iPad Streaming Video and More

By | Published: April 6, 2010

I've updated the configuration examples in the open source segmenter project to reflect Apple's recommended stream bitrates for iPad video streaming, added a few fixes and a few new features. If you are interested in streaming video on the iPad, iPhone or iPod Touch and haven't done so yet you it may help to start with my post on windowed streaming on for the iPhone, then read about iPhone HTTP streaming with FFMpeg and the open source segmenter and finally check out the iPad, iPhone, and iPod Touch live video streaming project page.

Here is a demo of the iPad streaming video created with the segmenter (I tried to show the progressive upgrade happening but it happens very quickly since the iPad is on WIFI, I also show that you can scrub without any issues and if you look in the background you can see the server log displaying entries as the segments are downloaded):

If you want to view the demo yourself I've created a demo for the iPad, iPhone, and iPod Touch. Note that those are two links, one for the iPad version and one for the iPhone/iPod Touch version. The main difference is the size of the video.

I used the open source video Big Buck Bunny (the 1920×1080 ogg version) for the above demos.

If you are interested in more details on what changed read on or skip to the bottom if you want to see what I'll be working towards in future versions of the segmenter.

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Using Cursors with PHP MySQLi and Multiple Prepared Statements

By | Published: March 30, 2010

After my post on using PHP MySQLi and multiple prepared statements at the same time someone commented that using cursors could do the same thing. With that comment I dug some more and found that modifying the cursor type that is used under the covers will indeed let you execute multiple prepared statements concurrently on the same connection.

First off you may ask yourself why you would want to use this. The best answer I have for that is that the solution in the other post loads the entire result set into memory from the very start while with this solution you can control just how many rows you load. To get started you will want to take a look at the MySQLi statement set attribute call. This call is will let you modify the underlying cursor type that is used with the prepared statement in two ways that are useful for this issue.

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Spring 3 File Upload Example

By | Published: March 22, 2010

I had the opportunity to figure out how to do file uploads using Spring 3 the other day and I couldn't find anything that pulled it all together. What follows is a complete example of how to do MVC based file uploads with Spring 3.

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Parsing the SXSW Twitter Stream for Fun

By | Published: March 10, 2010

Over the weekend I decided to toss together a simple twitter stream monitoring app that would capture SXSW tweets. I wanted to build on some of what I learned while hacking together the stuff for code2009 and it was also an excuse to play with node.js and a few other things. I figured I would put together a quick post with all the different parts and as I have time I'll pull together some of the more important sections into larger posts. Be warned that the site may stop functioning since it was only a few hours work and mostly put together with bailing wire and gum.

Server side:

  • node.js – Used to process the long polling requests
  • ngnix – Front for multiple nodejs instances and serving some static files
  • underscore.js
  • rabbitmq – Used to monitor the realtime feed
  • Redis – Used as a datastore for everything
  • ruby – Used to glue a bunch of things together, tons of gems used
  • Resque – Used to handle the screen captures

Browser side:

Hosting:

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Using Daemon-Kit and RobustThread to Build Ruby Daemons

By | Published: March 2, 2010

On a number of occasions I have found myself needing to assemble a daemon process for some type or processing done using Ruby. Each time I roll things a little different and I finally started to wonder if someone had already put together tools for doing the daemon parts. After some quick digging I ran into Daemon-Kit and after adding it together with a couple other tools it seems like what I've needed. I've put together a few recipes here to help guide others who might be looking for something similar.

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Building HipHop PHP for Fedora 12 on 64 bit and 32 bit Systems

By | Published: February 23, 2010

Now that Facebook has finally released the source for HipHop PHP it is time to give it a spin. Of course it is still a little rough around the edges so I figured I would toss together a quick howto on getting it to build.

The first thing to note is that they are only supporting 64 bit systems officially. Having said that it isn't too hard to modify the code to make it work on a 32 bit system although it may turn out that such early modifications are missing some fundamental bits on why they were only support 64 bit systems. I'm going to assume at first that you are using a 64 bit system and then end with what you need if you are still using a 32 bit system.

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Fedora 12 Bootable Root EBS on EC2

By | Published: February 16, 2010

I recently needed to create a clean EC2 AMI using a fairly new linux distro. It has been a while since I've needed to create a new AMI so I also wanted to move away from the older pre-packaged AMI and boot using EBS. After taking a look at what was currently available publicly I decided I would just create my own EBS bootable AMI using Fedora 12. It wasn't all that complicated but there are a decent number of steps so I figured I would document them for anyone else who might want to give it a try.

I'm going to assume you already understand how to do things like create instances, create EBS volumes and ssh into your running instance using key based authentication. I use the AWS management console for a lot of what follows with the exception of needing to register the AMI and for that you will need the Amazon EC2 API Tools and Amazon EC2 AMI Tools

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PHP MySQLi and Multiple Prepared Statements

By | Published: February 9, 2010

While sprucing up the PHP code I use to provide my own Stack Overflow API for GeeQe I ran into an error caused by trying to use multiple prepared statements with MySQLi. It turned up when I tried to execute one prepared statement while looping over the result set from another prepared statement that were both created on the same connection. What came out was the following error:

"Commands out of sync; you can't run this command now"

Details about this error can be found in the mysql docs. Reading those details makes it clear that the result sets of a prepared statement execution need to be fetched completely before executing another prepared statement on the same connection.

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Developing Adobe Air Apps with Linux

By | Published: January 12, 2010

I finally found a little project I wanted to do using Adobe Air and after some searching I found out you can use Linux to develop Air applications. At first I thought I would have to use Flex Builder which is still in alpha for Linux but it turns out there is a better option from Aptana.

The Aptana Air plugin supports developing Adobe Air applications using HTML and Javascript. It even support the 2.0 release of Air that is currently in beta. Aptana uses the Eclipse framework as an editor so if you are familure with Eclipse it will be even easier to use.

I started by downloading and installing the latest version of the Air runtime. Next I grabbed the Air SDK, the SDK doesn't come with the plugin so it is something you have to get directly from the Air developers site. After getting the SDK unpacked I installed the latest Aptana core release. Once the core is installed there is a big plugin button on the startup screen that currently has Air listed.

The install went smoothly except for a few issues. The first one I ran into was very noticeable since it kept any dialog buttons from working when they were clicked although they did work when I clicked them and then hit enter or navigated to them with the keyboard. Luckily someone has already figured out that there is an issue with Eclipse and GTK+ that is the cause (even though the post is for Ubuntu the same problem and solution worked for me on Fedora). The fix is to set the GDK_NATIVE_WINDOWS variable before running the Aptana binary:

GDK_NATIVE_WINDOWS=true; AptanaStudio

The next thing I noticed was the application.xml descriptor that Aptana created didn't generate correctly. It needs to start with the correct xmlns or the following error will be thrown on run: "invalid application descriptor: descriptor version does not match runtime version". To fix this check the version of the Air SDK by running the following command:

./adt -version
adt version "1.5.3.9120"

For the version of the Air SDK I downloaded the correct xmlns was http://ns.adobe.com/air/application/1.5 so I needed the following application tag:

<application xmlns="http://ns.adobe.com/air/application/1.5">

Once I had that working I was able to compile and execute a demo application. I was also able to create an Air application package from within Aptana using File > Export > Adobe AIR > Adobe AIR Package. Before creating the Air package I had to create a signing certificate. Creating the certificate can be done within Aptana too but because I had not yet fixed the above button issue I created a cert on the command line with the Air SDK and then imported it. To create the Air signing certificate from the command line I used the adt command from the SDK:

adt -certificate -cn SelfSigned 1024-RSA sampleCert.pfx samplePassword

Remember the password that gets used to generate the certificate because it will have to be used before a package is signed.

Finally Adobe has a lot of information on developing Air applications on their Air devnet site. The Air ajax section is especially important.

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Heroku Tips for the Cheap

By | Published: December 20, 2009

I've been playing around with the Ruby/Rails cloud provider Heroku a little bit lately just to try it out. It is somewhat like Google App Engine or Microsoft Azure in the way it works since you bundle your application and push it out to the Heroku cloud for deployment. It is very easy to get things going but I ran into a few interesting items that I figured I would share.

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