fb.dsp DSP Chain

fb.dsp inspects and modifies the active digital signal processing chain and applies saved DSP presets.

getChain()

Signature: fb.dsp.getChain(): Promise<DspGetChainResponse>

Returns the active DSP entries (DspChainEntry: index, guid, name) in execution order. A successful result always includes activePreset (null when no preset is selected) and activePresetIndex (-1 when none). An edit through addDsp(), removeDsp(), moveDsp(), or setChain() leaves the chain matching no preset, so both read as unselected afterwards.

const res = await fb.dsp.getChain();
if (res.success === false) throw new Error(res.error);
const { dsps, activePreset } = res;

setChain(dsps)

Signature: fb.dsp.setChain(dsps: ReadonlyArray<Pick<DspChainSpec, 'guid'>>): Promise<DspSetChainResponse>

Parameter	Type	Required	Description
dsps	{ guid: string }[]	Yes	The new chain in processing order. An empty array clears the chain

Replaces the active chain with the supplied entries; each entry carries only a guid. The SDK drops every other field before sending, so the rows getChain() and getAvailable() report can be passed as they are. The response reports the new count. The whole call is refused, and the chain left untouched, on the first entry that does not resolve to an installed DSP.

Every entry is rebuilt from its DSP's default settings. To reorder the chain without losing settings, use moveDsp().

const available = await fb.dsp.getAvailable();
if (available.success === false) throw new Error(available.error);
const eq = available.dsps.find((d) => d.name === 'Equalizer');
if (eq) await fb.dsp.setChain([{ guid: eq.guid }]);

getPresets()

Signature: fb.dsp.getPresets(): Promise<DspGetPresetsResponse>

Returns presets (DspPresetEntry: index, name, active), count, and selectedIndex (-1 when no preset is selected). A preset's name is also its file name under dsp-presets in the foobar2000 profile.

const res = await fb.dsp.getPresets();
if (res.success === false) throw new Error(res.error);
const names = res.presets.map((p) => p.name);

applyPreset(indexOrName)

Signature: fb.dsp.applyPreset(indexOrName: number | string): Promise<DspApplyPresetResponse>

Parameter	Type	Required	Description
indexOrName	number | string	Yes	Preset index or name from getPresets(). A number is sent as index, a string as name

Applies a saved preset by numeric index or display name. The preset replaces the whole active chain; the preset file is not written. The response echoes appliedPreset and appliedIndex.

await fb.dsp.applyPreset('Headphones');
await fb.dsp.applyPreset(0); // by index

getAvailable()

Signature: fb.dsp.getAvailable(): Promise<DspGetAvailableResponse>

Returns discoverable DSP entries in dsps, in service enumeration order, and their count. Each entry (DspAvailableEntry) has guid, name, and hasConfig fields; hasConfig is true when the DSP has a configuration dialog. The guid is what addDsp() and setChain() take.

const res = await fb.dsp.getAvailable();
if (res.success === false) throw new Error(res.error);
const configurable = res.dsps.filter((d) => d.hasConfig);

addDsp(guid, position?)

Signature: fb.dsp.addDsp(guid: string, position?: number): Promise<DspAddDspResponse>

Parameter	Type	Required	Description
guid	string	Yes	GUID of an installed DSP, as getAvailable() reports it
position	number	No	Chain index to insert at. Omitted, negative, or at or past the end of the chain, the DSP is appended

Adds the DSP identified by guid with its default settings, optionally at a specific chain position (-1 or omitted appends). The response carries addedDsp and the position it landed at.

await fb.dsp.addDsp('{00000000-0000-0000-0000-000000000000}', 0);

removeDsp(index)

Signature: fb.dsp.removeDsp(index: number): Promise<DspRemoveDspResponse>

Parameter	Type	Required	Description
index	number	Yes	Index of the entry in the active chain, as getChain() reports it

Removes the DSP at the supplied active-chain index. The response carries removedDsp and removedIndex.

const res = await fb.dsp.removeDsp(2);
if (res.success === false) throw new Error(res.error);
console.log(`Removed ${res.removedDsp}`);

moveDsp(from, to)

Signature: fb.dsp.moveDsp(from: number, to: number): Promise<DspMoveDspResponse>

Parameter	Type	Required	Description
from	number	Yes	Current index of the entry
to	number	Yes	Index of the entry in the reordered chain

Moves an active DSP from one chain index to another and keeps its settings, so prefer it over setChain() for reordering. The response echoes from and to, where to is the final landing index, and names the moved DSP in movedDsp. When from === to nothing moves: movedDsp is absent and message is present.

await fb.dsp.moveDsp(2, 0);