Only parse common-encryption sinf boxes

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=172124807

library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/AtomParsers.java

@@ -1064,8 +1064,8 @@ import java.util.List;
       Assertions.checkArgument(childAtomSize > 0, "childAtomSize should be positive");
       Assertions.checkArgument(childAtomSize > 0, "childAtomSize should be positive");
       int childAtomType = parent.readInt();
       int childAtomType = parent.readInt();
       if (childAtomType == Atom.TYPE_sinf) {
       if (childAtomType == Atom.TYPE_sinf) {
-        Pair<Integer, TrackEncryptionBox> result = parseSinfFromParent(parent, childPosition,
-            childAtomSize);
+        Pair<Integer, TrackEncryptionBox> result = parseCommonEncryptionSinfFromParent(parent,
+            childPosition, childAtomSize);
         if (result != null) {
         if (result != null) {
           return result;
           return result;
         }
         }
@@ -1075,8 +1075,8 @@ import java.util.List;
     return null;
     return null;
   }
   }
 
 
-  private static Pair<Integer, TrackEncryptionBox> parseSinfFromParent(ParsableByteArray parent,
-      int position, int size) {
+  /* package */ static Pair<Integer, TrackEncryptionBox> parseCommonEncryptionSinfFromParent(
+      ParsableByteArray parent, int position, int size) {
     int childPosition = position + Atom.HEADER_SIZE;
     int childPosition = position + Atom.HEADER_SIZE;
     int schemeInformationBoxPosition = C.POSITION_UNSET;
     int schemeInformationBoxPosition = C.POSITION_UNSET;
     int schemeInformationBoxSize = 0;
     int schemeInformationBoxSize = 0;
@@ -1090,7 +1090,7 @@ import java.util.List;
         dataFormat = parent.readInt();
         dataFormat = parent.readInt();
       } else if (childAtomType == Atom.TYPE_schm) {
       } else if (childAtomType == Atom.TYPE_schm) {
         parent.skipBytes(4);
         parent.skipBytes(4);
-        // scheme_type field. Defined in ISO/IEC 23001-7:2016, section 4.1.
+        // Common encryption scheme_type values are defined in ISO/IEC 23001-7:2016, section 4.1.
         schemeType = parent.readString(4);
         schemeType = parent.readString(4);
       } else if (childAtomType == Atom.TYPE_schi) {
       } else if (childAtomType == Atom.TYPE_schi) {
         schemeInformationBoxPosition = childPosition;
         schemeInformationBoxPosition = childPosition;
@@ -1099,7 +1099,8 @@ import java.util.List;
       childPosition += childAtomSize;
       childPosition += childAtomSize;
     }
     }
 
 
-    if (schemeType != null) {
+    if (C.CENC_TYPE_cenc.equals(schemeType) || C.CENC_TYPE_cbc1.equals(schemeType)
+        || C.CENC_TYPE_cens.equals(schemeType) || C.CENC_TYPE_cbcs.equals(schemeType)) {
       Assertions.checkArgument(dataFormat != null, "frma atom is mandatory");
       Assertions.checkArgument(dataFormat != null, "frma atom is mandatory");
       Assertions.checkArgument(schemeInformationBoxPosition != C.POSITION_UNSET,
       Assertions.checkArgument(schemeInformationBoxPosition != C.POSITION_UNSET,
           "schi atom is mandatory");
           "schi atom is mandatory");

library/core/src/test/java/com/google/android/exoplayer2/extractor/mp4/AtomParsersTest.java

@@ -41,21 +41,31 @@ public final class AtomParsersTest {
       + SAMPLE_COUNT + "0001000200030004");
       + SAMPLE_COUNT + "0001000200030004");
 
 
   @Test
   @Test
+  public void testParseCommonEncryptionSinfFromParentIgnoresUnknownSchemeType() {
+    byte[] cencSinf = new byte[] {
+        0, 0, 0, 24, 115, 105, 110, 102, // size (4), 'sinf' (4)
+        0, 0, 0, 16, 115, 99, 104, 109, // size (4), 'schm' (4)
+        0, 0, 0, 0, 88, 88, 88, 88}; // version (1), flags (3), 'xxxx' (4)
+    assertThat(AtomParsers.parseCommonEncryptionSinfFromParent(
+        new ParsableByteArray(cencSinf), 0, cencSinf.length)).isNull();
+  }
+
+  @Test
   public void testStz2Parsing4BitFieldSize() {
   public void testStz2Parsing4BitFieldSize() {
-    verifyParsing(new Atom.LeafAtom(Atom.TYPE_stsz, new ParsableByteArray(FOUR_BIT_STZ2)));
+    verifyStz2Parsing(new Atom.LeafAtom(Atom.TYPE_stsz, new ParsableByteArray(FOUR_BIT_STZ2)));
   }
   }
 
 
   @Test
   @Test
   public void testStz2Parsing8BitFieldSize() {
   public void testStz2Parsing8BitFieldSize() {
-    verifyParsing(new Atom.LeafAtom(Atom.TYPE_stsz, new ParsableByteArray(EIGHT_BIT_STZ2)));
+    verifyStz2Parsing(new Atom.LeafAtom(Atom.TYPE_stsz, new ParsableByteArray(EIGHT_BIT_STZ2)));
   }
   }
 
 
   @Test
   @Test
   public void testStz2Parsing16BitFieldSize() {
   public void testStz2Parsing16BitFieldSize() {
-    verifyParsing(new Atom.LeafAtom(Atom.TYPE_stsz, new ParsableByteArray(SIXTEEN_BIT_STZ2)));
+    verifyStz2Parsing(new Atom.LeafAtom(Atom.TYPE_stsz, new ParsableByteArray(SIXTEEN_BIT_STZ2)));
   }
   }
 
 
-  private void verifyParsing(Atom.LeafAtom stz2Atom) {
+  private static void verifyStz2Parsing(Atom.LeafAtom stz2Atom) {
     AtomParsers.Stz2SampleSizeBox box = new AtomParsers.Stz2SampleSizeBox(stz2Atom);
     AtomParsers.Stz2SampleSizeBox box = new AtomParsers.Stz2SampleSizeBox(stz2Atom);
     assertThat(box.getSampleCount()).isEqualTo(4);
     assertThat(box.getSampleCount()).isEqualTo(4);
     assertThat(box.isFixedSampleSize()).isFalse();
     assertThat(box.isFixedSampleSize()).isFalse();