Partial nullness annotations for AtomParsers

PiperOrigin-RevId: 284558886

Partial nullness annotations for AtomParsers
PiperOrigin-RevId: 284558886
539a1ac2 · olly · Oliver Woodman · 4b281cec · 539a1ac2
Commit 539a1ac2 authored Dec 09, 2019 by olly Committed by Oliver Woodman Dec 10, 2019
Showing with 94 additions and 55 deletions
library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/AtomParsers.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
@@ -40,6 +40,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import org.checkerframework.checker.nullness.compatqual.NullableType;
 /** Utility methods for parsing MP4 format atom payloads according to ISO 14496-12. */
 @SuppressWarnings({"ConstantField"})
@@ -85,15 +86,21 @@ import java.util.List;
   *
   * @param trak Atom to decode.
   * @param mvhd Movie header atom, used to get the timescale.
-   * @param duration The duration in units of the timescale declared in the mvhd atom, or
+   * @param duration The duration in units of the timescale declared in the mvhd atom, or {@link
-   *     {@link C#TIME_UNSET} if the duration should be parsed from the tkhd atom.
+   *     C#TIME_UNSET} if the duration should be parsed from the tkhd atom.
-   * @param drmInitData {@link DrmInitData} to be included in the format.
+   * @param drmInitData {@link DrmInitData} to be included in the format, or {@code null}.
   * @param ignoreEditLists Whether to ignore any edit lists in the trak box.
   * @param isQuickTime True for QuickTime media. False otherwise.
   * @return A {@link Track} instance, or {@code null} if the track's type isn't supported.
   */
-  public static Track parseTrak(Atom.ContainerAtom trak, Atom.LeafAtom mvhd, long duration,
+  @Nullable
-      DrmInitData drmInitData, boolean ignoreEditLists, boolean isQuickTime)
+  public static Track parseTrak(
+      Atom.ContainerAtom trak,
+      Atom.LeafAtom mvhd,
+      long duration,
+      @Nullable DrmInitData drmInitData,
+      boolean ignoreEditLists,
+      boolean isQuickTime)
      throws ParserException {
    Atom.ContainerAtom mdia = trak.getContainerAtomOfType(Atom.TYPE_mdia);
    int trackType = getTrackTypeForHdlr(parseHdlr(mdia.getLeafAtomOfType(Atom.TYPE_hdlr).data));
@@ -121,9 +128,12 @@ import java.util.List;
    long[] editListDurations = null;
    long[] editListMediaTimes = null;
    if (!ignoreEditLists) {
+      @Nullable
      Pair<long[], long[]> edtsData = parseEdts(trak.getContainerAtomOfType(Atom.TYPE_edts));
-      editListDurations = edtsData.first;
+      if (edtsData != null) {
-      editListMediaTimes = edtsData.second;
+        editListDurations = edtsData.first;
+        editListMediaTimes = edtsData.second;
+      }
    }
    return stsdData.format == null ? null
        : new Track(tkhdData.id, trackType, mdhdData.first, movieTimescale, durationUs,
@@ -736,19 +746,25 @@ import java.util.List;
   * @param trackId The track's identifier in its container.
   * @param rotationDegrees The rotation of the track in degrees.
   * @param language The language of the track.
-   * @param drmInitData {@link DrmInitData} to be included in the format.
+   * @param drmInitData {@link DrmInitData} to be included in the format, or {@code null}.
   * @param isQuickTime True for QuickTime media. False otherwise.
   * @return An object containing the parsed data.
   */
-  private static StsdData parseStsd(ParsableByteArray stsd, int trackId, int rotationDegrees,
+  private static StsdData parseStsd(
-      String language, DrmInitData drmInitData, boolean isQuickTime) throws ParserException {
+      ParsableByteArray stsd,
+      int trackId,
+      int rotationDegrees,
+      String language,
+      @Nullable DrmInitData drmInitData,
+      boolean isQuickTime)
+      throws ParserException {
    stsd.setPosition(Atom.FULL_HEADER_SIZE);
    int numberOfEntries = stsd.readInt();
    StsdData out = new StsdData(numberOfEntries);
    for (int i = 0; i < numberOfEntries; i++) {
      int childStartPosition = stsd.getPosition();
      int childAtomSize = stsd.readInt();
-      Assertions.checkArgument(childAtomSize > 0, "childAtomSize should be positive");
+      Assertions.checkState(childAtomSize > 0, "childAtomSize should be positive");
      int childAtomType = stsd.readInt();
      if (childAtomType == Atom.TYPE_avc1
          || childAtomType == Atom.TYPE_avc3
@@ -846,9 +862,17 @@ import java.util.List;
            initializationData);
  }
-  private static void parseVideoSampleEntry(ParsableByteArray parent, int atomType, int position,
+  private static void parseVideoSampleEntry(
-      int size, int trackId, int rotationDegrees, DrmInitData drmInitData, StsdData out,
+      ParsableByteArray parent,
-      int entryIndex) throws ParserException {
+      int atomType,
+      int position,
+      int size,
+      int trackId,
+      int rotationDegrees,
+      @Nullable DrmInitData drmInitData,
+      StsdData out,
+      int entryIndex)
+      throws ParserException {
    parent.setPosition(position + Atom.HEADER_SIZE + StsdData.STSD_HEADER_SIZE);
    parent.skipBytes(16);
@@ -860,8 +884,9 @@ import java.util.List;
    int childPosition = parent.getPosition();
    if (atomType == Atom.TYPE_encv) {
-      Pair<Integer, TrackEncryptionBox> sampleEntryEncryptionData = parseSampleEntryEncryptionData(
+      @Nullable
-          parent, position, size);
+      Pair<Integer, TrackEncryptionBox> sampleEntryEncryptionData =
+          parseSampleEntryEncryptionData(parent, position, size);
      if (sampleEntryEncryptionData != null) {
        atomType = sampleEntryEncryptionData.first;
        drmInitData = drmInitData == null ? null
@@ -875,10 +900,10 @@ import java.util.List;
    //   drmInitData = null;
    // }
-    List<byte[]> initializationData = null;
+    @Nullable List<byte[]> initializationData = null;
-    String mimeType = null;
+    @Nullable String mimeType = null;
-    String codecs = null;
+    @Nullable String codecs = null;
-    byte[] projectionData = null;
+    @Nullable byte[] projectionData = null;
    @C.StereoMode
    int stereoMode = Format.NO_VALUE;
    while (childPosition - position < size) {
@@ -889,7 +914,7 @@ import java.util.List;
        // Handle optional terminating four zero bytes in MOV files.
        break;
      }
-      Assertions.checkArgument(childAtomSize > 0, "childAtomSize should be positive");
+      Assertions.checkState(childAtomSize > 0, "childAtomSize should be positive");
      int childAtomType = parent.readInt();
      if (childAtomType == Atom.TYPE_avcC) {
        Assertions.checkState(mimeType == null);
@@ -925,10 +950,13 @@ import java.util.List;
        mimeType = MimeTypes.VIDEO_H263;
      } else if (childAtomType == Atom.TYPE_esds) {
        Assertions.checkState(mimeType == null);
-        Pair<String, byte[]> mimeTypeAndInitializationData =
+        Pair<@NullableType String, byte @NullableType []> mimeTypeAndInitializationDataBytes =
            parseEsdsFromParent(parent, childStartPosition);
-        mimeType = mimeTypeAndInitializationData.first;
+        mimeType = mimeTypeAndInitializationDataBytes.first;
-        initializationData = Collections.singletonList(mimeTypeAndInitializationData.second);
+        @Nullable byte[] initializationDataBytes = mimeTypeAndInitializationDataBytes.second;
+        if (initializationDataBytes != null) {
+          initializationData = Collections.singletonList(initializationDataBytes);
+        }
      } else if (childAtomType == Atom.TYPE_pasp) {
        pixelWidthHeightRatio = parsePaspFromParent(parent, childStartPosition);
        pixelWidthHeightRatioFromPasp = true;
@@ -988,13 +1016,14 @@ import java.util.List;
   * Parses the edts atom (defined in 14496-12 subsection 8.6.5).
   *
   * @param edtsAtom edts (edit box) atom to decode.
-   * @return Pair of edit list durations and edit list media times, or a pair of nulls if they are
+   * @return Pair of edit list durations and edit list media times, or {@code null} if they are not
-   *     not present.
+   *     present.
   */
+  @Nullable
  private static Pair<long[], long[]> parseEdts(Atom.ContainerAtom edtsAtom) {
    Atom.LeafAtom elst;
    if (edtsAtom == null || (elst = edtsAtom.getLeafAtomOfType(Atom.TYPE_elst)) == null) {
-      return Pair.create(null, null);
+      return null;
    }
    ParsableByteArray elstData = elst.data;
    elstData.setPosition(Atom.HEADER_SIZE);
@@ -1024,9 +1053,18 @@ import java.util.List;
    return (float) hSpacing / vSpacing;
  }
-  private static void parseAudioSampleEntry(ParsableByteArray parent, int atomType, int position,
+  private static void parseAudioSampleEntry(
-      int size, int trackId, String language, boolean isQuickTime, DrmInitData drmInitData,
+      ParsableByteArray parent,
-      StsdData out, int entryIndex) throws ParserException {
+      int atomType,
+      int position,
+      int size,
+      int trackId,
+      String language,
+      boolean isQuickTime,
+      @Nullable DrmInitData drmInitData,
+      StsdData out,
+      int entryIndex)
+      throws ParserException {
    parent.setPosition(position + Atom.HEADER_SIZE + StsdData.STSD_HEADER_SIZE);
    int quickTimeSoundDescriptionVersion = 0;
@@ -1064,8 +1102,9 @@ import java.util.List;
    int childPosition = parent.getPosition();
    if (atomType == Atom.TYPE_enca) {
-      Pair<Integer, TrackEncryptionBox> sampleEntryEncryptionData = parseSampleEntryEncryptionData(
+      @Nullable
-          parent, position, size);
+      Pair<Integer, TrackEncryptionBox> sampleEntryEncryptionData =
+          parseSampleEntryEncryptionData(parent, position, size);
      if (sampleEntryEncryptionData != null) {
        atomType = sampleEntryEncryptionData.first;
        drmInitData = drmInitData == null ? null
@@ -1080,7 +1119,7 @@ import java.util.List;
    // }
    // If the atom type determines a MIME type, set it immediately.
-    String mimeType = null;
+    @Nullable String mimeType = null;
    if (atomType == Atom.TYPE_ac_3) {
      mimeType = MimeTypes.AUDIO_AC3;
    } else if (atomType == Atom.TYPE_ec_3) {
@@ -1113,21 +1152,21 @@ import java.util.List;
      mimeType = MimeTypes.AUDIO_FLAC;
    }
-    byte[] initializationData = null;
+    @Nullable byte[] initializationData = null;
    while (childPosition - position < size) {
      parent.setPosition(childPosition);
      int childAtomSize = parent.readInt();
-      Assertions.checkArgument(childAtomSize > 0, "childAtomSize should be positive");
+      Assertions.checkState(childAtomSize > 0, "childAtomSize should be positive");
      int childAtomType = parent.readInt();
      if (childAtomType == Atom.TYPE_esds || (isQuickTime && childAtomType == Atom.TYPE_wave)) {
        int esdsAtomPosition = childAtomType == Atom.TYPE_esds ? childPosition
            : findEsdsPosition(parent, childPosition, childAtomSize);
        if (esdsAtomPosition != C.POSITION_UNSET) {
-          Pair<String, byte[]> mimeTypeAndInitializationData =
+          Pair<@NullableType String, byte @NullableType []> mimeTypeAndInitializationData =
              parseEsdsFromParent(parent, esdsAtomPosition);
          mimeType = mimeTypeAndInitializationData.first;
          initializationData = mimeTypeAndInitializationData.second;
-          if (MimeTypes.AUDIO_AAC.equals(mimeType)) {
+          if (MimeTypes.AUDIO_AAC.equals(mimeType) && initializationData != null) {
            // Update sampleRate and channelCount from the AudioSpecificConfig initialization data,
            // which is more reliable. See [Internal: b/10903778].
            Pair<Integer, Integer> audioSpecificConfig =
@@ -1204,7 +1243,7 @@ import java.util.List;
    while (childAtomPosition - position < size) {
      parent.setPosition(childAtomPosition);
      int childAtomSize = parent.readInt();
-      Assertions.checkArgument(childAtomSize > 0, "childAtomSize should be positive");
+      Assertions.checkState(childAtomSize > 0, "childAtomSize should be positive");
      int childType = parent.readInt();
      if (childType == Atom.TYPE_esds) {
        return childAtomPosition;
@@ -1214,10 +1253,9 @@ import java.util.List;
    return C.POSITION_UNSET;
  }
-  /**
+  /** Returns codec-specific initialization data contained in an esds box. */
-   * Returns codec-specific initialization data contained in an esds box.
+  private static Pair<@NullableType String, byte @NullableType []> parseEsdsFromParent(
-   */
+      ParsableByteArray parent, int position) {
-  private static Pair<String, byte[]> parseEsdsFromParent(ParsableByteArray parent, int position) {
    parent.setPosition(position + Atom.HEADER_SIZE + 4);
    // Start of the ES_Descriptor (defined in 14496-1)
    parent.skipBytes(1); // ES_Descriptor tag
@@ -1263,13 +1301,14 @@ import java.util.List;
   * unencrypted atom type and a {@link TrackEncryptionBox}. Null is returned if no common
   * encryption sinf atom was present.
   */
+  @Nullable
  private static Pair<Integer, TrackEncryptionBox> parseSampleEntryEncryptionData(
      ParsableByteArray parent, int position, int size) {
    int childPosition = parent.getPosition();
    while (childPosition - position < size) {
      parent.setPosition(childPosition);
      int childAtomSize = parent.readInt();
-      Assertions.checkArgument(childAtomSize > 0, "childAtomSize should be positive");
+      Assertions.checkState(childAtomSize > 0, "childAtomSize should be positive");
      int childAtomType = parent.readInt();
      if (childAtomType == Atom.TYPE_sinf) {
        Pair<Integer, TrackEncryptionBox> result = parseCommonEncryptionSinfFromParent(parent,
@@ -1283,6 +1322,7 @@ import java.util.List;
    return null;
  }
+  @Nullable
  /* package */ static Pair<Integer, TrackEncryptionBox> parseCommonEncryptionSinfFromParent(
      ParsableByteArray parent, int position, int size) {
    int childPosition = position + Atom.HEADER_SIZE;
@@ -1309,20 +1349,21 @@ import java.util.List;
    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.checkStateNotNull(dataFormat, "frma atom is mandatory");
-      Assertions.checkArgument(schemeInformationBoxPosition != C.POSITION_UNSET,
+      Assertions.checkState(
-          "schi atom is mandatory");
+          schemeInformationBoxPosition != C.POSITION_UNSET, "schi atom is mandatory");
      TrackEncryptionBox encryptionBox = parseSchiFromParent(parent, schemeInformationBoxPosition,
          schemeInformationBoxSize, schemeType);
-      Assertions.checkArgument(encryptionBox != null, "tenc atom is mandatory");
+      Assertions.checkStateNotNull(encryptionBox, "tenc atom is mandatory");
      return Pair.create(dataFormat, encryptionBox);
    } else {
      return null;
    }
  }
-  private static TrackEncryptionBox parseSchiFromParent(ParsableByteArray parent, int position,
+  @Nullable
-      int size, String schemeType) {
+  private static TrackEncryptionBox parseSchiFromParent(
+      ParsableByteArray parent, int position, int size, String schemeType) {
    int childPosition = position + Atom.HEADER_SIZE;
    while (childPosition - position < size) {
      parent.setPosition(childPosition);
@@ -1359,9 +1400,8 @@ import java.util.List;
    return null;
  }
-  /**
+  /** Parses the proj box from sv3d box, as specified by https://github.com/google/spatial-media. */
-   * Parses the proj box from sv3d box, as specified by https://github.com/google/spatial-media.
+  @Nullable
-   */
  private static byte[] parseProjFromParent(ParsableByteArray parent, int position, int size) {
    int childPosition = position + Atom.HEADER_SIZE;
    while (childPosition - position < size) {
@@ -1477,10 +1517,9 @@ import java.util.List;
    public final TrackEncryptionBox[] trackEncryptionBoxes;
-    public Format format;
+    @Nullable public Format format;
    public int nalUnitLengthFieldLength;
-    @Track.Transformation
+    @Track.Transformation public int requiredSampleTransformation;
-    public int requiredSampleTransformation;
    public StsdData(int numberOfEntries) {
      trackEncryptionBoxes = new TrackEncryptionBox[numberOfEntries];