AndrewEnsley.com » Programming

Clamdscan in Ubuntu

Andrew — Mon, 24 Jan 2011 20:43:45 +0000

This is a just a quick post. I need an answer to this question on Ask Ubuntu (powered by the ever-helpful StackExchange community).

I've even offered a 50+ reputation bounty on it if you happen to be a member of that site. If anyone has any input, it would be greatly appreciated. I've also posted the same question on ubuntuforums.org with no luck so far.

I will accept any advice, but I need to scan whole directories recursively with clamdscan.

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New WordPress Plugin: Youtube Feeder

Andrew — Thu, 09 Sep 2010 22:32:35 +0000

international

Inspired by my most recent post about embedding a Youtube feed with a shortcode, some features I wanted to add to it, and a certain amount of interest in expanding it, I have written my second WordPress plugin.

It's interesting that today is almost exactly 1 year from the date I released my first wordpress plugin (which I'll hopefully be updating soon).

Here's what the plugin does:

Youtube Feeder allows you to embed a dynamic Youtube video feed anywhere in your WordPress blog. The feed is always up to date because it pulls directly from Youtube's data api, but it can also cache the Youtube feed based on configurable settings.

The plugin is very flexible because every aspect is configurable. Each video feed can be configured separately, or you can use defaults that take effect site-wide. Each component is given highly accessible classes for complete customization of the display through CSS.

Head on over to the Youtube Feeder project page for more details!

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WordPress: Embed Youtube Feed With a Simple Shortcode

Andrew — Sat, 14 Aug 2010 02:20:15 +0000

address

UPDATE: Looking for more functionality and an easier installation method?

Check out my WordPress plugin: Youtube Feeder

It's based on this code and has a LOT more features

WordPress shortcodes are great. They let you perform complex operations or display dynamic content with just a tiny bit of text in any page or post.

I recently needed a way to embed the most recent videos from a Youtube channel (very dynamic information) in a WordPress page, so I decided to write a shortcode for it.

The code is actually pretty simple. Just add the following to your theme's functions.php file:

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function youtube_feed_shortcode($atts)
{
// Defaults:
extract(shortcode_atts(array(
'user' => 'flamadiddle86', // youtube user
'limit' => 5, // maximum number of videos
'height' => 385, // video height
'width' => 480 // video width
), $atts));
$data = @json_decode(file_get_contents('http://gdata.youtube.com/feeds/api/users/'.$user.'/uploads?alt=json'), TRUE);
$counter = 0;
$content = '

';
foreach($data['feed']['entry'] as $vid)
{
$url = $vid['media$group']['media$content'][0]['url'];
$title = $vid['title']['$t'];
$ycontent = $vid['content']['$t'];
$content.= '.$width.'" height="'.$height.'">'.
'.$url.'">'.
''.
''.
'.$url.'" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="'.$width.'" height="'.$height.'">'.
'

'.$title.'

'.
'

'.$ycontent.'

'."\n";
$counter++;
if($counter == $limit)
{
break;
}
}
$content .= '

';
return $content;
}

add_shortcode('youtubefeed', 'youtube_feed_shortcode');

And it couldn't be easier to use. The videos you see below were embedded simply by putting this code in the post:

1	[youtubefeed]

Neytiri Attacks

Mia "Stay" -ing

We've only been teaching this trick for a couple days. She learns fast.

Mia playing tug of war

Mia, our 11-week-old weimaraner, playing tug of war with a friend's dog.

Mantis kung fu

rm -rf /*

I've always wanted to do this.

The shortcode is completely configurable. The following code would have resulted in the exact same output:

1	[youtubefeed user="flamadiddle86" limit="5" height="385" width="480"]

You can change any option as needed.

You might have noticed the code gives each element a particular class to make it CSS friendly. All you have to do is add CSS rules for three classes: .youtubefeed, .youtubetitle, and .youtubecontent.

My stylesheet looks like this:

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.youtubefeed {
margin: 10px;
text-align: center;
}

.youtubetitle {
font-size: 1.6em;
font-weight: bold;
margin: 3px;
}

.youtubecontent {
margin-bottom: 20px;
}

A quick note about requirements:

Your server's PHP configuration needs to have allow_url_fopen set to On.
You'll also need the PHP JSON extension

Most hosts meet those requirements.

So there you have it. It's a quick and dirty way to get functional, always up-to-date Youtube streams in your WordPress posts and pages.

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service

Recover WordPress from broken theme

Andrew — Mon, 26 Apr 2010 15:42:16 +0000

If you ever find yourself with a broken theme and can't even access the admin side of your wordpress blog, here's a quick way to get back on your feet.

Simply run the following query from the command line or via a tool like phpMyAdmin

UPDATE wp_options SET option_value = 'default'
WHERE option_name IN ('template','stylesheet','current_theme');

(Make sure to select your wordpress database first, of course)

Sure. Your site looks like it was just setup 2 seconds ago, but at least now you can access all the GUI-licious tools of the WordPress Admin panel to fix whatever broke your theme.

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PHP: Validate an IP Address

Andrew — Sun, 14 Mar 2010 05:14:47 +0000

service

So you need to check if some string is a valid IP address. You could simply test it against a regular expression:

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function is_valid_ipv4($ip)
{
return preg_match('/\b(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.'.
'(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.'.
'(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.'.
'(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b/', $ip) !== 0;
}

Regular Expression obtained here

This will actually work for most situations, but it's lacking in a few ways. Suppose you want to exclude private or reserved IP addresses. Maybe you want to validate IPv6 addresses too; not just IPv4.

Enter PHP's Data Filtering Extension. It just works, and you don't have to worry about maintaining (or properly applying) complex regular expressions.

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function is_valid_ip($ip, $include_priv_res = true)
{
return $include_priv_res ?
filter_var($ip, FILTER_VALIDATE_IP) !== false :
filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE) !== false;
}

Now to test it.

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$ips = array('72.215.140.69',
'192.168.0.1',
'127.0.0.1',
'10.0.0.1',
'255.255.255.0',
'andrewensley.com',
'255.255.256.0',
'::1',
'fe00::0',
'2001:4860:0:1001::68');

foreach($ips as $ip)
{
echo $ip,' ', is_valid_ip($ip, false) ? 'yes' : 'no','
';
}

The above will output:

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72.215.140.69 yes
192.168.0.1 no
127.0.0.1 yes
10.0.0.1 no
255.255.255.0 no
andrewensley.com no
255.255.256.0 no
::1 yes
fe00::0 yes
2001:4860:0:1001::68 yes

Thank you PHP for making this otherwise complex task very simple. And even better: it's fast!

I tested the regular expression and the filter_var functions by running each 100,000 times. Here are the timings for each test:

1.53423094749 seconds with the filter_var function
3.1516289711 seconds with the regular expression function

Not bad! Happy filtering.

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international

Install Ejabberd 2.0 on Ubuntu Hardy Heron 8.04 LTS - 6 Steps!

Andrew — Thu, 12 Nov 2009 22:13:22 +0000

conditions

Problem:

You've chosen the most simple, solid Linux server - Ubuntu 8.04 LTS, and you want to run the most simple, solid XMPP server - ejabberd. BUT, the version of ejabberd in Hardy's repositories is the really old (Sep 03, 2007!) 1.1.4 release.

Solution:

You could of course build ejabberd from source, but that's not why you chose the "It Just Works^TM" Ubuntu server, is it? Have no fear. A simple and (mostly) painless solution awaits!

The key is in the Hardy-backports repository. Ubuntu Backports are updated versions of software that have not been fully tested with the default software packaged in the Ubuntu Installation. By default, the Ubuntu team only releases security updates and keeps all major versions of software constant throughout the release's lifecycle.

Backports are an option for brave souls that want the latest major versions of software on their still perfectly relevant (but chronologically gifted) operating system. I say "brave" souls because there is one serious issue with this:

The Ubuntu team does not release security updates for backported software!

So make sure you keep that in mind and carefully monitor the security bulletins of the writers of any software package you install from backports. Since we don't want every package to be upgraded to its non-security-checked newest backport version, we'll enable pinning. Pinning allows us to enable the backports repository only for those packages we specifically request from it.

Instructions:

Enough of the explanation, here's what you're reading this for.

1) First, we need to add the backports repository. Fire up your favorite text editor (beginners should probably use nano) and open `/etc/apt/sources.list`.

1	sudo nano /etc/apt/sources.list

and add these lines:

1 2	deb http://us.archive.ubuntu.com/ubuntu/ hardy-backports main restricted universe multiverse deb-src http://us.archive.ubuntu.com/ubuntu/ hardy-backports main restricted universe multiverse

In my case, the lines were already there, and I just had to un-comment them. Your experience may vary.

2) Next, we'll enable pinning. Run:

1	sudo nano /etc/apt/preferences

and add these lines:

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Package: *
Pin: release a=hardy-backports
Pin-Priority: 400

3) Now all that's left is to update apt and install ejabberd. The '-t hardy-backports' line specifies that we want to get ejabberd from the backports repository:

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sudo apt-get update
sudo apt-get dist-upgrade
sudo apt-get install build-essential
sudo apt-get install -t hardy-backports ejabberd

Or, you can do it all in one command:

1	sudo apt-get update && sudo apt-get dist-upgrade && sudo apt-get install build-essential && sudo apt-get install -t hardy-backports ejabberd

4) Once installation finishes, run:

1	sudo nano /etc/ejabberd/ejabberd.cfg

And change the following lines to set your domain name and admin user (make sure the domain name matches the output from the 'hostname' command):

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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Options which are set by Debconf and managed by ucf
%% Admin user
{acl, admin, {user, "admin_username", "yourdomain.com"}}.

%% Hostname
{hosts, ["yourdomain.com"]}.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

5) Now, restart ejabberd:

1	sudo /etc/init.d/ejabberd restart

6) Finally, create your admin user account:

1	sudo ejabberdctl register username yourdomain.com password

That's it! You're done! Enjoy your fully-functional, up-to-date XMPP server.

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RFC Standard for the transmission of IP datagrams on Avian Carriers

Andrew — Thu, 29 Oct 2009 02:43:07 +0000

Nerd alert: This post contains off-the-charts geek humor. You've been warned.

Thanks to my friend who sent me this.

Uber-geeks will recognize "RFC" (yet another TLA) as short for "Request For Comments." But those with lives normal folks might need an explanation.

The Internet Engineering Task Force (IETF) has created RFC as a standard for documentation of Internet-related subjects. There is an RFC for just about everything, including:

A lot of RFC's are standards, but the vast majority of them are not. Almost all of them, though, are painfully dry reads. That said, there are some glaring exceptions.

Take RFC 1149 for example:

Standard for the transmission of IP datagrams on Avian Carriers

Overview and Rational

   Avian carriers can provide high delay, low throughput, and low
   altitude service.  The connection topology is limited to a single
   point-to-point path for each carrier, used with standard carriers,
   but many carriers can be used without significant interference with
   each other, outside of early spring.  This is because of the 3D ether
   space available to the carriers, in contrast to the 1D ether used by
   IEEE802.3.  The carriers have an intrinsic collision avoidance
   system, which increases availability.  Unlike some network
   technologies, such as packet radio, communication is not limited to
   line-of-sight distance.  Connection oriented service is available in
   some cities, usually based upon a central hub topology.

That's just the overview. Here's the rest, including my favorite part: the Discussion.

Frame Format

   The IP datagram is printed, on a small scroll of paper, in
   hexadecimal, with each octet separated by whitestuff and blackstuff.
   The scroll of paper is wrapped around one leg of the avian carrier.
   A band of duct tape is used to secure the datagram's edges.  The
   bandwidth is limited to the leg length.  The MTU is variable, and
   paradoxically, generally increases with increased carrier age.  A
   typical MTU is 256 milligrams.  Some datagram padding may be needed.

   Upon receipt, the duct tape is removed and the paper copy of the
   datagram is optically scanned into a electronically transmittable
   form.

Discussion

   Multiple types of service can be provided with a prioritized pecking
   order.  An additional property is built-in worm detection and
   eradication.  Because IP only guarantees best effort delivery, loss
   of a carrier can be tolerated.  With time, the carriers are self-
   regenerating.  While broadcasting is not specified, storms can cause
   data loss.  There is persistent delivery retry, until the carrier
   drops.  Audit trails are automatically generated, and can often be
   found on logs and cable trays.

Security Considerations

   Security is not generally a problem in normal operation, but special
   measures must be taken (such as data encryption) when avian carriers
   are used in a tactical environment.

There are a lot more joke RFC's on this Wikipedia page.

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service

C# Detect Windows OS Version – Part 2 (WMI)

Andrew — Thu, 08 Oct 2009 04:57:20 +0000

Recap

In case you missed Part 1, I briefly summarized 4 different strategies for programmatically determining the current Operating System in C#. The code I posted there utilizes the System.Environment class. It works great and is sufficient for most uses, but sometimes you want need to know everything about the OS, including the edition (i.e. "XP Pro" vs. "XP Home").

Summary

For that, Microsoft gives us the lovely Windows Management Instrumentation (WMI) Interface. You can do a lot of really powerful and interesting things with WMI and WQL, but for this purpose, all we care about is getting some information from it.

The Code

Not all Windows versions support WMI, so we always have to fall back on the Environment class code from Part 1. Without wasting your time, let's get straight to the code.

WMI

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using System;
using System.Management;
using System.Text.RegularExpressions;

///

/// Gets Operating System Name, Service Pack, and Architecture using WMI with the legacy methods as a fallback
///

/// String containing the name of the operating system followed by its service pack (if any) and architecture
private string getOSInfo()
{
ManagementObjectSearcher objMOS = new ManagementObjectSearcher("SELECT * FROM Win32_OperatingSystem");

//Variables to hold our return value
string os = "";
int OSArch = 0;

try
{
foreach (ManagementObject objManagement in objMOS.Get())
{
// Get OS version from WMI - This also gives us the edition
object osCaption = objManagement.GetPropertyValue("Caption");
if (osCaption != null)
{
// Remove all non-alphanumeric characters so that only letters, numbers, and spaces are left.
string osC = Regex.Replace(osCaption.ToString(),"[^A-Za-z0-9 ]","");
//string osC = osCaption.ToString();
// If the OS starts with "Microsoft," remove it. We know that already
if (osC.StartsWith("Microsoft"))
{
osC = osC.Substring(9);
}
// If the OS now starts with "Windows," again... useless. Remove it.
if (osC.Trim().StartsWith("Windows"))
{
osC = osC.Trim().Substring(7);
}
// Remove any remaining beginning or ending spaces.
os = osC.Trim();
// Only proceed if we actually have an OS version - service pack is useless without the OS version.
if(!String.IsNullOrEmpty(os))
{
object osSP = null;
try
{
// Get OS service pack from WMI
osSP = objManagement.GetPropertyValue("ServicePackMajorVersion");
if (osSP != null && osSP.ToString() != "0")
{
os += " Service Pack " + osSP.ToString();
}
else
{
// Service Pack not found. Try built-in Environment class.
os += getOSServicePackLegacy();
}
}
catch (Exception)
{
// There was a problem getting the service pack from WMI. Try built-in Environment class.
os += getOSServicePackLegacy();
}
}
object osA = null;
try
{
// Get OS architecture from WMI
osA = objManagement.GetPropertyValue("OSArchitecture");
if (osA != null)
{
string osAString = osA.ToString();
// If "64" is anywhere in there, it's a 64-bit architectore.
OSArch = (osAString.Contains("64") ? 64 : 32);
}
}
catch (Exception)
{
}
}
}
}
catch (Exception)
{
}
// If WMI couldn't tell us the OS, use our legacy method.
// We won't get the exact OS edition, but something is better than nothing.
if (os == "")
{
os = getOSLegacy();
}
// If WMI couldn't tell us the architecture, use our legacy method.
if (OSArch == 0)
{
OSArch = getOSArchitectureLegacy();
}
return os + " " + OSArch.ToString() + "-bit";
}

Legacy code

///

/// Gets Operating System Name using .Net's Environment class.
///

/// String containing the name of the operating system followed by its service pack (if any)
private string getOSLegacy()
{
//Get Operating system information.
OperatingSystem os = Environment.OSVersion;
//Get version information about the os.
Version vs = os.Version;

//Variable to hold our return value
string operatingSystem = "";

if (os.Platform == PlatformID.Win32Windows)
{
//This is a pre-NT version of Windows
switch (vs.Minor)
{
case 0:
operatingSystem = "95";
break;
case 10:
if (vs.Revision.ToString() == "2222A")
operatingSystem = "98SE";
else
operatingSystem = "98";
break;
case 90:
operatingSystem = "Me";
break;
default:
break;
}
}
else if(os.Platform == PlatformID.Win32NT)
{
switch (vs.Major)
{
case 3:
operatingSystem = "NT 3.51";
break;
case 4:
operatingSystem = "NT 4.0";
break;
case 5:
if (vs.Minor == 0)
{
operatingSystem = "2000";
}
else
{
operatingSystem = "XP";
}
break;
case 6:
if (vs.Minor == 0)
{
operatingSystem = "Vista";
}
else
{
operatingSystem = "7";
}
break;
default:
break;
}
}
//Make sure we actually got something in our OS check
//We don't want to just return " Service Pack 2"
//That information is useless without the OS version.
if(operatingSystem != "")
{
//Got something. Let's see if there's a service pack installed.
operatingSystem += getOSServicePackLegacy();
}
//Return the information we've gathered.
return operatingSystem;
}

///

/// Gets the installed Operating System Service Pack using .Net's Environment class.
///

/// String containing the operating system's installed service pack (if any)
private string getOSServicePackLegacy()
{
// Get service pack from Environment Class
string sp = Environment.OSVersion.ServicePack;
if (sp != null && sp.ToString() != "" && sp.ToString() != " ")
{
// If there's a service pack, return it with a space in front (for formatting)
return " " + sp.ToString();
}
// No service pack. Return an empty string
return "";
}

///

/// Gets Operating System Architecture. This does not tell you if the program in running in
/// 32- or 64-bit mode or if the CPU is 64-bit capable. It tells you whether the actual Operating
/// System is 32- or 64-bit.
///

/// Int containing 32 or 64 representing the number of bits in the OS Architecture
private int getOSArchitectureLegacy()
{
string pa = Environment.GetEnvironmentVariable("PROCESSOR_ARCHITECTURE");
return ((String.IsNullOrEmpty(pa) || String.Compare(pa,0,"x86",0,3,true) == 0) ? 32 : 64);
}

Download this code

Notes

Server Versions

In part 1, the code was completely unaware of Windows Server operating systems. Fortunately, this WMI approach will tell us about server versions too! However, you'll notice that it falls back on the old, non-server-aware code.

If detecting server versions is really important to you, you'll probably want to separate out the functions so that you can know every case that the WMI code fails to detect the OS.

OS Architecture

Just a reminder: The code that detects OS Architecture (both WMI, and Environment-class-based) tells us about the Operating System version only.

Even though the physical CPU’s architecture may support 64-bit operations, the methods in my code will always return the architecture of the OS. So 32-bit Windows running on a 64-bit capable processor will return 32-bit.
Even though the CPU is 64-bit capable, and the OS architecture is 64-bit, your .Net program could still be running as a 32-bit application. Sometimes, this information is more useful than knowing whether Windows is 32- or 64-bit. To see if your program is actually running in 64-bit mode, check to see if IntPtr.Size == 8. It will be 4 in 32-bit mode and 8 in 64-bit mode.

Possibly Related posts:

PHP and FFMPEG - Performing intelligent video conversion

Andrew — Tue, 06 Oct 2009 04:28:28 +0000

service

international

Whenever I have limited experience with something or just need to do some research, I go straight to StackOverflow.com - a computer programming question and answer site. Out of the 24 questions I've asked on the site, only one has gone unanswered to date, and I've gleaned countless other answers from questions others have already asked. In case you haven't already guessed, I really like the site.

Not long ago, I needed to convert uploaded video files for a project in PHP. FFMPEG was a clear and obvious choice for the job, but I had never used it before, so I turned to my favorite resource. Sure enough, I got enough information in the answers to build a fully working solution. I posted that solution as an answer to my own question in case anyone else could use it.

Unfortunately, StackOverflow seems to be having trouble displaying my answer, so I've reposted it here for anyone who needs it.

The original question

I'm converting videos uploaded to a php script from various formats (.avi, .mpg, .wmv, .mov, etc.) to a single .flv format. The conversion is working great but what I'm having trouble with is the resolution of the videos.

This is the command I'm currently running (with PHP vars):

1	ffmpeg -i $original -ab 96k -b 700k -ar 44100 -s 640x480 -acodec mp3 $converted

Both $original and $converted contain the full paths to those files. My problem is that this always converts to 640x480 (like I'm telling it to) even when the source is smaller. Obviously, this is a waste of disk space and bandwidth when the video is downloaded. Also, this doesn't account for input videos being in any aspect ratio other than 4:3, resulting in a "squished" conversion if I upload a 16:9 video.

There are 3 things I need to do:

Determine the aspect ratio of the original video.
If not 4:3, pad top and bottom with black bars.
Convert to 640x480 if either dimension of the original is larger or a 4:3 aspect ratio relating to the width/height of the original (whichever is closer to 640x480).

I've run ffmpeg -i on a few videos, but I don't see a consistent format or location to find the original's resolution from. Once I'm able to figure that out, I know I can "do the math" to figure out the right size and specify padding to fix the aspect ratio with -padttop, -padbottom, etc.

The final result

Getting FFMPEG's output

First I had to get the output from ffmpeg -i, which was a challenge in itself. Thanks to hegemon's answer on my other question, I was finally able to get it working with 2>&1 at the end of my command. And thanks to Evert's answer to this question, I was able to parse the output with preg_match to find the original file's height and width.

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function get_vid_dim($file)
{
$command = '/usr/bin/ffmpeg -i ' . escapeshellarg($file) . ' 2>&1';
$dimensions = array();
exec($command,$output,$status);
if (!preg_match('/Stream #(?:[0-9\.]+)(?:.*)\: Video: (?P.*) (?P[0-9]*)x(?P[0-9]*)/',implode("\n",$output),$matches))
{
preg_match('/Could not find codec parameters $Video: (?P.*) (?P[0-9]*)x(?P[0-9]*)$/',implode("\n",$output),$matches);
}
if(!empty($matches['width']) && !empty($matches['height']))
{
$dimensions['width'] = $matches['width'];
$dimensions['height'] = $matches['height'];
}
return $dimensions;
}

Determining the best dimensions

I wrote this function to determine the best dimensions to use for conversion. It takes the original's dimensions, target dimensions, and whether or not to force conversion to the target aspect ratio (determined from its width/height). The target dimensions will always be the largest result this function can return.

/***********************************************************************************
get_dimensions()

Takes in a set of video dimensions - original and target - and returns the optimal conversion
dimensions. It will always return the smaller of the original or target dimensions.
For example: original dimensions of 320x240 and target dimensions of 640x480.
The result will be 320x240 because converting to 640x480 would be a waste of disk
space, processing, and bandwidth (assuming these videos are to be downloaded).

@param $original_width: The actual width of the original video file which is to be converted.
@param $original_height: The actual height of the original video file which is to be converted.
@param $target_width: The width of the video file which we will be converting to.
@param $target_height: The height of the video file which we will be converting to.
@param $force_aspect: Boolean value of whether or not to force conversion to the target's
aspect ratio using padding (so the video isn't stretched). If false, the
conversion dimensions will retain the aspect ratio of the original.
Optional parameter. Defaults to true.
@return: An array containing the size and padding information to be used for conversion.
Format:
Array
(
[width] => int
[height] => int
[padtop] => int // top padding (if applicable)
[padbottom] => int // bottom padding (if applicable)
[padleft] => int // left padding (if applicable)
[padright] => int // right padding (if applicable)
)
***********************************************************************************/
function get_dimensions($original_width,$original_height,$target_width,$target_height,$force_aspect = true)
{
// Array to be returned by this function
$target = array();
// Target aspect ratio (width / height)
$aspect = $target_width / $target_height;
// Target reciprocal aspect ratio (height / width)
$raspect = $target_height / $target_width;

if($original_width/$original_height !== $aspect)
{
// Aspect ratio is different
if($original_width/$original_height > $aspect)
{
// Width is the greater of the two dimensions relative to the target dimensions
if($original_width < $target_width)
{
// Original video is smaller. Scale down dimensions for conversion
$target_width = $original_width;
$target_height = round($raspect * $target_width);
}
// Calculate height from width
$original_height = round($original_height / $original_width * $target_width);
$original_width = $target_width;
if($force_aspect)
{
// Pad top and bottom
$dif = round(($target_height - $original_height) / 2);
$target['padtop'] = $dif;
$target['padbottom'] = $dif;
}
}
else
{
// Height is the greater of the two dimensions relative to the target dimensions
if($original_height < $target_height)
{
// Original video is smaller. Scale down dimensions for conversion
$target_height = $original_height;
$target_width = round($aspect * $target_height);
}
//Calculate width from height
$original_width = round($original_width / $original_height * $target_height);
$original_height = $target_height;
if($force_aspect)
{
// Pad left and right
$dif = round(($target_width - $original_width) / 2);
$target['padleft'] = $dif;
$target['padright'] = $dif;
}
}
}
else
{
// The aspect ratio is the same
if($original_width !== $target_width)
{
if($original_width < $target_width)
{
// The original video is smaller. Use its resolution for conversion
$target_width = $original_width;
$target_height = $original_height;
}
else
{
// The original video is larger, Use the target dimensions for conversion
$original_width = $target_width;
$original_height = $target_height;
}
}
}
if($force_aspect)
{
// Use the target_ vars because they contain dimensions relative to the target aspect ratio
$target['width'] = $target_width;
$target['height'] = $target_height;
}
else
{
// Use the original_ vars because they contain dimensions relative to the original's aspect ratio
$target['width'] = $original_width;
$target['height'] = $original_height;
}
return $target;
}

Usage

Here are a few examples of what you will get from get_dimensions() to make things more clear:

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get_dimensions(480,360,640,480,true);
-returns: Array([width] => 480, [height] => 360)

get_dimensions(480,182,640,480,true);
-returns: Array([padtop] => 89, [padbottom] => 89, [width] => 480, [height] => 360)

get_dimensions(480,182,640,480,false);
-returns: Array([width] => 480, [height] => 182)

get_dimensions(640,480,480,182,true);
-returns: Array([padleft] => 119, [padright] => 119, [width] => 480, [height] => 182)

get_dimensions(720,480,640,480,true);
-returns: Array([padtop] => 27, [padbottom] => 27, [width] => 640, [height] => 480)

get_dimensions(720,480,640,480,false);
-returns: Array([width] => 640, [height] => 427)

The Finished Product

Now, to put it all together:

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$src = '/var/videos/originals/original.mpg';
$original = get_vid_dim($src);
if(!empty($original['width']) && !empty($original['height']))
{
$target = get_dimensions($original['width'],$original['height'],640,480,true);
$command = '/usr/bin/ffmpeg -i ' . $src . ' -ab 96k -b 700k -ar 44100 -s ' . $target['width'] . 'x' . $target['height'];
$command .= (!empty($target['padtop']) ? ' -padtop ' . $target['padtop'] : '');
$command .= (!empty($target['padbottom']) ? ' -padbottom ' . $target['padbottom'] : '');
$command .= (!empty($target['padleft']) ? ' -padleft ' . $target['padleft'] : '');
$command .= (!empty($target['padright']) ? ' -padright ' . $target['padright'] : '');
$command .= ' -acodec mp3 /var/videos/converted/target.flv 2>&1';

exec($command,$output,$status);

if($status == 0)
{
// Success
echo 'Woohoo!';
}
else
{
// Error. $output has the details
echo '

',join("\n",$output),'

';
}
}

I hope this is helpful to someone.

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My first WordPress Plugin: Project Honey Pot

Andrew — Fri, 11 Sep 2009 07:48:53 +0000

conditions

address

I hate spam. I hate it. That's why I've been a participant in Project Honey Pot for the past several years. For those who don't know what Project Honey Pot is, here's their About page

To summarize, the project catches spammers by putting fake e-mail addresses on special pages that only harvesters crawling websites should ever find. When one of those addresses get spam, they've caught a harvester and know exactly when and from what IP the e-mail address was harvested.

It only just recently occurred to me that there really is no good WordPress plugin that allows you to hide honey pot links in your website. So I wrote one.

I was surprised at how easy it was actually. I hope it's helpful to someone, somewhere.

Go to the plugin page now

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