Reading ID3 Tags in Flash/AS3
       by kadaj and kirupa |  19 January 2010

If you glance at a media player while it is playing back mp3 files, you will see details such as the name of the song that is currently playing, the artist, and other related information:

[ Rome Rome Rome Rome Rome Rome.... ]

Have you ever wondered where the song details actually come from? They come from the MP3 file itself. Today, a standard MP3 file contains not only the data that makes up your music, but it also contains metadata stored in the form of ID3 tags.

It is these ID3 tags that store all of the information about a song that you see, and in this article, you will learn how to read these values in Flash.

The Sound Class
When you are working with sound in Flash, more than likely, you are using the Sound class to load and play back the sound. Here is a basic snippet of what code looks like to load an mp3 file and play it back once it has fully loaded:

var mySound:Sound;

 

function setup()

{

mySound = new Sound();

mySound.load(new URLRequest("07 - Rome.mp3"));

mySound.addEventListener(Event.COMPLETE, soundLoaded);

}

setup();

 

function soundLoaded(event:Event):void

{

mySound.play();

}

Since this article isn't about sound, I am not going to into great detail about how it works. There only two things you need to note. The soundLoaded event handler gets called when the sound file has loaded, and our Sound object is declared globally and called mySound.

The ID3 Property
One of the properties the Sound class exposes is called id3. As you can guess from its name, it stores the metadata the MP3 sound file exposes. To use the id3 property, you need to do two things. First, you need ensure your mp3 file has an ID3 property. Second, you need to access the property itself.

Checking to see if the File has an ID3 Region
The best way to check if your loaded file has an ID3 region is to use the Event.ID3 event on your sound object. The non-grayed out lines show you how I set that up:

var mySound:Sound;

 

function setup()

{

mySound = new Sound();

mySound.load(new URLRequest("07 - Rome.mp3"));

mySound.addEventListener(Event.COMPLETE, soundLoaded);

mySound.addEventListener(Event.ID3, id3Loaded);

}

setup();

 

function soundLoaded(event:Event):void

{

mySound.play();

}

 

function id3Loaded(event:Event):void

{

 

}

I set up the event listener on my sound object...aptly called mySound...and associate the Event.ID3 event with the id3Loaded event handler. If my sound file has an ID3 region, this event will get fired and the id3Loaded function will get called.

Note
You may find that your Event.ID3 event handler gets called more than once. Thanks to lewi-p on the forums who did some investigation, it has to do with the MP3 file having more than one ID3 tag specified. You can read the full thread here.

Reading the ID3 Values
Now that you know your mp3 file has some ID3 data, reading them is as easy as taking your Sound object, mySound, and accessing the id3 property:

[ the id3 property lives directly on you Sound object ]

From this id3 property, you can get direct access to the album name (album), genre (genre), song name (songName), artist (artist), track (track), year (year), and comment (comment).

In my id3Loaded event handler, I have added some trace statements that display the album information using the id3 properties that I listed in the previous sentence:

function id3Loaded(event:Event):void

{

trace("Album: " + mySound.id3.album);

trace("Song: " + mySound.id3.songName);

trace("Artist: " + mySound.id3.artist);

trace("Track: " + mySound.id3.track);

trace("Year: " + mySound.id3.year);

trace("Comment: " + mySound.id3.comment);

}

When I run my application, notice that the relevant details are displayed in my Output window:

[ the song's ID3 information is now displayed ]

While I only displayed the six properties actually defined, the Flash player actually exposes most (if not all) of the ID3 tags that do not have properties associated with them. You can view all of those properties in Adobe's Documentation for ID3.

Conclusion
Hopefully you found this short article helpful. As you can see, accessing the ID3 values from an MP3 is greatly simplified because the Sound class provides you with everything you need. You are saved the hassle of having to read the various regions that make up the MP3 file and parse out the relevant information manually.

If you have any questions, please post them on the kirupa.com Forums.

Cheers!

	kadaj
	kirupa