Fix pulse bpm sync

mic-sender.js

@@ -1,10 +1,14 @@
-import record from 'node-record-lpcm16'
+import mic from 'mic'
 import WebSocket from 'ws'
 
 const url = process.argv[2] || 'ws://localhost:8081'
 const ws = new WebSocket(url)
 
 ws.on('open', () => {
-  const mic = record.start({ sampleRate: 44100, channels: 1 })
-  mic.on('data', chunk => ws.send(chunk))
+  const micInst = mic({ rate: '44100', channels: '1' })
+  const micStream = micInst.getAudioStream()
+  micInst.start()
+  micStream.on('data', chunk => ws.send(chunk))
+  micStream.on('error', console.error)
 })
+

package.json

@@ -52,9 +52,9 @@
 		"d3-interpolate": "^3.0.1",
 		"dotenv": "^16.4.5",
 		"express": "^4.18.2",
-		"fft-js": "^0.0.12",
-		"music-tempo": "^1.0.3",
-		"node-record-lpcm16": "^1.0.1",
+                "fft-js": "^0.0.12",
+                "mic": "^2.1.1",
+                "essentia.js": "^0.1.3",
 		"react": "^19.1.0",
 		"react-colorful": "^5.6.1",
 		"react-dom": "^19.1.0",

src/backend/pattern/extra.ts

@@ -46,13 +46,27 @@ export const getStrobeColor: IColorGetter = (_, time) => {
 }
 
 export const getPulseColor: IColorGetter = (_, time) => {
-	const cycle = settings.syncToMusic && audioState.bpm ? 60000 / audioState.bpm : 1000
-	const t = (time * settings.effectSpeed) % cycle
-	if (t < lastPulse) {
+	const target = settings.syncToMusic && audioState.bpm ? 60000 / audioState.bpm : 1000
+
+	if (!lastPulseTime) {
+		lastPulseTime = time
+		pulseCycle = target
+	}
+
+	const dt = (time - lastPulseTime) * settings.effectSpeed
+	lastPulseTime = time
+
+	const elapsed = pulsePhase * pulseCycle + dt
+	pulseCycle = target
+	pulsePhase = elapsed / pulseCycle
+
+	if (pulsePhase >= 1) {
+		const cycles = Math.floor(pulsePhase)
+		pulsePhase -= cycles
 		pulseColor = hslToRgb(Math.random() * 360, 1, 0.5)
 	}
-	lastPulse = t
-	const intensity = Math.sin((t / cycle) * Math.PI)
+
+	const intensity = Math.sin(pulsePhase * Math.PI)
 	return pulseColor.map(c => Math.round(c * intensity)) as IArrColor
 }
 
@@ -82,7 +96,9 @@ export const getMultiPulseColor: IColorGetter = (index, time) => {
 let strobeColor: IArrColor = [255, 255, 255]
 let lastStrobe = 0
 let pulseColor: IArrColor = [255, 0, 0]
-let lastPulse = 0
+let pulseCycle = 1000
+let pulsePhase = 0
+let lastPulseTime = 0
 let multiPulseColors: IArrColor[] = Array(4)
 	.fill(null)
 	.map(() => hslToRgb(Math.random() * 360, 1, 0.5))
@@ -95,7 +111,9 @@ export function resetExtraPatterns() {
 	strobeColor = [255, 255, 255]
 	lastStrobe = 0
 	pulseColor = [255, 0, 0]
-	lastPulse = 0
+	pulseCycle = 1000
+	pulsePhase = 0
+	lastPulseTime = 0
 	multiPulseColors = Array(4)
 		.fill(null)
 		.map(() => hslToRgb(Math.random() * 360, 1, 0.5))

src/backend/wsAudio.ts

@@ -1,6 +1,6 @@
 import { WebSocketServer } from 'ws'
 import fftjs from 'fft-js'
-import MusicTempo from 'music-tempo'
+import { Essentia, EssentiaWASM } from 'essentia.js'
 // eslint-disable-next-line import/default
 import RingBufferTs from 'ring-buffer-ts'
 const RingBuffer = RingBufferTs.RingBuffer
@@ -29,8 +29,10 @@ const sampleRateDefault = 44100
 const bpmWindow = sampleRateDefault * 8
 const sampleBuffer = new RingBuffer<number>(bpmWindow)
 let lastBpmUpdate = 0
+const essentiaPromise = Promise.resolve(new Essentia(EssentiaWASM))
+let bpmSmoothed = 0
 
-export function processAudio(buffer: Buffer, sampleRate = sampleRateDefault) {
+export async function processAudio(buffer: Buffer, sampleRate = sampleRateDefault) {
 	const samples = new Int16Array(buffer.buffer, buffer.byteOffset, buffer.byteLength / 2)
 	const input = Array.from(samples, s => s / 32768)
 	for (const s of input) sampleBuffer.add(s)
@@ -56,9 +58,14 @@ export function processAudio(buffer: Buffer, sampleRate = sampleRateDefault) {
 	if (now - lastBpmUpdate > 2000 && sampleBuffer.getBufferLength() >= sampleRate * 4) {
 		lastBpmUpdate = now
 		try {
-			const mt = new MusicTempo(Float32Array.from(sampleBuffer.toArray()))
-			const tempo = parseFloat(String(mt.tempo))
-			if (!Number.isNaN(tempo)) audioState.bpm = tempo
+			const essentia = await essentiaPromise
+			const signal = essentia.arrayToVector(Float32Array.from(sampleBuffer.toArray()))
+			const res = essentia.RhythmExtractor2013(signal, 208, 'multifeature', 40)
+			const tempo = res.bpm
+			if (!Number.isNaN(tempo)) {
+				bpmSmoothed = bpmSmoothed ? bpmSmoothed * 0.8 + tempo * 0.2 : tempo
+				audioState.bpm = bpmSmoothed
+			}
 		} catch {
 			// ignore errors
 		}
@@ -73,4 +80,5 @@ export function resetAudioState() {
 	audioState.bins = []
 	sampleBuffer.clear()
 	lastBpmUpdate = 0
+	bpmSmoothed = 0
 }

src/types/essentia.js.d.ts

@@ -0,0 +1 @@
+declare module 'essentia.js'

tests/wsAudio.test.ts

@@ -24,16 +24,16 @@ describe('processAudio', () => {
         beforeEach(() => {
                 resetAudioState()
         })
-       test('detects frequency', () => {
+       test('detects frequency', async () => {
                const buf = genSine(440, 1234, 44100)
-               processAudio(buf)
+               await processAudio(buf)
                expect(audioState.freq).toBeGreaterThan(430)
                expect(audioState.freq).toBeLessThan(450)
        })
 
-       test('detects bpm', () => {
+       test('detects bpm', async () => {
                const buf = genBeat(120, 4, 44100)
-               processAudio(buf)
+               await processAudio(buf)
                expect(audioState.bpm).toBeGreaterThan(110)
                expect(audioState.bpm).toBeLessThan(130)
        })