Integrated libass-android to enable advanced subtitle rendering

app/build.gradle.kts

@@ -138,6 +138,7 @@ dependencies {
 	implementation(libs.androidx.media3.exoplayer.hls)
 	implementation(libs.androidx.media3.ui)
 	implementation(libs.jellyfin.androidx.media3.ffmpeg.decoder)
+	implementation(libs.libass.media3)
 
 	// Markdown
 	implementation(libs.bundles.markwon)

app/src/main/java/org/jellyfin/androidtv/di/PlaybackModule.kt

@@ -71,6 +71,7 @@ fun Scope.createPlaybackManager() = playbackManager(androidContext()) {
 	val userPreferences = get<UserPreferences>()
 	val exoPlayerOptions = ExoPlayerOptions(
 		preferFfmpeg = userPreferences[UserPreferences.preferExoPlayerFfmpeg],
+		enableLibass = userPreferences[UserPreferences.assDirectPlay],
 		enableDebugLogging = userPreferences[UserPreferences.debuggingEnabled],
 		baseDataSourceFactory = get<HttpDataSource.Factory>(),
 	)

app/src/main/java/org/jellyfin/androidtv/preference/UserPreferences.kt

@@ -226,6 +226,21 @@ class UserPreferences(context: Context) : SharedPreferenceStore(
 		 */
 		var trickPlayEnabled = booleanPreference("trick_play_enabled", false)
 
+		/**
+		 * Enable libass.
+		 */
+		var assDirectPlay = booleanPreference( "libass_enabled", false )
+
+		/**
+		 * The maximum amount of glyphs libass can cache.
+		 */
+		var libassGlyphSize = intPreference("libass_glyph_size", 10000)
+
+		/**
+		 * The cache size in MB for libass.
+		 */
+		var libassCacheSize = intPreference("libass_cache_size", 128)
+
 		/**
   		 * Enable PGS subtitle direct-play.
 		 */

app/src/main/java/org/jellyfin/androidtv/ui/playback/VideoManager.java

@@ -39,6 +39,7 @@
 import androidx.media3.exoplayer.trackselection.DefaultTrackSelector;
 import androidx.media3.exoplayer.util.EventLogger;
 import androidx.media3.extractor.DefaultExtractorsFactory;
+import androidx.media3.extractor.ExtractorsFactory;
 import androidx.media3.extractor.ts.TsExtractor;
 import androidx.media3.ui.AspectRatioFrameLayout;
 import androidx.media3.ui.CaptionStyleCompat;
@@ -59,6 +60,13 @@
 import java.util.List;
 import java.util.Optional;
 
+import io.github.peerless2012.ass.media.AssHandler;
+import io.github.peerless2012.ass.media.AssHandlerConfig;
+import io.github.peerless2012.ass.media.factory.AssRenderersFactory;
+import io.github.peerless2012.ass.media.kt.AssPlayerKt;
+import io.github.peerless2012.ass.media.parser.AssSubtitleParserFactory;
+import io.github.peerless2012.ass.media.type.AssRenderType;
+import io.github.peerless2012.ass.media.widget.AssSubtitleView;
 import timber.log.Timber;
 
 @OptIn(markerClass = UnstableApi.class)
@@ -88,7 +96,13 @@ public VideoManager(@NonNull Activity activity, @NonNull View view, @NonNull Pla
         _helper = helper;
         nightModeEnabled = userPreferences.get(UserPreferences.Companion.getAudioNightMode());
 
-        mExoPlayer = configureExoplayerBuilder(activity).build();
+        boolean assDirectPlay = userPreferences.get(UserPreferences.Companion.getAssDirectPlay());
+        int libassGlypSize = userPreferences.get(UserPreferences.Companion.getLibassGlyphSize());
+        int libassCacheSizeMB = userPreferences.get(UserPreferences.Companion.getLibassCacheSize());
+
+        AssHandler assHandler = assDirectPlay ? new AssHandler(AssRenderType.OVERLAY_CANVAS, new AssHandlerConfig(libassGlypSize, libassCacheSizeMB)) : null;
+
+        mExoPlayer = configureExoplayerBuilder(activity, assHandler).build();
 
         if (userPreferences.get(UserPreferences.Companion.getDebuggingEnabled())) {
             mExoPlayer.addAnalyticsListener(new EventLogger());
@@ -120,6 +134,11 @@ public void onAudioSessionIdChanged(AnalyticsListener.EventTime eventTime, int a
         mExoPlayerView.getSubtitleView().setBottomPaddingFraction(userPreferences.get(UserPreferences.Companion.getSubtitlesOffsetPosition()));
         mExoPlayerView.getSubtitleView().setStyle(subtitleStyle);
 
+        if(assHandler != null){
+            assHandler.init(mExoPlayer);
+            mExoPlayerView.getSubtitleView().addView(new AssSubtitleView(mActivity,assHandler));
+        }
+
         mExoPlayer.addListener(new Player.Listener() {
             @Override
             public void onPlayerError(@NonNull PlaybackException error) {
@@ -198,7 +217,7 @@ private int determineExoPlayerExtensionRendererMode() {
      * @param context The associated context
      * @return A configured builder for Exoplayer
      */
-    private ExoPlayer.Builder configureExoplayerBuilder(Context context) {
+    private ExoPlayer.Builder configureExoplayerBuilder(Context context, AssHandler assHandler) {
         ExoPlayer.Builder exoPlayerBuilder = new ExoPlayer.Builder(context);
         DefaultRenderersFactory defaultRendererFactory = new DefaultRenderersFactory(context);
         defaultRendererFactory.setEnableDecoderFallback(true);
@@ -219,8 +238,17 @@ private ExoPlayer.Builder configureExoplayerBuilder(Context context) {
         extractorsFactory.setConstantBitrateSeekingEnabled(true);
         extractorsFactory.setConstantBitrateSeekingAlwaysEnabled(true);
         DefaultDataSource.Factory dataSourceFactory = new DefaultDataSource.Factory(context, exoPlayerHttpDataSourceFactory);
-        exoPlayerBuilder.setRenderersFactory(defaultRendererFactory);
-        exoPlayerBuilder.setMediaSourceFactory(new DefaultMediaSourceFactory(dataSourceFactory, extractorsFactory));
+        if (assHandler != null) {
+            AssSubtitleParserFactory assSubtitleParserFactory = new AssSubtitleParserFactory(assHandler);
+            ExtractorsFactory assExtractorsFactory = AssPlayerKt.withAssMkvSupport(extractorsFactory, assSubtitleParserFactory, assHandler);
+            DefaultMediaSourceFactory mediaSourceFactory = new DefaultMediaSourceFactory(dataSourceFactory, assExtractorsFactory);
+            mediaSourceFactory.setSubtitleParserFactory(assSubtitleParserFactory);
+            exoPlayerBuilder.setMediaSourceFactory(mediaSourceFactory);
+            exoPlayerBuilder.setRenderersFactory(new AssRenderersFactory(assHandler, defaultRendererFactory));
+        } else {
+            exoPlayerBuilder.setRenderersFactory(defaultRendererFactory);
+            exoPlayerBuilder.setMediaSourceFactory(new DefaultMediaSourceFactory(dataSourceFactory, extractorsFactory));
+        }
 
         exoPlayerBuilder.setAudioAttributes(new AudioAttributes.Builder()
                 .setUsage(C.USAGE_MEDIA)

app/src/main/java/org/jellyfin/androidtv/ui/settings/screen/SettingsDeveloperScreen.kt

@@ -1,26 +1,41 @@
 package org.jellyfin.androidtv.ui.settings.screen
 
 import android.text.format.Formatter
+import androidx.compose.foundation.interaction.MutableInteractionSource
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.sizeIn
+import androidx.compose.foundation.layout.width
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableLongStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
 import coil3.ImageLoader
 import org.jellyfin.androidtv.BuildConfig
 import org.jellyfin.androidtv.R
 import org.jellyfin.androidtv.preference.SystemPreferences
 import org.jellyfin.androidtv.preference.UserPreferences
 import org.jellyfin.androidtv.ui.base.Text
 import org.jellyfin.androidtv.ui.base.form.Checkbox
+import org.jellyfin.androidtv.ui.base.form.RangeControl
 import org.jellyfin.androidtv.ui.base.list.ListButton
+import org.jellyfin.androidtv.ui.base.list.ListControl
 import org.jellyfin.androidtv.ui.base.list.ListSection
 import org.jellyfin.androidtv.ui.settings.compat.rememberPreference
 import org.jellyfin.androidtv.ui.settings.composable.SettingsColumn
+import org.jellyfin.androidtv.util.dp
 import org.jellyfin.androidtv.util.isTvDevice
+import org.jellyfin.design.Tokens
 import org.koin.compose.koinInject
+import kotlin.math.roundToInt
 
 @Composable
 fun SettingsDeveloperScreen() {
@@ -29,6 +44,10 @@ fun SettingsDeveloperScreen() {
 	val context = LocalContext.current
 	val isTvDevice = remember(context) { context.isTvDevice() }
 	val isDeveloperBuild = BuildConfig.DEVELOPMENT
+	var libassEnabled by rememberPreference(
+		userPreferences,
+		UserPreferences.assDirectPlay
+	)
 
 	SettingsColumn {
 		item {
@@ -115,5 +134,95 @@ fun SettingsDeveloperScreen() {
 				}
 			)
 		}
+
+		item {
+			ListButton(
+				headingContent = { Text(stringResource(R.string.enable_libass_subtitles)) },
+				trailingContent = { Checkbox(checked = libassEnabled) },
+				captionContent = { Text(stringResource(R.string.enable_libass_subtitles_description)) },
+				onClick = { libassEnabled = !libassEnabled }
+			)
+		}
+
+		if(libassEnabled) {
+			item {
+				var glyphSize by rememberPreference(
+					userPreferences,
+					UserPreferences.libassGlyphSize
+				)
+
+				val interactionSource = remember { MutableInteractionSource() }
+
+				ListControl(
+					headingContent = { Text(stringResource(R.string.libass_glyph_size)) },
+					interactionSource = interactionSource,
+				) {
+					Row(
+						verticalAlignment = Alignment.CenterVertically,
+					) {
+						RangeControl(
+							modifier = Modifier
+								.height(4.dp)
+								.weight(1f),
+							interactionSource = interactionSource,
+							min = 0f,
+							max = 20_000f,
+							stepForward = 100f,
+							value = glyphSize.toFloat(),
+							onValueChange = { glyphSize = it.roundToInt() }
+						)
+
+						Spacer(Modifier.width(Tokens.Space.spaceSm))
+
+						Box(
+							modifier = Modifier.sizeIn(minWidth = 56.dp),
+							contentAlignment = Alignment.CenterEnd
+						) {
+							Text(glyphSize.toString())
+						}
+					}
+				}
+			}
+
+			item {
+				var cacheSizeMb by rememberPreference(
+					userPreferences,
+					UserPreferences.libassCacheSize
+				)
+
+				val interactionSource = remember { MutableInteractionSource() }
+
+				ListControl(
+					headingContent = { Text(stringResource(R.string.libass_cache_size)) },
+					interactionSource = interactionSource,
+				) {
+					Row(
+						verticalAlignment = Alignment.CenterVertically,
+					) {
+						RangeControl(
+							modifier = Modifier
+								.height(4.dp)
+								.weight(1f),
+							interactionSource = interactionSource,
+							min = 0f,
+							max = 1024f,
+							stepForward = 16f,
+							value = cacheSizeMb.toFloat(),
+							onValueChange = { cacheSizeMb = it.roundToInt() }
+						)
+
+						Spacer(Modifier.width(Tokens.Space.spaceSm))
+
+						Box(
+							modifier = Modifier.sizeIn(minWidth = 56.dp),
+							contentAlignment = Alignment.CenterEnd
+						) {
+							Text("$cacheSizeMb")
+						}
+					}
+				}
+			}
+
+		}
 	}
 }

app/src/main/java/org/jellyfin/androidtv/util/profile/deviceProfile.kt

@@ -83,7 +83,7 @@ fun createDeviceProfile(
 	maxBitrate = userPreferences.getMaxBitrate(),
 	isAC3Enabled = userPreferences[UserPreferences.ac3Enabled],
 	downMixAudio = userPreferences[UserPreferences.audioBehaviour] == AudioBehavior.DOWNMIX_TO_STEREO,
-	assDirectPlay = false,
+	assDirectPlay = userPreferences[UserPreferences.assDirectPlay],
 	pgsDirectPlay = userPreferences[UserPreferences.pgsDirectPlay],
 )
 

app/src/main/res/values/strings.xml

@@ -618,4 +618,8 @@
         <item quantity="one">%1$s album</item>
         <item quantity="other">%1$s albums</item>
     </plurals>
+    <string name="enable_libass_subtitles">Enable libass subtitles</string>
+    <string name="enable_libass_subtitles_description">Use libass for advanced subtitle rendering</string>
+    <string name="libass_glyph_size">Libass glyph size</string>
+    <string name="libass_cache_size">Libass cache size (MB)</string>
 </resources>

gradle/libs.versions.toml

@@ -36,6 +36,7 @@ kotest = "6.1.3"
 kotlin = "2.3.10"
 kotlinx-coroutines = "1.10.2"
 kotlinx-serialization = "1.10.0"
+libass-android = "0.4.0-beta01"
 markwon = "4.6.2"
 mockk = "1.14.9"
 slf4j-timber = "0.0.4"
@@ -100,6 +101,7 @@ androidx-media3-exoplayer-hls = { module = "androidx.media3:media3-exoplayer-hls
 androidx-media3-session = { module = "androidx.media3:media3-session", version.ref = "androidx-media3" }
 androidx-media3-ui = { module = "androidx.media3:media3-ui", version.ref = "androidx-media3" }
 jellyfin-androidx-media3-ffmpeg-decoder = { module = "org.jellyfin.media3:media3-ffmpeg-decoder", version.ref = "jellyfin-androidx-media" }
+libass-media3 = { module = "io.github.peerless2012:ass-media", version.ref = "libass-android" }
 
 # Markwon
 markwon-core = { module = "io.noties.markwon:core", version.ref = "markwon" }

playback/media3/exoplayer/build.gradle.kts

@@ -37,6 +37,7 @@ dependencies {
 	implementation(libs.androidx.media3.exoplayer.hls)
 	implementation(libs.jellyfin.androidx.media3.ffmpeg.decoder)
 	implementation(libs.androidx.media3.ui)
+	implementation(libs.libass.media3)
 
 	// Logging
 	implementation(libs.timber)

playback/media3/exoplayer/src/main/kotlin/ExoPlayerBackend.kt

@@ -22,6 +22,13 @@ import androidx.media3.exoplayer.util.EventLogger
 import androidx.media3.extractor.DefaultExtractorsFactory
 import androidx.media3.extractor.ts.TsExtractor
 import androidx.media3.ui.SubtitleView
+import io.github.peerless2012.ass.media.AssHandler
+import io.github.peerless2012.ass.media.AssHandlerConfig
+import io.github.peerless2012.ass.media.factory.AssRenderersFactory
+import io.github.peerless2012.ass.media.kt.withAssMkvSupport
+import io.github.peerless2012.ass.media.parser.AssSubtitleParserFactory
+import io.github.peerless2012.ass.media.type.AssRenderType
+import io.github.peerless2012.ass.media.widget.AssSubtitleView
 import org.jellyfin.playback.core.backend.BasePlayerBackend
 import org.jellyfin.playback.core.mediastream.MediaStream
 import org.jellyfin.playback.core.mediastream.PlayableMediaStream
@@ -57,6 +64,15 @@ class ExoPlayerBackend(
 	private val audioPipeline = ExoPlayerAudioPipeline()
 	private val audioAttributeState = AudioAttributeState()
 
+	private val assHandler by lazy{
+		AssHandler(AssRenderType.OVERLAY_CANVAS,
+			config = AssHandlerConfig(
+				glyphSize = exoPlayerOptions.libassGlyphSize,
+				cacheSize = exoPlayerOptions.libassCacheSizeMB
+			)
+		)
+	}
+
 	private val exoPlayer by lazy {
 		val dataSourceFactory = DefaultDataSource.Factory(
 			context,
@@ -74,7 +90,14 @@ class ExoPlayerBackend(
 			setConstantBitrateSeekingAlwaysEnabled(true)
 		}
 
-		val mediaSourceFactory = DefaultMediaSourceFactory(dataSourceFactory, extractorsFactory)
+		val mediaSourceFactory = if (exoPlayerOptions.enableLibass) {
+			val assSubtitleParserFactory = AssSubtitleParserFactory(assHandler)
+			val assExtractorsFactory = extractorsFactory.withAssMkvSupport(assSubtitleParserFactory, assHandler)
+			DefaultMediaSourceFactory(dataSourceFactory, assExtractorsFactory).apply {
+				setSubtitleParserFactory(assSubtitleParserFactory)
+			}
+		} else DefaultMediaSourceFactory(dataSourceFactory, extractorsFactory)
+
 		val renderersFactory = DefaultRenderersFactory(context).apply {
 			setEnableDecoderFallback(true)
 			setExtensionRendererMode(
@@ -83,6 +106,9 @@ class ExoPlayerBackend(
 					false -> DefaultRenderersFactory.EXTENSION_RENDERER_MODE_ON
 				}
 			)
+		}.let { rendersFactory ->
+			if (exoPlayerOptions.enableLibass) AssRenderersFactory(assHandler, rendersFactory)
+			else rendersFactory
 		}
 
 		ExoPlayer.Builder(context)
@@ -106,6 +132,10 @@ class ExoPlayerBackend(
 				if (exoPlayerOptions.enableDebugLogging) {
 					player.addAnalyticsListener(EventLogger())
 				}
+
+				if(exoPlayerOptions.enableLibass){
+					assHandler.init(player)
+				}
 			}
 	}
 
@@ -164,7 +194,11 @@ class ExoPlayerBackend(
 	override fun setSubtitleView(surfaceView: PlayerSubtitleView?) {
 		if (surfaceView != null) {
 			if (subtitleView == null) {
-				subtitleView = SubtitleView(surfaceView.context)
+				subtitleView = SubtitleView(surfaceView.context).apply{
+					if(exoPlayerOptions.enableLibass){
+						addView(AssSubtitleView(surfaceView.context, assHandler ))
+					}
+				}
 			}
 
 			surfaceView.addView(subtitleView)

playback/media3/exoplayer/src/main/kotlin/ExoPlayerOptions.kt

@@ -6,5 +6,8 @@ import androidx.media3.datasource.DefaultHttpDataSource
 data class ExoPlayerOptions(
 	val preferFfmpeg: Boolean = false,
 	val enableDebugLogging: Boolean = false,
+	val enableLibass: Boolean = false,
+	val libassGlyphSize: Int = 0,
+	val libassCacheSizeMB: Int = 0,
 	val baseDataSourceFactory: DataSource.Factory = DefaultHttpDataSource.Factory(),
 )