Initial Commit

packages/media/audio/audio-analysis-pitch/tests/property.test.ts

@@ -0,0 +1,59 @@
+import { describe, expect, it } from "@suaveplan/testing/runner";
+import fc from "fast-check";
+import { yinPitch } from "../src/algorithms/yin.js";
+
+describe("yinPitch property tests", () => {
+    it("estimated pitch confidence is always in [0,1]", {
+        timeout: 30_000,
+    }, () => {
+        fc.assert(
+            fc.property(fc.integer({ min: 80, max: 2000 }), (freq) => {
+                const sr = 48_000;
+                const n = 4096;
+                const f = new Float32Array(n);
+                for (let i = 0; i < n; i++)
+                    f[i] = Math.sin((2 * Math.PI * freq * i) / sr);
+                const r = yinPitch(f, sr, 20, 20_000);
+                return r.confidence >= 0 && r.confidence <= 1;
+            }),
+            { numRuns: 30 }
+        );
+    });
+
+    it("estimated pitch is non-negative", { timeout: 30_000 }, () => {
+        fc.assert(
+            fc.property(fc.integer({ min: 100, max: 4000 }), (freq) => {
+                const sr = 48_000;
+                const n = 4096;
+                const f = new Float32Array(n);
+                for (let i = 0; i < n; i++)
+                    f[i] = Math.sin((2 * Math.PI * freq * i) / sr);
+                const r = yinPitch(f, sr, 20, 20_000);
+                return r.pitch >= 0;
+            }),
+            { numRuns: 30 }
+        );
+    });
+
+    it("silence always yields zero pitch", { timeout: 5_000 }, () => {
+        fc.assert(
+            fc.property(fc.integer({ min: 1024, max: 8192 }), (n) => {
+                const r = yinPitch(new Float32Array(n), 48_000, 20, 20_000);
+                return r.pitch === 0 && r.confidence === 0;
+            }),
+            { numRuns: 20 }
+        );
+    });
+});
+
+describe("440 Hz sine estimation", () => {
+    it("yields midi 69 for a 440 Hz tone", { timeout: 5_000 }, () => {
+        const sr = 48_000;
+        const n = 4096;
+        const f = new Float32Array(n);
+        for (let i = 0; i < n; i++)
+            f[i] = Math.sin((2 * Math.PI * 440 * i) / sr);
+        const r = yinPitch(f, sr, 20, 20_000);
+        expect(Math.abs(r.pitch - 440)).toBeLessThan(1);
+    });
+});