Add android graceful fallback to transcode & onPlaybackFailed event

android/app/src/main/java/com/audiobookshelf/app/data/PlaybackSession.kt

@@ -48,6 +48,8 @@ class PlaybackSession(
   @get:JsonIgnore
   val isHLS get() = playMethod == PLAYMETHOD_TRANSCODE
   @get:JsonIgnore
+  val isDirectPlay get() = playMethod == PLAYMETHOD_DIRECTPLAY
+  @get:JsonIgnore
   val isLocal get() = playMethod == PLAYMETHOD_LOCAL
   @get:JsonIgnore
   val currentTimeMs get() = (currentTime * 1000L).toLong()

android/app/src/main/java/com/audiobookshelf/app/player/PlayerListener.kt

@@ -15,8 +15,9 @@ class PlayerListener(var playerNotificationService:PlayerNotificationService) :
   private var onSeekBack: Boolean = false
 
   override fun onPlayerError(error: PlaybackException) {
-    error.message?.let { Log.e(tag, it) }
-    error.localizedMessage?.let { Log.e(tag, it) }
+    var errorMessage = error.message ?: "Unknown Error"
+    Log.e(tag, "onPlayerError $errorMessage")
+    playerNotificationService.handlePlayerPlaybackError(errorMessage) // If was direct playing session, fallback to transcode
   }
 
   override fun onEvents(player: Player, events: Player.Events) {

android/app/src/main/java/com/audiobookshelf/app/player/PlayerNotificationService.kt

@@ -55,6 +55,7 @@ class PlayerNotificationService : MediaBrowserServiceCompat()  {
     fun onSleepTimerEnded(currentPosition: Long)
     fun onSleepTimerSet(sleepTimeRemaining: Int)
     fun onLocalMediaProgressUpdate(localMediaProgress: LocalMediaProgress)
+    fun onPlaybackFailed(errorMessage:String)
   }
 
   private val tag = "PlayerService"
@@ -289,7 +290,6 @@ class PlayerNotificationService : MediaBrowserServiceCompat()  {
     mediaSession.setMetadata(metadata)
     var mediaItems = playbackSession.getMediaItems()
     if (mPlayer == currentPlayer) {
-
       var mediaSource:MediaSource
 
       if (playbackSession.isLocal) {
@@ -333,6 +333,26 @@ class PlayerNotificationService : MediaBrowserServiceCompat()  {
     currentPlayer.prepare()
   }
 
+  fun handlePlayerPlaybackError(errorMessage:String) {
+    // On error and was attempting to direct play - fallback to transcode
+    currentPlaybackSession?.let { playbackSession ->
+      if (playbackSession.isDirectPlay) {
+        Log.d(tag, "Fallback to transcode")
+
+        var libraryItemId = playbackSession.libraryItemId ?: "" // Must be true since direct play
+        var episodeId = playbackSession.episodeId
+        apiHandler.playLibraryItem(libraryItemId, episodeId, true) {
+          Handler(Looper.getMainLooper()).post() {
+            preparePlayer(it, true)
+          }
+        }
+      } else {
+        clientEventEmitter?.onPlaybackFailed(errorMessage)
+        closePlayback()
+      }
+    }
+  }
+
   fun switchToPlayer(useCastPlayer: Boolean) {
     currentPlayer = if (useCastPlayer) {
       Log.d(tag, "switchToPlayer: Using Cast Player " + castPlayer?.deviceInfo)

android/app/src/main/java/com/audiobookshelf/app/plugins/AbsAudioPlayer.kt

@@ -68,6 +68,10 @@ class AbsAudioPlayer : Plugin() {
         override fun onLocalMediaProgressUpdate(localMediaProgress: LocalMediaProgress) {
           notifyListeners("onLocalMediaProgressUpdate", JSObject(jacksonMapper.writeValueAsString(localMediaProgress)))
         }
+
+        override fun onPlaybackFailed(errorMessage: String) {
+          emit("onPlaybackFailed", errorMessage)
+        }
       })
     }
     mainActivity.pluginCallback = foregroundServiceReady

android/app/src/main/java/com/audiobookshelf/app/server/ApiHandler.kt

@@ -151,12 +151,11 @@ class ApiHandler {
     }
   }
 
-  fun playLibraryItem(libraryItemId:String, episodeId:String, forceTranscode:Boolean, cb: (PlaybackSession) -> Unit) {
+  fun playLibraryItem(libraryItemId:String, episodeId:String?, forceTranscode:Boolean, cb: (PlaybackSession) -> Unit) {
     var payload = JSObject()
     payload.put("mediaPlayer", "exo-player")
 
     // Only if direct play fails do we force transcode
-    // TODO: Fallback to transcode
     if (!forceTranscode) payload.put("forceDirectPlay", true)
     else payload.put("forceTranscode", true)