The Open Source Media Framework

I first heard about the Open Source Media Framework (OSMF) while watching one of the Adobe Max 2009 keynote speeches online. As a person who has built a lot of video players, galleries and mp3 players for my work I was very excited that this was being built. I have wanted to work on something like this myself for a long time. Now here was an open source project I could contribute to while building off of best practices others have contributed. Building robust custom players was going to be much quicker and easier.[ad#Adobe Banner]While watching the keynote I looked OSMF up, but it was still in early development. So I just added it too my ever growing research and development document. Recently I found a free ezine called Flash & Flex Developers Magazine and the most recent issue was focused around OSMF. I decided to take the framework for a test drive and while I was at it I would give the API docs a skimming read. Here is what I found.

Testing out the sample code

The first thing I did was try out the examples straight from the magazine. This was straightforward. The samples didn't build anything too advanced but I noticed something. It didn't take very many lines of code to get the video playing. Most of the code was for adding buttons and making them call a single function in the OSMF API. As usual when doing samples from an article I decide to tweak it to see has intuitive it was to do things. Adding and customizing simple playback controls and capabilities was a breeze. I only needed to check the documentation to make sure my assumptions were true, which they were in most cases. For a basic custom player, this thing is extremely easy to use.

Looking under the hood

The second thing I did is something I like to do with a framework I'm looking at, skim over the documentation. This consists of going through each package and seeing what classes are where. For the most part I will click into each classes documentation to find out what the class is meant for. Sure, this has me look at a lot of helper classes that I may never use ( which is a good learning exercise ), but it also has me find obscure classes that might be quite useful in a pinch. [ad#Google Adsense] One class that interested me both for educational and practical reasons was the ListenerProxyElement class. It is actually quite beautiful in its simple use. It is a class that is meant to be extended. The class itself sets up all the listeners for a MediaElement and has them trigger hook functions that you override to handle these events with custom code. I foresee using this in many projects. There are quite a few other things taken care of in this framework, such as handling of a video player that is sized differently from the video content.

Overall, Adobe ( who is in charge of this open source project ) has put together a very useful, intuitive and extensible framework that is still in the early stages. I'm looking forward to see what types of media players I can build now that so much is already handled for me. Is there anything you want to know about OSMF? Have you already used it on a project? If you have can we see your work (and hopefully code)?[ad#Adobe Banner]

For more information check out:

• The Open Source Media Framework main page
• The OSMF documentation
• The OSMF forums

AMFPHP $_explicitType understood

I've been using AMFPHP for a while now. Up until recently I have been using dumb objects and simple NetConnections to pass things back and forth between Flex and PHP. Over time, the objects I was passing back and forth got more complex and strong typing of the objects looked like a better way to go, but there was a lot of code that would have to change in my libraries to make it happen so I kept putting it off. ...

Recently, a couple projects I was working on had me take a look at the Cairngorm micro-architecture to help speed up (re)development. After finding some great tutorials on getting starting with Cairngorm I decided it fit the bill for my needs.

Cairngorm would allow me to refactor some basic frameworks I was going to use for these and future projects while allowing for easier customization and modification. The architecture makes use of RemoteObjects to pass data back and forth instead of raw NetConnection objects. Between RemoteObjects and the ValueObject design (anti?)pattern I felt it was time to work on strong typing my variables, specifically the ones traveling from PHP to Flex.

Two important parts to making this work are the RemoteClass meta tag in Flex and the $_explicitType variable in PHP. The RemoteClass meta tag lets your application know the fully qualified name of an alias class on your server. It works the same for AMFPHP, ColdFusion, Java and others. It should look something like this:

package path.to.asClasses
{
  [RemoteClass(alias="path.to.MyAliasClass")]
  public class MyASClass
  {
    public var id:uint;
    public var name:String;
  }
}

My first thought about the $_explicit type variable was that it would be the inverse of the RemoteClass meta tag and point to the actionscript class. With that in mind I wrote something like this:

<?php

class MyAliasClass
{
  var $_explicitType = "path.to.asClasses.MyASClass";

  var $id;
  var $name;

  public function MyAliasClass( ){}
}

?>

Unfortunately, the data that got passed back to Flex was typed as an ObjectProxy object instead of as a MyASClass object as intended. I did all the basic troubleshooting. I made sure everything was spelled the same. I tried to do searches online and got mostly references passing VOs from Flex to PHP and/or Patrick Mineaults opinion that doing so is wasteful. Not many of the search results talked about going from PHP to Flex and those that did just said you needed to use $_explicitType. Unfortunately I can't find the posting again, but I came across a short post that said they had a similar problem and got it to work by changing $_explicitType to a string representing the fully qualified path of the PHP class. He didn't know why it worked, and neither did I, but I tried the following code and class typing occured as expected:

<?php

class MyAliasClass
{
  var $_explicitType = "path.to.MyAliasClass";

  var $id;
  var $name;

  public function MyAliasClass( ){}
}

?>

As usual, I got it working and now I needed to understand why. Not only why did it work but why did they use the term explicit type? It turns out the use of the RemoteClass meta tag takes care of mapping in both directions. When the Flex app encounters an alias object from remoting ( in this case path.to.MyAliasClass ) it knows what AS class is equivalent. As for explicitType, you just have to think about the full notation ( MyAliasClass::_explicitType ). In object oriented languages an object's properties should represent it's state. In this case it represents the explicit type of MyAliasClass. This is required due to the constraints of PHP. PHP is not case sensitive when it comes to class names. Also, PHP doesn't actually use classpaths. When you include a file there is no reference to the directory structure passed along with it. Though one could be derived, it isn't built into AMFPHP natively.

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Some other good news related to AMFPHP. While looking for answers I see that AMFPHP now has a new lead who is working on getting version 2.0 out and ready to go. Supposedly he already got authentication working again. His name is Wade Arnold from T8Design. This is good news as it once again assured the future of the AMFPHP project.

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Daryl "Deacon" Ducharme is currently Director of Application Development for the Interactive Agency Provis Media Group, LLC which helps organizations enhance identity, connect with customers and increase productivity.

ATI Linux drivers going open source?

When I first tried installing linux one of my biggest problems was video card driver support problems. I have an ATI card and at the time had dual monitors. The open source drivers for my chipset didn't work as I would like with my setup. However, trying to get the binary drivers set up properly gave me problems as well. This was one of the big things that made me leave linux at that time. When Fedora 7 came out and I tried it again, I only had one ( much larger ) monitor to worry about so I was okay with the open source drivers that were set by default. Even though it bugs me that I use my CPU for my eye candy effects and the Graphics card just sits there. That is why this article on cnet news caught my eye. ...

So it looks like AMD/ATI wants to accelerate efforts in the open source community. The question on everyone's mind is what does this mean? Will the drivers be open source? Will they open up the specifications so that decent open source drivers can be written?

At this point nobody knows for sure. The best place to keep an eye would be phoronix.com that is the hub of ATI graphics card drivers for linux. All the articles I've looked at have pointed to the phoronix.com article on the acceleration of efforts in the open source community.

If ATI does open source the drivers this could be a big boon to Linux on the desktop. As more applications are able to tap into the full potential of graphics cards on the platform, higher end stuff will be made. Hopefully this will lead to one of the big downfalls of the linux desktop, games. If games can count on the ability to tap into the graphics card, more will be ported and written natively to the platform.

Uncertain Futures

As much as we hate it, our futures are uncertain. We do our best to figure out ways to keep what we know safe and secure. However some times that security gets shaken and sometimes it gets shattered.

From time to time my boss and I talk about open source software. He doesn't really like to look at it as a solution too often. There are many reasons he states, but one that often comes up is product stability. Will it be supported? Is it still actively developed? Good questions, and unfortunately it looks like some security I envisioned in the open source world is getting shaky around a product I just started using. ...

A little while ago I started a new project for work. In fact it was the first project I got the okay to do in Flex/AS3. While I was at it I thought I would take a look at using AMFPHP remoting for it as well, since it is a very server data centric application framework. I used it and loved it. No more serializing complex data structures into XML. No more deserializing and spending so much time creating specialized parsing engines. There was a small learning curve but otherwise, very easy to integrate and use.

Then I read this article on the 5 et demi blog. It seems Patrick Mineault is retiring from programming and the AMFPHP project. Luckily, he will be finishing AMFPHP 2.0 before he is done. Good luck to him on his new endeavors but what will become of AMFPHP? As far as I can see there is nobody in line to take over the project. Should I do it? I really don't believe that would be beneficial to the community at this juncture in my life. He does make a good point about not getting stuck to one software, and I can easily go back to what I was doing before, but this is a good project.

Here are some answers to my questions, at least for myself. First off, AMFPHP will work for current versions of PHP and the Actionscript Virtual Machine. So no big worries there. It is open source, so any bugs that I do run into after the 2.0 release can still be fixed. If the project does die off, it should still find some usefulness for quite some time. Once it is no longer a viable option, there will obviously be better solutions for me to use anyway. In fact, Flash/Flex/Actionscript may not even be the tool I am using so why sweat it. However, it is a good project and I would like to see it live on and evolve into something greater.

Do you know anyone who could take over this project? Can you? Are you willing to help in some way? If you answered yes to any of these questions it's probably a good idea to contact Patrick at 5 et demi and let him know. I'm sure he would be more than happy to toss you the keys to the project.

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Daryl "Deacon" Ducharme is currently "Code Czar" for the Interactive Agency Provis Media Group, LLC which helps organizations enhance identity, connect with customers and increase productivity.