murmuraba/dist/services/gain-service.js

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

/**
 * Optimized Gain Management Service
 * Reduces re-renders and provides centralized gain control
 */
import { GainController, validateGain } from '../utils/gain-control';
export class GainService {
    constructor(options = {}) {
        this.updateListeners = new Set();
        this.gainController = new GainController(options.initialGain);
        this.throttleMs = options.throttleMs ?? 16; // ~60fps
        this.enableSmoothing = options.enableSmoothing ?? true;
        this.smoothingTimeConstant = options.smoothingTimeConstant ?? 0.01; // 10ms
    }
    /**
     * Initialize the service with an audio context
     */
    initialize(audioContext) {
        this.audioContext = audioContext;
        this.createGainNode();
    }
    /**
     * Get the gain node for audio graph connection
     */
    getGainNode() {
        return this.gainNode;
    }
    /**
     * Set gain with throttling to prevent excessive updates
     */
    setGain(gain) {
        const validatedGain = validateGain(gain);
        // Update controller immediately for sync state
        this.gainController.setGain(validatedGain);
        // Throttle actual audio node updates
        this.pendingGain = validatedGain;
        if (this.throttleTimer) {
            return; // Update already scheduled
        }
        this.throttleTimer = setTimeout(() => {
            this.applyPendingGain();
            this.throttleTimer = undefined;
        }, this.throttleMs);
    }
    /**
     * Get current gain value
     */
    getCurrentGain() {
        return this.gainController.currentGain;
    }
    /**
     * Apply gain preset
     */
    applyPreset(preset) {
        this.gainController.applyPreset(preset);
        this.applyPendingGain();
    }
    /**
     * Get gain description for UI
     */
    getDescription() {
        return this.gainController.getDescription();
    }
    /**
     * Get gain in decibels for display
     */
    getDbValue() {
        return this.gainController.getDbValue();
    }
    /**
     * Subscribe to gain changes
     */
    onGainChange(callback) {
        this.updateListeners.add(callback);
        return () => this.updateListeners.delete(callback);
    }
    /**
     * Cleanup resources
     */
    destroy() {
        if (this.throttleTimer) {
            clearTimeout(this.throttleTimer);
        }
        this.gainController.destroy();
        this.updateListeners.clear();
        this.gainNode?.disconnect();
    }
    createGainNode() {
        if (!this.audioContext) {
            throw new Error('AudioContext not initialized');
        }
        this.gainNode = this.audioContext.createGain();
        this.gainNode.gain.value = this.gainController.currentGain;
    }
    applyPendingGain() {
        if (!this.gainNode || this.pendingGain === undefined) {
            return;
        }
        const targetGain = this.pendingGain;
        this.pendingGain = undefined;
        if (this.enableSmoothing && this.audioContext) {
            // Apply smooth transition to prevent audio clicks
            this.gainNode.gain.setTargetAtTime(targetGain, this.audioContext.currentTime, this.smoothingTimeConstant);
        }
        else {
            this.gainNode.gain.value = targetGain;
        }
        // Notify listeners with throttled updates
        this.notifyListeners(targetGain);
    }
    notifyListeners(gain) {
        this.updateListeners.forEach(callback => {
            try {
                callback(gain);
            }
            catch (error) {
                console.warn('Gain service listener error:', error);
            }
        });
    }
}
/**
 * Singleton instance for global use
 */
let globalGainService = null;
export function getGainService(options) {
    if (!globalGainService) {
        globalGainService = new GainService(options);
    }
    return globalGainService;
}
export function destroyGainService() {
    if (globalGainService) {
        globalGainService.destroy();
        globalGainService = null;
    }
}