murmuraba/dist/utils/gain-control.js

Real-time audio noise reduction with advanced chunked processing for web applications

/**
 * Centralized Gain Control Utilities
 * Eliminates code duplication and provides consistent gain management
 */
export const DEFAULT_GAIN_CONFIG = {
    min: 0.5,
    max: 3.0,
    default: 1.0,
    step: 0.1
};
export const GAIN_PRESETS = {
    LOW: 0.7,
    NORMAL: 1.0,
    HIGH: 1.5,
    BOOST: 2.0
};
/**
 * Validates and clamps gain value within acceptable range
 */
export function validateGain(gain, config = DEFAULT_GAIN_CONFIG) {
    if (typeof gain !== 'number' || isNaN(gain)) {
        return config.default;
    }
    return Math.max(config.min, Math.min(config.max, gain));
}
/**
 * Converts gain value to decibels for UI display
 */
export function gainToDb(gain) {
    return 20 * Math.log10(Math.max(0.001, gain));
}
/**
 * Converts decibels to gain value
 */
export function dbToGain(db) {
    return Math.pow(10, db / 20);
}
/**
 * Gets gain preset by name
 */
export function getGainPreset(preset) {
    return GAIN_PRESETS[preset];
}
/**
 * Gets descriptive text for gain level
 */
export function getGainDescription(gain) {
    if (gain < 1.0)
        return '⬇️ Reduced input level';
    if (gain === 1.0)
        return '✅ Normal input level';
    if (gain <= 1.5)
        return '⬆️ Increased input level';
    if (gain <= 2.0)
        return '📈 High input level';
    return '⚠️ Maximum boost - watch for clipping';
}
/**
 * Advanced Gain Controller Class
 * Encapsulates gain control logic with validation and events
 */
export class GainController {
    constructor(initialGain = DEFAULT_GAIN_CONFIG.default, config = DEFAULT_GAIN_CONFIG) {
        this.listeners = new Set();
        this.config = config;
        this._currentGain = validateGain(initialGain, config);
    }
    get currentGain() {
        return this._currentGain;
    }
    setGain(gain) {
        const validatedGain = validateGain(gain, this.config);
        if (validatedGain !== this._currentGain) {
            this._currentGain = validatedGain;
            this.notifyListeners();
            return true;
        }
        return false;
    }
    incrementGain() {
        const newGain = this._currentGain + this.config.step;
        this.setGain(newGain);
        return this._currentGain;
    }
    decrementGain() {
        const newGain = this._currentGain - this.config.step;
        this.setGain(newGain);
        return this._currentGain;
    }
    applyPreset(preset) {
        this.setGain(getGainPreset(preset));
    }
    getDescription() {
        return getGainDescription(this._currentGain);
    }
    getDbValue() {
        return gainToDb(this._currentGain);
    }
    onGainChange(callback) {
        this.listeners.add(callback);
        return () => this.listeners.delete(callback);
    }
    notifyListeners() {
        this.listeners.forEach(callback => callback(this._currentGain));
    }
    destroy() {
        this.listeners.clear();
    }
}