Creating a mathematical colour picker

The most common technique for creating a colour picker (at least in the ActionScript world) seems to use a colour wheel bitmap and then getting the colour of the pixel that was clicked on. I found that this was not a very accurate way to go about it and decided to build a colour picker that gave colours based on calculations in a HSV cube – Hue on the Z axis, Saturation on X axis, and Value on the Y axis.

Of course a 3D cube colour picker would be pretty hard to use, so what we end up with is a vertical hue slider, then an area that determines the saturation and value like so:


Windows ANE for native dialogs

My post on creating native alerts with Adobe AIR has proven to be quite popuplar so I decided to follow it up with something even better (at least for Windows apps).

Recently I have been dabbling in a bit of C# for creating Windows Store apps as well as some C/C++ to try and figure out how to create Native Extensions (ANE) for Adobe AIR. As a first ANE I decided to make a native dialog extension. Extensions for this already exist for iOS and Android but I was unable to find any for Windows.


Converting video with FFmpeg and Adobe AIR

Something I have been wanting to do for a while now is build a video converter into my Module Builder to enable automatic conversion of video into the various web friendly formats but I could never find a way to do it.

Over the weekend I discovered this tutorial on playing back any video in Adobe AIR. The tutorial runs through how to set up a NativeProcess to hook into FFmpeg to stream video from any format into FLV. FFmpeg is an open source media library for playback and conversion of almost any type of video or audio and is used by VLC and many other applications. I finally had a possible way of converting video within an AIR app! And one of the great things about this is since its using the NativeProcess API the conversion works asynchronously and the app doesn’t lock up while its converting.


Uploading video from iPad to server with AIR for iOS

In this part 2 post following on from Record and play back video with AIR for iOS on iPad I will show you how to take your freshly recorded video and upload it to a web server using PHP.

Assuming you have a MovieClip or some other button labeled ‘uploadbtn’ you first need to add a click event handler to it to trigger the upload.

[cc lang=”actionscript3″]
uploadbtn.addEventListener(MouseEvent.CLICK, onUpload);

Now for the click handler:

[cc lang=”actionscript3″]
function onUpload(e:MouseEvent):void
// create a URLRequest for the PHP file on you server (we’ll get to the PHP later)
var URLrequest:URLRequest = new URLRequest(“”);

// videoFile is a File object we created in the last post which references the recorded video
// attach the various listeners for errors, progress, complete
videoFile.addEventListener(DataEvent.UPLOAD_COMPLETE_DATA, uploadDataComplete);
videoFile.addEventListener(ProgressEvent.PROGRESS, progressHandler);
videoFile.addEventListener(IOErrorEvent.IO_ERROR, handleError);
videoFile.addEventListener(Event.COMPLETE, completeHandler);

// call upload on the File object and pass in the URLRequest

Now we can create the handlers for the attached listeners:

[cc lang=”actionscript3″]
function progressHandler(e:ProgressEvent):void
// just tracing the percentage of progress – you could show it in a progress bar
trace(“Uploading… ” + Math.ceil(100 * (e.bytesLoaded / e.bytesTotal)) + “%”);

function completeHandler(e:Event):void
// upload process is complete
trace( + ” has been uploaded.\n”);

function uploadDataComplete(e:DataEvent):void
//everything is complete, trace the message returned from the PHP script which is in XML format
var xml:XML = new XML(;


function handleError(e:IOErrorEvent):void
// simple error handler traces the error
trace(“Upload Error:” + e.text);

That is all that is required for the ActionScript side of things. Now for the PHP script. This is a very basic script and you should provide some security and validation on any production code.

All you need to do is save this into a blank PHP file and upload it to your server to the location matching the address in you URLRequest above.

[cc lang=”php”]
OK$file_name uploaded successfully.“;
// create a failed message if something went wrong
$message = “FAIL$file_name did not upload successfully.“;

echo $message;

That is all that’s required to upload a video from the iPad to a web server. It is surprisingly simple for how hard it was for me to work out.

I hope this helps somebody out!

AS3 – Split a camel case string

This is a little helper function which takes a string in camel case (camelCase) or pascal case (PascalCase) and splits it into separate words. The capitaliseFirst parameter will capitalise the first character in the first word if the string is in camel case.


Record and play back video with AIR for iOS on iPad

Recently I needed to figure out how to create an iPad app when you can record and play back video from the iPad’s camera, and then upload to it to a server using AIR for iOS. I wasn’t able to find a whole lot of info on it and so I eventually pieced it together from various places. I decided to share the first part of the process here, and I might share the second part in another post later.

I will assume you have a button on the Flash stage called ‘recordbtn’ which the code below will use to fire up the device’s camera.

First we have to set up some variables and check for StageVideo availability:
[cc lang=”actionscript3″]

// use stage video to playback recording
var stageVid:StageVideo;

// variables for displaying the video
var videoFile:File;
var ns:NetStream;
var nc:NetConnection;

// create instance of CameraUI for showing native camera app
var deviceCameraApp = new CameraUI();

// we’ll use StageVideo to display the recorded video, first we have to listen for availability
stage.addEventListener(StageVideoAvailabilityEvent.STAGE_VIDEO_AVAILABILITY, onStageVideoAvailability);

function onStageVideoAvailability(e:StageVideoAvailabilityEvent):void
// if StageVideo available
if (e.availability == StageVideoAvailability.AVAILABLE)
// get stage video instance
stageVid = stage.stageVideos[0];

// create a net connection for playing back the video
nc = new NetConnection();

// create a netstream for the net connection
ns = new NetStream(nc);
ns.client = this;

// add click event to record button
recordbtn.addEventListener(MouseEvent.CLICK, onRecord);

// add event for stage video render state
stageVid.addEventListener(StageVideoEvent.RENDER_STATE, onRender);


function onRender(e:StageVideoEvent):void
// when the video is ready to play set the viewport size so we can see the video
stageVid.viewPort = new Rectangle( 247 , 43 , 529 , 397 ) ;

AS3 / JS Constrain a value in one line

Here is a little snippet to constrain a value in a single line. It works by using two nested inline conditionals. The ‘else’ part of the first conditional is another conditional. It may not be the best approach but it works and is much easier and faster to write than two if-else statements.

In English it looks like this:
value = is value greater than max ? set to max, otherwise is value less than min ? set to min, otherwise leave it as is;

[cc lang=”actionscript3″]

// for js – remove the type declarations (:Number)
var minValue:Number = 0;
var maxValue:Number = 100;

value = value > maxValue ? maxValue : (value < minValue ? minValue : value); [/cc]

AS3 Getting colours blended between two other colours

Here is another function that can be added to my ColourUtil class. This one gets a specified number of colour steps between two blended colours.

I thought it would be much harder to achieve than it is, luckily the AS3 Color class has the static method interpolateColor which calculates a single colour at a specified position using a ratio value.

The function below is a simplified version of the function found at AS3 Adventure. This blog post also has a much better explanation of the interpolateColor method, and a great demo of the function.

function getColoursBetween(colour1:uint, colour2:uint, steps:int):Array
    var arr = [],


    for (i = 1; i < steps; i++)
        ratio = i / steps;
        arr.push(Color.interpolateColor(colour1, colour2, ratio)); 

    return arr; 

AS3 Hex Colour Dodge blending utility

The following is a function that takes two hex colours – a top colour and a bottom colour – and blends them using the Colour Dodge blend mode as found in Illustrator of Photoshop. This is handy for dynamically generating colour variants based on the blend mode. Instead of blending two display objects it simply returns a new hex value using the algorithm of the blend mode.

AS3 Easy gapless sound looping solution

If you have come accross the issue of sounds not looping seamlessly in a Flash project then try the following.
Simply offset the start of the sound by 80 milliseconds:
[cc lang=”actionscript3″]
var channel:SoundChannel = new SoundChannel();
var sound:Sound = new Sound();

sound.load(new URLRequest(‘sound.mp3’));
channel =;