diff --git a/app/src/main/java/com/fluxa/app/ui/catalog/NativeLibassSubtitleOverlay.kt b/app/src/main/java/com/fluxa/app/ui/catalog/NativeLibassSubtitleOverlay.kt
index fbaea01..46e5806 100644
--- a/app/src/main/java/com/fluxa/app/ui/catalog/NativeLibassSubtitleOverlay.kt
+++ b/app/src/main/java/com/fluxa/app/ui/catalog/NativeLibassSubtitleOverlay.kt
@@ -4,6 +4,7 @@ import android.content.Context
 import android.graphics.Bitmap
 import android.graphics.Canvas
 import android.net.Uri
+import android.os.SystemClock
 import android.util.Log
 import android.view.View
 import androidx.compose.runtime.Composable
@@ -19,6 +20,7 @@ import androidx.media3.common.Player
 import androidx.media3.exoplayer.ExoPlayer
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.fluxa.app.player.ExternalSubtitleTrack
+import com.fluxa.app.player.LibassDebugLog
 import com.fluxa.app.player.MediaPlayerController
 import com.fluxa.app.player.MediaTrack
 import com.fluxa.app.player.MkvNativeAssExtractor
@@ -72,6 +74,10 @@ internal fun NativeLibassSubtitleOverlay(
     var localRenderer by remember { mutableStateOf<NativeLibassRenderer?>(null) }
 
     LaunchedEffect(externalSubtitle?.url, embeddedSubtitle?.id) {
+        LibassDebugLog.d(
+            "overlay selection external=${externalSubtitle?.let { "${LibassDebugLog.urlSummary(it.url)} label=${it.label} lang=${it.language}" } ?: "<none>"} " +
+                "embedded=${embeddedSubtitle?.let { "id=${it.id} label=${it.label} lang=${it.language} bytes=${it.assData.size} fonts=${it.fonts.size}" } ?: "<none>"}"
+        )
         val previous = localRenderer
         localRenderer = null
         previous?.close()
@@ -83,19 +89,29 @@ internal fun NativeLibassSubtitleOverlay(
                     fonts = embedded.fonts,
                     fontsDir = context.filesDir.resolve("fonts").absolutePath
                 )
-            }.onFailure { e -> Log.w("NativeLibassOverlay", "Embedded renderer failed", e) }.getOrNull()
+            }.onFailure { e ->
+                Log.w("NativeLibassOverlay", "Embedded renderer failed", e)
+                LibassDebugLog.w("overlay embedded renderer failed id=${embedded.id}", e)
+            }.getOrNull()
+            LibassDebugLog.d("overlay embedded renderer ${if (localRenderer != null) "ready" else "not ready"} id=${embedded.id}")
             return@LaunchedEffect
         }
         val url = externalSubtitle?.url ?: return@LaunchedEffect
         localRenderer = runCatching {
             val data = fetchSubtitleBytes(context, url)
+            LibassDebugLog.d("overlay fetched external ASS bytes=${data.size} url=${LibassDebugLog.urlSummary(url)}")
             val fonts = MkvNativeAssExtractor.extractExternalFontHints(url)
+            LibassDebugLog.d("overlay external font hints fonts=${fonts.size} url=${LibassDebugLog.urlSummary(url)}")
             NativeLibassRenderer.create(
                 assData = data,
                 fonts = fonts,
                 fontsDir = context.filesDir.resolve("fonts").absolutePath
             )
-        }.onFailure { e -> Log.w("NativeLibassOverlay", "External renderer failed", e) }.getOrNull()
+        }.onFailure { e ->
+            Log.w("NativeLibassOverlay", "External renderer failed", e)
+            LibassDebugLog.w("overlay external renderer failed url=${LibassDebugLog.urlSummary(url)}", e)
+        }.getOrNull()
+        LibassDebugLog.d("overlay external renderer ${if (localRenderer != null) "ready" else "not ready"} url=${LibassDebugLog.urlSummary(url)}")
     }
 
     DisposableEffect(Unit) {
@@ -106,9 +122,14 @@ internal fun NativeLibassSubtitleOverlay(
     }
 
     val activeRenderer = when {
-        embeddedSubtitle != null -> relayRenderer ?: localRenderer
         externalSubtitle != null -> localRenderer
-        else -> null
+        else -> relayRenderer ?: localRenderer
+    }
+    LaunchedEffect(activeRenderer, relayRenderer, localRenderer, externalSubtitle?.url, embeddedSubtitle?.id) {
+        LibassDebugLog.d(
+            "overlay activeRenderer=${activeRenderer != null} relayRenderer=${relayRenderer != null} localRenderer=${localRenderer != null} " +
+                "external=${externalSubtitle != null} embedded=${embeddedSubtitle != null}"
+        )
     }
 
     AndroidView(
@@ -133,6 +154,9 @@ private class NativeLibassSubtitleView(context: Context) : View(context) {
 
     var renderer: NativeLibassRenderer? = null
         set(value) {
+            if (field !== value) {
+                LibassDebugLog.d("overlay view renderer changed active=${value != null} view=${width}x$height attached=$isAttachedToWindow")
+            }
             field = value
             if (isAttachedToWindow) postInvalidateOnAnimation()
         }
@@ -144,6 +168,8 @@ private class NativeLibassSubtitleView(context: Context) : View(context) {
         }
 
     private var bitmap: Bitmap? = null
+    private var lastDrawLogMs = 0L
+    private var lastDrawHadPixels: Boolean? = null
 
     private val playerListener = object : Player.Listener {
         override fun onIsPlayingChanged(isPlaying: Boolean) {
@@ -161,12 +187,14 @@ private class NativeLibassSubtitleView(context: Context) : View(context) {
 
     override fun onAttachedToWindow() {
         super.onAttachedToWindow()
+        LibassDebugLog.d("overlay view attached size=${width}x$height")
         player?.addListener(playerListener)
         postInvalidateOnAnimation()
     }
 
     override fun onDetachedFromWindow() {
         super.onDetachedFromWindow()
+        LibassDebugLog.d("overlay view detached")
         player?.removeListener(playerListener)
         bitmap?.recycle()
         bitmap = null
@@ -186,6 +214,15 @@ private class NativeLibassSubtitleView(context: Context) : View(context) {
 
         val result = activeRenderer.render(activePlayer.currentPosition + subtitleDelayMs, targetBitmap)
         if (result > 0) canvas.drawBitmap(targetBitmap, 0f, 0f, null)
+        val hasPixels = result > 0
+        val now = SystemClock.elapsedRealtime()
+        if (lastDrawHadPixels != hasPixels || now - lastDrawLogMs > 1_500L) {
+            LibassDebugLog.d(
+                "overlay draw positionMs=${activePlayer.currentPosition} delayMs=$subtitleDelayMs size=${width}x$height result=$result hasPixels=$hasPixels playing=${activePlayer.isPlaying} playWhenReady=${activePlayer.playWhenReady}"
+            )
+            lastDrawHadPixels = hasPixels
+            lastDrawLogMs = now
+        }
 
         if (activePlayer.isPlaying || activePlayer.playWhenReady) {
             if (result == 0) postInvalidateDelayed(100) else postInvalidateOnAnimation()