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Polish

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- show FFT bucket-width in cents
  - visual polish
  - up FFT size to max
This commit is contained in:
Aaron Gutierrez
2021-12-27 18:01:57 -08:00
parent c13225fb9e
commit 7c39ec3c2b
3 changed files with 47 additions and 21 deletions
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7
tuner.css
View File

@@ -5,7 +5,8 @@ body {
color: white;
display: flex;
flex-direction: column;
font-size: 48px;
font-family: sans-serif;
font-size: 2em;
height: 100vh;
margin: 0;
overflow: hidden;
@@ -28,10 +29,10 @@ h1, h2 {
}
h1 {
font-size: 96px;
font-size: 6em;
}
h2 {
font-size: 72px;
font-size: 3em;
}

8
tuner.html
View File

@@ -3,11 +3,11 @@
<meta name="viewport" conetnt="width=device-width, initial-scale=1">
<link rel="stylesheet" href="tuner.css">
<script src="tuner.js"></script>
<title>Tuner</title>
<body onload="setup()">
<h2 id="title">Tuner</h2>
<div id="frequency">Listening...</div>
<div><span id="rate">??</span> kHz</div>
<h1 id="note">A+</h2>
<h1 id="note">Listening...</h2>
<h2 id="tune"></h3>
<div id="frequency"></div>
<div>(<span id="rate">??</span> kHz sample rate)</div>
</bdoy>
</html>

53
tuner.js
View File

@@ -1,7 +1,5 @@
const NOTE_NAMES = ["A", "A#", "B", "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#"]
const TIMESLICE_MS = 500;
// We don't care about fundamenatls above 4kHz, so setting a lower sample rate
// gives us finer-graned FFT buckets
const TARGET_SAMPLE_RATE = 8000;
@@ -11,6 +9,7 @@ let dom_rate;
let dom_note;
let dom_tune;
const setup = () => {
dom_frequency = document.getElementById("frequency");
dom_rate = document.getElementById("rate");
@@ -24,27 +23,39 @@ const setup = () => {
console.error("Error calling getUserMedia", err);
});
};
if (navigator.wakeLock && navigator.wakeLock.request) {
try {
navigator.wakeLock
.request('screen')
.then(wakeLock =>
setTimeout(() => wakeLock.release(), 60000)
);
} catch (err) {}
}
};
const handleStream = stream => {
const audioContext = new AudioContext({
sampleRate: TARGET_SAMPLE_RATE,
});
const analyser = audioContext.createAnalyser();
analyser.fftSize = 8192;
analyser.fftSize = 32768;
analyser.minDecibels = -90;
analyser.maxDecibels = -10;
analyser.smoothingTimeConstant = 0.1;
analyser.smoothingTimeConstant = 0;
const bufferLength = analyser.frequencyBinCount;
const data = new Uint8Array(bufferLength);
const source = audioContext.createMediaStreamSource(stream);
source.connect(analyser);
setInterval(tune(analyser, data), 200);
setInterval(tune(analyser, data), 500);
};
const tune = (analyser, data) => () => {
analyser.getByteFrequencyData(data);
@@ -55,8 +66,6 @@ const tune = (analyser, data) => () => {
let max = 0;
let maxBucket = -1;
data.forEach((value, bucket) => {
if (value > max) {
max = value;
@@ -64,18 +73,26 @@ const tune = (analyser, data) => () => {
}
});
if (maxBucket === -1) {
return;
}
const frequency = maxBucket * bucketWidth;
dom_frequency.innerText = `${frequency} Hz`;
dom_frequency.innerText = `${Number.parseFloat(frequency).toFixed(2)} Hz`;
const semitones = frequencyToSemitones(frequency);
const margin = frequencyToSemitones(frequency + bucketWidth / 2) - semitones;
dom_note.innerText = semitonesToNote(semitones);
dom_tune.innerText = errorPercentage(semitones);
document.body.className = semitonesToClassname(semitones);
dom_tune.innerText = errorPercentage(semitones, margin);
document.body.className = semitonesToClassname(semitones, margin);
};
const frequencyToSemitones = frequency =>
12 * Math.log2(frequency / 440) + 69;
const semitonesToNote = semitones => {
const rounded = Math.round(semitones - 69);
@@ -86,17 +103,25 @@ const semitonesToNote = semitones => {
return NOTE_NAMES[index];
}
const errorPercentage = semitones => {
const errorPercentage = (semitones, margin) => {
const rounded = Math.round(semitones);
return Math.round((semitones - rounded ) * 100) + "%";
const cents = Math.round((semitones - rounded) * 100);
const accuracy = Number.parseFloat(margin * 100).toFixed(1);
const sign = cents > 0 ? "+" : ""
return `${sign}${cents} cents ± ${accuracy}`;
}
const semitonesToClassname = semitones => {
const semitonesToClassname = (semitones, margin) => {
const rounded = Math.round(semitones);
const error = Math.abs(semitones-rounded);
if (error <= 0.05) {
const ok = margin > 0.05 ? margin : 0.05
if (error <= ok) {
return "";
}