Looking Ahead

As JOAL continues to grow it will continue to implement new features and extensions that are available for the OpenAL platform. The two major extension inclusions for the near future include Creative’s EAX processing and the open format Ogg Vorbis. This section takes a brief look at both of these and their potential impact on JOAL.

EAX: Created by Creative Labs, the Environmental Audio Extensions (EAX) began as a way to improve the audio-rendering models for both DirectSound3D and OpenAL. Whereas both APIs contain powerful rendering tools that have been discussed in this chapter, they are limited with regard to their ability to properly process reverberation or objects that might block a sound, causing its rendering to be changed. EAX was created to extend the capabilities of these APIs to further enrich the immersion of the player through audio.

These effects are introduced into OpenAL through the use of Listener- and Source-based property effects. Each class has its own set of possible parameters regarding the effects. EAX gives developers the freedom to work at a high level of abstraction by setting environmental effects that provide a general algorithm for how a sound will be processed. One example of an environmental effect is EAX_ENVIRONMENT_AUDITORIUM. This environment gives an immediate idea of how sounds should be rendered with regard to the Listener. EAX also provides much lower-level abilities to manipulate the audible environment. Many current games use EAX, including Call of Duty and Tron 2.0. Look for a fully functioning implementation of EAX on the JOAL platform in the near future.

Ogg Vorbis: In recent times, the need for high rates of audio compression introduced the MP3 format to the world. Although MP3 is a popular and high-quality format, a group of developers decided it wasn’t good enough. Thus, the Ogg Vorbis format was born. These newly compressed files, seen with the .ogg extension, offer a royalty-free, high-quality format for use with audio. The most likely use for games comes in the form of streaming background music.

A beta version of the Ogg Vorbis extension to OpenAL was recently released. The streaming capabilities of OpenAL are limited, but it is highly likely that this feature will be adopted through JOAL and made available to game developers. For those who can’t wait and need to make Ogg Vorbis work in games immediately, check out the Jorbis project that offers a Java-based Ogg Vorbis decoder and the libraries to use them.