diff --git a/demos/cast/src/main/java/com/google/android/exoplayer2/castdemo/PlayerManager.java b/demos/cast/src/main/java/com/google/android/exoplayer2/castdemo/PlayerManager.java
index 70c4831bc5..9956cc827b 100644
--- a/demos/cast/src/main/java/com/google/android/exoplayer2/castdemo/PlayerManager.java
+++ b/demos/cast/src/main/java/com/google/android/exoplayer2/castdemo/PlayerManager.java
@@ -79,8 +79,8 @@ import java.util.ArrayList;
   private final CastPlayer castPlayer;
   private final ArrayList<DemoUtil.Sample> mediaQueue;
   private final QueuePositionListener queuePositionListener;
+  private final ConcatenatingMediaSource concatenatingMediaSource;
 
-  private ConcatenatingMediaSource concatenatingMediaSource;
   private boolean castMediaQueueCreationPending;
   private int currentItemIndex;
   private Player currentPlayer;
@@ -116,6 +116,7 @@ import java.util.ArrayList;
     this.castControlView = castControlView;
     mediaQueue = new ArrayList<>();
     currentItemIndex = C.INDEX_UNSET;
+    concatenatingMediaSource = new ConcatenatingMediaSource();
 
     DefaultTrackSelector trackSelector = new DefaultTrackSelector(BANDWIDTH_METER);
     RenderersFactory renderersFactory = new DefaultRenderersFactory(context, null);
@@ -154,9 +155,8 @@ import java.util.ArrayList;
    */
   public void addItem(Sample sample) {
     mediaQueue.add(sample);
-    if (currentPlayer == exoPlayer) {
-      concatenatingMediaSource.addMediaSource(buildMediaSource(sample));
-    } else {
+    concatenatingMediaSource.addMediaSource(buildMediaSource(sample));
+    if (currentPlayer == castPlayer) {
       castPlayer.addItems(buildMediaQueueItem(sample));
     }
   }
@@ -185,9 +185,8 @@ import java.util.ArrayList;
    * @return Whether the removal was successful.
    */
   public boolean removeItem(int itemIndex) {
-    if (currentPlayer == exoPlayer) {
-      concatenatingMediaSource.removeMediaSource(itemIndex);
-    } else {
+    concatenatingMediaSource.removeMediaSource(itemIndex);
+    if (currentPlayer == castPlayer) {
       if (castPlayer.getPlaybackState() != Player.STATE_IDLE) {
         Timeline castTimeline = castPlayer.getCurrentTimeline();
         if (castTimeline.getPeriodCount() <= itemIndex) {
@@ -214,9 +213,8 @@ import java.util.ArrayList;
    */
   public boolean moveItem(int fromIndex, int toIndex) {
     // Player update.
-    if (currentPlayer == exoPlayer) {
-      concatenatingMediaSource.moveMediaSource(fromIndex, toIndex);
-    } else if (castPlayer.getPlaybackState() != Player.STATE_IDLE) {
+    concatenatingMediaSource.moveMediaSource(fromIndex, toIndex);
+    if (currentPlayer == castPlayer && castPlayer.getPlaybackState() != Player.STATE_IDLE) {
       Timeline castTimeline = castPlayer.getCurrentTimeline();
       int periodCount = castTimeline.getPeriodCount();
       if (periodCount <= fromIndex || periodCount <= toIndex) {
@@ -262,6 +260,7 @@ import java.util.ArrayList;
   public void release() {
     currentItemIndex = C.INDEX_UNSET;
     mediaQueue.clear();
+    concatenatingMediaSource.clear();
     castPlayer.setSessionAvailabilityListener(null);
     castPlayer.release();
     localPlayerView.setPlayer(null);
@@ -349,10 +348,6 @@ import java.util.ArrayList;
     // Media queue management.
     castMediaQueueCreationPending = currentPlayer == castPlayer;
     if (currentPlayer == exoPlayer) {
-      concatenatingMediaSource = new ConcatenatingMediaSource();
-      for (int i = 0; i < mediaQueue.size(); i++) {
-        concatenatingMediaSource.addMediaSource(buildMediaSource(mediaQueue.get(i)));
-      }
       exoPlayer.prepare(concatenatingMediaSource);
     }
 
diff --git a/demos/main/src/main/java/com/google/android/exoplayer2/demo/PlayerActivity.java b/demos/main/src/main/java/com/google/android/exoplayer2/demo/PlayerActivity.java
index e91feaa291..97b1eb8269 100644
--- a/demos/main/src/main/java/com/google/android/exoplayer2/demo/PlayerActivity.java
+++ b/demos/main/src/main/java/com/google/android/exoplayer2/demo/PlayerActivity.java
@@ -118,6 +118,7 @@ public class PlayerActivity extends Activity
 
   private DataSource.Factory mediaDataSourceFactory;
   private SimpleExoPlayer player;
+  private MediaSource mediaSource;
   private DefaultTrackSelector trackSelector;
   private TrackSelectionHelper trackSelectionHelper;
   private DebugTextViewHelper debugViewHelper;
@@ -253,9 +254,8 @@ public class PlayerActivity extends Activity
   // Internal methods
 
   private void initializePlayer() {
-    Intent intent = getIntent();
-    boolean needNewPlayer = player == null;
-    if (needNewPlayer) {
+    if (player == null) {
+      Intent intent = getIntent();
       TrackSelection.Factory adaptiveTrackSelectionFactory =
           new AdaptiveTrackSelection.Factory(BANDWIDTH_METER);
       trackSelector = new DefaultTrackSelector(adaptiveTrackSelectionFactory);
@@ -315,52 +315,53 @@ public class PlayerActivity extends Activity
       playerView.setPlaybackPreparer(this);
       debugViewHelper = new DebugTextViewHelper(player, debugTextView);
       debugViewHelper.start();
-    }
-    String action = intent.getAction();
-    Uri[] uris;
-    String[] extensions;
-    if (ACTION_VIEW.equals(action)) {
-      uris = new Uri[]{intent.getData()};
-      extensions = new String[]{intent.getStringExtra(EXTENSION_EXTRA)};
-    } else if (ACTION_VIEW_LIST.equals(action)) {
-      String[] uriStrings = intent.getStringArrayExtra(URI_LIST_EXTRA);
-      uris = new Uri[uriStrings.length];
-      for (int i = 0; i < uriStrings.length; i++) {
-        uris[i] = Uri.parse(uriStrings[i]);
-      }
-      extensions = intent.getStringArrayExtra(EXTENSION_LIST_EXTRA);
-      if (extensions == null) {
-        extensions = new String[uriStrings.length];
-      }
-    } else {
-      showToast(getString(R.string.unexpected_intent_action, action));
-      return;
-    }
-    if (Util.maybeRequestReadExternalStoragePermission(this, uris)) {
-      // The player will be reinitialized if the permission is granted.
-      return;
-    }
-    MediaSource[] mediaSources = new MediaSource[uris.length];
-    for (int i = 0; i < uris.length; i++) {
-      mediaSources[i] = buildMediaSource(uris[i], extensions[i], mainHandler, eventLogger);
-    }
-    MediaSource mediaSource = mediaSources.length == 1 ? mediaSources[0]
-        : new ConcatenatingMediaSource(mediaSources);
-    String adTagUriString = intent.getStringExtra(AD_TAG_URI_EXTRA);
-    if (adTagUriString != null) {
-      Uri adTagUri = Uri.parse(adTagUriString);
-      if (!adTagUri.equals(loadedAdTagUri)) {
-        releaseAdsLoader();
-        loadedAdTagUri = adTagUri;
-      }
-      MediaSource adsMediaSource = createAdsMediaSource(mediaSource, Uri.parse(adTagUriString));
-      if (adsMediaSource != null) {
-        mediaSource = adsMediaSource;
+
+      String action = intent.getAction();
+      Uri[] uris;
+      String[] extensions;
+      if (ACTION_VIEW.equals(action)) {
+        uris = new Uri[] {intent.getData()};
+        extensions = new String[] {intent.getStringExtra(EXTENSION_EXTRA)};
+      } else if (ACTION_VIEW_LIST.equals(action)) {
+        String[] uriStrings = intent.getStringArrayExtra(URI_LIST_EXTRA);
+        uris = new Uri[uriStrings.length];
+        for (int i = 0; i < uriStrings.length; i++) {
+          uris[i] = Uri.parse(uriStrings[i]);
+        }
+        extensions = intent.getStringArrayExtra(EXTENSION_LIST_EXTRA);
+        if (extensions == null) {
+          extensions = new String[uriStrings.length];
+        }
       } else {
-        showToast(R.string.ima_not_loaded);
+        showToast(getString(R.string.unexpected_intent_action, action));
+        return;
+      }
+      if (Util.maybeRequestReadExternalStoragePermission(this, uris)) {
+        // The player will be reinitialized if the permission is granted.
+        return;
+      }
+      MediaSource[] mediaSources = new MediaSource[uris.length];
+      for (int i = 0; i < uris.length; i++) {
+        mediaSources[i] = buildMediaSource(uris[i], extensions[i], mainHandler, eventLogger);
+      }
+      mediaSource =
+          mediaSources.length == 1 ? mediaSources[0] : new ConcatenatingMediaSource(mediaSources);
+      String adTagUriString = intent.getStringExtra(AD_TAG_URI_EXTRA);
+      if (adTagUriString != null) {
+        Uri adTagUri = Uri.parse(adTagUriString);
+        if (!adTagUri.equals(loadedAdTagUri)) {
+          releaseAdsLoader();
+          loadedAdTagUri = adTagUri;
+        }
+        MediaSource adsMediaSource = createAdsMediaSource(mediaSource, Uri.parse(adTagUriString));
+        if (adsMediaSource != null) {
+          mediaSource = adsMediaSource;
+        } else {
+          showToast(R.string.ima_not_loaded);
+        }
+      } else {
+        releaseAdsLoader();
       }
-    } else {
-      releaseAdsLoader();
     }
     boolean haveResumePosition = resumeWindow != C.INDEX_UNSET;
     if (haveResumePosition) {
@@ -424,6 +425,7 @@ public class PlayerActivity extends Activity
       updateResumePosition();
       player.release();
       player = null;
+      mediaSource = null;
       trackSelector = null;
       trackSelectionHelper = null;
       eventLogger = null;