diff --git a/extensions/mediasession/src/main/java/com/google/android/exoplayer2/ext/mediasession/MediaSessionConnector.java b/extensions/mediasession/src/main/java/com/google/android/exoplayer2/ext/mediasession/MediaSessionConnector.java
index 3b92e7e4ff..ceaa1ae995 100644
--- a/extensions/mediasession/src/main/java/com/google/android/exoplayer2/ext/mediasession/MediaSessionConnector.java
+++ b/extensions/mediasession/src/main/java/com/google/android/exoplayer2/ext/mediasession/MediaSessionConnector.java
@@ -31,7 +31,6 @@ import android.support.v4.media.session.MediaSessionCompat;
 import android.support.v4.media.session.PlaybackStateCompat;
 import android.util.Pair;
 import androidx.annotation.LongDef;
-import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ControlDispatcher;
@@ -1225,7 +1224,7 @@ public final class MediaSessionConnector {
     }
 
     @Override
-    public void onCustomAction(@NonNull String action, @Nullable Bundle extras) {
+    public void onCustomAction(String action, @Nullable Bundle extras) {
       if (player != null && customActionMap.containsKey(action)) {
         customActionMap.get(action).onCustomAction(player, controlDispatcher, action, extras);
         invalidateMediaSessionPlaybackState();
diff --git a/extensions/mediasession/src/main/java/com/google/android/exoplayer2/ext/mediasession/TimelineQueueEditor.java b/extensions/mediasession/src/main/java/com/google/android/exoplayer2/ext/mediasession/TimelineQueueEditor.java
index d5fed2958b..41bda3bf44 100644
--- a/extensions/mediasession/src/main/java/com/google/android/exoplayer2/ext/mediasession/TimelineQueueEditor.java
+++ b/extensions/mediasession/src/main/java/com/google/android/exoplayer2/ext/mediasession/TimelineQueueEditor.java
@@ -20,7 +20,6 @@ import android.os.ResultReceiver;
 import android.support.v4.media.MediaDescriptionCompat;
 import android.support.v4.media.session.MediaControllerCompat;
 import android.support.v4.media.session.MediaSessionCompat;
-import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ControlDispatcher;
@@ -129,10 +128,10 @@ public final class TimelineQueueEditor
    * @param sourceFactory The {@link MediaSourceFactory} to build media sources.
    */
   public TimelineQueueEditor(
-      @NonNull MediaControllerCompat mediaController,
-      @NonNull ConcatenatingMediaSource queueMediaSource,
-      @NonNull QueueDataAdapter queueDataAdapter,
-      @NonNull MediaSourceFactory sourceFactory) {
+      MediaControllerCompat mediaController,
+      ConcatenatingMediaSource queueMediaSource,
+      QueueDataAdapter queueDataAdapter,
+      MediaSourceFactory sourceFactory) {
     this(mediaController, queueMediaSource, queueDataAdapter, sourceFactory,
         new MediaIdEqualityChecker());
   }
@@ -147,11 +146,11 @@ public final class TimelineQueueEditor
    * @param equalityChecker The {@link MediaDescriptionEqualityChecker} to match queue items.
    */
   public TimelineQueueEditor(
-      @NonNull MediaControllerCompat mediaController,
-      @NonNull ConcatenatingMediaSource queueMediaSource,
-      @NonNull QueueDataAdapter queueDataAdapter,
-      @NonNull MediaSourceFactory sourceFactory,
-      @NonNull MediaDescriptionEqualityChecker equalityChecker) {
+      MediaControllerCompat mediaController,
+      ConcatenatingMediaSource queueMediaSource,
+      QueueDataAdapter queueDataAdapter,
+      MediaSourceFactory sourceFactory,
+      MediaDescriptionEqualityChecker equalityChecker) {
     this.mediaController = mediaController;
     this.queueMediaSource = queueMediaSource;
     this.queueDataAdapter = queueDataAdapter;
diff --git a/library/core/src/androidTest/java/com/google/android/exoplayer2/upstream/ContentDataSourceTest.java b/library/core/src/androidTest/java/com/google/android/exoplayer2/upstream/ContentDataSourceTest.java
index a76b5cf6c1..2021cb21c2 100644
--- a/library/core/src/androidTest/java/com/google/android/exoplayer2/upstream/ContentDataSourceTest.java
+++ b/library/core/src/androidTest/java/com/google/android/exoplayer2/upstream/ContentDataSourceTest.java
@@ -26,7 +26,6 @@ import android.database.Cursor;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.ParcelFileDescriptor;
-import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.test.InstrumentationRegistry;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
@@ -134,14 +133,13 @@ public final class ContentDataSourceTest {
     }
 
     @Override
-    public Cursor query(@NonNull Uri uri, String[] projection, String selection,
-        String[] selectionArgs, String sortOrder) {
+    public Cursor query(
+        Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
       throw new UnsupportedOperationException();
     }
 
     @Override
-    public AssetFileDescriptor openAssetFile(@NonNull Uri uri, @NonNull String mode)
-        throws FileNotFoundException {
+    public AssetFileDescriptor openAssetFile(Uri uri, String mode) throws FileNotFoundException {
       if (uri.getPath() == null) {
         return null;
       }
@@ -162,29 +160,32 @@ public final class ContentDataSourceTest {
     }
 
     @Override
-    public String getType(@NonNull Uri uri) {
+    public String getType(Uri uri) {
       throw new UnsupportedOperationException();
     }
 
     @Override
-    public Uri insert(@NonNull Uri uri, ContentValues values) {
+    public Uri insert(Uri uri, ContentValues values) {
       throw new UnsupportedOperationException();
     }
 
     @Override
-    public int delete(@NonNull Uri uri, String selection, String[] selectionArgs) {
+    public int delete(Uri uri, String selection, String[] selectionArgs) {
       throw new UnsupportedOperationException();
     }
 
     @Override
-    public int update(@NonNull Uri uri, ContentValues values, String selection,
-        String[] selectionArgs) {
+    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
       throw new UnsupportedOperationException();
     }
 
     @Override
-    public void writeDataToPipe(@NonNull ParcelFileDescriptor output, @NonNull Uri uri,
-        @NonNull String mimeType, @Nullable Bundle opts, @Nullable Object args) {
+    public void writeDataToPipe(
+        ParcelFileDescriptor output,
+        Uri uri,
+        String mimeType,
+        @Nullable Bundle opts,
+        @Nullable Object args) {
       try {
         byte[] data = TestUtil.getByteArray(getContext(), getFileName(uri));
         FileOutputStream outputStream = new FileOutputStream(output.getFileDescriptor());
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImplInternal.java b/library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImplInternal.java
index 94faf92475..db5483be1d 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImplInternal.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImplInternal.java
@@ -22,7 +22,6 @@ import android.os.Message;
 import android.os.Process;
 import android.os.SystemClock;
 import android.util.Pair;
-import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.DefaultMediaClock.PlaybackParameterListener;
 import com.google.android.exoplayer2.Player.DiscontinuityReason;
@@ -1964,7 +1963,7 @@ import java.util.concurrent.atomic.AtomicBoolean;
     }
 
     @Override
-    public int compareTo(@NonNull PendingMessageInfo other) {
+    public int compareTo(PendingMessageInfo other) {
       if ((resolvedPeriodUid == null) != (other.resolvedPeriodUid == null)) {
         // PendingMessageInfos with a resolved period position are always smaller.
         return resolvedPeriodUid != null ? -1 : 1;
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/offline/SegmentDownloader.java b/library/core/src/main/java/com/google/android/exoplayer2/offline/SegmentDownloader.java
index 808df6d36f..969003101f 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/offline/SegmentDownloader.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/offline/SegmentDownloader.java
@@ -17,7 +17,6 @@ package com.google.android.exoplayer2.offline;
 
 import android.net.Uri;
 import android.util.Pair;
-import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.upstream.DataSource;
@@ -57,7 +56,7 @@ public abstract class SegmentDownloader<M extends FilterableManifest<M>> impleme
     }
 
     @Override
-    public int compareTo(@NonNull Segment other) {
+    public int compareTo(Segment other) {
       return Util.compareLong(startTimeUs, other.startTimeUs);
     }
   }
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/offline/StreamKey.java b/library/core/src/main/java/com/google/android/exoplayer2/offline/StreamKey.java
index 977be9a198..f9a48868d9 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/offline/StreamKey.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/offline/StreamKey.java
@@ -17,7 +17,6 @@ package com.google.android.exoplayer2.offline;
 
 import android.os.Parcel;
 import android.os.Parcelable;
-import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
 /**
@@ -92,7 +91,7 @@ public final class StreamKey implements Comparable<StreamKey>, Parcelable {
   // Comparable implementation.
 
   @Override
-  public int compareTo(@NonNull StreamKey o) {
+  public int compareTo(StreamKey o) {
     int result = periodIndex - o.periodIndex;
     if (result == 0) {
       result = groupIndex - o.groupIndex;
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/video/MediaCodecVideoRenderer.java b/library/core/src/main/java/com/google/android/exoplayer2/video/MediaCodecVideoRenderer.java
index d09087b8c6..7c5ae5f0cb 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/video/MediaCodecVideoRenderer.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/video/MediaCodecVideoRenderer.java
@@ -30,7 +30,6 @@ import android.os.SystemClock;
 import android.util.Pair;
 import android.view.Surface;
 import androidx.annotation.CallSuper;
-import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ExoPlaybackException;
@@ -1746,7 +1745,7 @@ public class MediaCodecVideoRenderer extends MediaCodecRenderer {
     }
 
     @Override
-    public void onFrameRendered(@NonNull MediaCodec codec, long presentationTimeUs, long nanoTime) {
+    public void onFrameRendered(MediaCodec codec, long presentationTimeUs, long nanoTime) {
       if (this != tunnelingOnFrameRenderedListener) {
         // Stale event.
         return;
diff --git a/library/core/src/test/java/com/google/android/exoplayer2/extractor/amr/AmrExtractorTest.java b/library/core/src/test/java/com/google/android/exoplayer2/extractor/amr/AmrExtractorTest.java
index de7642a94b..7d6917d092 100644
--- a/library/core/src/test/java/com/google/android/exoplayer2/extractor/amr/AmrExtractorTest.java
+++ b/library/core/src/test/java/com/google/android/exoplayer2/extractor/amr/AmrExtractorTest.java
@@ -22,7 +22,6 @@ import static com.google.android.exoplayer2.extractor.amr.AmrExtractor.frameSize
 import static com.google.common.truth.Truth.assertThat;
 import static junit.framework.Assert.fail;
 
-import androidx.annotation.NonNull;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import com.google.android.exoplayer2.ParserException;
 import com.google.android.exoplayer2.extractor.Extractor;
@@ -235,7 +234,6 @@ public final class AmrExtractorTest {
     return result;
   }
 
-  @NonNull
   private static AmrExtractor setupAmrExtractorWithOutput() {
     AmrExtractor amrExtractor = new AmrExtractor();
     FakeExtractorOutput output = new FakeExtractorOutput();
@@ -243,12 +241,10 @@ public final class AmrExtractorTest {
     return amrExtractor;
   }
 
-  @NonNull
   private static FakeExtractorInput fakeExtractorInputWithData(byte[] data) {
     return new FakeExtractorInput.Builder().setData(data).build();
   }
 
-  @NonNull
   private static ExtractorAsserts.ExtractorFactory createAmrExtractorFactory(boolean withSeeking) {
     return () -> {
       if (!withSeeking) {
diff --git a/library/ui/src/main/java/com/google/android/exoplayer2/ui/SimpleExoPlayerView.java b/library/ui/src/main/java/com/google/android/exoplayer2/ui/SimpleExoPlayerView.java
index e55666e178..fae3382a32 100644
--- a/library/ui/src/main/java/com/google/android/exoplayer2/ui/SimpleExoPlayerView.java
+++ b/library/ui/src/main/java/com/google/android/exoplayer2/ui/SimpleExoPlayerView.java
@@ -17,7 +17,6 @@ package com.google.android.exoplayer2.ui;
 
 import android.content.Context;
 import android.util.AttributeSet;
-import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.Player;
 import com.google.android.exoplayer2.SimpleExoPlayer;
@@ -49,7 +48,7 @@ public final class SimpleExoPlayerView extends PlayerView {
   @Deprecated
   @SuppressWarnings("deprecation")
   public static void switchTargetView(
-      @NonNull SimpleExoPlayer player,
+      SimpleExoPlayer player,
       @Nullable SimpleExoPlayerView oldPlayerView,
       @Nullable SimpleExoPlayerView newPlayerView) {
     PlayerView.switchTargetView(player, oldPlayerView, newPlayerView);