diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index e6874dbe69..f8381ce4e2 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -36,9 +36,11 @@
         even though the class was not used
         ([#8058](https://github.com/google/ExoPlayer/issues/8058)).
 *   Extractors:
-    *   Add support for .mp2 boxes in the `AtomParsers`
+    *   Add support for `_mp2` boxes in `Mp4Extractor`
         ([#7967](https://github.com/google/ExoPlayer/issues/7967)).
-    *   Use TLEN ID3 tag to compute the duration in Mp3Extractor
+    *   Fix playback of MP4 and MOV files containing `pcm_alaw` or `pcm_mulaw`
+        audio tracks, by enabling sample rechunking of such tracks
+    *   Use TLEN ID3 tag to compute the duration in `Mp3Extractor`
         ([#7949](https://github.com/google/ExoPlayer/issues/7949)).
     *   Fix regression for Ogg files with packets that span multiple pages
         ([#7992](https://github.com/google/ExoPlayer/issues/7992)).
diff --git a/library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mp4/AtomParsers.java b/library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mp4/AtomParsers.java
index 573451ef6a..58cb57f261 100644
--- a/library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mp4/AtomParsers.java
+++ b/library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mp4/AtomParsers.java
@@ -384,9 +384,13 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
     }
 
     // Fixed sample size raw audio may need to be rechunked.
-    boolean isFixedSampleSizeRawAudio =
-        sampleSizeBox.isFixedSampleSize()
-            && MimeTypes.AUDIO_RAW.equals(track.format.sampleMimeType)
+    int fixedSampleSize = sampleSizeBox.getFixedSampleSize();
+    @Nullable String sampleMimeType = track.format.sampleMimeType;
+    boolean rechunkFixedSizeSamples =
+        fixedSampleSize != C.LENGTH_UNSET
+            && (MimeTypes.AUDIO_RAW.equals(sampleMimeType)
+                || MimeTypes.AUDIO_MLAW.equals(sampleMimeType)
+                || MimeTypes.AUDIO_ALAW.equals(sampleMimeType))
             && remainingTimestampDeltaChanges == 0
             && remainingTimestampOffsetChanges == 0
             && remainingSynchronizationSamples == 0;
@@ -399,15 +403,13 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
     long timestampTimeUnits = 0;
     long duration;
 
-    if (isFixedSampleSizeRawAudio) {
+    if (rechunkFixedSizeSamples) {
       long[] chunkOffsetsBytes = new long[chunkIterator.length];
       int[] chunkSampleCounts = new int[chunkIterator.length];
       while (chunkIterator.moveNext()) {
         chunkOffsetsBytes[chunkIterator.index] = chunkIterator.offset;
         chunkSampleCounts[chunkIterator.index] = chunkIterator.numSamples;
       }
-      int fixedSampleSize =
-          Util.getPcmFrameSize(track.format.pcmEncoding, track.format.channelCount);
       FixedSampleSizeRechunker.Results rechunkedResults =
           FixedSampleSizeRechunker.rechunk(
               fixedSampleSize, chunkOffsetsBytes, chunkSampleCounts, timestampDeltaInTimeUnits);
@@ -1661,16 +1663,11 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
      */
     int getSampleCount();
 
-    /**
-     * Returns the size for the next sample.
-     */
+    /** Returns the size of each sample if fixed, or {@link C#LENGTH_UNSET} otherwise. */
+    int getFixedSampleSize();
+
+    /** Returns the size for the next sample. */
     int readNextSampleSize();
-
-    /**
-     * Returns whether samples have a fixed size.
-     */
-    boolean isFixedSampleSize();
-
   }
 
   /**
@@ -1685,7 +1682,8 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
     public StszSampleSizeBox(Atom.LeafAtom stszAtom) {
       data = stszAtom.data;
       data.setPosition(Atom.FULL_HEADER_SIZE);
-      fixedSampleSize = data.readUnsignedIntToInt();
+      int fixedSampleSize = data.readUnsignedIntToInt();
+      this.fixedSampleSize = fixedSampleSize == 0 ? C.LENGTH_UNSET : fixedSampleSize;
       sampleCount = data.readUnsignedIntToInt();
     }
 
@@ -1695,15 +1693,14 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
     }
 
     @Override
-    public int readNextSampleSize() {
-      return fixedSampleSize == 0 ? data.readUnsignedIntToInt() : fixedSampleSize;
+    public int getFixedSampleSize() {
+      return fixedSampleSize;
     }
 
     @Override
-    public boolean isFixedSampleSize() {
-      return fixedSampleSize != 0;
+    public int readNextSampleSize() {
+      return fixedSampleSize == C.LENGTH_UNSET ? data.readUnsignedIntToInt() : fixedSampleSize;
     }
-
   }
 
   /**
@@ -1731,6 +1728,11 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
       return sampleCount;
     }
 
+    @Override
+    public int getFixedSampleSize() {
+      return C.LENGTH_UNSET;
+    }
+
     @Override
     public int readNextSampleSize() {
       if (fieldSize == 8) {
@@ -1750,12 +1752,6 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
         }
       }
     }
-
-    @Override
-    public boolean isFixedSampleSize() {
-      return false;
-    }
-
   }
 
 }
diff --git a/library/extractor/src/test/java/com/google/android/exoplayer2/extractor/mp4/AtomParsersTest.java b/library/extractor/src/test/java/com/google/android/exoplayer2/extractor/mp4/AtomParsersTest.java
index 9ca974afb8..651384094f 100644
--- a/library/extractor/src/test/java/com/google/android/exoplayer2/extractor/mp4/AtomParsersTest.java
+++ b/library/extractor/src/test/java/com/google/android/exoplayer2/extractor/mp4/AtomParsersTest.java
@@ -18,6 +18,7 @@ package com.google.android.exoplayer2.extractor.mp4;
 import static com.google.common.truth.Truth.assertThat;
 
 import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.util.ParsableByteArray;
 import com.google.android.exoplayer2.util.Util;
 import org.junit.Test;
@@ -64,7 +65,7 @@ public final class AtomParsersTest {
   private static void verifyStz2Parsing(Atom.LeafAtom stz2Atom) {
     AtomParsers.Stz2SampleSizeBox box = new AtomParsers.Stz2SampleSizeBox(stz2Atom);
     assertThat(box.getSampleCount()).isEqualTo(4);
-    assertThat(box.isFixedSampleSize()).isFalse();
+    assertThat(box.getFixedSampleSize()).isEqualTo(C.LENGTH_UNSET);
     for (int i = 0; i < box.getSampleCount(); i++) {
       assertThat(box.readNextSampleSize()).isEqualTo(i + 1);
     }