UPDATE #2 (08-23-2009): Just realized that the text file with the sample ActionScript class was called “BasicAnalysis.txt”. It should’ve been called “BasicAnalyzer.txt”, which you’d need to rename to “BasicAnalyzer.as”. The link has been updated below.

Most of my traffic comes from searches for Actionscript 3 spectrum analysis. Because of this, I decided to post an updated example that you can use to conquer your SoundMixer.computeSpectrum() woes. I realized that my original post had source code that wasn’t entirely transparent — and thus, probably not as useful as it could be.

This new example shows how you can draw a series of columns (using basic Graphics.drawRect() code) and how you can do something a little more interesting. I wanted to include both so that people learning from this code don’t get too confused.

Download the source: BasicAnalyzer.txt (you’ll want to rename the extension to .as).

Things you might gain from referencing this class:

• A better understanding of what’s going on with the ByteArray that SoundMixer.computeSpectrum() writes to
• A means for averaging the values in the ByteArray so that you don’t have to represent all 256 values of each stereo channel
• A simple example for doing something a little more “interesting” with the float values in the ByteArray

The source is fully commented, so feel free to snag it for your own use.

You can either make this class your FLA’s document class if you want to try it out, or you can add it as a child of any DisplayObject. Though, there’s some positioning based on stage.stageHeight in there, so your mileage may vary. If you do make it your document class, the Flash movie you’re seeing is 560px by 400px.

Also if you’re interested, the music is “Venus Morning” off an album called “Talk Strange: A Beat Tape Inspired by Bjork” by Dert. Click on his name for the download. Highly recommended.

UPDATE #3 I created a ZIP file with the code and an FLA demonstrating how to use it. You can grab that package here: BasicAnalyzer.zip. It was created using Flash CS4, but should be able to be opened using Flash CS3.

After some deliberation, I decided to go ahead and start learning ActionScript 3 (but not necessarily Flex). I have some ideas for an image generation technique based on audio data. The first step toward that is the audio analysis.

I was initially going to attempt this using Processing, but after looking at the new AS3 language API, I found that ActionScript had the capabilities I needed. On top of that, we’re going to start moving to some AS3 development at work. So I can kill two birds with one stone.

Let me know if you’re interested in the source code for this. I need to clean it up a bit, but it might be useful to some folks.

[UPDATE]:

I’ve updated the song on the demo page to be something that’s much more beautiful and visually interesting. It’s a song called model d by a Japanese artist named so inagawa. The song is from a free netlabel release at unfoundsound’s free mp3 releases (unfound17). You can also download it from archive.org.

I’ve added the source code for the project to the demo page as well. Enjoy!

The story: odopod is having a holiday party next week. I was asked by one of the partners, Jacquie Moss, to put together about an hour of music for the dinner-portion of the event. I asked her if there were any specific qualities I should look out for. Her reply:

Conversational. Upbeat, but low-key. Ambient. Interesting. Lovely.

So, here’s my stab at meeting that request: Download Mike Creighton’s Odopod Holiday Mix.

And for those of you that are curious about the playlist, here it is:

1. Khonnor – Rooms
2. DNTEL – (This Is) The Dream of Evan and Chan [Barbara Morgenstern Remix]
3. Herrmann & Kleine – Shuttle
4. múm – awake on a train
5. Solvent – When the Sun Hits
6. Air – Mike Mills
7. Sondre Lerche – Stupid Memory
8. John C. Kelley – surfs up
9. Broken Social Scene – Looks Just Like the Sun
10. Modest Mouse – Gravity Rides Everything
11. Matmos – For the Trees
12. Cornelius – Brazil
13. Boards of Canada – Satellite Anthem Icarus
14. Skanfrom – Here She Comes
15. Herrmann & Kleine – Leaving You Behind
16. Thom Yorke – Atoms For Peace
17. Ulrich Schnauss – Wherever You Are

Did I do okay?