Audio Processing Library for Flash (ALF)

Quick Links

ALF v1.0.2 is here!
View the ALF documentation.
Download Pulse 2 here.
Hide & Speak and Tone Bender available at the METgames site.

What is ALF?

In recent years, there has been sharp rise in the number of games on web-based platforms, which are ideal for rapid game development and easy deployment. In a parallel but unrelated trend, music-centric video games that incorporate well-known popular music directly into the gameplay Guitar Hero and Rock Band have attained widespread popularity on console platforms. The limitations of such web-based platforms as Adobe Flash, however, have made it difficult for developers to utilize complex sound and music interaction within web games. Furthermore, the real-time audio processing and synchronization required in music-centric games demands significant computational power and specialized audio algorithms, which have been difficult or impossible to implement using Flash scripting. Taking advantage of features recently added to the platform, including dynamic audio control and C-compilation for near-native performance, we have developed the Audio processing Library for Flash (ALF), providing developers with a library of common audio processing routines and affording web games with a degree of sound interaction previously available only on console or native PC platforms. We also present several audio-intensive games that incorporate ALF to demonstrate its utility. One example, Pulse 2, performs real-time analysis of songs in a user's music library to drive the gameplay, providing a novel form of game-music interaction.

Games and Apps using ALF

Pulse 2
Pulse 2 is a musically reactive, side scrolling action game that is totally driven by songs in the player's music library. This creates a unique, open-ended gaming experience limited only by the number of .mp3s in your music collection!

Download Pulse 2 here (Requires Adobe Air Components).

Check out Pulse 2 in Action (Click to Play)

Click to Play

Apps for Psychoacoustic Data Collection and Education

Can you find the spy? Hide & Speak* explores your ability to solve the Cocktail Party Problem , a well known phenomena that determines if you can identify a particular speaker in a room with many interfering audio sources. Hide & Speak simulates a real acoustic environment with multiple, conversing speakers and reverberation.

Talk is cheap. Like to know more about musical instruments? Tone Bender* does just that: allowing you to explore the timbre of musical instrument sounds, or "the way a sound sounds". Tone Bender allows you to dynamically modify the acoustics of musical instrument sounds. It also tests your ability to identify the true instrument another player has created.

*Requires Flash Player 10. Get it here.
**Requires Adobe Air Components. Get it here.

Sample Application

The sample Flash movie below demonstrates the functionality and features available in ALF v1.0.1. The Flash 10 plug-in is required for this demo.

Published Work on ALF:

  • R. V. Migneco, T. M. Doll, J. J. Scott, C. Hahn, P. Diefenbach and Y. E. Kim, "An Audio Processing Library for Game Development in Flash," in Proceedings of the ICE Games Innovation Conference, 2009. [PDF]

  • T. M. Doll, R. V. Migneco, J. J. Scott and Y. E. Kim, "An Audio DSP Toolkit for Rapid Application Development in Flash," in Proceedings of the IEEE Multimedia Signal Processing Conference, 2009. [PDF]

  • Y. E. Kim, T. M. Doll, and R. Migneco, "Collaborative online activities for acoustics education and psychoacoustic data collection," in IEEE Transactions on Learning Technologies, 2009. [PDF]

Presentations on ALF:

  • R. V. Migneco and J. J. Scott "An Audio Processing Library for Game Development in Flash," presentation given at: ICE Games Innovation Conference, 2009. [PDF]