diff --git a/extensions/media2/src/androidTest/java/com/google/android/exoplayer2/ext/media2/PlayerTestRule.java b/extensions/media2/src/androidTest/java/com/google/android/exoplayer2/ext/media2/PlayerTestRule.java
index 9400a90ffc..df6963c2fc 100644
--- a/extensions/media2/src/androidTest/java/com/google/android/exoplayer2/ext/media2/PlayerTestRule.java
+++ b/extensions/media2/src/androidTest/java/com/google/android/exoplayer2/ext/media2/PlayerTestRule.java
@@ -15,8 +15,6 @@
  */
 package com.google.android.exoplayer2.ext.media2;
 
-import static com.google.android.exoplayer2.util.Assertions.checkState;
-
 import android.content.Context;
 import android.net.Uri;
 import android.os.Looper;
@@ -145,7 +143,6 @@ import org.junit.rules.ExternalResource;
 
     private final DataSource wrappedDataSource;
     private final DataSourceInstrumentation instrumentation;
-    private boolean opened;
 
     public InstrumentedDataSource(
         DataSource wrappedDataSource, DataSourceInstrumentation instrumentation) {
@@ -160,11 +157,8 @@ import org.junit.rules.ExternalResource;
 
     @Override
     public long open(DataSpec dataSpec) throws IOException {
-      checkState(!opened);
       instrumentation.onPreOpen(dataSpec);
-      long length = wrappedDataSource.open(dataSpec);
-      opened = true;
-      return length;
+      return wrappedDataSource.open(dataSpec);
     }
 
     @Nullable
@@ -186,7 +180,6 @@ import org.junit.rules.ExternalResource;
     @Override
     public void close() throws IOException {
       wrappedDataSource.close();
-      opened = false;
     }
   }
 }
diff --git a/extensions/okhttp/src/main/java/com/google/android/exoplayer2/ext/okhttp/OkHttpDataSource.java b/extensions/okhttp/src/main/java/com/google/android/exoplayer2/ext/okhttp/OkHttpDataSource.java
index b0f091ef45..92bf8281f5 100644
--- a/extensions/okhttp/src/main/java/com/google/android/exoplayer2/ext/okhttp/OkHttpDataSource.java
+++ b/extensions/okhttp/src/main/java/com/google/android/exoplayer2/ext/okhttp/OkHttpDataSource.java
@@ -16,7 +16,6 @@
 package com.google.android.exoplayer2.ext.okhttp;
 
 import static com.google.android.exoplayer2.ExoPlayerLibraryInfo.DEFAULT_USER_AGENT;
-import static com.google.android.exoplayer2.util.Assertions.checkState;
 import static com.google.android.exoplayer2.util.Util.castNonNull;
 import static java.lang.Math.min;
 
@@ -278,7 +277,6 @@ public class OkHttpDataSource extends BaseDataSource implements HttpDataSource {
 
   @Override
   public long open(DataSpec dataSpec) throws HttpDataSourceException {
-    checkState(!opened);
     this.dataSpec = dataSpec;
     this.bytesRead = 0;
     this.bytesSkipped = 0;
diff --git a/extensions/rtmp/src/main/java/com/google/android/exoplayer2/ext/rtmp/RtmpDataSource.java b/extensions/rtmp/src/main/java/com/google/android/exoplayer2/ext/rtmp/RtmpDataSource.java
index d228972ca0..587e310d64 100644
--- a/extensions/rtmp/src/main/java/com/google/android/exoplayer2/ext/rtmp/RtmpDataSource.java
+++ b/extensions/rtmp/src/main/java/com/google/android/exoplayer2/ext/rtmp/RtmpDataSource.java
@@ -15,7 +15,6 @@
  */
 package com.google.android.exoplayer2.ext.rtmp;
 
-import static com.google.android.exoplayer2.util.Assertions.checkState;
 import static com.google.android.exoplayer2.util.Util.castNonNull;
 
 import android.net.Uri;
@@ -38,7 +37,6 @@ public final class RtmpDataSource extends BaseDataSource {
 
   @Nullable private RtmpClient rtmpClient;
   @Nullable private Uri uri;
-  private boolean opened;
 
   public RtmpDataSource() {
     super(/* isNetwork= */ true);
@@ -46,14 +44,12 @@ public final class RtmpDataSource extends BaseDataSource {
 
   @Override
   public long open(DataSpec dataSpec) throws RtmpIOException {
-    checkState(!opened);
     transferInitializing(dataSpec);
     rtmpClient = new RtmpClient();
     rtmpClient.open(dataSpec.uri.toString(), false);
 
     this.uri = dataSpec.uri;
     transferStarted(dataSpec);
-    opened = true;
     return C.LENGTH_UNSET;
   }
 
@@ -77,7 +73,6 @@ public final class RtmpDataSource extends BaseDataSource {
       rtmpClient.close();
       rtmpClient = null;
     }
-    opened = false;
   }
 
   @Override
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/upstream/AssetDataSource.java b/library/core/src/main/java/com/google/android/exoplayer2/upstream/AssetDataSource.java
index fa171094d9..e529e28846 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/upstream/AssetDataSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/upstream/AssetDataSource.java
@@ -15,7 +15,6 @@
  */
 package com.google.android.exoplayer2.upstream;
 
-import static com.google.android.exoplayer2.util.Assertions.checkState;
 import static com.google.android.exoplayer2.util.Util.castNonNull;
 import static java.lang.Math.min;
 
@@ -58,7 +57,6 @@ public final class AssetDataSource extends BaseDataSource {
 
   @Override
   public long open(DataSpec dataSpec) throws AssetDataSourceException {
-    checkState(!opened);
     try {
       uri = dataSpec.uri;
       String path = Assertions.checkNotNull(uri.getPath());
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/upstream/ByteArrayDataSource.java b/library/core/src/main/java/com/google/android/exoplayer2/upstream/ByteArrayDataSource.java
index 1d1d7cfea5..17e9073128 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/upstream/ByteArrayDataSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/upstream/ByteArrayDataSource.java
@@ -15,7 +15,6 @@
  */
 package com.google.android.exoplayer2.upstream;
 
-import static com.google.android.exoplayer2.util.Assertions.checkState;
 import static java.lang.Math.min;
 
 import android.net.Uri;
@@ -46,7 +45,6 @@ public final class ByteArrayDataSource extends BaseDataSource {
 
   @Override
   public long open(DataSpec dataSpec) throws IOException {
-    checkState(!opened);
     uri = dataSpec.uri;
     transferInitializing(dataSpec);
     readPosition = (int) dataSpec.position;
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/upstream/ContentDataSource.java b/library/core/src/main/java/com/google/android/exoplayer2/upstream/ContentDataSource.java
index a7bad13437..b659c5ca98 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/upstream/ContentDataSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/upstream/ContentDataSource.java
@@ -15,7 +15,6 @@
  */
 package com.google.android.exoplayer2.upstream;
 
-import static com.google.android.exoplayer2.util.Assertions.checkState;
 import static com.google.android.exoplayer2.util.Util.castNonNull;
 import static java.lang.Math.min;
 
@@ -63,8 +62,6 @@ public final class ContentDataSource extends BaseDataSource {
 
   @Override
   public long open(DataSpec dataSpec) throws ContentDataSourceException {
-    checkState(!opened);
-
     try {
       Uri uri = dataSpec.uri;
       this.uri = uri;
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/upstream/DataSchemeDataSource.java b/library/core/src/main/java/com/google/android/exoplayer2/upstream/DataSchemeDataSource.java
index 515f757183..2c3670f52a 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/upstream/DataSchemeDataSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/upstream/DataSchemeDataSource.java
@@ -15,7 +15,6 @@
  */
 package com.google.android.exoplayer2.upstream;
 
-import static com.google.android.exoplayer2.util.Assertions.checkState;
 import static com.google.android.exoplayer2.util.Util.castNonNull;
 import static java.lang.Math.min;
 
@@ -45,7 +44,6 @@ public final class DataSchemeDataSource extends BaseDataSource {
 
   @Override
   public long open(DataSpec dataSpec) throws IOException {
-    checkState(this.dataSpec == null);
     transferInitializing(dataSpec);
     this.dataSpec = dataSpec;
     readPosition = (int) dataSpec.position;
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/upstream/DefaultHttpDataSource.java b/library/core/src/main/java/com/google/android/exoplayer2/upstream/DefaultHttpDataSource.java
index 7a70d1a546..15bee2c118 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/upstream/DefaultHttpDataSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/upstream/DefaultHttpDataSource.java
@@ -16,7 +16,6 @@
 package com.google.android.exoplayer2.upstream;
 
 import static com.google.android.exoplayer2.ExoPlayerLibraryInfo.DEFAULT_USER_AGENT;
-import static com.google.android.exoplayer2.util.Assertions.checkState;
 import static java.lang.Math.max;
 import static java.lang.Math.min;
 
@@ -343,7 +342,6 @@ public class DefaultHttpDataSource extends BaseDataSource implements HttpDataSou
    */
   @Override
   public long open(DataSpec dataSpec) throws HttpDataSourceException {
-    checkState(!opened);
     this.dataSpec = dataSpec;
     this.bytesRead = 0;
     this.bytesSkipped = 0;
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/upstream/FileDataSource.java b/library/core/src/main/java/com/google/android/exoplayer2/upstream/FileDataSource.java
index f9ccf044c7..d34e43eb46 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/upstream/FileDataSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/upstream/FileDataSource.java
@@ -15,7 +15,6 @@
  */
 package com.google.android.exoplayer2.upstream;
 
-import static com.google.android.exoplayer2.util.Assertions.checkState;
 import static com.google.android.exoplayer2.util.Util.castNonNull;
 import static java.lang.Math.min;
 
@@ -81,7 +80,6 @@ public final class FileDataSource extends BaseDataSource {
 
   @Override
   public long open(DataSpec dataSpec) throws FileDataSourceException {
-    checkState(!opened);
     try {
       Uri uri = dataSpec.uri;
       this.uri = uri;
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/upstream/PriorityDataSource.java b/library/core/src/main/java/com/google/android/exoplayer2/upstream/PriorityDataSource.java
index 2a73461bdc..e52e1db376 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/upstream/PriorityDataSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/upstream/PriorityDataSource.java
@@ -15,8 +15,6 @@
  */
 package com.google.android.exoplayer2.upstream;
 
-import static com.google.android.exoplayer2.util.Assertions.checkState;
-
 import android.net.Uri;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.util.Assertions;
@@ -42,7 +40,6 @@ public final class PriorityDataSource implements DataSource {
   private final DataSource upstream;
   private final PriorityTaskManager priorityTaskManager;
   private final int priority;
-  private boolean opened;
 
   /**
    * @param upstream The upstream {@link DataSource}.
@@ -64,11 +61,8 @@ public final class PriorityDataSource implements DataSource {
 
   @Override
   public long open(DataSpec dataSpec) throws IOException {
-    checkState(!opened);
     priorityTaskManager.proceedOrThrow(priority);
-    long length = upstream.open(dataSpec);
-    opened = true;
-    return length;
+    return upstream.open(dataSpec);
   }
 
   @Override
@@ -91,7 +85,6 @@ public final class PriorityDataSource implements DataSource {
   @Override
   public void close() throws IOException {
     upstream.close();
-    opened = false;
   }
 
 }
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/upstream/RawResourceDataSource.java b/library/core/src/main/java/com/google/android/exoplayer2/upstream/RawResourceDataSource.java
index b154fa5c16..7538cc67a4 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/upstream/RawResourceDataSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/upstream/RawResourceDataSource.java
@@ -15,7 +15,6 @@
  */
 package com.google.android.exoplayer2.upstream;
 
-import static com.google.android.exoplayer2.util.Assertions.checkState;
 import static com.google.android.exoplayer2.util.Util.castNonNull;
 import static java.lang.Math.min;
 
@@ -99,7 +98,6 @@ public final class RawResourceDataSource extends BaseDataSource {
 
   @Override
   public long open(DataSpec dataSpec) throws RawResourceDataSourceException {
-    checkState(!opened);
     Uri uri = dataSpec.uri;
     this.uri = uri;
 
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/upstream/ResolvingDataSource.java b/library/core/src/main/java/com/google/android/exoplayer2/upstream/ResolvingDataSource.java
index c60e6daf68..958780cbc3 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/upstream/ResolvingDataSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/upstream/ResolvingDataSource.java
@@ -16,7 +16,6 @@
 package com.google.android.exoplayer2.upstream;
 
 import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
-import static com.google.android.exoplayer2.util.Assertions.checkState;
 
 import android.net.Uri;
 import androidx.annotation.Nullable;
@@ -104,7 +103,6 @@ public final class ResolvingDataSource implements DataSource {
 
   @Override
   public long open(DataSpec dataSpec) throws IOException {
-    checkState(!upstreamOpened);
     DataSpec resolvedDataSpec = resolver.resolveDataSpec(dataSpec);
     upstreamOpened = true;
     return upstreamDataSource.open(resolvedDataSpec);
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/upstream/StatsDataSource.java b/library/core/src/main/java/com/google/android/exoplayer2/upstream/StatsDataSource.java
index aabbb094e7..4340169f45 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/upstream/StatsDataSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/upstream/StatsDataSource.java
@@ -15,8 +15,6 @@
  */
 package com.google.android.exoplayer2.upstream;
 
-import static com.google.android.exoplayer2.util.Assertions.checkState;
-
 import android.net.Uri;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
@@ -37,7 +35,6 @@ public final class StatsDataSource implements DataSource {
   private long bytesRead;
   private Uri lastOpenedUri;
   private Map<String, List<String>> lastResponseHeaders;
-  private boolean opened;
 
   /**
    * Creates the stats data source.
@@ -81,14 +78,12 @@ public final class StatsDataSource implements DataSource {
 
   @Override
   public long open(DataSpec dataSpec) throws IOException {
-    checkState(!opened);
     // Reassign defaults in case dataSource.open throws an exception.
     lastOpenedUri = dataSpec.uri;
     lastResponseHeaders = Collections.emptyMap();
     long availableBytes = dataSource.open(dataSpec);
     lastOpenedUri = Assertions.checkNotNull(getUri());
     lastResponseHeaders = getResponseHeaders();
-    opened = true;
     return availableBytes;
   }
 
@@ -115,6 +110,5 @@ public final class StatsDataSource implements DataSource {
   @Override
   public void close() throws IOException {
     dataSource.close();
-    opened = false;
   }
 }
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/upstream/UdpDataSource.java b/library/core/src/main/java/com/google/android/exoplayer2/upstream/UdpDataSource.java
index 947c5fb798..2da837e788 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/upstream/UdpDataSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/upstream/UdpDataSource.java
@@ -15,7 +15,6 @@
  */
 package com.google.android.exoplayer2.upstream;
 
-import static com.google.android.exoplayer2.util.Assertions.checkState;
 import static java.lang.Math.min;
 
 import android.net.Uri;
@@ -90,8 +89,6 @@ public final class UdpDataSource extends BaseDataSource {
 
   @Override
   public long open(DataSpec dataSpec) throws UdpDataSourceException {
-    checkState(!opened);
-
     uri = dataSpec.uri;
     String host = uri.getHost();
     int port = uri.getPort();
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/upstream/cache/CacheDataSource.java b/library/core/src/main/java/com/google/android/exoplayer2/upstream/cache/CacheDataSource.java
index fc1acb4d47..c2bbdbb893 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/upstream/cache/CacheDataSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/upstream/cache/CacheDataSource.java
@@ -16,7 +16,6 @@
 package com.google.android.exoplayer2.upstream.cache;
 
 import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
-import static com.google.android.exoplayer2.util.Assertions.checkState;
 import static com.google.android.exoplayer2.util.Util.castNonNull;
 import static java.lang.Math.min;
 
@@ -34,6 +33,7 @@ import com.google.android.exoplayer2.upstream.PriorityDataSource;
 import com.google.android.exoplayer2.upstream.TeeDataSource;
 import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.upstream.cache.Cache.CacheException;
+import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.PriorityTaskManager;
 import java.io.IOException;
 import java.io.InterruptedIOException;
@@ -397,7 +397,6 @@ public final class CacheDataSource implements DataSource {
   private boolean currentRequestIgnoresCache;
   private long totalCachedBytesRead;
   private long checkCachePosition;
-  private boolean opened;
 
   /**
    * Constructs an instance with default {@link DataSource} and {@link DataSink} instances for
@@ -553,7 +552,6 @@ public final class CacheDataSource implements DataSource {
 
   @Override
   public long open(DataSpec dataSpec) throws IOException {
-    checkState(!opened);
     try {
       String key = cacheKeyFactory.buildCacheKey(dataSpec);
       DataSpec requestDataSpec = dataSpec.buildUpon().setKey(key).build();
@@ -579,7 +577,6 @@ public final class CacheDataSource implements DataSource {
         }
       }
       openNextSource(requestDataSpec, false);
-      opened = true;
       return bytesRemaining;
     } catch (Throwable e) {
       handleBeforeThrow(e);
@@ -652,7 +649,6 @@ public final class CacheDataSource implements DataSource {
     notifyBytesRead();
     try {
       closeCurrentSource();
-      opened = false;
     } catch (Throwable e) {
       handleBeforeThrow(e);
       throw e;
@@ -743,7 +739,7 @@ public final class CacheDataSource implements DataSource {
             ? readPosition + MIN_READ_BEFORE_CHECKING_CACHE
             : Long.MAX_VALUE;
     if (checkCache) {
-      checkState(isBypassingCache());
+      Assertions.checkState(isBypassingCache());
       if (nextDataSource == upstreamDataSource) {
         // Continue reading from upstream.
         return;
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/upstream/crypto/AesCipherDataSource.java b/library/core/src/main/java/com/google/android/exoplayer2/upstream/crypto/AesCipherDataSource.java
index 13040377ad..5abe42b937 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/upstream/crypto/AesCipherDataSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/upstream/crypto/AesCipherDataSource.java
@@ -16,7 +16,6 @@
 package com.google.android.exoplayer2.upstream.crypto;
 
 import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
-import static com.google.android.exoplayer2.util.Assertions.checkState;
 import static com.google.android.exoplayer2.util.Util.castNonNull;
 
 import android.net.Uri;
@@ -37,7 +36,6 @@ public final class AesCipherDataSource implements DataSource {
 
   private final DataSource upstream;
   private final byte[] secretKey;
-  private boolean opened;
 
   @Nullable private AesFlushingCipher cipher;
 
@@ -54,13 +52,11 @@ public final class AesCipherDataSource implements DataSource {
 
   @Override
   public long open(DataSpec dataSpec) throws IOException {
-    checkState(!opened);
     long dataLength = upstream.open(dataSpec);
     long nonce = CryptoUtil.getFNV64Hash(dataSpec.key);
     cipher =
         new AesFlushingCipher(
             Cipher.DECRYPT_MODE, secretKey, nonce, dataSpec.uriPositionOffset + dataSpec.position);
-    opened = true;
     return dataLength;
   }
 
@@ -92,6 +88,5 @@ public final class AesCipherDataSource implements DataSource {
   public void close() throws IOException {
     cipher = null;
     upstream.close();
-    opened = false;
   }
 }
diff --git a/library/core/src/test/java/com/google/android/exoplayer2/upstream/BaseDataSourceTest.java b/library/core/src/test/java/com/google/android/exoplayer2/upstream/BaseDataSourceTest.java
index 09cc1522f0..1eb49188bf 100644
--- a/library/core/src/test/java/com/google/android/exoplayer2/upstream/BaseDataSourceTest.java
+++ b/library/core/src/test/java/com/google/android/exoplayer2/upstream/BaseDataSourceTest.java
@@ -15,7 +15,6 @@
  */
 package com.google.android.exoplayer2.upstream;
 
-import static com.google.android.exoplayer2.util.Assertions.checkState;
 import static com.google.common.truth.Truth.assertThat;
 
 import android.net.Uri;
@@ -90,18 +89,14 @@ public class BaseDataSourceTest {
 
   private static final class TestSource extends BaseDataSource {
 
-    private boolean opened;
-
     public TestSource(boolean isNetwork) {
       super(isNetwork);
     }
 
     @Override
     public long open(DataSpec dataSpec) throws IOException {
-      checkState(!opened);
       transferInitializing(dataSpec);
       transferStarted(dataSpec);
-      opened = true;
       return C.LENGTH_UNSET;
     }
 
@@ -120,7 +115,6 @@ public class BaseDataSourceTest {
     @Override
     public void close() throws IOException {
       transferEnded();
-      opened = false;
     }
   }
 
diff --git a/library/core/src/test/java/com/google/android/exoplayer2/upstream/DataSchemeDataSourceTest.java b/library/core/src/test/java/com/google/android/exoplayer2/upstream/DataSchemeDataSourceTest.java
index 6a52be184e..7a99b97bd5 100644
--- a/library/core/src/test/java/com/google/android/exoplayer2/upstream/DataSchemeDataSourceTest.java
+++ b/library/core/src/test/java/com/google/android/exoplayer2/upstream/DataSchemeDataSourceTest.java
@@ -17,7 +17,6 @@ package com.google.android.exoplayer2.upstream;
 
 import static com.google.android.exoplayer2.C.RESULT_END_OF_INPUT;
 import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.fail;
 
 import android.net.Uri;
@@ -131,20 +130,19 @@ public final class DataSchemeDataSourceTest {
   }
 
   @Test
-  public void malformedData_throwsIOException() {
-    assertThrows(
-        IOException.class,
-        () ->
-            schemeDataDataSource.open(
-                buildDataSpec("data:text/plain;base64,,This%20is%20Content")));
-  }
-
-  @Test
-  public void malformedData_incorrectPadding_throwsIOException() {
-    assertThrows(
-        IOException.class,
-        () ->
-            schemeDataDataSource.open(buildDataSpec("data:text/plain;base64,IncorrectPadding==")));
+  public void malformedData() {
+    try {
+      schemeDataDataSource.open(buildDataSpec("data:text/plain;base64,,This%20is%20Content"));
+      fail();
+    } catch (IOException e) {
+      // Expected.
+    }
+    try {
+      schemeDataDataSource.open(buildDataSpec("data:text/plain;base64,IncorrectPadding=="));
+      fail();
+    } catch (IOException e) {
+      // Expected.
+    }
   }
 
   @Test
diff --git a/library/core/src/test/java/com/google/android/exoplayer2/upstream/cache/CacheDataSourceTest.java b/library/core/src/test/java/com/google/android/exoplayer2/upstream/cache/CacheDataSourceTest.java
index f761afac55..5ee8e423b7 100644
--- a/library/core/src/test/java/com/google/android/exoplayer2/upstream/cache/CacheDataSourceTest.java
+++ b/library/core/src/test/java/com/google/android/exoplayer2/upstream/cache/CacheDataSourceTest.java
@@ -284,7 +284,6 @@ public final class CacheDataSourceTest {
             cacheDataSource.open(
                 buildDataSpec(TEST_DATA.length - 2, C.LENGTH_UNSET, defaultCacheKey)))
         .isEqualTo(2);
-    cacheDataSource.close();
 
     // An unbounded request with offset for not cached content.
     dataSpec =
diff --git a/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/Aes128DataSource.java b/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/Aes128DataSource.java
index 2f8786e11e..11d68b1c08 100644
--- a/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/Aes128DataSource.java
+++ b/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/Aes128DataSource.java
@@ -15,8 +15,6 @@
  */
 package com.google.android.exoplayer2.source.hls;
 
-import static com.google.android.exoplayer2.util.Assertions.checkState;
-
 import android.net.Uri;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
@@ -52,7 +50,6 @@ import javax.crypto.spec.SecretKeySpec;
   private final DataSource upstream;
   private final byte[] encryptionKey;
   private final byte[] encryptionIv;
-  private boolean opened;
 
   @Nullable private CipherInputStream cipherInputStream;
 
@@ -75,7 +72,6 @@ import javax.crypto.spec.SecretKeySpec;
 
   @Override
   public final long open(DataSpec dataSpec) throws IOException {
-    checkState(!opened);
     Cipher cipher;
     try {
       cipher = getCipherInstance();
@@ -95,7 +91,7 @@ import javax.crypto.spec.SecretKeySpec;
     DataSourceInputStream inputStream = new DataSourceInputStream(upstream, dataSpec);
     cipherInputStream = new CipherInputStream(inputStream, cipher);
     inputStream.open();
-    opened = true;
+
     return C.LENGTH_UNSET;
   }
 
@@ -125,7 +121,6 @@ import javax.crypto.spec.SecretKeySpec;
     if (cipherInputStream != null) {
       cipherInputStream = null;
       upstream.close();
-      opened = false;
     }
   }
 
diff --git a/library/hls/src/test/java/com/google/android/exoplayer2/source/hls/Aes128DataSourceTest.java b/library/hls/src/test/java/com/google/android/exoplayer2/source/hls/Aes128DataSourceTest.java
index 881697e4af..3eef5c36d2 100644
--- a/library/hls/src/test/java/com/google/android/exoplayer2/source/hls/Aes128DataSourceTest.java
+++ b/library/hls/src/test/java/com/google/android/exoplayer2/source/hls/Aes128DataSourceTest.java
@@ -15,7 +15,6 @@
  */
 package com.google.android.exoplayer2.source.hls;
 
-import static com.google.android.exoplayer2.util.Assertions.checkState;
 import static com.google.common.truth.Truth.assertThat;
 
 import android.net.Uri;
@@ -105,7 +104,6 @@ public class Aes128DataSourceTest {
 
     @Override
     public long open(DataSpec dataSpec) throws IOException {
-      checkState(!opened);
       opened = true;
       return C.LENGTH_UNSET;
     }