Add NonNull at package level for extractor.mp4

PiperOrigin-RevId: 286191078

Add NonNull at package level for extractor.mp4
PiperOrigin-RevId: 286191078
821d4fb1 · olly · Oliver Woodman · 7a03e8ed · 821d4fb1 · 821d4fb1
Commit 821d4fb1 authored Dec 18, 2019 by olly Committed by Oliver Woodman Dec 18, 2019
Showing with 150 additions and 100 deletions
library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/AtomParsers.java
library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/FragmentedMp4Extractor.java
library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/MdtaMetadataEntry.java
library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/MetadataUtil.java
library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/Mp4Extractor.java
library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/PsshAtomUtil.java
library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/TrackFragment.java
library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/package-info.java
--- a/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/AtomParsers.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/AtomParsers.java
@@ -125,14 +125,16 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
    Pair<Long, String> mdhdData = parseMdhd(mdia.getLeafAtomOfType(Atom.TYPE_mdhd).data);
    StsdData stsdData = parseStsd(stbl.getLeafAtomOfType(Atom.TYPE_stsd).data, tkhdData.id,
        tkhdData.rotationDegrees, mdhdData.second, drmInitData, isQuickTime);
-    long[] editListDurations = null;
+    @Nullable long[] editListDurations = null;
-    long[] editListMediaTimes = null;
+    @Nullable long[] editListMediaTimes = null;
    if (!ignoreEditLists) {
-      @Nullable
+      @Nullable Atom.ContainerAtom edtsAtom = trak.getContainerAtomOfType(Atom.TYPE_edts);
-      Pair<long[], long[]> edtsData = parseEdts(trak.getContainerAtomOfType(Atom.TYPE_edts));
+      if (edtsAtom != null) {
-      if (edtsData != null) {
+        @Nullable Pair<long[], long[]> edtsData = parseEdts(edtsAtom);
-        editListDurations = edtsData.first;
+        if (edtsData != null) {
-        editListMediaTimes = edtsData.second;
+          editListDurations = edtsData.first;
+          editListMediaTimes = edtsData.second;
+        }
      }
    }
    return stsdData.format == null ? null
@@ -154,11 +156,11 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
      Track track, Atom.ContainerAtom stblAtom, GaplessInfoHolder gaplessInfoHolder)
      throws ParserException {
    SampleSizeBox sampleSizeBox;
-    Atom.LeafAtom stszAtom = stblAtom.getLeafAtomOfType(Atom.TYPE_stsz);
+    @Nullable Atom.LeafAtom stszAtom = stblAtom.getLeafAtomOfType(Atom.TYPE_stsz);
    if (stszAtom != null) {
      sampleSizeBox = new StszSampleSizeBox(stszAtom);
    } else {
-      Atom.LeafAtom stz2Atom = stblAtom.getLeafAtomOfType(Atom.TYPE_stz2);
+      @Nullable Atom.LeafAtom stz2Atom = stblAtom.getLeafAtomOfType(Atom.TYPE_stz2);
      if (stz2Atom == null) {
        throw new ParserException("Track has no sample table size information");
      }
@@ -179,7 +181,7 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
    // Entries are byte offsets of chunks.
    boolean chunkOffsetsAreLongs = false;
-    Atom.LeafAtom chunkOffsetsAtom = stblAtom.getLeafAtomOfType(Atom.TYPE_stco);
+    @Nullable Atom.LeafAtom chunkOffsetsAtom = stblAtom.getLeafAtomOfType(Atom.TYPE_stco);
    if (chunkOffsetsAtom == null) {
      chunkOffsetsAreLongs = true;
      chunkOffsetsAtom = stblAtom.getLeafAtomOfType(Atom.TYPE_co64);
@@ -190,11 +192,11 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
    // Entries are (number of samples, timestamp delta between those samples).
    ParsableByteArray stts = stblAtom.getLeafAtomOfType(Atom.TYPE_stts).data;
    // Entries are the indices of samples that are synchronization samples.
-    Atom.LeafAtom stssAtom = stblAtom.getLeafAtomOfType(Atom.TYPE_stss);
+    @Nullable Atom.LeafAtom stssAtom = stblAtom.getLeafAtomOfType(Atom.TYPE_stss);
-    ParsableByteArray stss = stssAtom != null ? stssAtom.data : null;
+    @Nullable ParsableByteArray stss = stssAtom != null ? stssAtom.data : null;
    // Entries are (number of samples, timestamp offset).
-    Atom.LeafAtom cttsAtom = stblAtom.getLeafAtomOfType(Atom.TYPE_ctts);
+    @Nullable Atom.LeafAtom cttsAtom = stblAtom.getLeafAtomOfType(Atom.TYPE_ctts);
-    ParsableByteArray ctts = cttsAtom != null ? cttsAtom.data : null;
+    @Nullable ParsableByteArray ctts = cttsAtom != null ? cttsAtom.data : null;
    // Prepare to read chunk information.
    ChunkIterator chunkIterator = new ChunkIterator(stsc, chunkOffsets, chunkOffsetsAreLongs);
@@ -542,9 +544,9 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
   */
  @Nullable
  public static Metadata parseMdtaFromMeta(Atom.ContainerAtom meta) {
-    Atom.LeafAtom hdlrAtom = meta.getLeafAtomOfType(Atom.TYPE_hdlr);
+    @Nullable Atom.LeafAtom hdlrAtom = meta.getLeafAtomOfType(Atom.TYPE_hdlr);
-    Atom.LeafAtom keysAtom = meta.getLeafAtomOfType(Atom.TYPE_keys);
+    @Nullable Atom.LeafAtom keysAtom = meta.getLeafAtomOfType(Atom.TYPE_keys);
-    Atom.LeafAtom ilstAtom = meta.getLeafAtomOfType(Atom.TYPE_ilst);
+    @Nullable Atom.LeafAtom ilstAtom = meta.getLeafAtomOfType(Atom.TYPE_ilst);
    if (hdlrAtom == null
        || keysAtom == null
        || ilstAtom == null
@@ -575,6 +577,7 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
      int keyIndex = ilst.readInt() - 1;
      if (keyIndex >= 0 && keyIndex < keyNames.length) {
        String key = keyNames[keyIndex];
+        @Nullable
        Metadata.Entry entry =
            MetadataUtil.parseMdtaMetadataEntryFromIlst(ilst, atomPosition + atomSize, key);
        if (entry != null) {
@@ -609,7 +612,7 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
    ilst.skipBytes(Atom.HEADER_SIZE);
    ArrayList<Metadata.Entry> entries = new ArrayList<>();
    while (ilst.getPosition() < limit) {
-      Metadata.Entry entry = MetadataUtil.parseIlstElement(ilst);
+      @Nullable Metadata.Entry entry = MetadataUtil.parseIlstElement(ilst);
      if (entry != null) {
        entries.add(entry);
      }
@@ -817,12 +820,18 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
    return out;
  }
-  private static void parseTextSampleEntry(ParsableByteArray parent, int atomType, int position,
+  private static void parseTextSampleEntry(
-      int atomSize, int trackId, String language, StsdData out) throws ParserException {
+      ParsableByteArray parent,
+      int atomType,
+      int position,
+      int atomSize,
+      int trackId,
+      String language,
+      StsdData out) {
    parent.setPosition(position + Atom.HEADER_SIZE + StsdData.STSD_HEADER_SIZE);
    // Default values.
-    List<byte[]> initializationData = null;
+    @Nullable List<byte[]> initializationData = null;
    long subsampleOffsetUs = Format.OFFSET_SAMPLE_RELATIVE;
    String mimeType;
@@ -934,7 +943,7 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
        initializationData = hevcConfig.initializationData;
        out.nalUnitLengthFieldLength = hevcConfig.nalUnitLengthFieldLength;
      } else if (childAtomType == Atom.TYPE_dvcC || childAtomType == Atom.TYPE_dvvC) {
-        DolbyVisionConfig dolbyVisionConfig = DolbyVisionConfig.parse(parent);
+        @Nullable DolbyVisionConfig dolbyVisionConfig = DolbyVisionConfig.parse(parent);
        if (dolbyVisionConfig != null) {
          codecs = dolbyVisionConfig.codecs;
          mimeType = MimeTypes.VIDEO_DOLBY_VISION;
@@ -1021,11 +1030,11 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
   */
  @Nullable
  private static Pair<long[], long[]> parseEdts(Atom.ContainerAtom edtsAtom) {
-    Atom.LeafAtom elst;
+    @Nullable Atom.LeafAtom elstAtom = edtsAtom.getLeafAtomOfType(Atom.TYPE_elst);
-    if (edtsAtom == null || (elst = edtsAtom.getLeafAtomOfType(Atom.TYPE_elst)) == null) {
+    if (elstAtom == null) {
      return null;
    }
-    ParsableByteArray elstData = elst.data;
+    ParsableByteArray elstData = elstAtom.data;
    elstData.setPosition(Atom.HEADER_SIZE);
    int fullAtom = elstData.readInt();
    int version = Atom.parseFullAtomVersion(fullAtom);
@@ -1328,8 +1337,8 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
    int childPosition = position + Atom.HEADER_SIZE;
    int schemeInformationBoxPosition = C.POSITION_UNSET;
    int schemeInformationBoxSize = 0;
-    String schemeType = null;
+    @Nullable String schemeType = null;
-    Integer dataFormat = null;
+    @Nullable Integer dataFormat = null;
    while (childPosition - position < size) {
      parent.setPosition(childPosition);
      int childAtomSize = parent.readInt();
@@ -1352,9 +1361,11 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
      Assertions.checkStateNotNull(dataFormat, "frma atom is mandatory");
      Assertions.checkState(
          schemeInformationBoxPosition != C.POSITION_UNSET, "schi atom is mandatory");
-      TrackEncryptionBox encryptionBox = parseSchiFromParent(parent, schemeInformationBoxPosition,
+      TrackEncryptionBox encryptionBox =
-          schemeInformationBoxSize, schemeType);
+          Assertions.checkStateNotNull(
-      Assertions.checkStateNotNull(encryptionBox, "tenc atom is mandatory");
+              parseSchiFromParent(
+                  parent, schemeInformationBoxPosition, schemeInformationBoxSize, schemeType),
+              "tenc atom is mandatory");
      return Pair.create(dataFormat, encryptionBox);
    } else {
      return null;

--- 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
@@ -55,6 +55,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.UUID;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 /** Extracts data from the FMP4 container format. */
 @SuppressWarnings("ConstantField")
@@ -155,14 +156,14 @@ public class FragmentedMp4Extractor implements Extractor {
  private int atomType;
  private long atomSize;
  private int atomHeaderBytesRead;
-  private ParsableByteArray atomData;
+  @Nullable private ParsableByteArray atomData;
  private long endOfMdatPosition;
  private int pendingMetadataSampleBytes;
  private long pendingSeekTimeUs;
  private long durationUs;
  private long segmentIndexEarliestPresentationTimeUs;
-  private TrackBundle currentTrackBundle;
+  @Nullable private TrackBundle currentTrackBundle;
  private int sampleSize;
  private int sampleBytesWritten;
  private int sampleCurrentNalBytesRemaining;
@@ -170,7 +171,7 @@ public class FragmentedMp4Extractor implements Extractor {
  private boolean isAc4HeaderRequired;
  // Extractor output.
-  private ExtractorOutput extractorOutput;
+  @MonotonicNonNull private ExtractorOutput extractorOutput;
  private TrackOutput[] emsgTrackOutputs;
  private TrackOutput[] cea608TrackOutputs;
@@ -495,6 +496,7 @@ public class FragmentedMp4Extractor implements Extractor {
    for (int i = 0; i < moovContainerChildrenSize; i++) {
      Atom.ContainerAtom atom = moov.containerChildren.get(i);
      if (atom.type == Atom.TYPE_trak) {
+        @Nullable
        Track track =
            modifyTrack(
                AtomParsers.parseTrak(
@@ -712,7 +714,7 @@ public class FragmentedMp4Extractor implements Extractor {
  private static void parseTraf(ContainerAtom traf, SparseArray<TrackBundle> trackBundleArray,
      @Flags int flags, byte[] extendedTypeScratch) throws ParserException {
    LeafAtom tfhd = traf.getLeafAtomOfType(Atom.TYPE_tfhd);
-    TrackBundle trackBundle = parseTfhd(tfhd.data, trackBundleArray);
+    @Nullable TrackBundle trackBundle = parseTfhd(tfhd.data, trackBundleArray);
    if (trackBundle == null) {
      return;
    }
@@ -721,33 +723,34 @@ public class FragmentedMp4Extractor implements Extractor {
    long decodeTime = fragment.nextFragmentDecodeTime;
    trackBundle.reset();
-    LeafAtom tfdtAtom = traf.getLeafAtomOfType(Atom.TYPE_tfdt);
+    @Nullable LeafAtom tfdtAtom = traf.getLeafAtomOfType(Atom.TYPE_tfdt);
    if (tfdtAtom != null && (flags & FLAG_WORKAROUND_IGNORE_TFDT_BOX) == 0) {
      decodeTime = parseTfdt(traf.getLeafAtomOfType(Atom.TYPE_tfdt).data);
    }
    parseTruns(traf, trackBundle, decodeTime, flags);
-    TrackEncryptionBox encryptionBox = trackBundle.track
+    @Nullable
-        .getSampleDescriptionEncryptionBox(fragment.header.sampleDescriptionIndex);
+    TrackEncryptionBox encryptionBox =
+        trackBundle.track.getSampleDescriptionEncryptionBox(fragment.header.sampleDescriptionIndex);
-    LeafAtom saiz = traf.getLeafAtomOfType(Atom.TYPE_saiz);
+    @Nullable LeafAtom saiz = traf.getLeafAtomOfType(Atom.TYPE_saiz);
    if (saiz != null) {
      parseSaiz(encryptionBox, saiz.data, fragment);
    }
-    LeafAtom saio = traf.getLeafAtomOfType(Atom.TYPE_saio);
+    @Nullable LeafAtom saio = traf.getLeafAtomOfType(Atom.TYPE_saio);
    if (saio != null) {
      parseSaio(saio.data, fragment);
    }
-    LeafAtom senc = traf.getLeafAtomOfType(Atom.TYPE_senc);
+    @Nullable LeafAtom senc = traf.getLeafAtomOfType(Atom.TYPE_senc);
    if (senc != null) {
      parseSenc(senc.data, fragment);
    }
-    LeafAtom sbgp = traf.getLeafAtomOfType(Atom.TYPE_sbgp);
+    @Nullable LeafAtom sbgp = traf.getLeafAtomOfType(Atom.TYPE_sbgp);
-    LeafAtom sgpd = traf.getLeafAtomOfType(Atom.TYPE_sgpd);
+    @Nullable LeafAtom sgpd = traf.getLeafAtomOfType(Atom.TYPE_sgpd);
    if (sbgp != null && sgpd != null) {
      parseSgpd(sbgp.data, sgpd.data, encryptionBox != null ? encryptionBox.schemeType : null,
          fragment);
@@ -863,13 +866,14 @@ public class FragmentedMp4Extractor implements Extractor {
   * @return The {@link TrackBundle} to which the {@link TrackFragment} belongs, or null if the tfhd
   *     does not refer to any {@link TrackBundle}.
   */
+  @Nullable
  private static TrackBundle parseTfhd(
      ParsableByteArray tfhd, SparseArray<TrackBundle> trackBundles) {
    tfhd.setPosition(Atom.HEADER_SIZE);
    int fullAtom = tfhd.readInt();
    int atomFlags = Atom.parseFullAtomFlags(fullAtom);
    int trackId = tfhd.readInt();
-    TrackBundle trackBundle = getTrackBundle(trackBundles, trackId);
+    @Nullable TrackBundle trackBundle = getTrackBundle(trackBundles, trackId);
    if (trackBundle == null) {
      return null;
    }
@@ -1053,8 +1057,12 @@ public class FragmentedMp4Extractor implements Extractor {
    out.fillEncryptionData(senc);
  }
-  private static void parseSgpd(ParsableByteArray sbgp, ParsableByteArray sgpd, String schemeType,
+  private static void parseSgpd(
-      TrackFragment out) throws ParserException {
+      ParsableByteArray sbgp,
+      ParsableByteArray sgpd,
+      @Nullable String schemeType,
+      TrackFragment out)
+      throws ParserException {
    sbgp.setPosition(Atom.HEADER_SIZE);
    int sbgpFullAtom = sbgp.readInt();
    if (sbgp.readInt() != SAMPLE_GROUP_TYPE_seig) {
@@ -1216,7 +1224,7 @@ public class FragmentedMp4Extractor implements Extractor {
  private boolean readSample(ExtractorInput input) throws IOException, InterruptedException {
    if (parserState == STATE_READING_SAMPLE_START) {
      if (currentTrackBundle == null) {
-        TrackBundle currentTrackBundle = getNextFragmentRun(trackBundles);
+        @Nullable TrackBundle currentTrackBundle = getNextFragmentRun(trackBundles);
        if (currentTrackBundle == null) {
          // We've run out of samples in the current mdat. Discard any trailing data and prepare to
          // read the header of the next atom.
@@ -1388,6 +1396,7 @@ public class FragmentedMp4Extractor implements Extractor {
   * Returns the {@link TrackBundle} whose fragment run has the earliest file position out of those
   * yet to be consumed, or null if all have been consumed.
   */
+  @Nullable
  private static TrackBundle getNextFragmentRun(SparseArray<TrackBundle> trackBundles) {
    TrackBundle nextTrackBundle = null;
    long nextTrackRunOffset = Long.MAX_VALUE;
@@ -1410,7 +1419,7 @@ public class FragmentedMp4Extractor implements Extractor {
  /** Returns DrmInitData from leaf atoms. */
  private static DrmInitData getDrmInitDataFromAtoms(List<Atom.LeafAtom> leafChildren) {
-    ArrayList<SchemeData> schemeDatas = null;
+    @Nullable ArrayList<SchemeData> schemeDatas = null;
    int leafChildrenSize = leafChildren.size();
    for (int i = 0; i < leafChildrenSize; i++) {
      LeafAtom child = leafChildren.get(i);
@@ -1419,7 +1428,7 @@ public class FragmentedMp4Extractor implements Extractor {
          schemeDatas = new ArrayList<>();
        }
        byte[] psshData = child.data.data;
-        UUID uuid = PsshAtomUtil.parseUuid(psshData);
+        @Nullable UUID uuid = PsshAtomUtil.parseUuid(psshData);
        if (uuid == null) {
          Log.w(TAG, "Skipped pssh atom (failed to extract uuid)");
        } else {
@@ -1496,9 +1505,10 @@ public class FragmentedMp4Extractor implements Extractor {
    }
    public void updateDrmInitData(DrmInitData drmInitData) {
+      @Nullable
      TrackEncryptionBox encryptionBox =
          track.getSampleDescriptionEncryptionBox(fragment.header.sampleDescriptionIndex);
-      String schemeType = encryptionBox != null ? encryptionBox.schemeType : null;
+      @Nullable String schemeType = encryptionBox != null ? encryptionBox.schemeType : null;
      output.format(track.format.copyWithDrmInitData(drmInitData.copyWithSchemeType(schemeType)));
    }
@@ -1595,7 +1605,7 @@ public class FragmentedMp4Extractor implements Extractor {
    /** Skips the encryption data for the current sample. */
    private void skipSampleEncryptionData() {
-      TrackEncryptionBox encryptionBox = getEncryptionBoxIfEncrypted();
+      @Nullable TrackEncryptionBox encryptionBox = getEncryptionBoxIfEncrypted();
      if (encryptionBox == null) {
        return;
      }
@@ -1609,8 +1619,10 @@ public class FragmentedMp4Extractor implements Extractor {
      }
    }
+    @Nullable
    private TrackEncryptionBox getEncryptionBoxIfEncrypted() {
      int sampleDescriptionIndex = fragment.header.sampleDescriptionIndex;
+      @Nullable
      TrackEncryptionBox encryptionBox =
          fragment.trackEncryptionBox != null
              ? fragment.trackEncryptionBox

--- a/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/MdtaMetadataEntry.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/MdtaMetadataEntry.java
@@ -47,8 +47,7 @@ public final class MdtaMetadataEntry implements Metadata.Entry {
  private MdtaMetadataEntry(Parcel in) {
    key = Util.castNonNull(in.readString());
-    value = new byte[in.readInt()];
+    value = Util.castNonNull(in.createByteArray());
-    in.readByteArray(value);
    localeIndicator = in.readInt();
    typeIndicator = in.readInt();
  }
@@ -88,7 +87,6 @@ public final class MdtaMetadataEntry implements Metadata.Entry {
  @Override
  public void writeToParcel(Parcel dest, int flags) {
    dest.writeString(key);
-    dest.writeInt(value.length);
    dest.writeByteArray(value);
    dest.writeInt(localeIndicator);
    dest.writeInt(typeIndicator);

--- a/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/MetadataUtil.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/MetadataUtil.java
@@ -325,8 +325,11 @@ import com.google.android.exoplayer2.util.ParsableByteArray;
  @Nullable
  private static TextInformationFrame parseStandardGenreAttribute(ParsableByteArray data) {
    int genreCode = parseUint8AttributeValue(data);
-    String genreString = (0 < genreCode && genreCode <= STANDARD_GENRES.length)
+    @Nullable
-        ? STANDARD_GENRES[genreCode - 1] : null;
+    String genreString =
+        (0 < genreCode && genreCode <= STANDARD_GENRES.length)
+            ? STANDARD_GENRES[genreCode - 1]
+            : null;
    if (genreString != null) {
      return new TextInformationFrame("TCON", /* description= */ null, genreString);
    }
@@ -341,7 +344,7 @@ import com.google.android.exoplayer2.util.ParsableByteArray;
    if (atomType == Atom.TYPE_data) {
      int fullVersionInt = data.readInt();
      int flags = Atom.parseFullAtomFlags(fullVersionInt);
-      String mimeType = flags == 13 ? "image/jpeg" : flags == 14 ? "image/png" : null;
+      @Nullable String mimeType = flags == 13 ? "image/jpeg" : flags == 14 ? "image/png" : null;
      if (mimeType == null) {
        Log.w(TAG, "Unrecognized cover art flags: " + flags);
        return null;
@@ -361,8 +364,8 @@ import com.google.android.exoplayer2.util.ParsableByteArray;
  @Nullable
  private static Id3Frame parseInternalAttribute(ParsableByteArray data, int endPosition) {
-    String domain = null;
+    @Nullable String domain = null;
-    String name = null;
+    @Nullable String name = null;
    int dataAtomPosition = -1;
    int dataAtomSize = -1;
    while (data.getPosition() < endPosition) {

--- a/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/Mp4Extractor.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/Mp4Extractor.java
@@ -16,6 +16,7 @@
 package com.google.android.exoplayer2.extractor.mp4;
 import androidx.annotation.IntDef;
+import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.ParserException;
@@ -42,6 +43,7 @@ import java.lang.annotation.RetentionPolicy;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.List;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 /**
 * Extracts data from the MP4 container format.
@@ -105,7 +107,7 @@ public final class Mp4Extractor implements Extractor, SeekMap {
  private int atomType;
  private long atomSize;
  private int atomHeaderBytesRead;
-  private ParsableByteArray atomData;
+  @Nullable private ParsableByteArray atomData;
  private int sampleTrackIndex;
  private int sampleBytesWritten;
@@ -113,7 +115,7 @@ public final class Mp4Extractor implements Extractor, SeekMap {
  private boolean isAc4HeaderRequired;
  // Extractor outputs.
-  private ExtractorOutput extractorOutput;
+  @MonotonicNonNull private ExtractorOutput extractorOutput;
  private Mp4Track[] tracks;
  private long[][] accumulatedSampleSizes;
  private int firstVideoTrackIndex;
@@ -290,8 +292,11 @@ public final class Mp4Extractor implements Extractor, SeekMap {
      // The atom extends to the end of the file. Note that if the atom is within a container we can
      // work out its size even if the input length is unknown.
      long endPosition = input.getLength();
-      if (endPosition == C.LENGTH_UNSET && !containerAtoms.isEmpty()) {
+      if (endPosition == C.LENGTH_UNSET) {
-        endPosition = containerAtoms.peek().endPosition;
+        @Nullable ContainerAtom containerAtom = containerAtoms.peek();
+        if (containerAtom != null) {
+          endPosition = containerAtom.endPosition;
+        }
      }
      if (endPosition != C.LENGTH_UNSET) {
        atomSize = endPosition - input.getPosition() + atomHeaderBytesRead;
@@ -386,17 +391,17 @@ public final class Mp4Extractor implements Extractor, SeekMap {
    List<Mp4Track> tracks = new ArrayList<>();
    // Process metadata.
-    Metadata udtaMetadata = null;
+    @Nullable Metadata udtaMetadata = null;
    GaplessInfoHolder gaplessInfoHolder = new GaplessInfoHolder();
-    Atom.LeafAtom udta = moov.getLeafAtomOfType(Atom.TYPE_udta);
+    @Nullable Atom.LeafAtom udta = moov.getLeafAtomOfType(Atom.TYPE_udta);
    if (udta != null) {
      udtaMetadata = AtomParsers.parseUdta(udta, isQuickTime);
      if (udtaMetadata != null) {
        gaplessInfoHolder.setFromMetadata(udtaMetadata);
      }
    }
-    Metadata mdtaMetadata = null;
+    @Nullable Metadata mdtaMetadata = null;
-    Atom.ContainerAtom meta = moov.getContainerAtomOfType(Atom.TYPE_meta);
+    @Nullable Atom.ContainerAtom meta = moov.getContainerAtomOfType(Atom.TYPE_meta);
    if (meta != null) {
      mdtaMetadata = AtomParsers.parseMdtaFromMeta(meta);
    }
@@ -453,6 +458,7 @@ public final class Mp4Extractor implements Extractor, SeekMap {
      if (atom.type != Atom.TYPE_trak) {
        continue;
      }
+      @Nullable
      Track track =
          AtomParsers.parseTrak(
              atom,

--- a/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/PsshAtomUtil.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/PsshAtomUtil.java
@@ -49,8 +49,6 @@ public final class PsshAtomUtil {
   * @param data The scheme specific data.
   * @return The PSSH atom.
   */
-  // dereference of possibly-null reference keyId
-  @SuppressWarnings({"ParameterNotNullable", "nullness:dereference.of.nullable"})
  public static byte[] buildPsshAtom(
      UUID systemId, @Nullable UUID[] keyIds, @Nullable byte[] data) {
    int dataLength = data != null ? data.length : 0;
@@ -97,8 +95,9 @@ public final class PsshAtomUtil {
   * @return The parsed UUID. Null if the input is not a valid PSSH atom, or if the PSSH atom has an
   *     unsupported version.
   */
-  public static @Nullable UUID parseUuid(byte[] atom) {
+  @Nullable
-    PsshAtom parsedAtom = parsePsshAtom(atom);
+  public static UUID parseUuid(byte[] atom) {
+    @Nullable PsshAtom parsedAtom = parsePsshAtom(atom);
    if (parsedAtom == null) {
      return null;
    }
@@ -115,7 +114,7 @@ public final class PsshAtomUtil {
   *     an unsupported version.
   */
  public static int parseVersion(byte[] atom) {
-    PsshAtom parsedAtom = parsePsshAtom(atom);
+    @Nullable PsshAtom parsedAtom = parsePsshAtom(atom);
    if (parsedAtom == null) {
      return -1;
    }
@@ -133,8 +132,9 @@ public final class PsshAtomUtil {
   * @return The parsed scheme specific data. Null if the input is not a valid PSSH atom, or if the
   *     PSSH atom has an unsupported version, or if the PSSH atom does not match the passed UUID.
   */
-  public static @Nullable byte[] parseSchemeSpecificData(byte[] atom, UUID uuid) {
+  @Nullable
-    PsshAtom parsedAtom = parsePsshAtom(atom);
+  public static byte[] parseSchemeSpecificData(byte[] atom, UUID uuid) {
+    @Nullable PsshAtom parsedAtom = parsePsshAtom(atom);
    if (parsedAtom == null) {
      return null;
    }
@@ -153,7 +153,8 @@ public final class PsshAtomUtil {
   *     has an unsupported version.
   */
  // TODO: Support parsing of the key ids for version 1 PSSH atoms.
-  private static @Nullable PsshAtom parsePsshAtom(byte[] atom) {
+  @Nullable
+  private static PsshAtom parsePsshAtom(byte[] atom) {
    ParsableByteArray atomData = new ParsableByteArray(atom);
    if (atomData.limit() < Atom.FULL_HEADER_SIZE + 16 /* UUID */ + 4 /* DataSize */) {
      // Data too short.

--- a/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/TrackFragment.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/TrackFragment.java
@@ -15,19 +15,19 @@
 */
 package com.google.android.exoplayer2.extractor.mp4;
+import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.extractor.ExtractorInput;
 import com.google.android.exoplayer2.util.ParsableByteArray;
 import java.io.IOException;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 /**
 * A holder for information corresponding to a single fragment of an mp4 file.
 */
 /* package */ final class TrackFragment {
-  /**
+  /** The default values for samples from the track fragment header. */
-   * The default values for samples from the track fragment header.
+  @MonotonicNonNull public DefaultSampleValues header;
-   */
-  public DefaultSampleValues header;
  /**
   * The position (byte offset) of the start of fragment.
   */
@@ -81,20 +81,13 @@ import java.io.IOException;
   * Undefined otherwise.
   */
  public boolean[] sampleHasSubsampleEncryptionTable;
-  /**
+  /** Fragment specific track encryption. May be null. */
-   * Fragment specific track encryption. May be null.
+  @Nullable public TrackEncryptionBox trackEncryptionBox;
-   */
-  public TrackEncryptionBox trackEncryptionBox;
-  /**
-   * If {@link #definesEncryptionData} is true, indicates the length of the sample encryption data.
-   * Undefined otherwise.
-   */
-  public int sampleEncryptionDataLength;
  /**
   * If {@link #definesEncryptionData} is true, contains binary sample encryption data. Undefined
   * otherwise.
   */
-  public ParsableByteArray sampleEncryptionData;
+  public final ParsableByteArray sampleEncryptionData;
  /**
   * Whether {@link #sampleEncryptionData} needs populating with the actual encryption data.
   */
@@ -104,6 +97,17 @@ import java.io.IOException;
   */
  public long nextFragmentDecodeTime;
+  public TrackFragment() {
+    trunDataPosition = new long[0];
+    trunLength = new int[0];
+    sampleSizeTable = new int[0];
+    sampleCompositionTimeOffsetTable = new int[0];
+    sampleDecodingTimeTable = new long[0];
+    sampleIsSyncFrameTable = new boolean[0];
+    sampleHasSubsampleEncryptionTable = new boolean[0];
+    sampleEncryptionData = new ParsableByteArray();
+  }
  /**
   * Resets the fragment.
   * <p>
@@ -130,11 +134,11 @@ import java.io.IOException;
  public void initTables(int trunCount, int sampleCount) {
    this.trunCount = trunCount;
    this.sampleCount = sampleCount;
-    if (trunLength == null || trunLength.length < trunCount) {
+    if (trunLength.length < trunCount) {
      trunDataPosition = new long[trunCount];
      trunLength = new int[trunCount];
    }
-    if (sampleSizeTable == null || sampleSizeTable.length < sampleCount) {
+    if (sampleSizeTable.length < sampleCount) {
      // Size the tables 25% larger than needed, so as to make future resize operations less
      // likely. The choice of 25% is relatively arbitrary.
      int tableSize = (sampleCount * 125) / 100;
@@ -148,18 +152,14 @@ import java.io.IOException;
  /**
   * Configures the fragment to be one that defines encryption data of the specified length.
-   * <p>
+   *
-   * {@link #definesEncryptionData} is set to true, {@link #sampleEncryptionDataLength} is set to
+   * <p>{@link #definesEncryptionData} is set to true, and the {@link ParsableByteArray#limit()
-   * the specified length, and {@link #sampleEncryptionData} is resized if necessary such that it
+   * limit} of {@link #sampleEncryptionData} is set to the specified length.
-   * is at least this length.
   *
   * @param length The length in bytes of the encryption data.
   */
  public void initEncryptionData(int length) {
-    if (sampleEncryptionData == null || sampleEncryptionData.limit() < length) {
+    sampleEncryptionData.reset(length);
-      sampleEncryptionData = new ParsableByteArray(length);
-    }
-    sampleEncryptionDataLength = length;
    definesEncryptionData = true;
    sampleEncryptionDataNeedsFill = true;
  }
@@ -170,7 +170,7 @@ import java.io.IOException;
   * @param input An {@link ExtractorInput} from which to read the encryption data.
   */
  public void fillEncryptionData(ExtractorInput input) throws IOException, InterruptedException {
-    input.readFully(sampleEncryptionData.data, 0, sampleEncryptionDataLength);
+    input.readFully(sampleEncryptionData.data, 0, sampleEncryptionData.limit());
    sampleEncryptionData.setPosition(0);
    sampleEncryptionDataNeedsFill = false;
  }
@@ -181,7 +181,7 @@ import java.io.IOException;
   * @param source A source from which to read the encryption data.
   */
  public void fillEncryptionData(ParsableByteArray source) {
-    source.readBytes(sampleEncryptionData.data, 0, sampleEncryptionDataLength);
+    source.readBytes(sampleEncryptionData.data, 0, sampleEncryptionData.limit());
    sampleEncryptionData.setPosition(0);
    sampleEncryptionDataNeedsFill = false;
  }

--- a/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/package-info.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/package-info.java
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+@NonNullApi
+package com.google.android.exoplayer2.extractor.mp4;
+import com.google.android.exoplayer2.util.NonNullApi;