fix: fall back to native audio on YouTube embed error 150/101

src/player/AudioEngine.check.ts

@@ -0,0 +1,39 @@
+/**
+ * Self-check for `isEmbedRestrictedPlaybackError`, the switch that decides whether an IFrame
+ * playback failure is the one kind worth retrying on native audio (owner disabled embedding)
+ * versus every other kind (network hiccup, removed video, ...) where retrying elsewhere would
+ * just fail the same way. Run via `npm run check`.
+ */
+export {};
+
+import { isEmbedRestrictedPlaybackError } from "./AudioEngine";
+
+function check(condition: boolean, message: string): void {
+  if (!condition) throw new Error(`FAILED: ${message}`);
+}
+
+check(
+  isEmbedRestrictedPlaybackError(new Error("YouTube player error 150")),
+  "150 is the owner-disabled-embedding code",
+);
+check(
+  isEmbedRestrictedPlaybackError(new Error("YouTube player error 101")),
+  "101 is 150's alias",
+);
+check(
+  !isEmbedRestrictedPlaybackError(new Error("YouTube player error 100")),
+  "100 (video removed/private) is not embed-restriction and should not be retried",
+);
+check(
+  !isEmbedRestrictedPlaybackError(new Error("YouTube player error 2")),
+  "2 (invalid parameter) is not embed-restriction",
+);
+check(
+  !isEmbedRestrictedPlaybackError(new Error("Some other failure")),
+  "unrelated error messages don't match",
+);
+check(!isEmbedRestrictedPlaybackError("YouTube player error 150"), "non-Error values don't match");
+check(!isEmbedRestrictedPlaybackError(null), "null doesn't throw or match");
+
+// eslint-disable-next-line no-console
+console.log("AudioEngine.check.ts passed");

src/player/AudioEngine.ts

@@ -160,6 +160,17 @@ function isPlayerStateTimeout(error: unknown): boolean {
     && /^Timed out waiting for YouTube player state: /.test(error.message);
 }
 
+/**
+ * True for IFrame error 101/150 — YouTube's own "the owner of this video does not allow it to
+ * be played in embedded players" (150 is 101 in disguise, same restriction, same fix).
+ *
+ * A property of the *embed*, not of the video: a directly resolved stream URL is not an embed
+ * and is not subject to it, which is what makes falling back to one worth trying.
+ */
+export function isEmbedRestrictedPlaybackError(error: unknown): boolean {
+  return error instanceof Error && /^YouTube player error (101|150)$/.test(error.message);
+}
+
 function detectAudioMimeType(bytes: Uint8Array): string {
   if (
     bytes.length >= 4

src/player/PlayerController.ts

@@ -2,7 +2,7 @@ import type { DataSource, StreamData } from "../datasource/DataSource";
 import type { Lyrics, Track } from "../datasource/types";
 import { logInternalDebug, logInternalError, logInternalInfo, logInternalWarn } from "../internal/logging";
 import { isPrematureEnd } from "./prematureEnd";
-import { AudioEngine } from "./AudioEngine";
+import { AudioEngine, isEmbedRestrictedPlaybackError } from "./AudioEngine";
 import { Queue } from "./Queue";
 import { NavigationCoalescer } from "./navigationCoalescer";
 import { recordPlay } from "./playHistory";
@@ -1310,6 +1310,14 @@ export class PlayerController {
        * saved on purpose.
        */
       const canFallBackToIframe = this.audioEngine.usesRustAudio() && !isDownloaded;
+      /*
+       * The mirror case: the embed is refused not because Google won't resolve the track but
+       * because its owner disallows embedded playback at all (error 101/150) — a restriction
+       * on the embed, not on the video. A directly resolved stream is not an embed and
+       * sidesteps it, so a track that would otherwise be permanently unplayable on this engine
+       * gets one try at native audio before giving up.
+       */
+      const canFallBackToNative = !useNativeAudio && !isDownloaded;
 
       try {
         const audioData = useNativeAudio
@@ -1339,12 +1347,30 @@ export class PlayerController {
           );
         }
       } catch (error) {
-        if (!canFallBackToIframe) throw error;
-        logInternalWarn("PlayerController.ensureTrackLoaded falling back to the YouTube player", {
-          trackId: track.id,
-          error: getErrorMessage(error),
-        });
-        await this.audioEngine.loadIframeFallback(track.id);
+        if (canFallBackToIframe) {
+          logInternalWarn("PlayerController.ensureTrackLoaded falling back to the YouTube player", {
+            trackId: track.id,
+            error: getErrorMessage(error),
+          });
+          await this.audioEngine.loadIframeFallback(track.id);
+        } else if (canFallBackToNative && isEmbedRestrictedPlaybackError(error)) {
+          const nativeAudioData = await this.dataSource.getStreamData?.(track);
+          if (!nativeAudioData) throw error;
+          logInternalWarn("PlayerController.ensureTrackLoaded falling back to native audio", {
+            trackId: track.id,
+            error: getErrorMessage(error),
+          });
+          await this.audioEngine.loadNativeFallback(
+            track.id,
+            nativeAudioData.bytes,
+            nativeAudioData.mimeType,
+            nativeAudioData.sourceUrl,
+            nativeAudioData.rustSource,
+            track.durationSec,
+          );
+        } else {
+          throw error;
+        }
       }
 
       this.loadedTrackId = track.id;