WIP 2

src/plugins/exponential-volume/index.ts

@@ -1,17 +1,50 @@
-import { createPluginBuilder } from '../utils/builder';
+import { createPlugin } from '@/utils';
 
-const builder = createPluginBuilder('exponential-volume', {
+export default createPlugin({
   name: 'Exponential Volume',
   restartNeeded: true,
   config: {
     enabled: false,
   },
-});
+  renderer: {
+    onPlayerApiReady() {
+      // "YouTube Music fix volume ratio 0.4" by Marco Pfeiffer
+      // https://greasyfork.org/en/scripts/397686-youtube-music-fix-volume-ratio/
 
-export default builder;
+      // Manipulation exponent, higher value = lower volume
+      // 3 is the value used by pulseaudio, which Barteks2x figured out this gist here: https://gist.github.com/Barteks2x/a4e189a36a10c159bb1644ffca21c02a
+      // 0.05 (or 5%) is the lowest you can select in the UI which with an exponent of 3 becomes 0.000125 or 0.0125%
+      const EXPONENT = 3;
 
-declare global {
-  interface PluginBuilderList {
-    [builder.id]: typeof builder;
+      const storedOriginalVolumes = new WeakMap<HTMLMediaElement, number>();
+      const propertyDescriptor = Object.getOwnPropertyDescriptor(
+        HTMLMediaElement.prototype,
+        'volume',
+      );
+      Object.defineProperty(HTMLMediaElement.prototype, 'volume', {
+        get(this: HTMLMediaElement) {
+          const lowVolume = propertyDescriptor?.get?.call(this) as number ?? 0;
+          const calculatedOriginalVolume = lowVolume ** (1 / EXPONENT);
+
+          // The calculated value has some accuracy issues which can lead to problems for implementations that expect exact values.
+          // To avoid this, I'll store the unmodified volume to return it when read here.
+          // This mostly solves the issue, but the initial read has no stored value and the volume can also change though external influences.
+          // To avoid ill effects, I check if the stored volume is somewhere in the same range as the calculated volume.
+          const storedOriginalVolume = storedOriginalVolumes.get(this) ?? 0;
+          const storedDeviation = Math.abs(
+            storedOriginalVolume - calculatedOriginalVolume,
+          );
+
+          return storedDeviation < 0.01
+            ? storedOriginalVolume
+            : calculatedOriginalVolume;
+        },
+        set(this: HTMLMediaElement, originalVolume: number) {
+          const lowVolume = originalVolume ** EXPONENT;
+          storedOriginalVolumes.set(this, originalVolume);
+          propertyDescriptor?.set?.call(this, lowVolume);
+        },
+      });
+    }
   }
-}
+});