Audio

NOTE: This document will be deprecated in the near future. Some items may be outdated/incorrect

Audio is handled by MusicController (source/controllers/MusicController.h), a wrapper around Maxmod for SFX and a custom PCM streaming system for background music.

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Music

Format

Maxmod supports MOD, S3M, XM, and IT, but the team is only using PCM formats at the moment.

All music is stored as raw PCM in data/music/. Source files are .mp3 in assets/music/ and are converted automatically by the Makefile via FFmpeg:

ffmpeg -i input.mp3 -f s16le -ar 32000 -ac 2 output.pcm

• Sample rate: 32,000 Hz
• Channels: Stereo (2)
• Bit depth: 16-bit signed

Playing Music

musicCtrl.init(filePath, loopStartSeconds, loopEndSeconds);

Parameter	Description
filePath	Path to .pcm in FAT, e.g. "fatBasePath + "music/tightrope.pcm"
loopStartSeconds	Time in seconds to loop back to when the loop end is reached
loopEndSeconds	Time in seconds to trigger the loop. Use -1.0f to play through without looping

musicCtrl.update() must be called every frame (including inside fade loops) to keep the audio stream alive.

Adding New Music

1. Drop the .mp3 into assets/music/
2. Run make, it converts automatically to data/music/<name>.pcm
3. Reference it in code as "fatBasePath + "music/<name>.pcm"

To find loop points, open the file in Audacity and locate the loop region visually. For extended/full-play tracks, use 0.0f as loop start and the full duration as loop end (get duration via ffprobe -v quiet -show_entries format=duration -of csv=p=0 input.mp3).

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SFX

SFX uses Maxmod directly. Effects are defined in assets/sfx/ and compiled into soundbank.bin.

musicCtrl.loadSFX(SFX_SELECT);                        // load effect
mm_sfxhand h = musicCtrl.playSFX(SFX_SELECT, 255, 128); // play (volume, panning)
musicCtrl.stopSFX(h);                                 // stop

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Intro Screen (IntroView)

Tightrope plays on the title/intro screen with

Track	File	Chance	Loop Start	Loop End
Tightrope	tightrope.pcm	50%	17.962s	66.082s

Intro Video (IntroVideoView)

By default, the reload intro video plays, but you can change the intro via MainMenuView Settings

Video	File
Persona 3 Base intro	base.vid
Persona 3 FES intro	fes.vid
Persona 3 Portable intro	portable.vid
Persona 3 Reload intro	reload.vid

Video audio is embedded in the .vid file and handled separately via musicCtrl.initVideoAudio().

Iwatodai Dorm (IwatodaiDormView)

Plays the standard dorm theme.

Track	File	Loop Start	Loop End
Iwatodai Dorm	iwatodai_dorm.pcm	0.0s	920.973s (full play)

Random Music Selection

The random seed is set once at boot in main.cpp using the DS hardware timer:

TIMER0_CR = TIMER_ENABLE | TIMER_DIV_1;
srand(TIMER0_DATA);

This gives a different seed each run since TIMER0_DATA counts CPU cycles from power-on.

Adding a Random Selection

// equal chance between N tracks
const std::string tracks[] = {
        fatBasePath + "music/a.pcm",
        fatBasePath + "music/b.pcm"
};
musicCtrl.init(tracks[rand() % 2].c_str(), loopStart, loopEnd);

// weighted (e.g. 1/3 chance of easter egg)
if (rand() % 3 == 0) {
    musicCtrl.init((fatBasePath + "music/easter_egg.pcm").c_str(), 0.0f, duration);
} else {
    musicCtrl.init((fatBasePath + "music/normal.pcm").c_str(), 0.0f, duration);
}

// per-track loop points
const std::string tracks[] = {
        fatBasePath + "music/a.pcm",
        fatBasePath + "music/a.pcm"
};
const float loopStarts[] = {17.962f, 0.0f};
const float loopEnds[]   = {66.082f, 295.706f};
int pick = rand() % 2;
musicCtrl.init(tracks[pick].c_str(), loopStarts[pick], loopEnds[pick]);