Initial Commit

packages/media/audio/audio-analysis-beat/tests/fixtures.ts

@@ -0,0 +1,56 @@
+import { AudioDocument } from "@suaveplan/audio-core";
+
+/** Build a synthetic metronome audio document. */
+export function makeMetronome(opts: {
+    bpm: number;
+    durationSeconds: number;
+    sampleRate?: number;
+    clickSamples?: number;
+    clickFreq?: number;
+}): AudioDocument {
+    const sampleRate = opts.sampleRate ?? 8000;
+    const total = Math.floor(opts.durationSeconds * sampleRate);
+    const data = new Float32Array(total);
+    const beatPeriodSamples = Math.floor((60 / opts.bpm) * sampleRate);
+    const clickSamples = opts.clickSamples ?? 200;
+    const clickFreq = opts.clickFreq ?? 1000;
+    for (let beat = 0; beat * beatPeriodSamples < total; beat++) {
+        const start = beat * beatPeriodSamples;
+        for (let i = 0; i < clickSamples && start + i < total; i++) {
+            const env = Math.exp(-i / (clickSamples / 4));
+            data[start + i] =
+                env * Math.sin((2 * Math.PI * clickFreq * i) / sampleRate);
+        }
+    }
+    return new AudioDocument({
+        sampleRate,
+        channels: 1,
+        sourceLength: total,
+        pages: [{ channelData: [data], startSample: 0 }],
+    });
+}
+
+/** Build a silent audio document. */
+export function makeSilence(opts: {
+    durationSeconds: number;
+    sampleRate?: number;
+}): AudioDocument {
+    const sampleRate = opts.sampleRate ?? 8000;
+    const total = Math.floor(opts.durationSeconds * sampleRate);
+    return new AudioDocument({
+        sampleRate,
+        channels: 1,
+        sourceLength: total,
+        pages: [{ channelData: [new Float32Array(total)], startSample: 0 }],
+    });
+}
+
+/** Empty document. */
+export function makeEmpty(): AudioDocument {
+    return new AudioDocument({
+        sampleRate: 8000,
+        channels: 1,
+        sourceLength: 0,
+        pages: [],
+    });
+}