Implement parsing for output compressor and sidechain effects state

tests/project-effects.test.ts

@@ -0,0 +1,68 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { collectEffects } from '../src/lib/parsers';
+import { TarFile } from '../src/lib/untar';
+
+function effectsFile(length: number) {
+  const data = new Uint8Array(length);
+  data[4] = 6;
+  return {
+    data,
+    file: new TarFile('fx_settings', data.length, data),
+    view: new DataView(data.buffer),
+  };
+}
+
+test('preserves selected FX parsing for short files without extended state', () => {
+  const fixture = effectsFile(100);
+  fixture.view.setFloat32(32, 0.25, true);
+  fixture.view.setFloat32(96, 0.75, true);
+
+  const effects = collectEffects([fixture.file]);
+
+  assert.equal(effects.effectType, 6);
+  assert.equal(effects.param1, 0.25);
+  assert.equal(effects.param2, 0.75);
+  assert.equal(effects.rawData, fixture.data);
+  assert.equal(effects.outputCompressor, undefined);
+  assert.equal(effects.sidechain, undefined);
+});
+
+test('parses output compressor state from a 144-byte file without sidechain state', () => {
+  const fixture = effectsFile(144);
+  fixture.view.setFloat32(136, 0.25, true);
+  fixture.view.setFloat32(140, 0.75, true);
+
+  const effects = collectEffects([fixture.file]);
+
+  assert.deepEqual(effects.outputCompressor, { drive: 0.25, speed: 0.75 });
+  assert.equal(effects.sidechain, undefined);
+});
+
+test('parses P07-like output dynamics and sidechain state from a 160-byte file', () => {
+  const fixture = effectsFile(160);
+  fixture.view.setFloat32(32, 0.5, true);
+  fixture.view.setFloat32(96, 0.5, true);
+  fixture.view.setFloat32(136, 0.5, true);
+  fixture.view.setFloat32(140, 0.5, true);
+  fixture.view.setFloat32(144, 0, true);
+  fixture.view.setFloat32(148, 0.5, true);
+  fixture.view.setUint16(152, 0x0600, true);
+  fixture.view.setUint16(154, 0x8000, true);
+  fixture.view.setUint16(156, 0x8000, true);
+  fixture.view.setUint16(158, 0x8000, true);
+
+  const effects = collectEffects([fixture.file]);
+
+  assert.deepEqual(effects.outputCompressor, { drive: 0.5, speed: 0.5 });
+  assert.deepEqual(effects.sidechain, {
+    length: 0,
+    shape: 0.5,
+    routing: {
+      a: { rawValue: 0x0600, sourcePadMask: 0x0600, duckedDestination: false },
+      b: { rawValue: 0x8000, sourcePadMask: 0, duckedDestination: true },
+      c: { rawValue: 0x8000, sourcePadMask: 0, duckedDestination: true },
+      d: { rawValue: 0x8000, sourcePadMask: 0, duckedDestination: true },
+    },
+  });
+});