XACT

XACT is the Microsoft cross-platform audio creation tool (Xbox and PC). It allows the creation of wave and sound banks via the XACT Authoring Tool and includes a set of API functions to integrate the audio into the game.

XACT Pages

The XACT area of this site is split into the following pages

• XACT Introduction - this page
• XACT Content Driven - playing sounds back that have been created with the content creation tool
• XACT Code Driven - shows how to play sounds without involving the content creation side of XACT

XACT Introduction

XACT Features

• Support for the following formats: WAV, AIFF, XMA (Xbox 360 only), ADCPM
• Note: also supports embedded loop points in WAV and AIFF formats
• 16 and 8 bit PCM data
• Supports Stereo and 5.1 speaker arrangements
• Organisation of sounds
• Multiple audio files can be grouped together into Wave Banks (XWB extension)
• Cues and settings can be bundled with the Waves in Sound Banks (XSB extension)
• Auditioning
• Audio console window can be used to preview audio
• Audio settings can be adjusted in-game (with debug mode libraries)

XACT API Programming Features

• The API allows the integration of the wave, sound and cue information from the creation phase
• In memory and streaming support
• Audio event notification

From the December update of DirectX XACT now includes a code-driven API allowing lower level loading and playback of sounds without having to use all the XACT sound organisation features.

XACT Terminology and File Types

• Content Creation Tool Projects (.xap)
• Sound Banks (.xsb) - a collection of sounds and cues.
• Sounds - a sound has one or more waves together with properties like volume and pitch. Sounds are made up of tracks.
• Tracks - tracks are made up events E.g. the simplest track has a Play Wave event
• Events - various actions that take place within a track. Actions include: Play, Stop, Set Volume, Set Pitch etc.
• Cues - a cue is used in code to trigger sounds. Each cue is made up of one or more sounds
• Wave Banks (.xwb ) - a file format containing a collection of waves
• Waves - the raw wave data in wav, aiff or xma format
• Global Settings (.xgs) - defines rules and settings for sounds.
• Categories - sounds can be assigned to a category (only one each) that specifies certain rules like number of instances along with settings like volume. You could create a category for the sounds of one character in your game so they all have the same volume. There are three predefined categories: global, default and Music.
• Variables - these can be defined in the design stage and then referenced by the programmer in code to control Run-Time Parameter Controls
• Run-Time Parameter Controls - also known as 'sliders'. These allow the control of sound parameters as the sound plays. For example they could be used to control the pitch of a car engine sound so as the accelerator is pressed the pitch is changed
• DSP Effect Path Presets (DSPs) - allow effects like reverb to be applied to sounds
• Compression Presets - compression can be applied to waves or wave banks