fix(windows): make VLC playback work through the stream proxy

The proxy copied every upstream header, duplicating Content-Length, which VLC
rejects. Forward only the range/validator headers. Bump vlcj-bundler to 0.2.1,
which bundles the Matroska demuxer needed for WebM. Make StreamingUrlRepository's
platform injectable and add VLC log switch via DebugConfig.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

composeApp/src/commonMain/kotlin/org/spotube/spotube/core/DebugConfig.kt

@@ -39,4 +39,6 @@ object DebugConfig {
      * Keep it `false` when committing.
      */
     const val FORCE_SUPPORT_REMINDER: Boolean = false
+
+    const val FORCE_VLC_LOGS: Boolean = false
 }

composeApp/src/commonMain/kotlin/org/spotube/spotube/core/server/StreamProxy.kt

@@ -425,7 +425,7 @@ internal class StreamProxy(
         if (requestMethod == HttpMethod.Head) {
             call.respond(object : OutgoingContent.NoContent() {
                 override val status: HttpStatusCode = upstream.status
-                override val headers: Headers = downstreamHeaders
+                override val headers: Headers = downstreamHeaders.passthroughForPlayer()
                 override val contentLength: Long? = downstreamContentLength
             })
             return
@@ -446,7 +446,7 @@ internal class StreamProxy(
 
         call.respond(object : OutgoingContent.WriteChannelContent() {
             override val status: HttpStatusCode = upstream.status
-            override val headers: Headers = downstreamHeaders
+            override val headers: Headers = downstreamHeaders.passthroughForPlayer()
             override val contentLength: Long? = downstreamContentLength
             override val contentType: ContentType? =
                 downstreamHeaders[HttpHeaders.ContentType]?.let(ContentType.Companion::parse)
@@ -594,4 +594,28 @@ internal class StreamProxy(
             }
         }.build()
     }
+
+}
+
+private val PLAYER_PASSTHROUGH_HEADERS = listOf(
+    HttpHeaders.ContentRange,
+    HttpHeaders.AcceptRanges,
+    HttpHeaders.ETag,
+    HttpHeaders.LastModified,
+)
+
+/**
+ * The upstream headers a player actually needs. Copying them all makes Ktor emit duplicate
+ * Content-Length/Content-Type (also set through the OutgoingContent) and forwards hop-by-hop
+ * headers like `Connection: keep-alive`, which VLC rejects by closing the socket right after
+ * the response headers. Content-Range and Accept-Ranges must stay: without them the player
+ * treats a 206 as invalid and the stream as unseekable, and e.g. WebM can't be demuxed.
+ */
+internal fun Headers.passthroughForPlayer(): Headers {
+    val upstream = this
+    return HeadersBuilder().apply {
+        PLAYER_PASSTHROUGH_HEADERS.forEach { name ->
+            upstream.getAll(name)?.forEach { value -> append(name, value) }
+        }
+    }.build()
 }

composeApp/src/commonMain/kotlin/org/spotube/spotube/core/server/StreamingUrlRepository.kt

@@ -80,7 +80,8 @@ class StreamingUrlRepository(
     private val audioPlayerQueue: AudioPlayerQueue,
     private val matchedTracksRepository: TrackSourceRepository,
     private val settingsRepository: UserSettingsSource,
-    private val streamUrlCacheTtlMs: Long = 30.seconds.inWholeMilliseconds) : KoinComponent {
+    private val streamUrlCacheTtlMs: Long = 30.seconds.inWholeMilliseconds,
+    private val platform: PlatformType = currentPlatform) : KoinComponent {
 
     private val logger by injectLogger<StreamingUrlRepository>()
     private val streamUrlCacheMutex = Mutex()
@@ -145,7 +146,7 @@ class StreamingUrlRepository(
             } else {
                 stream.streams
             }
-            return selectPreferredAudioStream(candidates, preferredFormat, preferredQuality)
+            return selectPreferredAudioStream(candidates, preferredFormat, preferredQuality, platform)
                 .also { logSelection(trackId, origin, candidates, preferredFormat, preferredQuality, it) }
         }
 
@@ -259,7 +260,7 @@ class StreamingUrlRepository(
                 "lowest wins):\n" +
                 streams.joinToString("\n") { stream ->
                     val marker = if (stream === selected) "  -> " else "     "
-                    "$marker${stream.describeForLog()} key=(${if (stream.isPlayableOn(currentPlatform)) 0 else 1}, " +
+                    "$marker${stream.describeForLog()} key=(${if (stream.isPlayableOn(platform)) 0 else 1}, " +
                         "${formatMismatchCount(stream, preferredFormat)}, " +
                         "${if (stream.matchesQualityType(preferredQuality)) 0 else 1}, " +
                         "${stream.qualityDistance(preferredQuality).let { if (it == Long.MAX_VALUE) "inf" else "$it" }}, " +
@@ -268,8 +269,8 @@ class StreamingUrlRepository(
         }
         when {
             selected == null -> logger.w { "[Resolve $trackId] no stream selected" }
-            !selected.isPlayableOn(currentPlatform) -> logger.w {
-                "[Resolve $trackId] NO PLAYABLE STREAM on $currentPlatform; falling back to " +
+            !selected.isPlayableOn(platform) -> logger.w {
+                "[Resolve $trackId] NO PLAYABLE STREAM on $platform; falling back to " +
                     "${selected.describeForLog()}, which the player will likely reject"
             }
             formatMismatchCount(selected, preferredFormat) > 0 -> logger.w {
@@ -424,12 +425,16 @@ internal fun selectPreferredAudioStream(
     }
 )
 
-// AVPlayer has no WebM/Ogg/Matroska demuxer, so e.g. YouTube's opus/webm streams fail to load.
-private val IOS_UNSUPPORTED_CONTAINERS = setOf("webm", "ogg", "oga", "mkv", "matroska")
+private val MATROSKA_CONTAINERS = setOf("webm", "mkv", "matroska")
+
+// Containers a platform's player can't open, so e.g. YouTube's opus/webm streams fail to load there.
+private val UNSUPPORTED_CONTAINERS: Map<PlatformType, Set<String>> = mapOf(
+    // AVPlayer has no WebM/Ogg/Matroska demuxer.
+    PlatformType.IOS to MATROSKA_CONTAINERS + setOf("ogg", "oga"))
 
 /**
- * Whether [platform]'s player can play this stream. VLC (desktop) and ExoPlayer (Android)
- * handle everything plugins return; AVPlayer (iOS) can't demux WebM/Ogg and can't play DASH.
+ * Whether [platform]'s player can play this stream. ExoPlayer (Android) and VLC elsewhere handle
+ * everything plugins return; AVPlayer (iOS) can't demux WebM/Ogg and can't play DASH.
  */
 internal fun AudioStream.isPlayableOn(platform: PlatformType): Boolean =
     isContainerPlayableOn(container, platform) &&
@@ -437,7 +442,7 @@ internal fun AudioStream.isPlayableOn(platform: PlatformType): Boolean =
 
 /** Whether [platform]'s player can open [container] at all; see [AudioStream.isPlayableOn]. */
 internal fun isContainerPlayableOn(container: String, platform: PlatformType): Boolean =
-    platform != PlatformType.IOS || container.lowercase() !in IOS_UNSUPPORTED_CONTAINERS
+    container.lowercase() !in UNSUPPORTED_CONTAINERS[platform].orEmpty()
 
 private fun formatMismatchCount(stream: AudioStream, preferredFormat: AudioFormat): Int =
     (if (stream.codec.equals(preferredFormat.codec, ignoreCase = true)) 0 else 1) +

composeApp/src/commonMain/kotlin/org/spotube/spotube/modules/settings/SettingsModels.kt

@@ -108,14 +108,14 @@ data class JamBroker(
     val connectionTimeoutSeconds: Int = 10)
 
 /**
- * opus/webm everywhere except iOS, whose AVPlayer can't open WebM/Ogg, so it streams AAC.
+ * opus/webm wherever the platform's player can open WebM; iOS (AVPlayer) can't, so it streams AAC.
  * TODO: revisit once iOS can play Opus (e.g. remuxing to CAF or a non-AVPlayer backend).
  */
 internal fun defaultStreamingMusicFormat(platform: PlatformType = currentPlatform): AudioFormat {
-    val ios = platform == PlatformType.IOS
+    val aac = !isContainerPlayableOn("webm", platform)
     return AudioFormat(
-        codec = if (ios) "aac" else "opus",
-        container = if (ios) "mp4" else "webm",
+        codec = if (aac) "aac" else "opus",
+        container = if (aac) "mp4" else "webm",
         qualities = listOf(
             AudioQuality.Lossy(bitrate = 44_000),
             AudioQuality.Lossy(bitrate = 96_000),

composeApp/src/commonTest/kotlin/org/spotube/spotube/core/server/StreamProxyHeadersTest.kt

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2026 Kingkor Roy Tirtho and Spotube Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package org.spotube.spotube.core.server
+
+import io.ktor.http.HeadersBuilder
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertNull
+
+class StreamProxyHeadersTest {
+
+    // Lowercase names and values as googlevideo sends them
+    private val upstream = HeadersBuilder().apply {
+        append("accept-ranges", "bytes")
+        append("alt-svc", "h3=\":443\"")
+        append("cache-control", "private, max-age=21298")
+        append("connection", "keep-alive")
+        append("content-length", "3523553")
+        append("content-range", "bytes 0-3523552/3523553")
+        append("content-type", "audio/webm")
+        append("last-modified", "Tue, 18 Feb 2025 22:42:11 GMT")
+    }.build()
+
+    @Test
+    fun `keeps the headers a player needs to seek`() {
+        val forwarded = upstream.passthroughForPlayer()
+        assertEquals("bytes 0-3523552/3523553", forwarded["Content-Range"])
+        assertEquals("bytes", forwarded["Accept-Ranges"])
+        assertEquals("Tue, 18 Feb 2025 22:42:11 GMT", forwarded["Last-Modified"])
+    }
+
+    @Test
+    fun `drops headers that are duplicated or hop-by-hop`() {
+        val forwarded = upstream.passthroughForPlayer()
+        // Length and type are set on the OutgoingContent; forwarding them too emits them twice
+        assertNull(forwarded["Content-Length"])
+        assertNull(forwarded["Content-Type"])
+        assertNull(forwarded["Connection"])
+        assertNull(forwarded["Alt-Svc"])
+        assertNull(forwarded["Cache-Control"])
+    }
+}

composeApp/src/commonTest/kotlin/org/spotube/spotube/core/server/StreamingUrlRepositoryBehaviorTest.kt

@@ -5,6 +5,7 @@ import org.spotube.plugin_interfaces.plugin_apis.audio.AudioSource
 import org.spotube.plugin_interfaces.plugin_apis.audio.AudioStream
 import org.spotube.plugin_interfaces.plugin_apis.audio.StreamProtocol
 import org.spotube.plugin_interfaces.plugin_apis.metadata.track.MetadataTrack
+import org.spotube.spotube.PlatformType
 import org.spotube.spotube.core.audioplayer.QueueEntry
 import org.spotube.spotube.modules.settings.UserSettings
 import co.touchlab.kermit.Logger
@@ -99,7 +100,9 @@ class StreamingUrlRepositoryBehaviorTest {
             audioPlayerQueue = queue,
             matchedTracksRepository = matchedTracksRepository,
             settingsRepository = settings,
-            streamUrlCacheTtlMs = cacheTtlMs)
+            streamUrlCacheTtlMs = cacheTtlMs,
+            // Not the host's platform: Windows and iOS don't prefer opus/webm
+            platform = PlatformType.Linux)
 
         fun selectPlugin(pluginId: String, audioAPI: FakeAudioAPI = FakeAudioAPI()): FakeAudioPluginService {
             val service = FakeAudioPluginService(pluginId, audioAPI)
@@ -236,6 +239,11 @@ class StreamingUrlRepositoryBehaviorTest {
             )
         }
 
+        // The default format depends on the host platform (aac/mp4 on Windows and iOS)
+        h.settings.update {
+            copy(streamingMusicFormat = streamingMusicFormat.copy(codec = "opus", container = "webm"))
+        }
+
         val first = h.repository.resolveStreamInfo(t)
         assertEquals("https://example.com/opus.webm", first?.url)
 

composeApp/src/commonTest/kotlin/org/spotube/spotube/modules/settings/StreamingFormatDefaultsTest.kt

@@ -35,8 +35,10 @@ class StreamingFormatDefaultsTest {
 
     @Test
     fun `other platforms keep opus in webm`() {
-        val format = defaultStreamingMusicFormat(PlatformType.Android)
-        assertEquals("opus" to "webm", format.codec to format.container)
+        listOf(PlatformType.Android, PlatformType.Linux, PlatformType.MacOS, PlatformType.Windows).forEach { platform ->
+            val format = defaultStreamingMusicFormat(platform)
+            assertEquals("opus" to "webm", format.codec to format.container, platform.name)
+        }
     }
 
     @Test

composeApp/src/jvmMain/kotlin/org/spotube/spotube/core/audioplayer/AudioPlayer.jvm.kt

@@ -34,6 +34,7 @@ import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.isActive
 import kotlinx.coroutines.launch
 import org.koin.core.component.KoinComponent
+import org.spotube.spotube.core.DebugConfig
 import uk.co.caprica.vlcj.factory.MediaPlayerFactory
 import uk.co.caprica.vlcj.factory.discovery.NativeDiscovery
 import uk.co.caprica.vlcj.medialist.MediaList
@@ -87,11 +88,13 @@ actual class AudioPlayer actual constructor(context: Any) : AudioPlayerInterface
     private val _error = MutableSharedFlow<Throwable>(extraBufferCapacity = 1)
 
     actual override val playerStateFlow: StateFlow<PlayerState> = _playerState.asStateFlow()
-    actual override val currentMediaItemFlow: StateFlow<MediaItem?> = _currentMediaItem.asStateFlow()
+    actual override val currentMediaItemFlow: StateFlow<MediaItem?> =
+        _currentMediaItem.asStateFlow()
     actual override val playlistFlow: StateFlow<List<MediaItem>> = _playlist.asStateFlow()
     actual override val durationFlow: StateFlow<Duration> = _duration.asStateFlow()
     actual override val positionFlow: StateFlow<Duration> = _position.asStateFlow()
-    actual override val bufferingPositionFlow: StateFlow<Duration> = _bufferingPosition.asStateFlow()
+    actual override val bufferingPositionFlow: StateFlow<Duration> =
+        _bufferingPosition.asStateFlow()
     actual override val loopStateFlow: StateFlow<LoopState> = _loopState.asStateFlow()
     actual override val shuffleModeFlow: StateFlow<Boolean> = _shuffleMode.asStateFlow()
     actual override val playbackSpeedFlow: StateFlow<Float> = _playbackSpeed.asStateFlow()
@@ -101,6 +104,7 @@ actual class AudioPlayer actual constructor(context: Any) : AudioPlayerInterface
 
     init {
         VLCBundleLoaderGenerated.getVerifiedPath()
+        val vlcLogArgs = if (DebugConfig.FORCE_VLC_LOGS) arrayOf("--verbose=2") else emptyArray()
         mediaPlayerFactory = MediaPlayerFactory(
             null as NativeDiscovery?,
             "--no-video",
@@ -108,8 +112,7 @@ actual class AudioPlayer actual constructor(context: Any) : AudioPlayerInterface
             "--aout=any",
             "--no-osd",
             "--no-snapshot-preview",
-//            "--verbose=2"
-//            "--quiet"
+            *vlcLogArgs
         )
         audioListPlayerComponent = object : AudioListPlayerComponent(mediaPlayerFactory) {
             override fun opening(mediaPlayer: MediaPlayer) {
@@ -122,7 +125,8 @@ actual class AudioPlayer actual constructor(context: Any) : AudioPlayerInterface
             ) {
                 val durationMs = mediaPlayer.status().length()
                 _bufferingPosition.tryEmit(
-                    if (durationMs > 0) (durationMs * (newCache / 100f)).toLong().milliseconds else Duration.ZERO)
+                    if (durationMs > 0) (durationMs * (newCache / 100f)).toLong().milliseconds else Duration.ZERO
+                )
                 _playerState.tryEmit(if (newCache < 100f) PlayerState.BUFFERING else PlayerState.READY)
             }
 
@@ -184,7 +188,8 @@ actual class AudioPlayer actual constructor(context: Any) : AudioPlayerInterface
 
             override fun nextItem(
                 mediaListPlayer: uk.co.caprica.vlcj.player.list.MediaListPlayer,
-                item: uk.co.caprica.vlcj.media.MediaRef) {
+                item: uk.co.caprica.vlcj.media.MediaRef
+            ) {
                 lock.withLock {
                     val targetIndex = pendingNextIndex ?: run {
                         val currentMrl = runCatching {
@@ -336,7 +341,11 @@ actual class AudioPlayer actual constructor(context: Any) : AudioPlayerInterface
         }
     }
 
-    actual override suspend fun load(playlist: List<MediaItem>, autoPlay: Boolean, startPosition: Int) {
+    actual override suspend fun load(
+        playlist: List<MediaItem>,
+        autoPlay: Boolean,
+        startPosition: Int
+    ) {
         lock.withLock {
             if (disposed) return
 

gradle/libs.versions.toml

@@ -72,7 +72,7 @@ ksp = "2.3.12"
 spotube-gradle = "0.1.2"
 cryptography = "0.6.0"
 reorderable = "3.1.0"
-vlcjBundler = "0.2.0"
+vlcjBundler = "0.2.1"
 vanniktechMavenPublish = "0.37.0"
 uniffi = "0.3.7"
 kotlinx-atomicfu = "0.33.0"