XACT Features

Microsoft Cross-Platform Audio Creation Tool (XACT) is a production-ready environment for integrating audio resources into game titles. It is expected that audio designers will use one of the many linear audio editing packages that are available commercially to develop the core audio elements (waves) for the game. The designer will then use XACT to package those audio resources to aid the programmer in making them an interactive part of gameplay.

This topic describes the benefits of XACT as pertains to each partner in the development process for title audio:

For Audio Designers
For Title Programmers

For Audio Designers

The XACT authoring tool allows the designer to group waves into cues and sequences, which include settings for volume and pitch levels.

These are the key features of the XACT authoring tool:

Audio File Formats
Speaker Channels
Organizing
Auditioning

Audio File Formats

XACT supports a variety of audio file formats, including:

WAV - the standard audio file format for Microsoft® Windows® environments.
AIFF - the standard audio file format for Apple® Macintosh® environments.
XMA - A file format based on Microsoft WMA.

The XACT authoring tool supports both 16-bit and 8-bit PCM data.

XACT will also recognize and properly act on loop points embedded within WAV and AIFF files. This means that loop markers created with commercially available linear audio design tools will be honored by XACT.

Speaker Channels

XACT supports stereo and 5.1 channel speaker arrangements. Currently no other speaker arrangements are supported.

Organizing

XACT provides the audio designer with a variety of ways to bundle audio elements into collections and group them into sequences for events in the game.

Wave banks allow the designer to package collections of multiple audio files into single files. These files are identified by the .XWB extension.

This feature simplifies management of audio data for the programmer. Rather than trying to manage many audio files, titles can now load a more manageable set of wave banks that bundle the waves necessary for a section of the game.
Sound banks allow the designer to package collections of cues, waves and settings for ready playback by a game title. A sound bank file is identified by its .XSB extension.

Auditioning

XACT provides the designer with the ability to preview audio content on the game platform. An audio console application that executes on the game platform is provided with Microsoft development kits that accepts information from the Windows-based XACT running on the development system, and allows controlled playback of audio sequences.

Designers can also perform "in-game" auditioning with XACT. When a game title is built with special development-only libraries, a designer can adjust the audio settings while the game application is running. This allows the designer to test and discover what works best under conditions of actual gameplay.

For Title Programmers

The XACT API functions allow the programmer to integrate the designer's work into the game title flexibly and efficiently.

The XACT run-time libraries:

Ease the integration of wave, sound and cue information from the audio designer.
Support in-memory and streaming wave banks with minimal programmer intervention.
Free the game title developer to focus on gameplay rather than feeding audio hardware.
Allow audio resources to be invoked by cue name rather than by specific components.
Provide notification of audio events to the game title.
Provide a powerful feature called zero-latency streaming that solves the problem of fitting waves within allocated memory. This feature is discussed in more detail in XACT Streaming Wave Banks.