Show the audio track playback starts on in Details

packages/app/src/services/playback.js

@@ -297,7 +297,7 @@ const buildPlaybackUrl = (itemId, mediaSource, playSessionId, playMethod, creden
 	throw new Error('No playback URL available');
 };
 
-const extractAudioStreams = (mediaSource) => {
+export const extractAudioStreams = (mediaSource) => {
 	if (!mediaSource.MediaStreams) return [];
 	return mediaSource.MediaStreams
 		.filter(s => s.Type === 'Audio')

packages/app/src/views/Details/Details.js

@@ -8,6 +8,8 @@ import {useSettings} from '../../context/SettingsContext';
 import {useSeerr} from '../../context/SeerrContext';
 import {useSyncPlay} from '../../context/SyncPlayContext';
 import * as jellyfinApi from '../../services/jellyfinApi';
+import {extractAudioStreams} from '../../services/playback';
+import {initialAudioPosition} from '../Player/initialAudio';
 import ModernDetailContent from './ModernDetailContent';
 import DetailSkeleton from './DetailSkeleton';
 import {formatDuration, getImageUrl, getBackdropId, getLogoUrl} from '../../utils/helpers';
@@ -572,19 +574,13 @@ const Details = ({itemId: itemIdProp, initialItem, onPlay, onSelectItem, onSelec
 		}
 	}, [remoteSubtitleResults, item, effectiveApi, selectedVersionIndex, closeModal, tagWithServerInfo, setItem, setSelectedSubtitleIndex]);
 
-	const handleSelectVersion = useCallback((e) => {
+	const handleSelectVersion = useCallback(async (e) => {
 		const index = parseInt(e.currentTarget.dataset.index, 10);
 		if (isNaN(index) || !item?.MediaSources?.[index]) return;
 		setSelectedVersionIndex(index);
 		const ms = item.MediaSources[index];
-		const versionAudioStreams = ms.MediaStreams?.filter(s => s.Type === 'Audio') || [];
 		const versionSubtitleStreams = ms.MediaStreams?.filter(s => s.Type === 'Subtitle') || [];
-		if (ms.DefaultAudioStreamIndex != null) {
-			const idx = versionAudioStreams.findIndex(s => s.Index === ms.DefaultAudioStreamIndex);
-			setSelectedAudioIndex(idx >= 0 ? idx : 0);
-		} else {
-			setSelectedAudioIndex(0);
-		}
+		setSelectedAudioIndex(await initialAudioPosition(item, extractAudioStreams(ms), settings));
 		// A different version brings its own tracks, so whatever was picked for the old
 		// one no longer stands.
 		subtitleChosenRef.current = false;
@@ -596,7 +592,7 @@ const Details = ({itemId: itemIdProp, initialItem, onPlay, onSelectItem, onSelec
 			setSelectedSubtitleIndex(-1);
 		}
 		closeModal();
-	}, [item, closeModal, setSelectedVersionIndex, setSelectedAudioIndex, setSelectedSubtitleIndex]);
+	}, [item, settings, closeModal, setSelectedVersionIndex, setSelectedAudioIndex, setSelectedSubtitleIndex]);
 
 	const handleSeasonSelect = useCallback((ev) => {
 		const seasonId = ev.currentTarget.dataset.seasonId;

packages/app/src/views/Details/useDetailsItem.js

@@ -2,8 +2,9 @@ import {useState, useEffect, useCallback, useMemo, useRef} from 'react';
 import $L from '@enact/i18n/$L';
 
 import * as playback from '../../services/playback';
+import {initialAudioPosition} from '../Player/initialAudio';
 import {fetchTmdbSeasonRatings, resolveSeriesTmdbId, isRatingSourceAllowed} from '../../services/mdblistApi';
-import {getItemSubtitlePref, getSeriesSubtitlePref, getSeriesAudioPref} from '../../services/subtitlePrefs';
+import {getItemSubtitlePref, getSeriesSubtitlePref} from '../../services/subtitlePrefs';
 import {fromServerStream, matchSeriesTrackIndex} from '../../utils/seriesTrackPrefs';
 import {findParentCollections} from './parentCollection';
 import {canScoreSeedLocally, getOnlineRecommendations, getRecommendations, mergeRecommendations} from '../../services/homeRecommendations';
@@ -187,23 +188,8 @@ const useDetailsItem = ({itemId, initialItem, effectiveApi, effectiveServerUrl,
 			setSelectedVersionIndex(0);
 			const ms = data.MediaSources?.[0];
 			if (ms) {
-				const initAudioStreams = ms.MediaStreams?.filter(s => s.Type === 'Audio') || [];
 				const initSubtitleStreams = ms.MediaStreams?.filter(s => s.Type === 'Subtitle') || [];
-				// A track remembered for the series shows as active, and only when there
-				// is none does the server's own default stand in.
-				const seriesAudioPref = data.SeriesId ? await getSeriesAudioPref(data.SeriesId) : undefined;
-				const matchedAudio = seriesAudioPref
-					? matchSeriesTrackIndex(initAudioStreams.map(fromServerStream), seriesAudioPref)
-					: null;
-				const rememberedAudioPos = matchedAudio !== null && matchedAudio >= 0
-					? initAudioStreams.findIndex(s => s.Index === matchedAudio)
-					: -1;
-				if (rememberedAudioPos >= 0) {
-					setSelectedAudioIndex(rememberedAudioPos);
-				} else if (ms.DefaultAudioStreamIndex != null) {
-					const idx = initAudioStreams.findIndex(s => s.Index === ms.DefaultAudioStreamIndex);
-					if (idx >= 0) setSelectedAudioIndex(idx);
-				}
+				setSelectedAudioIndex(await initialAudioPosition(data, playback.extractAudioStreams(ms), settingsRef.current));
 				// Show the remembered pick as active so it doesn't look like it needs
 				// reselecting. The per-item index restores the exact track, and an episode
 				// otherwise inherits its series' remembered language.

packages/app/src/views/Player/initialAudio.js

@@ -1,4 +1,5 @@
 import {getSeriesAudioPref} from '../../services/subtitlePrefs';
+import {selectPreferredAudioStream} from '../../utils/audioTrackSelection';
 import {matchSeriesTrackIndex} from '../../utils/seriesTrackPrefs';
 
 /**
@@ -16,3 +17,12 @@ export const resolveSeriesAudio = async (item, audioStreams) => {
 
 	return audioStreams.find((stream) => stream.index === matched) || null;
 };
+
+/**
+ * Where among these audio tracks the player starts when none is picked, so Details
+ * can show that track.
+ */
+export const initialAudioPosition = async (item, audioStreams, settings) => {
+	const start = await resolveSeriesAudio(item, audioStreams) || selectPreferredAudioStream(audioStreams, settings);
+	return Math.max(0, audioStreams.indexOf(start));
+};

packages/app/src/views/Player/initialAudio.test.js

@@ -0,0 +1,26 @@
+import {initialAudioPosition} from './initialAudio';
+import {getSeriesAudioPref} from '../../services/subtitlePrefs';
+
+jest.mock('../../services/subtitlePrefs', () => ({
+	getSeriesAudioPref: jest.fn()
+}));
+
+const jpn = {index: 1, language: 'jpn', isDefault: true, channels: 2};
+const spa = {index: 2, language: 'spa', isDefault: false, channels: 2};
+const episode = {Id: 'episode-1', SeriesId: 'series-1'};
+
+beforeEach(() => {
+	getSeriesAudioPref.mockResolvedValue(undefined);
+});
+
+describe('initialAudioPosition', () => {
+	test('is the fallback language rather than the default track, as the player picks', async () => {
+		const settings = {audioLanguage: 'cat', fallbackAudioLanguage: 'spa'};
+		expect(await initialAudioPosition(episode, [jpn, spa], settings)).toBe(1);
+	});
+
+	test('puts the track remembered for the series before the language preferences', async () => {
+		getSeriesAudioPref.mockResolvedValue({language: 'jpn', title: '', relativeIndex: 0});
+		expect(await initialAudioPosition(episode, [jpn, spa], {audioLanguage: 'spa'})).toBe(0);
+	});
+});