sgpd support in ExoV2

This is basically clone of [] for Exo V2.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=124682237

library/src/main/java/com/google/android/exoplayer/extractor/mp4/Atom.java

@@ -99,6 +99,8 @@ import java.util.List;
   public static final int TYPE_frma = Util.getIntegerCodeForString("frma");
   public static final int TYPE_saiz = Util.getIntegerCodeForString("saiz");
   public static final int TYPE_saio = Util.getIntegerCodeForString("saio");
+  public static final int TYPE_sbgp = Util.getIntegerCodeForString("sbgp");
+  public static final int TYPE_sgpd = Util.getIntegerCodeForString("sgpd");
   public static final int TYPE_uuid = Util.getIntegerCodeForString("uuid");
   public static final int TYPE_senc = Util.getIntegerCodeForString("senc");
   public static final int TYPE_pasp = Util.getIntegerCodeForString("pasp");

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

@@ -1075,10 +1075,9 @@ import java.util.List;
       int childAtomSize = parent.readInt();
       int childAtomType = parent.readInt();
       if (childAtomType == Atom.TYPE_tenc) {
-        parent.skipBytes(4);
-        int firstInt = parent.readInt();
-        boolean defaultIsEncrypted = (firstInt >> 8) == 1;
-        int defaultInitVectorSize = firstInt & 0xFF;
+        parent.skipBytes(6);
+        boolean defaultIsEncrypted = parent.readUnsignedByte() == 1;
+        int defaultInitVectorSize = parent.readUnsignedByte();
         byte[] defaultKeyId = new byte[16];
         parent.readBytes(defaultKeyId, 0, defaultKeyId.length);
         return new TrackEncryptionBox(defaultIsEncrypted, defaultInitVectorSize, defaultKeyId);

library/src/main/java/com/google/android/exoplayer/extractor/mp4/FragmentedMp4Extractor.java

@@ -51,6 +51,7 @@ import java.util.UUID;
 public final class FragmentedMp4Extractor implements Extractor {
 
   private static final String TAG = "FragmentedMp4Extractor";
+  private static final int SAMPLE_GROUP_TYPE_seig = Util.getIntegerCodeForString("seig");
 
   /**
    * Flag to work around an issue in some video streams where every frame is marked as a sync frame.
@@ -474,6 +475,12 @@ public final class FragmentedMp4Extractor implements Extractor {
       parseSenc(senc.data, fragment);
     }
 
+    LeafAtom sbgp = traf.getLeafAtomOfType(Atom.TYPE_sbgp);
+    LeafAtom sgpd = traf.getLeafAtomOfType(Atom.TYPE_sgpd);
+    if (sbgp != null && sgpd != null) {
+      parseSgpd(sbgp.data, sgpd.data, fragment);
+    }
+
     int childrenSize = traf.leafChildren.size();
     for (int i = 0; i < childrenSize; i++) {
       LeafAtom atom = traf.leafChildren.get(i);
@@ -721,6 +728,51 @@ public final class FragmentedMp4Extractor implements Extractor {
     out.fillEncryptionData(senc);
   }
 
+  private static void parseSgpd(ParsableByteArray sbgp, ParsableByteArray sgpd, TrackFragment out)
+      throws ParserException {
+    sbgp.setPosition(Atom.HEADER_SIZE);
+    int sbgpFullAtom = sbgp.readInt();
+    if (sbgp.readInt() != SAMPLE_GROUP_TYPE_seig) {
+      // Only seig grouping type is supported.
+      return;
+    }
+    if (Atom.parseFullAtomVersion(sbgpFullAtom) == 1) {
+      sbgp.skipBytes(4);
+    }
+    if (sbgp.readInt() != 1) {
+      throw new ParserException("Entry count in sbgp != 1 (unsupported).");
+    }
+
+    sgpd.setPosition(Atom.HEADER_SIZE);
+    int sgpdFullAtom = sgpd.readInt();
+    if (sgpd.readInt() != SAMPLE_GROUP_TYPE_seig) {
+      // Only seig grouping type is supported.
+      return;
+    }
+    int sgpdVersion = Atom.parseFullAtomVersion(sgpdFullAtom);
+    if (sgpdVersion == 1) {
+      if (sgpd.readUnsignedInt() == 0) {
+        throw new ParserException("Variable length decription in sgpd found (unsupported)");
+      }
+    } else if (sgpdVersion >= 2) {
+      sgpd.skipBytes(4);
+    }
+    if (sgpd.readUnsignedInt() != 1) {
+      throw new ParserException("Entry count in sgpd != 1 (unsupported).");
+    }
+    // CencSampleEncryptionInformationGroupEntry
+    sgpd.skipBytes(2);
+    boolean isProtected = sgpd.readUnsignedByte() == 1;
+    if (!isProtected) {
+      return;
+    }
+    int initVectorSize = sgpd.readUnsignedByte();
+    byte[] keyId = new byte[16];
+    sgpd.readBytes(keyId, 0, keyId.length);
+    out.definesEncryptionData = true;
+    out.trackEncryptionBox = new TrackEncryptionBox(isProtected, initVectorSize, keyId);
+  }
+
   /**
    * Parses a sidx atom (defined in 14496-12).
    */
@@ -897,8 +949,12 @@ public final class FragmentedMp4Extractor implements Extractor {
     int sampleFlags = (fragment.definesEncryptionData ? C.BUFFER_FLAG_ENCRYPTED : 0)
         | (fragment.sampleIsSyncFrameTable[sampleIndex] ? C.BUFFER_FLAG_KEY_FRAME : 0);
     int sampleDescriptionIndex = fragment.header.sampleDescriptionIndex;
-    byte[] encryptionKey = fragment.definesEncryptionData
-        ? track.sampleDescriptionEncryptionBoxes[sampleDescriptionIndex].keyId : null;
+    byte[] encryptionKey = null;
+    if (fragment.definesEncryptionData) {
+      encryptionKey = fragment.trackEncryptionBox != null
+          ? fragment.trackEncryptionBox.keyId
+          : track.sampleDescriptionEncryptionBoxes[sampleDescriptionIndex].keyId;
+    }
     output.sampleMetadata(sampleTimeUs, sampleFlags, sampleSize, 0, encryptionKey);
 
     currentTrackBundle.currentSampleIndex++;
@@ -945,8 +1001,9 @@ public final class FragmentedMp4Extractor implements Extractor {
     TrackFragment trackFragment = trackBundle.fragment;
     ParsableByteArray sampleEncryptionData = trackFragment.sampleEncryptionData;
     int sampleDescriptionIndex = trackFragment.header.sampleDescriptionIndex;
-    TrackEncryptionBox encryptionBox = trackBundle.track
-        .sampleDescriptionEncryptionBoxes[sampleDescriptionIndex];
+    TrackEncryptionBox encryptionBox = trackFragment.trackEncryptionBox != null
+        ? trackFragment.trackEncryptionBox
+        : trackBundle.track.sampleDescriptionEncryptionBoxes[sampleDescriptionIndex];
     int vectorSize = encryptionBox.initializationVectorSize;
     boolean subsampleEncryption = trackFragment
         .sampleHasSubsampleEncryptionTable[trackBundle.currentSampleIndex];
@@ -977,7 +1034,8 @@ public final class FragmentedMp4Extractor implements Extractor {
         || atom == Atom.TYPE_tfhd || atom == Atom.TYPE_tkhd || atom == Atom.TYPE_trex
         || atom == Atom.TYPE_trun || atom == Atom.TYPE_pssh || atom == Atom.TYPE_saiz
         || atom == Atom.TYPE_saio || atom == Atom.TYPE_senc || atom == Atom.TYPE_uuid
-        || atom == Atom.TYPE_elst || atom == Atom.TYPE_mehd;
+        || atom == Atom.TYPE_sbgp || atom == Atom.TYPE_sgpd || atom == Atom.TYPE_elst 
+        || atom == Atom.TYPE_mehd;
   }
 
   /** Returns whether the extractor should parse a container atom with type {@code atom}. */

library/src/main/java/com/google/android/exoplayer/extractor/mp4/TrackEncryptionBox.java

@@ -16,7 +16,8 @@
 package com.google.android.exoplayer.extractor.mp4;
 
 /**
- * Encapsulates information parsed from a track encryption (tenc) box in an MP4 stream.
+ * Encapsulates information parsed from a track encryption (tenc) box or sample group description 
+ * (sgpd) box in an MP4 stream.
  */
 public final class TrackEncryptionBox {
 

library/src/main/java/com/google/android/exoplayer/extractor/mp4/TrackFragment.java

@@ -67,6 +67,10 @@ import java.io.IOException;
    */
   public boolean[] sampleHasSubsampleEncryptionTable;
   /**
+   * Fragment specific track encryption. May be null.
+   */
+  public TrackEncryptionBox trackEncryptionBox;
+  /**
    * If {@link #definesEncryptionData} is true, indicates the length of the sample encryption data.
    * Undefined otherwise.
    */
@@ -89,13 +93,15 @@ import java.io.IOException;
    * Resets the fragment.
    * <p>
    * {@link #length} and {@link #nextFragmentDecodeTime} are set to 0, and both
-   * {@link #definesEncryptionData} and {@link #sampleEncryptionDataNeedsFill} is set to false.
+   * {@link #definesEncryptionData} and {@link #sampleEncryptionDataNeedsFill} is set to false,
+   * and {@link #trackEncryptionBox} is set to null.
    */
   public void reset() {
     length = 0;
     nextFragmentDecodeTime = 0;
     definesEncryptionData = false;
     sampleEncryptionDataNeedsFill = false;
+    trackEncryptionBox = null;
   }
 
   /**