diff --git a/extensions/opus/src/main/java/com/google/android/exoplayer/ext/opus/LibopusAudioTrackRenderer.java b/extensions/opus/src/main/java/com/google/android/exoplayer/ext/opus/LibopusAudioTrackRenderer.java
index 3a71a67536..5c32dd44d5 100644
--- a/extensions/opus/src/main/java/com/google/android/exoplayer/ext/opus/LibopusAudioTrackRenderer.java
+++ b/extensions/opus/src/main/java/com/google/android/exoplayer/ext/opus/LibopusAudioTrackRenderer.java
@@ -31,6 +31,7 @@ import com.google.android.exoplayer.util.MimeTypes;
 import android.os.Handler;
 
 import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
 import java.util.List;
 
 /**
@@ -165,12 +166,13 @@ public final class LibopusAudioTrackRenderer extends SampleSourceTrackRenderer
       long codecDelayNs = -1;
       long seekPreRollNs = -1;
       if (initializationData.size() == 3) {
-        if (initializationData.get(1).length != Long.SIZE
-            || initializationData.get(2).length != Long.SIZE) {
+        if (initializationData.get(1).length != 8 || initializationData.get(2).length != 8) {
           throw new ExoPlaybackException("Invalid Codec Delay or Seek Preroll");
         }
-        codecDelayNs = ByteBuffer.wrap(initializationData.get(1)).getLong();
-        seekPreRollNs = ByteBuffer.wrap(initializationData.get(2)).getLong();
+        codecDelayNs =
+            ByteBuffer.wrap(initializationData.get(1)).order(ByteOrder.LITTLE_ENDIAN).getLong();
+        seekPreRollNs =
+            ByteBuffer.wrap(initializationData.get(2)).order(ByteOrder.LITTLE_ENDIAN).getLong();
       }
       try {
         decoder = new OpusDecoderWrapper(initializationData.get(0), codecDelayNs, seekPreRollNs);
diff --git a/library/src/androidTest/java/com/google/android/exoplayer/extractor/webm/WebmExtractorTest.java b/library/src/androidTest/java/com/google/android/exoplayer/extractor/webm/WebmExtractorTest.java
index 0c0e916596..898c282a83 100644
--- a/library/src/androidTest/java/com/google/android/exoplayer/extractor/webm/WebmExtractorTest.java
+++ b/library/src/androidTest/java/com/google/android/exoplayer/extractor/webm/WebmExtractorTest.java
@@ -34,6 +34,7 @@ import android.test.InstrumentationTestCase;
 
 import java.io.IOException;
 import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
 import java.util.Arrays;
 import java.util.UUID;
 
@@ -731,8 +732,10 @@ public final class WebmExtractorTest extends InstrumentationTestCase {
       assertEquals(3, format.initializationData.size());
       android.test.MoreAsserts.assertEquals(TEST_OPUS_CODEC_PRIVATE,
           format.initializationData.get(0));
-      assertEquals(TEST_CODEC_DELAY, ByteBuffer.wrap(format.initializationData.get(1)).getLong());
-      assertEquals(TEST_SEEK_PRE_ROLL, ByteBuffer.wrap(format.initializationData.get(2)).getLong());
+      assertEquals(TEST_CODEC_DELAY, ByteBuffer.wrap(format.initializationData.get(1))
+          .order(ByteOrder.LITTLE_ENDIAN).getLong());
+      assertEquals(TEST_SEEK_PRE_ROLL, ByteBuffer.wrap(format.initializationData.get(2))
+          .order(ByteOrder.LITTLE_ENDIAN).getLong());
     } else if (MimeTypes.AUDIO_VORBIS.equals(expectedMimeType)) {
       assertEquals(2, format.initializationData.size());
       assertEquals(TEST_VORBIS_INFO_SIZE, format.initializationData.get(0).length);
diff --git a/library/src/main/java/com/google/android/exoplayer/extractor/webm/WebmExtractor.java b/library/src/main/java/com/google/android/exoplayer/extractor/webm/WebmExtractor.java
index 41134b4731..facce45b02 100644
--- a/library/src/main/java/com/google/android/exoplayer/extractor/webm/WebmExtractor.java
+++ b/library/src/main/java/com/google/android/exoplayer/extractor/webm/WebmExtractor.java
@@ -37,6 +37,7 @@ import android.util.Pair;
 
 import java.io.IOException;
 import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -1104,8 +1105,10 @@ public final class WebmExtractor implements Extractor {
           maxInputSize = OPUS_MAX_INPUT_SIZE;
           initializationData = new ArrayList<>(3);
           initializationData.add(codecPrivate);
-          initializationData.add(ByteBuffer.allocate(Long.SIZE).putLong(codecDelayNs).array());
-          initializationData.add(ByteBuffer.allocate(Long.SIZE).putLong(seekPreRollNs).array());
+          initializationData.add(
+              ByteBuffer.allocate(8).order(ByteOrder.LITTLE_ENDIAN).putLong(codecDelayNs).array());
+          initializationData.add(
+              ByteBuffer.allocate(8).order(ByteOrder.LITTLE_ENDIAN).putLong(seekPreRollNs).array());
           break;
         case CODEC_ID_AAC:
           mimeType = MimeTypes.AUDIO_AAC;