diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index d99656b5a9..29c50c1b29 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -1,5 +1,13 @@
 # Release notes #
 
+### 2.11.8 (2020-08-25) ###
+
+*   MP4: Add support for `piff` and `isml` brands
+    ([#7584](https://github.com/google/ExoPlayer/issues/7584)).
+*   FMP4: Fix `saiz` and `senc` sample count checks, resolving a "length
+    mismatch" `ParserException` when playing certain protected FMP4 streams
+    ([#7592](https://github.com/google/ExoPlayer/issues/7592)).
+
 ### 2.11.7 (2020-06-29) ###
 
 *   IMA extension: Fix the way postroll "content complete" notifications are
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/FragmentedMp4Extractor.java b/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/FragmentedMp4Extractor.java
index c0d1581c39..f75c40d448 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/FragmentedMp4Extractor.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/FragmentedMp4Extractor.java
@@ -798,8 +798,12 @@ public class FragmentedMp4Extractor implements Extractor {
     int defaultSampleInfoSize = saiz.readUnsignedByte();
 
     int sampleCount = saiz.readUnsignedIntToInt();
-    if (sampleCount != out.sampleCount) {
-      throw new ParserException("Length mismatch: " + sampleCount + ", " + out.sampleCount);
+    if (sampleCount > out.sampleCount) {
+      throw new ParserException(
+          "Saiz sample count "
+              + sampleCount
+              + " is greater than fragment sample count"
+              + out.sampleCount);
     }
 
     int totalSize = 0;
@@ -815,7 +819,10 @@ public class FragmentedMp4Extractor implements Extractor {
       totalSize += defaultSampleInfoSize * sampleCount;
       Arrays.fill(out.sampleHasSubsampleEncryptionTable, 0, sampleCount, subsampleEncryption);
     }
-    out.initEncryptionData(totalSize);
+    Arrays.fill(out.sampleHasSubsampleEncryptionTable, sampleCount, out.sampleCount, false);
+    if (totalSize > 0) {
+      out.initEncryptionData(totalSize);
+    }
   }
 
   /**
@@ -1055,8 +1062,16 @@ public class FragmentedMp4Extractor implements Extractor {
 
     boolean subsampleEncryption = (flags & 0x02 /* use_subsample_encryption */) != 0;
     int sampleCount = senc.readUnsignedIntToInt();
-    if (sampleCount != out.sampleCount) {
-      throw new ParserException("Length mismatch: " + sampleCount + ", " + out.sampleCount);
+    if (sampleCount == 0) {
+      // Samples are unencrypted.
+      Arrays.fill(out.sampleHasSubsampleEncryptionTable, 0, out.sampleCount, false);
+      return;
+    } else if (sampleCount != out.sampleCount) {
+      throw new ParserException(
+          "Senc sample count "
+              + sampleCount
+              + " is different from fragment sample count"
+              + out.sampleCount);
     }
 
     Arrays.fill(out.sampleHasSubsampleEncryptionTable, 0, sampleCount, subsampleEncryption);