Audio
Banished has music, ambient sounds (forest, river, wind, rain), sound effects in the world (animals, work, fire, tornadoes) and interface sounds. Un-Banished plays all of them from the original files, on the desktop and in the browser. This page explains the parts. The code is in banished-audio and banished-wma.
Sound files
A sound is a SoundBuffer resource. It holds a format header, a loop flag, the length, and the data in xWMA: Windows Media Audio version 2, in a container that Microsoft's XAudio2 uses. The 16 music tracks are streamed: their data is in a separate raw entry (.str) in the package.
Browsers cannot play xWMA, and no Rust library decoded WMA v2. So Un-Banished has its own decoder, banished-wma: pure Rust, no dependencies, no unsafe, and it builds for WebAssembly. A test decodes every sound of the game and compares it with FFmpeg's decoder; the signal-to-noise ratio must be at least 60 dB.
The device
The original plays sound on an Audio::Device with 64 channels. Play takes the first free channel, and returns nothing when all 64 are busy, so the 65th sound at the same time is not heard. The port keeps the same rule. On the desktop, each channel is a rodio sink; in the browser, each channel is a Web Audio source node with its own volume. The samples of a sound are decoded once and shared by all channels that play it.
Pitch is given in semitones: a pitch of p plays at 1.05946314^p times the normal speed, as in the original.
Sound effects and the scene
The game rarely plays a sound directly. It plays a sound effect (SoundEffect resource): a timeline of sounds, each with several variants, a pitch range and a volume. When an effect starts, the scene chooses a variant and a pitch with random numbers, and starts each sound at its time.
The Audio::Scene has 256 slots for playing effects, and 4,096 slots for effects in the world. An effect in the world has a position. Its volume is 1 inside its inner radius and falls in a straight line to 0 at its outer radius, measured from the camera. Emitters are ambient sounds tied to places: a river, a forest, a field, a burning house. An effect with several emitters plays at the volume of the loudest one.
Every sound has a type, and each type has its volume in Options → Audio:
| Type | Sound | Default volume |
|---|---|---|
| 1 | Interface | 100 |
| 2 | Music | 50 |
| 3 | Ambient | 100 |
| 4 | Effects | 100 |
In the browser
Browsers start sound only after the player clicks or types on the page. So the browser version starts its Web Audio context on the first click. Until then, no sound plays.
Read more
- AUDIO.md: the device, the scene and the effects in detail.
- STARTING-AUDIO-EMITTERS.md: the emitters of a new town.
- The viewer: listen to every sound of the game.
- banished-cli: export every sound to MP3.