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Streaming Live with Red5 Media Server: Two-Way

By Marina Lohova
March 7, 2013

I already wrote about the basics of publishing and broadcasting with Red5 Media Server. Let’s fast forward to the advanced topics and create a video conference now!

Getting Ready

First, a word about the technology stack: a little bit of Java6/Java EE will be used for the server-side work (Red5 is written in Java), ActionScript2/Adobe Flash CS6 will be the primary tool for the client side development, and OS X Mountain Lion is my operating system.

Red5 Server comes with the set of sample applications that provide the source code for about everything you may want to achieve. The primary challenge is to unleash the power of it, since the samples fall extremely short of documentation! The “fitcDemo” application will serve as a base for all our customization.

Originally I made all the development in Red5 RC 1.0 version where fitcDemo was present. Unfortunately, when I downloaded the latest Red5 1.0.1 release yesterday it was simply not there! The source code was still in the repo, just outdated and not working. Well, I did all the work for Red5 team, so you can just download fitcDemo.war from my repo and drop it into the “webapps” directory of Red5 1.0.1 installation—​and you are good! …

Data binding in web applications

By Kamil Ciemniewski
March 6, 2013

Ever since JavaScript was introduced the world of web programming has constantly been visited by creative minds, ready to solve burning problems web developers were experiencing.

Navigating through some of the oldest web-dev articles, we still can feel the pain of manipulating the DOM, the-vanilla-way and creating ever so clever hacks to make the code work on all of the web browsers.

Then, the JS-frameworks epidemy started to disseminate. As web developers—​we started to have some powerful tools. The productivity of average nerdy Joe raised immediately as he started using Prototype.js, Mootools or jQuery.

Evolution of UI programming for browsers

And so was the start of our global evolution, towards making the Web—​our main means of interacting with users. Few with big enough imagination were already seeing HTML, CSS & JS as the future standard of creating user interfaces for data-rich applications. Of course, there were toolkits like ExtJS which aimed at nothing but this—​but who would have known back then, that we will be able to build apps for smartphones the way we are building ones for the web?

I have my little observation in life — all hot stuff in the world of technology, …

Installing Python in local directory

By Szymon Lipiński
February 20, 2013

On one of our client’s Ubuntu 10.04 machines, I needed to upgrade Python from 2.6 to 2.7. Unfortunately, after installing Python 2.7 from apt the virtualenv, version 1.4.5, did not work correctly. This bug was fixed in a newer virtualenv version, however there were no Ubuntu packages available.

I thought about trying something else: why not install all the software locally in my home directory on the server? When virtualenv is used to create a new environment, it copies the Python executable in to the virtualenv directory.

First I install pythonbrew, which is great software for installing many different Python versions in a local directory.

$ curl -kL http://xrl.us/pythonbrewinstall | bash

Then I activate pythonbrew with:

$ source "$HOME/.pythonbrew/etc/bashrc"

And install the Python version I want:

$ pythonbrew install 2.7.3

The installation took a couple of minutes. The script downloaded the tarball with the Python source code for the required version, compiled it and installed. It was writing all the information into a log file, which I was looking at by running the command below in another console:

$ tail -f $HOME/.pythonbrew/log/build.log

You can also add the …

Crossed siting; or How to Debug iOS Flash issues with Chrome

By Jeff Boes
February 19, 2013

This situation had all the elements of a programming war story: unfamiliar code, an absent author, a failure that only happens in production, and a platform inaccessible to the person in charge of fixing this: namely, me.

Some time ago, an engineer wrote some Javascript code to replace a Flash element on a page with an HTML5 snippet, for browsers that don’t support Flash (looking at you, iOS). For various reasons, said code didn’t make it to production. Fast forward many months, and that engineer has left for another position, so I’m asked to test it, and get it into production.

Of course, it works fine. My only test platform is an iPod, but it looks great here. Roll it out, and ker-thunk: it doesn’t work. Of course, debugging Javascript on an iPod is less than optimal, so I enlisted others with Apple devices and found that it mostly failed, but maybe worked a few times, depending on [SOMETHING].

To make matters a bit worse, the Apache configurations for the test and production environments differed, just enough to raise my suspicions and convince me that was worth investigating. Once I went down that path, it was tough to jar myself loose from that suspicion.

I tried disabling …

To ask or not to ask? Debug first.

By Miguel Alatorre
February 18, 2013

Jumping head first into a project, the ramp up will likely lead to questions galore. In the eagerness of getting things done, it seems like the best thing to do when stuck is to just ask the seasoned developers to tell you how to move forward. After all, they did build the application. However, when to reach out for help can be dependent on the deadline and priority of the task at hand as well as your subjective definition of “stuck.” Knowing when it’s too early, just right, or too late to get help can be a tricky thing. Here are some things to consider when reaching out for help early:

Pros.

 1. Time/money is of the essence and getting a quick answer is best.

 2. Time saved debugging a particular issue that does not further your understanding of the application can be applied elsewhere.

Cons.

 1. You risk a learning opportunity by throwing in the towel too early.

 2. You risk looking lazy or unprepared if the person whom you are reaching out to believes you could have done more.

 3. Developers are busy, too.

All cases being different, there is no right time to reach out for help but steps can be taken to ensure that you have your part. First, get better at reading source code. The …

Configuring RailsAdmin 0.0.5 with CKeditor 3.7.2

By Marina Lohova
February 15, 2013

If you like adventures, read on! Because recently I went trough a really tough one with RailsAdmin 0.0.5 and Ckeditor 3.7.2 in production mode. I only needed to enable the WYSIWYG editor for one of the fields in admin, yet it turned out to be a bit more than just that.

After I installed ckeditor gem, created the custom config file as described in Ckeditor gem readme and added ckeditor support to the field as suggested by RailsAdmin configuration tutorial, both frontend and backend in production mode were broken in pieces with JavaScript errors. So what did I do wrong?

The problem with frontend

After careful investigation it turned out that ckeditor files were not loading on the frontend, but my custom ckeditor configuration file was. And because CKEDITOR was not defined anywhere, the following code in my config.js failed:

CKEDITOR.editorConfig = function( config )
 {
   config.toolbar = 'Basic';
   config.toolbar_Basic =
   [
     ['Source', 'Bold', 'Italic', 'NumberedList', 'BulletedList', 'Link', 'Unlink']
   ];

   config.enterMode = CKEDITOR.ENTER_BR;
   config.shiftEnterMode = CKEDITOR.ENTER_BR; …

Kamelopard Updates

By Josh Tolley
February 15, 2013

I’ve just pushed Kamelopard v0.0.10 to RubyGems. With the last couple of releases, Kamelopard has gained a couple of useful features I felt deserved some additional attention.

Support for viewsyncrelay actions

Many of our Liquid Galaxy tours require more than just Google Earth. For instance, it’s not uncommon to want audio or video media to play at a certain point in the tour. We may want our Liquid Galaxy enabled panoramic image viewer to start up and display an image, or perhaps we need to signal some other external process. Unfortunately Google Earth tours don’t support configuration to run these actions directly upon reaching a certain point, but there are alternatives. Google Earth synchronizes nodes in a Liquid Galaxy with what are called ViewSync packets, which tell all the slave nodes exactly where a master node’s camera is positioned, in terms of latitude, longitude, tilt, etc. We can watch this traffic to determine the master node’s progress through a tour and trigger actions at defined locations, and we use an application called viewsyncrelay (available here) to do exactly that. We configure viewsyncrelay to run certain actions when the ViewSync traffic matches a set of …

Git as rsync

By Jeff Boes
February 14, 2013

I had a quick-and-dirty problem to solve recently:

The clients had uploaded many assorted images to a development camp, but the .gitignore meant those updates were not picked up when we committed and pushed and rolled out to the live site. Normally, one would just rsync the files, but for various reasons this was not practical.

So my solution, which I think can get filed under “Stupid ‘git’ tricks (as opposed to Tricks of a Stupid Git)”:

(on the source repo)

$ git checkout -b images_update
$ git add -f path-to-missing-images
$ git commit -m 'Do not push me! I'm just a silly temporary commit'

(“add -f” forces the images into the index, overriding our gitignore settings)

(on the target repo)

$ git remote add images /path/to/source/repo
$ git fetch
$ git checkout -f images/images_update path-to-missing-images
$ git remote rm images
$ git reset HEAD path-to-missing-images

That last “git reset” is because the newly-restored images will be git-added by default, and we didn’t want them committed to the central repo.

So what did we do here? For those dumbfounded by the level of silly, we used git to record the state of all the files in a certain path; then we pulled them back …