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AudioFilters

Utility class for managing FFmpeg audio filter definitions. Provides built-in filters and methods to create, validate, and manage custom audio filters.

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Static Properties

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filters
Record<FiltersName, string>
Collection of all available FFmpeg filter definitions. Built-in filters include:Bass Filters:
  • bassboost_low - Low bass boost (15dB)
  • bassboost - Medium bass boost (20dB)
  • bassboost_high - High bass boost (30dB)
  • subboost - Subwoofer boost
Effect Filters:
  • 8D - 8D audio effect (pulsator)
  • vaporwave - Vaporwave effect (slowed audio)
  • nightcore - Nightcore effect (sped up audio)
  • lofi - Lo-fi effect (slowed with extra stereo)
  • phaser - Phaser effect
  • tremolo - Tremolo effect
  • vibrato - Vibrato effect
  • reverse - Reverse audio
  • flanger - Flanger effect
  • haas - Haas effect
Frequency Filters:
  • treble - Treble boost
  • normalizer - Audio normalization (compressor)
  • normalizer2 - Dynamic audio normalization
Spatial Filters:
  • surrounding - Surround sound
  • pulsator - Pulsator effect
  • karaoke - Karaoke effect (reduce vocals)
  • mono - Convert to mono
  • mstlr - Mid-side to left-right
  • mstrr - Mid-side to right-right
Dynamic Range Filters:
  • gate - Audio gate
  • mcompand - Multi-band compressor
  • compressor - Dynamic range compressor
  • expander - Dynamic range expander
  • softlimiter - Soft limiter
Chorus Filters:
  • chorus - Chorus effect
  • chorus2d - 2D chorus effect
  • chorus3d - 3D chorus effect
Other Filters:
  • fadein - Fade in effect
  • dim - Dim/muffle effect
  • earrape - Earrape effect (extreme distortion)
  • silenceremove - Remove silence
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names
FiltersName[]
Array of all filter names
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length
number
Number of available filters

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Static Methods

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get

Retrieve the FFmpeg filter string for a specific filter. 
static get<K extends FiltersName>(name: K): string
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name
FiltersName
required
The name of the filter to retrieve
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return
string
The FFmpeg filter string, or the input name if not found
Example: 
const nightcoreFilter = AudioFilters.get('nightcore');
console.log(nightcoreFilter); // 'aresample=48000,asetrate=48000*1.25'

const bassFilter = AudioFilters.get('bassboost');
console.log(bassFilter); // 'bass=g=20:f=110:w=0.3'

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has

Check if a filter name exists. 
static has<K extends FiltersName>(name: K): boolean
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name
FiltersName
required
The filter name to check
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return
boolean
true if the filter exists, false otherwise
Example: 
if (AudioFilters.has('nightcore')) {
  console.log('Nightcore filter is available');
}

if (!AudioFilters.has('customFilter')) {
  console.log('Custom filter does not exist');
}

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create

Create FFmpeg filter arguments from filter names. 
static create<K extends FiltersName>(filters?: (K | string)[]): string
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filters
(FiltersName | string)[]
Array of filter names to combine. If not provided, returns all filters
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return
string
Comma-separated FFmpeg filter string ready to use with -af flag
Example: 
// Create filter string from multiple filters
const filterString = AudioFilters.create(['bassboost', 'nightcore', '8D']);
console.log(filterString);
// Output: 'bass=g=20:f=110:w=0.3,aresample=48000,asetrate=48000*1.25,apulsator=hz=0.09'

// Create all filters
const allFilters = AudioFilters.create();

// Empty array returns all filters
const allFilters2 = AudioFilters.create([]);

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define

Define a new custom audio filter. 
static define(filterName: string, value: string): void
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filterName
string
required
The name for the new filter
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value
string
required
The FFmpeg filter string
Example: 
// Define a custom speed filter
AudioFilters.define('doublespeed', 'asetrate=48000*2,aresample=48000');

// Define a custom pitch filter
AudioFilters.define('highpitch', 'asetrate=48000*1.5,aresample=48000,atempo=0.67');

// Now you can use it
const customFilter = AudioFilters.get('doublespeed');

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defineBulk

Define multiple custom filters at once. 
static defineBulk(filtersArray: { name: string; value: string }[]): void
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filtersArray
{ name: string; value: string }[]
required
Array of filter definitions with name and value properties
Example: 
AudioFilters.defineBulk([
  {
    name: 'slowmotion',
    value: 'asetrate=48000*0.5,aresample=48000'
  },
  {
    name: 'chipmunk',
    value: 'asetrate=48000*1.75,aresample=48000'
  },
  {
    name: 'deep',
    value: 'asetrate=48000*0.75,aresample=48000'
  }
]);

// Use the custom filters
const filters = AudioFilters.create(['slowmotion', 'deep']);

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toString

Convert all filters to a single FFmpeg filter string. 
static toString(): string
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return
string
Comma-separated string of all filter values
Example: 
const allFiltersString = AudioFilters.toString();
console.log(allFiltersString);
// Output: 'bass=g=15:f=110:w=0.3,bass=g=20:f=110:w=0.3,...'

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[Symbol.iterator]

Makes AudioFilters iterable over all filter definitions. 
static *[Symbol.iterator](): IterableIterator<{
  name: FiltersName;
  value: string;
}>
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return
IterableIterator<{ name: FiltersName; value: string }>
Iterator yielding objects with name and value properties
Example: 
// Iterate over all filters
for (const { name, value } of AudioFilters) {
  console.log(`${name}: ${value}`);
}

// Convert to array
const allFilters = [...AudioFilters];
console.log(allFilters);
// Output: [
//   { name: 'bassboost_low', value: 'bass=g=15:f=110:w=0.3' },
//   { name: 'bassboost', value: 'bass=g=20:f=110:w=0.3' },
//   ...
// ]

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Types

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FiltersName

Type representing all valid filter names. 
type FiltersName = keyof QueueFilters;

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QueueFilters

Interface defining all available FFmpeg filters. 
interface QueueFilters {
  bassboost_low?: boolean;
  bassboost?: boolean;
  bassboost_high?: boolean;
  '8D'?: boolean;
  vaporwave?: boolean;
  nightcore?: boolean;
  phaser?: boolean;
  tremolo?: boolean;
  vibrato?: boolean;
  reverse?: boolean;
  treble?: boolean;
  normalizer?: boolean;
  normalizer2?: boolean;
  surrounding?: boolean;
  pulsator?: boolean;
  subboost?: boolean;
  karaoke?: boolean;
  flanger?: boolean;
  gate?: boolean;
  haas?: boolean;
  mcompand?: boolean;
  mono?: boolean;
  mstlr?: boolean;
  mstrr?: boolean;
  compressor?: boolean;
  expander?: boolean;
  softlimiter?: boolean;
  chorus?: boolean;
  chorus2d?: boolean;
  chorus3d?: boolean;
  fadein?: boolean;
  dim?: boolean;
  earrape?: boolean;
  lofi?: boolean;
  silenceremove?: boolean;
}

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Usage Example

import { AudioFilters } from 'discord-player';

// Get a specific filter
const nightcore = AudioFilters.get('nightcore');

// Check if filter exists
if (AudioFilters.has('vaporwave')) {
  console.log('Vaporwave filter available');
}

// Create combined filter string
const combined = AudioFilters.create(['bassboost', 'nightcore', '8D']);

// Define custom filters
AudioFilters.define('myfilter', 'volume=2.0');

// Define multiple custom filters
AudioFilters.defineBulk([
  { name: 'underwater', value: 'aecho=0.8:0.88:60:0.4' },
  { name: 'telephone', value: 'highpass=f=300,lowpass=f=3000' }
]);

// List all available filters
console.log('Available filters:', AudioFilters.names);
console.log('Total filters:', AudioFilters.length);

// Iterate over all filters
for (const { name, value } of AudioFilters) {
  console.log(`${name}: ${value}`);
}

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