308 lines
8.6 KiB
JavaScript
308 lines
8.6 KiB
JavaScript
// js/audio-context.js
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// Shared Audio Context Manager - handles EQ and provides context for visualizer
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import { equalizerSettings } from './storage.js';
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// Standard 16-band ISO center frequencies (Hz)
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const EQ_FREQUENCIES = [
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25, 40, 63, 100, 160, 250, 400, 630,
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1000, 1600, 2500, 4000, 6300, 10000, 16000, 20000
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];
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// EQ Presets (gain values in dB for each of the 16 bands)
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const EQ_PRESETS = {
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flat: {
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name: 'Flat',
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gains: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
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},
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bass_boost: {
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name: 'Bass Boost',
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gains: [6, 5, 4.5, 4, 3, 2, 1, 0.5, 0, 0, 0, 0, 0, 0, 0, 0]
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},
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bass_reducer: {
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name: 'Bass Reducer',
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gains: [-6, -5, -4, -3, -2, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
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},
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treble_boost: {
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name: 'Treble Boost',
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gains: [0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 5.5, 6]
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},
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treble_reducer: {
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name: 'Treble Reducer',
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gains: [0, 0, 0, 0, 0, 0, 0, 0, 0, -1, -2, -3, -4, -5, -5.5, -6]
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},
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vocal_boost: {
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name: 'Vocal Boost',
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gains: [-2, -1, 0, 0, 1, 2, 3, 4, 4, 3, 2, 1, 0, 0, -1, -2]
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},
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loudness: {
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name: 'Loudness',
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gains: [5, 4, 3, 1, 0, -1, -1, 0, 0, 1, 2, 3, 4, 4.5, 4, 3]
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},
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rock: {
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name: 'Rock',
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gains: [4, 3.5, 3, 2, -1, -2, -1, 1, 2, 3, 3.5, 4, 4, 3, 2, 1]
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},
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pop: {
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name: 'Pop',
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gains: [-1, 0, 1, 2, 3, 3, 2, 1, 0, 1, 2, 2, 2, 2, 1, 0]
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},
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classical: {
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name: 'Classical',
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gains: [3, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 3, 2]
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},
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jazz: {
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name: 'Jazz',
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gains: [3, 2, 1, 1, -1, -1, 0, 1, 2, 2, 2, 2, 2, 2, 2, 2]
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},
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electronic: {
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name: 'Electronic',
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gains: [4, 3.5, 3, 1, 0, -1, 0, 1, 2, 3, 3, 2, 2, 3, 4, 3.5]
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},
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hip_hop: {
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name: 'Hip-Hop',
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gains: [5, 4.5, 4, 3, 1, 0, 0, 1, 1, 1, 1, 1, 1, 2, 2, 2]
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},
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r_and_b: {
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name: 'R&B',
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gains: [3, 5, 4, 2, 1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1]
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},
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acoustic: {
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name: 'Acoustic',
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gains: [3, 2, 1, 1, 2, 2, 1, 0, 0, 1, 1, 2, 3, 3, 2, 1]
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},
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podcast: {
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name: 'Podcast / Speech',
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gains: [-3, -2, -1, 0, 1, 2, 3, 4, 4, 3, 2, 1, 0, -1, -2, -3]
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}
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};
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class AudioContextManager {
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constructor() {
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this.audioContext = null;
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this.source = null;
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this.analyser = null;
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this.filters = [];
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this.outputNode = null;
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this.isInitialized = false;
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this.isEQEnabled = false;
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this.currentGains = new Array(16).fill(0);
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this.audio = null;
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// Load saved settings
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this._loadSettings();
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}
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/**
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* Initialize the audio context and connect to the audio element
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* This should be called when audio starts playing
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*/
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init(audioElement) {
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if (this.isInitialized) return;
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if (!audioElement) return;
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try {
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this.audio = audioElement;
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const AudioContext = window.AudioContext || window.webkitAudioContext;
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this.audioContext = new AudioContext();
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// Create the media element source
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this.source = this.audioContext.createMediaElementSource(audioElement);
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// Create analyser for visualizer
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this.analyser = this.audioContext.createAnalyser();
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this.analyser.fftSize = 512;
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this.analyser.smoothingTimeConstant = 0.7;
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// Create 16 biquad filters for EQ
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this.filters = EQ_FREQUENCIES.map((freq, index) => {
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const filter = this.audioContext.createBiquadFilter();
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filter.type = 'peaking';
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filter.frequency.value = freq;
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filter.Q.value = 2.5; // Constant-Q design
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filter.gain.value = this.currentGains[index];
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return filter;
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});
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// Create output gain node
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this.outputNode = this.audioContext.createGain();
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this.outputNode.gain.value = 1;
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// Connect filter chain: filter[0] -> filter[1] -> ... -> filter[15] -> outputNode
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for (let i = 0; i < this.filters.length - 1; i++) {
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this.filters[i].connect(this.filters[i + 1]);
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}
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this.filters[this.filters.length - 1].connect(this.outputNode);
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// Connect the audio graph based on EQ state
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this._connectGraph();
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this.isInitialized = true;
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console.log('[AudioContext] Initialized with 16-band EQ');
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} catch (e) {
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console.warn('[AudioContext] Init failed:', e);
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}
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}
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/**
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* Connect the audio graph based on EQ enabled state
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*/
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_connectGraph() {
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if (!this.source || !this.audioContext) return;
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try {
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// Disconnect everything first
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this.source.disconnect();
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this.outputNode.disconnect();
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this.analyser.disconnect();
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if (this.isEQEnabled && this.filters.length > 0) {
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// EQ enabled: source -> EQ filters -> output -> analyser -> destination
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this.source.connect(this.filters[0]);
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this.outputNode.connect(this.analyser);
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this.analyser.connect(this.audioContext.destination);
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console.log('[AudioContext] EQ connected');
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} else {
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// EQ disabled: source -> analyser -> destination
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this.source.connect(this.analyser);
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this.analyser.connect(this.audioContext.destination);
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console.log('[AudioContext] EQ bypassed');
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}
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} catch (e) {
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console.warn('[AudioContext] Failed to connect graph:', e);
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// Fallback: direct connection
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try {
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this.source.connect(this.audioContext.destination);
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} catch { }
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}
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}
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/**
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* Resume audio context (required after user interaction)
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*/
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resume() {
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if (this.audioContext && this.audioContext.state === 'suspended') {
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this.audioContext.resume();
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}
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}
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/**
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* Get the analyser node for the visualizer
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*/
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getAnalyser() {
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return this.analyser;
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}
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/**
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* Get the audio context
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*/
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getAudioContext() {
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return this.audioContext;
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}
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/**
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* Check if initialized
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*/
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isReady() {
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return this.isInitialized;
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}
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/**
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* Toggle EQ on/off
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*/
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toggleEQ(enabled) {
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this.isEQEnabled = enabled;
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equalizerSettings.setEnabled(enabled);
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if (this.isInitialized) {
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this._connectGraph();
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}
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return this.isEQEnabled;
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}
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/**
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* Check if EQ is active
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*/
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isEQActive() {
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return this.isInitialized && this.isEQEnabled;
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}
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/**
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* Set gain for a specific band
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*/
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setBandGain(bandIndex, gainDb) {
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if (bandIndex < 0 || bandIndex >= 16) return;
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const clampedGain = Math.max(-30, Math.min(30, gainDb));
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this.currentGains[bandIndex] = clampedGain;
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if (this.filters[bandIndex] && this.audioContext) {
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const now = this.audioContext.currentTime;
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this.filters[bandIndex].gain.setTargetAtTime(clampedGain, now, 0.01);
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}
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equalizerSettings.setGains(this.currentGains);
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}
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/**
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* Set all band gains at once
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*/
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setAllGains(gains) {
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if (!Array.isArray(gains) || gains.length !== 16) return;
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const now = this.audioContext?.currentTime || 0;
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gains.forEach((gain, index) => {
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const clampedGain = Math.max(-30, Math.min(30, gain));
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this.currentGains[index] = clampedGain;
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if (this.filters[index]) {
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this.filters[index].gain.setTargetAtTime(clampedGain, now, 0.01);
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}
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});
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equalizerSettings.setGains(this.currentGains);
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}
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/**
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* Apply a preset
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*/
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applyPreset(presetKey) {
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const preset = EQ_PRESETS[presetKey];
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if (!preset) return;
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this.setAllGains(preset.gains);
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equalizerSettings.setPreset(presetKey);
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}
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/**
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* Reset all bands to flat
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*/
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reset() {
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this.setAllGains(new Array(16).fill(0));
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equalizerSettings.setPreset('flat');
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}
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/**
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* Get current gains
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*/
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getGains() {
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return [...this.currentGains];
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}
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/**
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* Load settings from storage
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*/
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_loadSettings() {
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this.isEQEnabled = equalizerSettings.isEnabled();
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this.currentGains = equalizerSettings.getGains();
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}
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}
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// Export singleton instance
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export const audioContextManager = new AudioContextManager();
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// Export presets for settings UI
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export { EQ_PRESETS };
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