diff --git a/library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImpl.java b/library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImpl.java
index 7a3da68d02..b9ab94a543 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImpl.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImpl.java
@@ -65,6 +65,7 @@ import java.util.concurrent.CopyOnWriteArraySet;
 
   // Playback information when there is a pending seek/set source operation.
   private int maskingWindowIndex;
+  private int maskingPeriodIndex;
   private long maskingWindowPositionMs;
 
   /**
@@ -187,6 +188,22 @@ import java.util.concurrent.CopyOnWriteArraySet;
     }
     pendingSeekAcks++;
     maskingWindowIndex = windowIndex;
+    if (timeline.isEmpty()) {
+      maskingPeriodIndex = 0;
+    } else {
+      timeline.getWindow(windowIndex, window);
+      long resolvedPositionMs =
+          positionMs == C.TIME_UNSET ? window.getDefaultPositionUs() : positionMs;
+      int periodIndex = window.firstPeriodIndex;
+      long periodPositionUs = window.getPositionInFirstPeriodUs() + C.msToUs(resolvedPositionMs);
+      long periodDurationUs = timeline.getPeriod(periodIndex, period).getDurationUs();
+      while (periodDurationUs != C.TIME_UNSET && periodPositionUs >= periodDurationUs
+          && periodIndex < window.lastPeriodIndex) {
+        periodPositionUs -= periodDurationUs;
+        periodDurationUs = timeline.getPeriod(++periodIndex, period).getDurationUs();
+      }
+      maskingPeriodIndex = periodIndex;
+    }
     if (positionMs == C.TIME_UNSET) {
       maskingWindowPositionMs = 0;
       internalPlayer.seekTo(timeline, windowIndex, C.TIME_UNSET);
@@ -235,7 +252,11 @@ import java.util.concurrent.CopyOnWriteArraySet;
 
   @Override
   public int getCurrentPeriodIndex() {
-    return playbackInfo.periodIndex;
+    if (timeline.isEmpty() || pendingSeekAcks > 0) {
+      return maskingPeriodIndex;
+    } else {
+      return playbackInfo.periodIndex;
+    }
   }
 
   @Override
diff --git a/library/ui/src/main/java/com/google/android/exoplayer2/ui/PlaybackControlView.java b/library/ui/src/main/java/com/google/android/exoplayer2/ui/PlaybackControlView.java
index dfa5e9abe0..405595a5ed 100644
--- a/library/ui/src/main/java/com/google/android/exoplayer2/ui/PlaybackControlView.java
+++ b/library/ui/src/main/java/com/google/android/exoplayer2/ui/PlaybackControlView.java
@@ -21,7 +21,6 @@ import android.content.Context;
 import android.content.res.TypedArray;
 import android.os.SystemClock;
 import android.util.AttributeSet;
-import android.util.Log;
 import android.view.KeyEvent;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -34,6 +33,7 @@ import com.google.android.exoplayer2.PlaybackParameters;
 import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.source.TrackGroupArray;
 import com.google.android.exoplayer2.trackselection.TrackSelectionArray;
+import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import java.util.Arrays;
 import java.util.Formatter;
@@ -345,8 +345,9 @@ public class PlaybackControlView extends FrameLayout {
 
   /**
    * Sets whether the time bar should show all windows, as opposed to just the current one. If the
-   * timeline has more than {@link #MAX_WINDOWS_FOR_MULTI_WINDOW_TIME_BAR} windows the time bar will
-   * fall back to showing a single window.
+   * timeline has a period with unknown duration or more than
+   * {@link #MAX_WINDOWS_FOR_MULTI_WINDOW_TIME_BAR} windows the time bar will fall back to showing a
+   * single window.
    *
    * @param showMultiWindowTimeBar Whether the time bar should show all windows.
    */
@@ -523,14 +524,8 @@ public class PlaybackControlView extends FrameLayout {
     if (player == null) {
       return;
     }
-    if (showMultiWindowTimeBar) {
-      if (player.getCurrentTimeline().getWindowCount() <= MAX_WINDOWS_FOR_MULTI_WINDOW_TIME_BAR) {
-        multiWindowTimeBar = true;
-        return;
-      }
-      Log.w(TAG, "Too many windows for multi-window time bar. Falling back to showing one window.");
-    }
-    multiWindowTimeBar = false;
+    multiWindowTimeBar = showMultiWindowTimeBar
+        && canShowMultiWindowTimeBar(player.getCurrentTimeline(), period);
   }
 
   private void updateProgress() {
@@ -568,10 +563,7 @@ public class PlaybackControlView extends FrameLayout {
             } else {
               isInAdBreak = false;
               long periodDurationUs = period.getDurationUs();
-              if (periodDurationUs == C.TIME_UNSET) {
-                durationUs = C.TIME_UNSET;
-                break;
-              }
+              Assertions.checkState(periodDurationUs != C.TIME_UNSET);
               long periodDurationInWindowUs = periodDurationUs;
               if (j == window.firstPeriodIndex) {
                 periodDurationInWindowUs -= window.positionInFirstPeriodUs;
@@ -797,6 +789,26 @@ public class PlaybackControlView extends FrameLayout {
         || keyCode == KeyEvent.KEYCODE_MEDIA_PREVIOUS;
   }
 
+  /**
+   * Returns whether the specified {@code timeline} can be shown on a multi-window time bar.
+   *
+   * @param timeline The {@link Timeline} to check.
+   * @param period A scratch {@link Timeline.Period} instance.
+   * @return Whether the specified timeline can be shown on a multi-window time bar.
+   */
+  private static boolean canShowMultiWindowTimeBar(Timeline timeline, Timeline.Period period) {
+    if (timeline.getWindowCount() > MAX_WINDOWS_FOR_MULTI_WINDOW_TIME_BAR) {
+      return false;
+    }
+    int periodCount = timeline.getPeriodCount();
+    for (int i = 0; i < periodCount; i++) {
+      if (timeline.getPeriod(i, period).durationUs == C.TIME_UNSET) {
+        return false;
+      }
+    }
+    return true;
+  }
+
   private final class ComponentListener implements ExoPlayer.EventListener, TimeBar.OnScrubListener,
       OnClickListener {