as3icy is a drop-in replacement for the Flash Player’s Sound object that can reliably play Shoutcast, Icecast and Limewire MP3 streams. And it extracts metadata info from the stream in real time. It also reliably plays VBR MP3.

DISCLAIMER IN CAPITAL LETTERS. This is experimental code. I basically threw this code together in two 24 hour coding sessions. Also, i know as much about sound engineering as i know about pottery – i blind-ported a big chunk of Java code (the excellent JLayer MP3 decoder, originally ported from C if i’m not mistaken) to Actionscript 3 without really knowing what i was doing. So expect a few WTF moments when reading through the code, and do not expect everything to work perfectly just yet.

Some known issues

• IT IS SLOW AND STRESSES YOUR CPU. Depending on the encoding, i get around 20-50% load on my 2.4GHz Core 2 Duo (Vista), which is way too much. On my MacBook Air 2.16 GHz: full load and playback chokes, which is unacceptable. There is plenty of room for optimization though, the code is currently not optimized at all. It’s probably worth taking a look at Apparat, or Alchemy in general for more performant alternatives to decode MP3..
• Only Layer III is supported (Layer I and II decoders not ported yet).
• Only 44100Hz playback is supported (up/down-sampling to 44100Hz not implemented yet).
• Only stereo modes are supported (mono not implemented yet).
• The stream parser seems to be with problems yet, sometimes it happens that it runs out of sync for some reason.

Also, Adobe AIR is recommended to play Shoutcast streams, for two reasons: The meta data interval is passed back to the client via HTTP response headers, which are not available in the plugin version of the Flash Player, and as soon as you put the thing online you need the streaming server to host a crossdomain.xml file. If you happen to have access to the streaming server, you can of course solve these issues by hardcoding the meta data interval and have the streaming server serve an appropriate crossdomain.xml, or by using a proxy script of some sort. Also, this only applies to playing Shoutcast streams. You can play static MP3 files (for example VBR MP3s) using as3swf in the plugin version of the Flash Player without any problem (security restrictions still apply of course).

A simple example: Shoutcast stream playback

package
{
  import com.codeazur.as3icy.ICYSound;
  import com.codeazur.as3icy.events.ICYMetaDataEvent;

  import flash.display.Sprite;
  import flash.events.HTTPStatusEvent;
  import flash.net.URLRequest;
  import flash.net.URLRequestHeader;

  public class SimpleShoutcastPlayer extends Sprite
  {
    protected static const URL:String = "http://72.233.14.70/hype";

    protected var icySound:ICYSound;

    public function SimpleShoutcastPlayer()
    {
      var req:URLRequest = new URLRequest(URL);
      req.requestHeaders = [ new URLRequestHeader("Icy-Metadata", "1") ];
      icySound = new ICYSound();
      icySound.addEventListener(ICYMetaDataEvent.METADATA, metaDataHandler);
      icySound.addEventListener(HTTPStatusEvent.HTTP_RESPONSE_STATUS, httpResponseStatusHandler);
      icySound.load(req);
      icySound.play();
    }

    protected function httpResponseStatusHandler(e:HTTPStatusEvent):void {
      // The HTTP_RESPONSE_STATUS event is fired when the stream is opened and starting to load.
      var s:String = "Connected!";
      if (icySound.icyName.length > 0) { s += "\rName: " + icySound.icyName; }
      if (icySound.icyDescription.length > 0) { s += "\rDescription: " + icySound.icyDescription; }
      if (icySound.icyUrl.length > 0) { s += "\rURL: " + icySound.icyUrl; }
      if (icySound.icyServer.length > 0) { s += "\rServer: " + icySound.icyServer; }
      if (icySound.icyMetaInterval > 0) { s += "\rMeta Interval: " + icySound.icyMetaInterval; }
      trace(s);
    }

    protected function metaDataHandler(e:ICYMetaDataEvent):void {
      // The METADATA event is fired when new metadata is available.
      if (e.metaData.length > 0) {
        trace("Now playing: " + e.metaData.slice(13, -2));
      }
    }
  }
}

This code (Adobe AIR required) plays the Hype Machine live radio stream, and traces out general information about the station, as well as the names of currently playing songs.

Note that we set a custom request header, Icy-Metadata: 1. This tells the server to periodically send meta data with the stream. Under the hood, as3icy transparently extracts this meta data from the stream in real time and passes it to the application via the ICYMetaDataEvent. This event won’t be fired when the request header above is not sent.

The trace output should look something like this:

Connected!
Name: Hype Radio
Description: Radio powered by music blogs
URL: http://hypem.com/radio/
Server: Icecast 2.3.1
Meta Interval: 16000
Now playing: Collider - Time Concerns
Now playing: Rogue Wave - Birds (Neil Young cover)
Now playing: The Big Pink – Dominos
[..]

import com.codeazur.as3swf.SWF;
var swf:SWF = new SWF(root.loaderInfo.bytes);
trace(swf);

Trace output:

[SWF]
  Header:
    Version: 10
    FileLength: 149405
    FileLengthCompressed: 149405
    FrameSize: (550,400)
    FrameRate: 24
    FrameCount: 1
  Tags:
    [69:FileAttributes] AS3: true, HasMetadata: false,
      UseDirectBlit: false, UseGPU: false, UseNetwork: false
    [09:SetBackgroundColor] Color: #FFFFFF
    [86:DefineSceneAndFrameLabelData]
      Scenes:
        [0] Frame: 0, Name: Scene 1
    [82:DoABC] Lazy: true, Length: 149219
    [76:SymbolClass]
      Symbols:
        [0] TagID: 0, Name: Untitled_fla.MainTimeline
    [01:ShowFrame]
    [00:End]

Excercise: Draw something on stage, and run the code again.

Want more? Drop by my session Hacking SWF at FITC Amsterdam (Feb 22th, 16:00).

[Edit] Jim Cheng deserves credits. He was the one who whispered “root.loaderInfo.bytes” into my virtual ear on IM.

I was able to identify two so far:

ProductInfo (Tag ID 41)

The ProductInfo tag contains infos about the tool used to generate the SWF, as well as the date and time the SWF was compiled. It also contains info about the “Edition” of the software used (see below), and although this seems to be always set to “None” in Flex Builder 3 and Flash Builder 4, it potentially could become a privacy issue, especially being an undocumented feature (you better know about this tag just in case you accidentally publish commercial work with your non commercial Flash Builder license).

• ProductID (UI32)
  0: Unknown
  1: Macromedia Flex for J2EE
  2: Macromedia Flex for .NET
  3: Adobe Flex
• Edition (UI32)
  0: Developer Edition
  1: Full Commercial Edition
  2: Non Commercial Edition
  3: Educational Edition
  4: Not For Resale (NFR) Edition
  5: Trial Edition
  6: None
• MajorVersion (UI8)
• MinorVersion (UI8)
• BuildLow (UI32)
• BuildHigh (UI32)
• CompilationDate (UI64)
  Milliseconds since 1.1.1970

Examples:

Flex 4.0 – [41:ProductInfo] ProductID: 3, Edition: 6, Version: 4.0.0.7791, CompileDate: Fri Aug 21 05:18:21 GMT-0300 2009

Flex 3.2 – [41:ProductInfo] ProductID: 3, Edition: 6, Version: 3.2.0.3958, CompileDate: Fri Aug 21 05:23:22 GMT-0300 2009

DebugID (Tag ID 63)

This tag is written to SWFs that are enabled for debugging. It contains a 16 byte UUID.

• UUID (UI8[16])

Example:

[63:DebugID] UUID: b8f36d6a-c735-a340-daa7-44730af92505

Reference

Flex SDK:

• TagValues.java
• ProductInfo.java
• DebugID.java

Community:

• Igor Costa: Reading the compilation date of SWF with the magic of ByteArray
• Judah Frangipane: Cache busting your Flex SWF and the SWF Compilation Date

The problem is that the user needs to install the RPC server before she installs the actual AIR application. The install process should be seamless (one installer installs RPC server, AIR runtime if needed, and the application itself in one go) and the installer should be as small as possible. Currently there is no info available from Adobe on how to write custom installers that automatically download/install the AIR runtime if needed (is there?).

Artemis is another project aiming at extending AIR using a local socket server, but it seems that the project has been shut down because of the reasons stated above.

So i have been pulling out my hair lately on how to solve that problem.

I think i found a feasible solution. I am not sure because i haven’t tested all this, but i wanted to throw it online for discussion. The drawback is that the user needs to install your application with a OS native custom installer.

First you write standard installers for both Mac OS X and Windows, that install the local socket server either as a service/daemon or as an agent so that the server always starts at system launch or user login. Nothing special here yet.

The trick would be to write a simple SWHX application that basically implements the code included with the AIR Installer badge. That helper application can then be included with the installer, which executes it after the local socket server has been installed.

As i said i haven’t tested this yet (will do soonish), but this should work, no?

The question remains why i don’t just use SWHX for the main app and screw AIR alltogether.

So i finally sat down this weekend and added that.

The code is not tested very well (it works for me but may not work for you) and has no ASDocs yet, so i release it as an alpha version, with the hope of massive bug feedback.. :)

Download: fzip_1_0_52_alpha.zip fzip.zip

New methods in class FZip:

• addFile(name:String, date:Date, content:ByteArray)
• addFileAt(index:uint, name:String, date:Date, content:ByteArray)
• removeFileAt(index:uint)
• serialize(stream:IDataOutput)

Sample code:

// Create file contents
var ba:ByteArray = new ByteArray();
ba.writeUTFBytes("Hello World!");
// Create ZIP archive and add file
var zip:FZip = new FZip();
zip.addFile("hello.txt", null, ba);
// Serialize ZIP into a new file
// (we use the Adobe AIR specific class FileStream here,
// but you can as well use ByteArray or anything that
// implements IDataOutput)
var file:File = File.applicationStorageDirectory;
file = file.resolvePath("hello.zip");
var stream:FileStream = new FileStream();
stream.open(file, FileMode.WRITE);
zip.serialize(stream);
stream.close();

FZip now uses ByteArray.uncompress(CompressionAlgorithm.DEFLATE) instead of the now deprecated ByteArray.inflate(). I also tweaked FZip to throw an exception when a parsing error occurs and no event listener is registered for FZipErrorEvent.PARSE_ERROR events.

AIRRemoteUpdater now gets the local descriptor XML via Shell.shell.applicationDescriptor which was added in AIR Beta 2, and uses the upgraded FZip sources.

Enjoy, and please let me know if you run into any problems with this new release.

It transparently checks version numbers, downloads the .AIR installer file if needed and triggers the AIR-native update process.

It grabs the version number directly from the remote .AIR file without having to download the entire file, eliminating the potential error prone need of having to put a separate descriptor file online along with the .AIR installer file.

Background:

An .AIR installer file is a PKZIP archive containing metadata files along with the packaged application files. The files contained in a .AIR installer file are, in this order:

1. /mimetype
2. /META-INF/AIR/application.xml (contains version info)
3. /META-INF/AIR/hash
4. /META-INF/signatures.xml
5. packaged application files

The file we are interested in, /META-INF/AIR/application.xml (the “application descriptor file” that contains the version number), is always the second file in the archive. AIR Remote Updater uses FZip to stream in the remote .AIR until (and only until) the application descriptor file has loaded. We can then close the stream, uncompress that file and extract the version number.

More info and download here:
http://codeazur.com.br/lab/airremoteupdater/

• Added support for Adobe Air. The Adobe Air runtime provides a low level inflate method, making it possible to load any ZIP archive and decompress compressed files without the need of injecting Adler32 checksums.
• Added FZipLibrary class for higher level access to files in a ZIP archive. “FZipLibrary processes files (based on file extensions) from an FZip instance and converts them into usable formats. Files can be converted to either a BitmapData or DisplayObject classes. Data embedded in SWF files (like classes) can also be retrieved. Flash’s built-in Loader class is used to convert formats, so the only formats currently supported are ones that Loader supports. As of this writing they are SWF, JPEG, GIF, and PNG.”
• Bug fix: There was a problem with filenames containing special characters. Filename encoding now defaults to UTF-8. In case the filenames are encoded differently in your ZIP, you can specify the encoding in the FZip constructor.

Special thanks to Daniel Wabyick at Adobe for contributing the Adobe Air support!

Enjoy!

http://codeazur.com.br/lab/fzip/

Last.fm provides an application along with plugins for pretty much all existing media players on all major platforms (Windows, MacOS, Linux, etc) that does exactly that. During installation of the Last.fm client, the user is prompted to install the required plugins for the media players she uses. When a media player executes and plays a song, the plugin establishes a TCP socket connection with the client application and sends status and song infos.

The problem: The Apollo runtime (alpha) that is currently available on Adobe Labs doesn’t provide any documented way of (a) talking to shared libraries, (b) launching executables or (c) serving as a socket server, and Adobe indicated that Apollo likely is not going to support those features in it’s 1.0 release version.

There is hope though. Afaik, the last word on launching executables at runtime from an Apollo app isn’t spoken yet, and there exist some undocumented hacks that enable Apollo apps to do just that. If Adobe should decide against letting apps launch executables, then the only way of solving it is to provide second installers that install a socket server of some sort to do the dirty work.

However, i sat down last night and wrote a proof of concept Flash application that can live in Apollo, which talks to a custom daemon via sockets. The daemon in this proof of concept runs as a Windows Service. I took the Last.fm iTunes plugin and modified a bit so that it also connects to that daemon. The daemon then simply echoes the messages it receives from the Last.fm plugin to the socket listener in Flash. Voilà.

Here’s a screenshot of the app in action (iTunes on top, Flash below):

[Update] I also modified the Last.fm Windows Media Player plugin to work with my daemon. All plugins can be used simultaneously. See this screenshot (Windows Media Player on top, Flash below):

Note that this is only a proof of concept, and sources aren’t ready for release yet. I would very much like to make this an open source project (The Last.fm plugins are released under GPL), so if there are any interested developers out there who like to help, please contact me or leave a comment. Thanks!