SFX Format

Overview

A custom binary format is used for storing every single sound effect used in the game. The format is identical across all versions of the game, with each sound consisting of raw PSX ADPCM audio data and an associated pitch value that determines playback frequency.

All values are in little endian, and the following data types will be used:

Encoding	Description
u32	Unsigned 32-bit integer

Structure

The format is comprised of the following structure:

Sound count
Offset and pitch value for each sound
Sound data

The first 4 bytes in the file (note there is no magic header) specify how many compressed files are inside the archive:

Offset(h)	Size	Type	Description
0x00	4	u32	Number of sound entries

Sound Table

Starting at offset 0x04, each sound entry is 8 bytes:

Offset(h)	Size	Type	Description
+0x00	4	u32	Absolute offset to audio data for the sound
+0x04	4	u32	Pitch value

Audio Data

Raw PSX ADPCM compressed audio data begins at the specified offsets. Each sound's data continues until the next sound's offset (or end of file for the last sound). Every sound uses 1 channel (Mono).

Pitch Value

The 4-byte pitch value encodes musical note information used by the PlayStation SPU (Sound Processing Unit) to determine playback frequency.

pitch_value = (note << 8) | fine_tune

Upper 24 bits: Base musical note offset
Lower 8 bits: Fine pitch adjustment (0-255)