antigravity one shot

src/audio/PitchAnalyzer.ts

@@ -0,0 +1,66 @@
+import { YIN } from "pitchfinder";
+
+export class PitchAnalyzer {
+    private detector: (buffer: Float32Array) => number | null;
+    private audioContext: AudioContext | null = null;
+    private analyser: AnalyserNode | null = null;
+    private mediaStream: MediaStream | null = null;
+    private source: MediaStreamAudioSourceNode | null = null;
+    private buffer: Float32Array;
+
+    constructor() {
+        this.detector = YIN({ sampleRate: 44100 }); // Default, will update on start
+        this.buffer = new Float32Array(2048); // Standard size
+    }
+
+    async start(): Promise<void> {
+        if (this.audioContext) return;
+
+        this.audioContext = new (window.AudioContext || (window as any).webkitAudioContext)();
+        this.detector = YIN({ sampleRate: this.audioContext.sampleRate });
+
+        try {
+            this.mediaStream = await navigator.mediaDevices.getUserMedia({ audio: true });
+            this.source = this.audioContext.createMediaStreamSource(this.mediaStream);
+            this.analyser = this.audioContext.createAnalyser();
+            this.analyser.fftSize = 4096; // Higher FFT size for better resolution at low frequencies
+            this.buffer = new Float32Array(this.analyser.fftSize);
+
+            this.source.connect(this.analyser);
+        } catch (e) {
+            console.error("Error accessing microphone:", e);
+            throw e;
+        }
+    }
+
+    stop() {
+        if (this.mediaStream) {
+            this.mediaStream.getTracks().forEach(track => track.stop());
+            this.mediaStream = null;
+        }
+        if (this.audioContext) {
+            this.audioContext.close();
+            this.audioContext = null;
+        }
+    }
+
+    /**
+     * getPitch returns the detected frequency in Hz, or null if no pitch detected
+     */
+    getPitch(): number | null {
+        if (!this.analyser) return null;
+        this.analyser.getFloatTimeDomainData(this.buffer as any);
+
+        // Simple RMS volume check to avoid noise
+        let rms = 0;
+        for (let i = 0; i < this.buffer.length; i++) {
+            rms += this.buffer[i] * this.buffer[i];
+        }
+        rms = Math.sqrt(rms / this.buffer.length);
+
+        if (rms < 0.01) return null; // Silence threshold
+
+        const pitch = this.detector(this.buffer);
+        return pitch;
+    }
+}