Adding a Sound Effect

Star Rod Classic can rebuild Paper Mario’s editable sound-effect archive. A sound effect is not merely a compressed WAV file. It is a logical sound ID mapped to either an instrument with preset properties or a small script which can use multiple instruments and trigger other sound effects.

This guide fills an unused sound ID with a simple one-shot effect. See Adding a New Instrument first if the sound should use a new waveform.

Choose a Sound ID

Open $mod/audio/SoundEffects.xml and find an entry marked empty="true". For example, slot 0007 is empty in the original game:

<Sound id="0007" name="Empty_0007" empty="true"/>

Replace an existing empty entry rather than adding a new one. The engine’s sound ID space has fixed ranges and gaps; adding another entry to the table does not create another usable ID.

Add a One-Shot Effect

The following example plays an existing menu sample:

<Sound id="0007" name="TutorialBell" desc="Tutorial sound">
    <Routing allocation="dynamic" maxPlayer="7" priority="0"/>
    <OneShot wav="SYS2_04_CreateFileMoveCursor" volume="70" lockVolume="true" lockPitch="true"/>
</Sound>

Routing determines which of the engine’s eight SFX players may play the sound and how it competes with sounds already playing. The example uses:

Attribute	Meaning
allocation="dynamic"	Let the engine choose an SFX player when the sound begins.
maxPlayer="7"	Allow the engine to choose any player from 0 through 7.
priority="0"	Assign the lowest priority. Priorities range from 0 (lowest) through 3 (highest); a new sound may replace one with an equal or lower priority when they compete for a player.

Fixed routing uses allocation="fixed" and a player value when a sound must use a particular player. An exclusiveGroup from 1 through 3 may also be used for sounds which should replace one another. These choices affect how sounds interrupt one another; they do not change the sample or its volume, pan, or pitch.

name becomes the project sound enum name. wav selects an instrument by the stem used in its sound bank’s SoundBank.xml; the .wav extension is omitted. Volume is written in hexadecimal, so 70 means 0x70. lockVolume and lockPitch prevent playback calls from overriding the values defined by the effect.

This routing is suitable for an ordinary one-shot sound. Begin with a similar existing sound when the new effect needs different routing.

One-shot effects may also set pan, reverb, pitch, random pitch, or an envelope variant. Omitted values use the format defaults. Begin with the smallest definition and add only the controls the sound needs.

Preview the Source

Open Audio Booth and select the SFX tab. Choose 0007 TutorialBell to hear the effect. After editing the source, choose Selected → Reload or reopen Audio Booth.

Audio Booth reads the project XML and sound banks directly. A successful preview verifies the instrument reference and basic program, but the effect must still be built and tested in the game.

Build the Archive

Enable Inject Audio Files in the project build options and use Compile Mod. Star Rod builds SoundEffects.xml and any referenced files under audio/sfx/ into DAT1.sef, rebuilds the audio catalogs, and injects the selected audio files into the ROM.

DAT1.sef is not limited to its original 0x5200-byte allocation. Star Rod adjusts the allocation to the rebuilt file and increases the audio heap when necessary.

Use the Sound

The name in SoundEffects.xml replaces the corresponding entry in the project’s .Sound enum. A map script can now use:

Call PlaySound ( .Sound:TutorialBell )

Write a Sequenced Effect

Store the program in a separate file under $mod/audio/sfx/ when the effect needs several notes, tracks, loops, envelopes, or spawned sub-effects. SoundEffects.xml then names that file:

<Sound id="0007" name="TutorialBell" src="sfx/0007_TutorialBell.xml">
    <Routing allocation="dynamic" maxPlayer="7" priority="0"/>
</Sound>

Begin with an existing effect which behaves similarly and give it a new filename. A sequence can play several notes, change their timing and sound, and repeat sections.