fix(jellyfin): use the current audio track for media generation (#271)

changes/jellyfin-review-audio-track.md

@@ -0,0 +1,4 @@
+type: fixed
+area: jellyfin
+
+- Timing review previews and mined card audio now use the audio track you are playing on Jellyfin direct-play streams, instead of the track Jellyfin marks as default.

src/anki-integration/media-source.test.ts

@@ -213,6 +213,30 @@ test('resolveMediaGenerationInput reads file-local mpv request options', async (
   });
 });
 
+test('resolveMediaGenerationInput keeps stream selection for a directly played remote container', async () => {
+  const resolver = (
+    mediaSource as typeof mediaSource & {
+      resolveMediaGenerationInput?: StructuredMediaResolver;
+    }
+  ).resolveMediaGenerationInput;
+  assert.equal(typeof resolver, 'function');
+
+  // Jellyfin direct play: mpv opens the URL as-is, so it can hold several audio streams.
+  const jellyfinUrl = 'http://jellyfin.local:8096/Videos/abc/stream?static=true';
+  const result = await resolver!(
+    {
+      currentVideoPath: jellyfinUrl,
+      requestProperty: async (name: string) =>
+        name === 'stream-open-filename' ? jellyfinUrl : null,
+    },
+    'audio',
+  );
+
+  assert.equal(result?.path, jellyfinUrl);
+  assert.equal(result?.source, 'stream-open-filename');
+  assert.equal(result?.singleResolvedStream, false);
+});
+
 test('resolveMediaGenerationInput prefers a ready cached media file for YouTube extraction', async () => {
   const resolver = (
     mediaSource as typeof mediaSource & {

src/anki-integration/media-source.ts

@@ -400,12 +400,15 @@ export async function resolveMediaGenerationInput(
       return result;
     }
     if (streamOpenFilename) {
+      // A URL that yt-dlp resolved (e.g. youtube.com -> googlevideo) is one picked stream.
+      // When mpv opens the path as-is (e.g. Jellyfin direct play), it is the full container,
+      // so mpv's audio stream index still applies.
       const result = await toResolvedMediaGenerationInput(
         mpvClient,
         streamOpenFilename,
         kind,
         'stream-open-filename',
-        isRemoteMediaPath(streamOpenFilename),
+        isRemoteMediaPath(streamOpenFilename) && streamOpenFilename !== currentVideoPath,
       );
       logResolvedMediaGenerationInput(options, currentVideoPath, result);
       return result;