diff --git a/extensions/flac/src/androidTest/assets/bear.flac.0.dump b/extensions/flac/src/androidTest/assets/bear.flac.0.dump
index 816356a1e6..d562052a4f 100644
--- a/extensions/flac/src/androidTest/assets/bear.flac.0.dump
+++ b/extensions/flac/src/androidTest/assets/bear.flac.0.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
   total output bytes = 526272
   sample count = 33
diff --git a/extensions/flac/src/androidTest/assets/bear.flac.1.dump b/extensions/flac/src/androidTest/assets/bear.flac.1.dump
index 4a6b06725f..93f38227b8 100644
--- a/extensions/flac/src/androidTest/assets/bear.flac.1.dump
+++ b/extensions/flac/src/androidTest/assets/bear.flac.1.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
   total output bytes = 362432
   sample count = 23
diff --git a/extensions/flac/src/androidTest/assets/bear.flac.2.dump b/extensions/flac/src/androidTest/assets/bear.flac.2.dump
index dddb6dc264..9c53a95b06 100644
--- a/extensions/flac/src/androidTest/assets/bear.flac.2.dump
+++ b/extensions/flac/src/androidTest/assets/bear.flac.2.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
   total output bytes = 182208
   sample count = 12
diff --git a/extensions/flac/src/androidTest/assets/bear.flac.3.dump b/extensions/flac/src/androidTest/assets/bear.flac.3.dump
index 0dbe575ecf..82e23a21c1 100644
--- a/extensions/flac/src/androidTest/assets/bear.flac.3.dump
+++ b/extensions/flac/src/androidTest/assets/bear.flac.3.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
   total output bytes = 18368
   sample count = 2
diff --git a/extensions/flac/src/main/java/com/google/android/exoplayer2/ext/flac/FlacExtractor.java b/extensions/flac/src/main/java/com/google/android/exoplayer2/ext/flac/FlacExtractor.java
index 7c69a93fc9..2c6f51da02 100644
--- a/extensions/flac/src/main/java/com/google/android/exoplayer2/ext/flac/FlacExtractor.java
+++ b/extensions/flac/src/main/java/com/google/android/exoplayer2/ext/flac/FlacExtractor.java
@@ -212,6 +212,7 @@ public final class FlacExtractor implements Extractor {
               input.getLength(),
               extractorOutput,
               outputFrameHolder);
+      @Nullable
       Metadata metadata = streamMetadata.getMetadataCopyWithAppendedEntriesFrom(id3Metadata);
       outputFormat(streamMetadata, metadata, trackOutput);
     }
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/extractor/FlacMetadataReader.java b/library/core/src/main/java/com/google/android/exoplayer2/extractor/FlacMetadataReader.java
index e86c9b0129..e66f39de8c 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/extractor/FlacMetadataReader.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/extractor/FlacMetadataReader.java
@@ -81,7 +81,8 @@ public final class FlacMetadataReader {
       throws IOException, InterruptedException {
     @Nullable
     Id3Decoder.FramePredicate id3FramePredicate = parseData ? null : Id3Decoder.NO_FRAMES_PREDICATE;
-    return new Id3Peeker().peekId3Data(input, id3FramePredicate);
+    @Nullable Metadata id3Metadata = new Id3Peeker().peekId3Data(input, id3FramePredicate);
+    return id3Metadata == null || id3Metadata.length() == 0 ? null : id3Metadata;
   }
 
   /**
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/util/FlacStreamMetadata.java b/library/core/src/main/java/com/google/android/exoplayer2/util/FlacStreamMetadata.java
index 2772f7e0c6..db1de183ac 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/util/FlacStreamMetadata.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/util/FlacStreamMetadata.java
@@ -80,8 +80,8 @@ public final class FlacStreamMetadata {
   /** Total number of samples, or 0 if the value is unknown. */
   public final long totalSamples;
 
-  /** Content metadata. */
-  private final Metadata metadata;
+  /** Content metadata, or {@code null} if it is not provided. */
+  @Nullable private final Metadata metadata;
 
   /**
    * Parses binary FLAC stream info metadata.
@@ -102,7 +102,7 @@ public final class FlacStreamMetadata {
     bitsPerSample = scratch.readBits(5) + 1;
     bitsPerSampleLookupKey = getBitsPerSampleLookupKey(bitsPerSample);
     totalSamples = scratch.readBitsToLong(36);
-    metadata = new Metadata();
+    metadata = null;
   }
 
   // Used in native code.
@@ -138,7 +138,7 @@ public final class FlacStreamMetadata {
       int channels,
       int bitsPerSample,
       long totalSamples,
-      Metadata metadata) {
+      @Nullable Metadata metadata) {
     this.minBlockSizeSamples = minBlockSizeSamples;
     this.maxBlockSizeSamples = maxBlockSizeSamples;
     this.minFrameSize = minFrameSize;
@@ -213,7 +213,7 @@ public final class FlacStreamMetadata {
     // Set the last metadata block flag, ignore the other blocks.
     streamMarkerAndInfoBlock[4] = (byte) 0x80;
     int maxInputSize = maxFrameSize > 0 ? maxFrameSize : Format.NO_VALUE;
-    Metadata metadataWithId3 = metadata.copyWithAppendedEntriesFrom(id3Metadata);
+    @Nullable Metadata metadataWithId3 = getMetadataCopyWithAppendedEntriesFrom(id3Metadata);
 
     return Format.createAudioSampleFormat(
         /* id= */ null,
@@ -234,14 +234,16 @@ public final class FlacStreamMetadata {
   }
 
   /** Returns a copy of the content metadata with entries from {@code other} appended. */
+  @Nullable
   public Metadata getMetadataCopyWithAppendedEntriesFrom(@Nullable Metadata other) {
-    return metadata.copyWithAppendedEntriesFrom(other);
+    return metadata == null ? other : metadata.copyWithAppendedEntriesFrom(other);
   }
 
   /** Returns a copy of {@code this} with the given Vorbis comments added to the metadata. */
   public FlacStreamMetadata copyWithVorbisComments(List<String> vorbisComments) {
+    @Nullable
     Metadata appendedMetadata =
-        metadata.copyWithAppendedEntriesFrom(
+        getMetadataCopyWithAppendedEntriesFrom(
             buildMetadata(vorbisComments, Collections.emptyList()));
     return new FlacStreamMetadata(
         minBlockSizeSamples,
@@ -257,8 +259,10 @@ public final class FlacStreamMetadata {
 
   /** Returns a copy of {@code this} with the given picture frames added to the metadata. */
   public FlacStreamMetadata copyWithPictureFrames(List<PictureFrame> pictureFrames) {
+    @Nullable
     Metadata appendedMetadata =
-        metadata.copyWithAppendedEntriesFrom(buildMetadata(Collections.emptyList(), pictureFrames));
+        getMetadataCopyWithAppendedEntriesFrom(
+            buildMetadata(Collections.emptyList(), pictureFrames));
     return new FlacStreamMetadata(
         minBlockSizeSamples,
         maxBlockSizeSamples,
@@ -317,10 +321,11 @@ public final class FlacStreamMetadata {
     }
   }
 
+  @Nullable
   private static Metadata buildMetadata(
       List<String> vorbisComments, List<PictureFrame> pictureFrames) {
     if (vorbisComments.isEmpty() && pictureFrames.isEmpty()) {
-      return new Metadata();
+      return null;
     }
 
     ArrayList<Metadata.Entry> metadataEntries = new ArrayList<>();
@@ -336,6 +341,6 @@ public final class FlacStreamMetadata {
     }
     metadataEntries.addAll(pictureFrames);
 
-    return metadataEntries.isEmpty() ? new Metadata() : new Metadata(metadataEntries);
+    return metadataEntries.isEmpty() ? null : new Metadata(metadataEntries);
   }
 }
diff --git a/library/core/src/test/assets/flac/bear.flac.0.dump b/library/core/src/test/assets/flac/bear.flac.0.dump
index 109cc49ebb..bd8f1827e4 100644
--- a/library/core/src/test/assets/flac/bear.flac.0.dump
+++ b/library/core/src/test/assets/flac/bear.flac.0.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
       data = length 42, hash 83F6895
   total output bytes = 164431
diff --git a/library/core/src/test/assets/flac/bear_no_min_max_frame_size.flac.0.dump b/library/core/src/test/assets/flac/bear_no_min_max_frame_size.flac.0.dump
index a7c8b628ba..4ef7138487 100644
--- a/library/core/src/test/assets/flac/bear_no_min_max_frame_size.flac.0.dump
+++ b/library/core/src/test/assets/flac/bear_no_min_max_frame_size.flac.0.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
       data = length 42, hash 9218FDB7
   total output bytes = 164431
diff --git a/library/core/src/test/assets/flac/bear_no_num_samples.flac.0.dump b/library/core/src/test/assets/flac/bear_no_num_samples.flac.0.dump
index 7606154ddd..45b75392b3 100644
--- a/library/core/src/test/assets/flac/bear_no_num_samples.flac.0.dump
+++ b/library/core/src/test/assets/flac/bear_no_num_samples.flac.0.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
       data = length 42, hash 49FA2C21
   total output bytes = 164431
diff --git a/library/core/src/test/assets/flac/bear_one_metadata_block.flac.0.dump b/library/core/src/test/assets/flac/bear_one_metadata_block.flac.0.dump
index 109cc49ebb..bd8f1827e4 100644
--- a/library/core/src/test/assets/flac/bear_one_metadata_block.flac.0.dump
+++ b/library/core/src/test/assets/flac/bear_one_metadata_block.flac.0.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
       data = length 42, hash 83F6895
   total output bytes = 164431
diff --git a/library/core/src/test/assets/flac/bear_uncommon_sample_rate.flac.0.dump b/library/core/src/test/assets/flac/bear_uncommon_sample_rate.flac.0.dump
index 488517947c..e6caad8e84 100644
--- a/library/core/src/test/assets/flac/bear_uncommon_sample_rate.flac.0.dump
+++ b/library/core/src/test/assets/flac/bear_uncommon_sample_rate.flac.0.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
       data = length 42, hash 7249A1B8
   total output bytes = 144086
diff --git a/library/core/src/test/assets/flac/bear_with_id3_disabled.flac.0.dump b/library/core/src/test/assets/flac/bear_with_id3_disabled.flac.0.dump
index 109cc49ebb..bd8f1827e4 100644
--- a/library/core/src/test/assets/flac/bear_with_id3_disabled.flac.0.dump
+++ b/library/core/src/test/assets/flac/bear_with_id3_disabled.flac.0.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
       data = length 42, hash 83F6895
   total output bytes = 164431
diff --git a/library/core/src/test/assets/ogg/bear_flac.ogg.0.dump b/library/core/src/test/assets/ogg/bear_flac.ogg.0.dump
index 896c8ad6c5..d32342619c 100644
--- a/library/core/src/test/assets/ogg/bear_flac.ogg.0.dump
+++ b/library/core/src/test/assets/ogg/bear_flac.ogg.0.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
       data = length 42, hash 83F6895
   total output bytes = 164431
diff --git a/library/core/src/test/assets/ogg/bear_flac.ogg.1.dump b/library/core/src/test/assets/ogg/bear_flac.ogg.1.dump
index e85b504a39..17e6c6d862 100644
--- a/library/core/src/test/assets/ogg/bear_flac.ogg.1.dump
+++ b/library/core/src/test/assets/ogg/bear_flac.ogg.1.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
       data = length 42, hash 83F6895
   total output bytes = 113666
diff --git a/library/core/src/test/assets/ogg/bear_flac.ogg.2.dump b/library/core/src/test/assets/ogg/bear_flac.ogg.2.dump
index 63bc130424..e52b8897c8 100644
--- a/library/core/src/test/assets/ogg/bear_flac.ogg.2.dump
+++ b/library/core/src/test/assets/ogg/bear_flac.ogg.2.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
       data = length 42, hash 83F6895
   total output bytes = 55652
diff --git a/library/core/src/test/assets/ogg/bear_flac.ogg.3.dump b/library/core/src/test/assets/ogg/bear_flac.ogg.3.dump
index fdebce7743..dabf5552da 100644
--- a/library/core/src/test/assets/ogg/bear_flac.ogg.3.dump
+++ b/library/core/src/test/assets/ogg/bear_flac.ogg.3.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
       data = length 42, hash 83F6895
   total output bytes = 445
diff --git a/library/core/src/test/assets/ogg/bear_flac.ogg.unklen.dump b/library/core/src/test/assets/ogg/bear_flac.ogg.unklen.dump
index 896c8ad6c5..d32342619c 100644
--- a/library/core/src/test/assets/ogg/bear_flac.ogg.unklen.dump
+++ b/library/core/src/test/assets/ogg/bear_flac.ogg.unklen.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
       data = length 42, hash 83F6895
   total output bytes = 164431
diff --git a/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.0.dump b/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.0.dump
index b09453f208..efbf8a3609 100644
--- a/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.0.dump
+++ b/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.0.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
       data = length 42, hash 83F6895
   total output bytes = 164431
diff --git a/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.1.dump b/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.1.dump
index 4ab08524ae..80ad2045ce 100644
--- a/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.1.dump
+++ b/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.1.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
       data = length 42, hash 83F6895
   total output bytes = 113666
diff --git a/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.2.dump b/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.2.dump
index 3a846736d2..c2efd50a33 100644
--- a/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.2.dump
+++ b/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.2.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
       data = length 42, hash 83F6895
   total output bytes = 55652
diff --git a/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.3.dump b/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.3.dump
index 5bf1a92472..26601231a6 100644
--- a/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.3.dump
+++ b/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.3.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
       data = length 42, hash 83F6895
   total output bytes = 445
diff --git a/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.unklen.dump b/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.unklen.dump
index 1a0686c5fd..67a1fecee4 100644
--- a/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.unklen.dump
+++ b/library/core/src/test/assets/ogg/bear_flac_noseektable.ogg.unklen.dump
@@ -24,7 +24,7 @@ track 0:
     selectionFlags = 0
     language = null
     drmInitData = -
-    metadata = entries=[]
+    metadata = null
     initializationData:
       data = length 42, hash 83F6895
   total output bytes = 164431
diff --git a/library/core/src/test/java/com/google/android/exoplayer2/util/FlacStreamMetadataTest.java b/library/core/src/test/java/com/google/android/exoplayer2/util/FlacStreamMetadataTest.java
index d3d3e53458..ddaa550b7f 100644
--- a/library/core/src/test/java/com/google/android/exoplayer2/util/FlacStreamMetadataTest.java
+++ b/library/core/src/test/java/com/google/android/exoplayer2/util/FlacStreamMetadataTest.java
@@ -75,7 +75,7 @@ public final class FlacStreamMetadataTest {
                 /* pictureFrames= */ new ArrayList<>())
             .getMetadataCopyWithAppendedEntriesFrom(/* other= */ null);
 
-    assertThat(metadata.length()).isEqualTo(0);
+    assertThat(metadata).isNull();
   }
 
   @Test