ARS Format Specification
📄 Technical
The ARS (AURIS Resource Sound) format is the open audio bank format used by AURIS.
Overview
| Property | Value |
|---|---|
| Magic | ARSB (0x42535241) |
| Version | 4 |
| Extension | .ars |
| Endianness | Little-endian |
| Alignment | 16-byte data alignment |
Supported Codecs
| ID | Codec | Status |
|---|---|---|
| 0 | PCM16 | Built-in |
| 1 | PCM24 | Built-in |
| 2 | PCM32F | Built-in |
| 3 | IMA ADPCM | Built-in |
| 4 | Vorbis | Native encoder |
| 5 | Opus | Experimental |
| 6 | MP3 | Via FFmpeg |
| 7 | FLAC | Via FFmpeg |
| 8 | AAC | Via FFmpeg |
File Structure
[ARSB Header 64 bytes] Magic + version + offsets
[Sample Table 96xN bytes] Sample metadata entries
[Event Table variable] Event definitions
[Audio Data 16-aligned] Raw audio data section
[FMETA Data variable] Embedded FMOD metadata (v3+)
[Proxy Data variable] Embedded proxy DLL (v3+)
[Effects Data variable] DSP effect presets (v4+)
[Marker Data variable] Cue point markers (v4+)
FMOD Proxy
The AURIS proxy (fmodstudio.dll) intercepts FMOD's loadBankFile and loadBankMemory functions. When a game requests a .bank file, the proxy:
- Checks if the player has an active AURIS mod with a matching
.ars - Checks for a companion
.arsfile next to the.bank - Falls back to the original
.bankif no.arsfound
The proxy reconstructs a valid FMOD bank in memory from the .ars data, so the game sees no difference.
Compared to FMOD .bank
| Feature | FMOD .bank | AURIS .ars |
|---|---|---|
| Format | Proprietary | Open |
| Editable | No | Yes |
| Codec lock | Vorbis only | Any codec |
| Moddable | Replace entire file | Per-sample editing |
| Tools | FMOD Studio ($) | AURIS Launcher (free) |