dumpCommand . "\n";
	$result = system($dumpCommand );
	if ($result) { $fileError = 1; }

	if ( !$fileError ) {
		my $remoteMakeTarball = "ssh $dumpJobs{$dumpJob}{'remoteServer'} '$tarCmd ";
		$remoteMakeTarball .= "cvfz $tarballFilename $dumpJobs{$dumpJob}{'dumpFilename'}'";
		print $remoteMakeTarball . "\n";
		$result = system($remoteMakeTarball );
		if ($result) { $fileError = 1; }
	}

	if ( !$fileError ) {

		# using a more flexible naming scheme now
		my $downloadCommand = "scp $dumpJobs{$dumpJob}{'remoteServer'}:$tarballFilename .";
		print $downloadCommand . "\n";
		$result = system($downloadCommand );
		if ($result) { $fileError = 1; }
	}

	if ($fileError) {
		$jobError = 1;
		$jobErrors .= "$dumpJob ";
	}
}
if ($jobError) {
	warn "Errors were encountered: $jobErrors\n";
	exit(1);
}


sub tarDateSegment {
	my $dt = DateTime->now();

	my ( $sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst ) = localtime(time);
	$year += 1900;
	my $dateTime = sprintf "%4d-%02d-%02d %02d:%02d:%02d", $year, $mon + 1, $mday, $hour, $min, $sec;
	my $date     = sprintf "%4d-%02d-%02d",                $year, $mon + 1, $mday;
	my @weekdays = qw( sun mon tue wed thu fri sat );
	my $weekday  = $weekdays[$wday];
	my @months   = qw( jan feb mar apr may jun jul aug sep oct nov dec );
	my $month    = $months[$mon];

	my $weekOfMonth = $dt->week_of_month;

	my $dateTar = "";

	# if the first day of the year, set $dateTar like: 2009-1st
	if ( $yday == 1 ) {
		$dateTar = "$year-1st";
	}

	# if the first day of the month, set $dateTar like: feb-1st
	elsif ( $mday == 1 ) {
		$dateTar = "$month-1st";
	}

	# if the first day of the week, set $dateTar like: mon-1
	# where the number is the week of the month number
	elsif ( $wday == 1 ) {
		$dateTar = "$weekday-$weekOfMonth";
	}

	# otherwise, set the $dateTar like: mon
	else {
		$dateTar = "$weekday";
	}

	# $sec      seconds          54
	# $min      monutes          37
	# $hour     hour             11
	# $mon      month            4
	# $year     year             2009
	# $wday     weekday          3
	# $yday     day of the year  146
	# $isdst    is DST           1
	# $weekday  day of the week  wed
	# $month    month            may
	# $dateTime date and time    2009-05-27 11:37:54
	# $date     date             2009-05-27
	return $dateTar;
}

=head1 NAME

rtar_mysql.pl - Andrew's remote MySQL archive program.

=head1 SYNOPSIS

    use: rtar_mysql.pl

=head1 DESCRIPTION

This is a program I wrote to SSH/dump/tar/download/rotate archives of MySQL databases.

=over

=back

=head1 LICENSE

None.

=head1 AUTHOR

Andrew Ault 

=cut