Sound bank

A sound bank groups together references to all the assets your game needs at runtime — sounds, collections, switch containers, events, effects, attenuations, switches, and RTPCs. By loading a sound bank, the engine registers all its referenced assets and makes them available for playback.

A sound bank file contains the following properties:

id¶

uint64 required

A unique identifier for the sound bank. This value is used to reference the sound bank at runtime when loading or unloading it. This value should be different from 0.

name¶

string required

A unique name for the sound bank. This can also be used at runtime to reference the sound bank.

sounds¶

string[] optional

An array of Sound asset file names to include in this sound bank. Each entry is the compiled binary file name (.amsound extension).

collections¶

string[] optional

An array of Collection asset file names to include in this sound bank.

switch_containers¶

string[] optional

An array of Switch Container asset file names to include in this sound bank.

events¶

string[] optional

An array of Event asset file names to include in this sound bank.

attenuators¶

string[] optional

An array of Attenuation asset file names to include in this sound bank.

switches¶

string[] optional

An array of Switch asset file names to include in this sound bank.

rtpc¶

string[] optional

An array of RTPC asset file names to include in this sound bank.

effects¶

string[] optional

An array of Effect asset file names to include in this sound bank.

Reference Counting¶

Assets are reference-counted across sound banks. If the same asset is referenced by multiple loaded sound banks, it is only loaded into memory once. Its reference count decrements each time a sound bank referencing it is unloaded, and the asset's memory is released when the last sound bank referencing it is unloaded.

This means you can organize your sound banks however best fits your game — by level, by category, or by feature — without worrying about duplicating memory for shared assets.

Example¶

A sound bank that loads background music, footstep sounds with surface-type switching, and a set of effects:

{
  "id": 1,
  "name": "init",
  "switch_containers": [
    "footsteps.amswitchcontainer"
  ],
  "collections": [
    "grass_footsteps.amcollection",
    "metal_footsteps.amcollection",
    "snow_footsteps.amcollection"
  ],
  "sounds": [
    "background/AMBForst_Forest.wav.amsound"
  ],
  "events": [
    "play_throw.amevent",
    "stop_throw.amevent"
  ],
  "attenuators": [
    "impact.amattenuation",
    "room.amattenuation"
  ],
  "switches": [
    "surface_type.amswitch"
  ],
  "rtpc": [
    "wind_force.amrtpc"
  ],
  "effects": [
    "delay.amfx",
    "equalizer.amfx"
  ]
}

Loading at Runtime¶

Once your sound bank is compiled, load it at runtime using the engine API:

// Load the sound bank (synchronous — returns true on success)
AmBankID bankId = kAmInvalidObjectId;
if (!amEngine->LoadSoundBank(AM_OS_STRING("init.ambank"), bankId))
{
    amLogError("Failed to load sound bank");
}

// Start loading the actual audio data (asynchronous)
amEngine->StartLoadSoundFiles();
while (!amEngine->TryFinalizeLoadSoundFiles())
    Thread::Sleep(1);

// Unload when no longer needed
amEngine->UnloadSoundBank(bankId);
// Or by filename:
amEngine->UnloadSoundBank(AM_OS_STRING("init.ambank"));

See Loading Sound Banks for the full loading workflow.