auto format analyze.js

analyze.js

@@ -1,78 +1,78 @@
 document.querySelector('#analyze-pitch button').addEventListener('click', startListening);
 
 function startListening() {
-    navigator.mediaDevices.getUserMedia({ audio: true, video: false })
+	navigator.mediaDevices.getUserMedia({ audio: true, video: false })
-        .then(stream => {
+		.then(stream => {
-            const audioContext = new (window.AudioContext || window.webkitAudioContext)();
+			const audioContext = new (window.AudioContext || window.webkitAudioContext)();
-            const analyser = audioContext.createAnalyser();
+			const analyser = audioContext.createAnalyser();
-            const microphone = audioContext.createMediaStreamSource(stream);
+			const microphone = audioContext.createMediaStreamSource(stream);
-            const scriptProcessor = audioContext.createScriptProcessor(2048, 1, 1);
+			const scriptProcessor = audioContext.createScriptProcessor(2048, 1, 1);
 
-            analyser.smoothingTimeConstant = 0.3;
+			analyser.smoothingTimeConstant = 0.3;
-            analyser.fftSize = 2048;
+			analyser.fftSize = 2048;
 
-            microphone.connect(analyser);
+			microphone.connect(analyser);
-            analyser.connect(scriptProcessor);
+			analyser.connect(scriptProcessor);
-            scriptProcessor.connect(audioContext.destination);
+			scriptProcessor.connect(audioContext.destination);
 
-            scriptProcessor.onaudioprocess = () => {
+			scriptProcessor.onaudioprocess = () => {
-                const buffer = new Float32Array(analyser.fftSize);
+				const buffer = new Float32Array(analyser.fftSize);
-                analyser.getFloatTimeDomainData(buffer);
+				analyser.getFloatTimeDomainData(buffer);
-                const pitch = autoCorrelate(buffer, audioContext.sampleRate);
+				const pitch = autoCorrelate(buffer, audioContext.sampleRate);
-                document.querySelector('#analyze-pitch dd').textContent = pitch.toFixed(2);
+				document.querySelector('#analyze-pitch dd').textContent = pitch.toFixed(2);
-            };
+			};
-        })
+		})
-        .catch(err => {
+		.catch(err => {
-            console.error('Error accessing microphone: ' + err);
+			console.error('Error accessing microphone: ' + err);
-        });
+		});
 }
 
 function autoCorrelate(buffer, sampleRate) {
-    const SIZE = buffer.length;
+	const SIZE = buffer.length;
-    const MAX_SAMPLES = Math.floor(SIZE / 2);
+	const MAX_SAMPLES = Math.floor(SIZE / 2);
-    const MIN_SAMPLES = 0;
+	const MIN_SAMPLES = 0;
-    const GOOD_ENOUGH_CORRELATION = 0.9;
+	const GOOD_ENOUGH_CORRELATION = 0.9;
 
-    let bestOffset = -1;
+	let bestOffset = -1;
-    let bestCorrelation = 0;
+	let bestCorrelation = 0;
-    let rms = 0;
+	let rms = 0;
-    let foundGoodCorrelation = false;
+	let foundGoodCorrelation = false;
-    let correlations = new Array(MAX_SAMPLES);
+	let correlations = new Array(MAX_SAMPLES);
 
-    for (let i = 0; i < SIZE; i++) {
+	for (let i = 0; i < SIZE; i++) {
-        const val = buffer[i];
+		const val = buffer[i];
-        rms += val * val;
+		rms += val * val;
-    }
+	}
-    rms = Math.sqrt(rms / SIZE);
+	rms = Math.sqrt(rms / SIZE);
 
-    if (rms < 0.01) // not enough signal
+	if (rms < 0.01) // not enough signal
-        return -1;
+		return -1;
 
-    let lastCorrelation = 1;
+	let lastCorrelation = 1;
-    for (let offset = MIN_SAMPLES; offset < MAX_SAMPLES; offset++) {
+	for (let offset = MIN_SAMPLES; offset < MAX_SAMPLES; offset++) {
-        let correlation = 0;
+		let correlation = 0;
 
-        for (let i = 0; i < MAX_SAMPLES; i++) {
+		for (let i = 0; i < MAX_SAMPLES; i++) {
-            correlation += Math.abs((buffer[i]) - (buffer[i + offset]));
+			correlation += Math.abs((buffer[i]) - (buffer[i + offset]));
-        }
+		}
-        correlation = 1 - (correlation / MAX_SAMPLES);
+		correlation = 1 - (correlation / MAX_SAMPLES);
-        correlations[offset] = correlation;
+		correlations[offset] = correlation;
 
-        if ((correlation > GOOD_ENOUGH_CORRELATION) && (correlation > lastCorrelation)) {
+		if ((correlation > GOOD_ENOUGH_CORRELATION) && (correlation > lastCorrelation)) {
-            foundGoodCorrelation = true;
+			foundGoodCorrelation = true;
-            if (correlation > bestCorrelation) {
+			if (correlation > bestCorrelation) {
-                bestCorrelation = correlation;
+				bestCorrelation = correlation;
-                bestOffset = offset;
+				bestOffset = offset;
-            }
+			}
-        } else if (foundGoodCorrelation) {
+		} else if (foundGoodCorrelation) {
-            const shift = (correlations[bestOffset + 1] - correlations[bestOffset - 1]) / correlations[bestOffset];
+			const shift = (correlations[bestOffset + 1] - correlations[bestOffset - 1]) / correlations[bestOffset];
-            return sampleRate / (bestOffset + (8 * shift));
+			return sampleRate / (bestOffset + (8 * shift));
-        }
+		}
-        lastCorrelation = correlation;
+		lastCorrelation = correlation;
-    }
+	}
-    if (bestCorrelation > 0.01) {
+	if (bestCorrelation > 0.01) {
-        return sampleRate / bestOffset;
+		return sampleRate / bestOffset;
-    }
+	}
-    return -1;
+	return -1;
 }