| 1 | import { Frequency } from "../core/type/Units.js";
|
| 2 | import { Effect, EffectOptions } from "../effect/Effect.js";
|
| 3 | import { Signal } from "../signal/Signal.js";
|
| 4 | interface FrequencyShifterOptions extends EffectOptions {
|
| 5 | frequency: Frequency;
|
| 6 | }
|
| 7 | /**
|
| 8 | * FrequencyShifter can be used to shift all frequencies of a signal by a fixed amount.
|
| 9 | * The amount can be changed at audio rate and the effect is applied in real time.
|
| 10 | * The frequency shifting is implemented with a technique called single side band modulation using a ring modulator.
|
| 11 | * Note: Contrary to pitch shifting, all frequencies are shifted by the same amount,
|
| 12 | * destroying the harmonic relationship between them. This leads to the classic ring modulator timbre distortion.
|
| 13 | * The algorithm will produces some aliasing towards the high end, especially if your source material
|
| 14 | * contains a lot of high frequencies. Unfortunatelly the webaudio API does not support resampling
|
| 15 | * buffers in real time, so it is not possible to fix it properly. Depending on the use case it might
|
| 16 | * be an option to low pass filter your input before frequency shifting it to get ride of the aliasing.
|
| 17 | * You can find a very detailed description of the algorithm here: https://larzeitlin.github.io/RMFS/
|
| 18 | *
|
| 19 | * @example
|
| 20 | * const input = new Tone.Oscillator(230, "sawtooth").start();
|
| 21 | * const shift = new Tone.FrequencyShifter(42).toDestination();
|
| 22 | * input.connect(shift);
|
| 23 | * @category Effect
|
| 24 | */
|
| 25 | export declare class FrequencyShifter extends Effect<FrequencyShifterOptions> {
|
| 26 | readonly name: string;
|
| 27 | /**
|
| 28 | * The ring modulators carrier frequency. This frequency determines
|
| 29 | * by how many Hertz the input signal will be shifted up or down. Default is 0.
|
| 30 | */
|
| 31 | readonly frequency: Signal<"frequency">;
|
| 32 | /**
|
| 33 | * The ring modulators sine carrier
|
| 34 | */
|
| 35 | private _sine;
|
| 36 | /**
|
| 37 | * The ring modulators cosine carrier
|
| 38 | */
|
| 39 | private _cosine;
|
| 40 | /**
|
| 41 | * The sine multiply operator
|
| 42 | */
|
| 43 | private _sineMultiply;
|
| 44 | /**
|
| 45 | * The cosine multiply operator
|
| 46 | */
|
| 47 | private _cosineMultiply;
|
| 48 | /**
|
| 49 | * The negate operator
|
| 50 | */
|
| 51 | private _negate;
|
| 52 | /**
|
| 53 | * The final add operator
|
| 54 | */
|
| 55 | private _add;
|
| 56 | /**
|
| 57 | * The phase shifter to create the initial 90° phase offset
|
| 58 | */
|
| 59 | private _phaseShifter;
|
| 60 | /**
|
| 61 | * @param frequency The incoming signal is shifted by this frequency value.
|
| 62 | */
|
| 63 | constructor(frequency?: Frequency);
|
| 64 | constructor(options?: Partial<FrequencyShifterOptions>);
|
| 65 | static getDefaults(): FrequencyShifterOptions;
|
| 66 | dispose(): this;
|
| 67 | }
|
| 68 | export {};
|