Optimize out quite a few allocations in FragmentedMp4Parser.

4a745b1c · Oliver Woodman · 005e98fc · 4a745b1c · 4a745b1c · 4a745b1c
Commit 4a745b1c authored Aug 12, 2014 by Oliver Woodman
Showing with 187 additions and 127 deletions
library/src/main/java/com/google/android/exoplayer/chunk/Chunk.java
library/src/main/java/com/google/android/exoplayer/parser/mp4/Atom.java
library/src/main/java/com/google/android/exoplayer/parser/mp4/CodecSpecificDataUtil.java
library/src/main/java/com/google/android/exoplayer/parser/mp4/FragmentedMp4Extractor.java
library/src/main/java/com/google/android/exoplayer/parser/mp4/ParsableByteArray.java
library/src/main/java/com/google/android/exoplayer/parser/mp4/TrackEncryptionBox.java
library/src/main/java/com/google/android/exoplayer/parser/mp4/TrackFragment.java
--- a/library/src/main/java/com/google/android/exoplayer/chunk/Chunk.java
+++ b/library/src/main/java/com/google/android/exoplayer/chunk/Chunk.java
@@ -52,7 +52,7 @@ public abstract class Chunk implements Loadable {
  /**
   * @param dataSource The source from which the data should be loaded.
   * @param dataSpec Defines the data to be loaded. {@code dataSpec.length} must not exceed
-   *     {@link Integer#MAX_VALUE}. If {@code dataSpec.length == DataSpec.LENGTH_UNBOUNDED} then
+   *     {@link Integer#MAX_VALUE}. If {@code dataSpec.length == C.LENGTH_UNBOUNDED} then
   *     the length resolved by {@code dataSource.open(dataSpec)} must not exceed
   *     {@link Integer#MAX_VALUE}.
   * @param format See {@link #format}.

--- a/library/src/main/java/com/google/android/exoplayer/parser/mp4/Atom.java
+++ b/library/src/main/java/com/google/android/exoplayer/parser/mp4/Atom.java
@@ -16,7 +16,6 @@
 package com.google.android.exoplayer.parser.mp4;
 import java.util.ArrayList;
-import java.util.List;
 /* package */ abstract class Atom {
@@ -24,7 +23,6 @@ import java.util.List;
  public static final int TYPE_avc3 = 0x61766333;
  public static final int TYPE_esds = 0x65736473;
  public static final int TYPE_mdat = 0x6D646174;
-  public static final int TYPE_mfhd = 0x6D666864;
  public static final int TYPE_mp4a = 0x6D703461;
  public static final int TYPE_tfdt = 0x74666474;
  public static final int TYPE_tfhd = 0x74666864;
@@ -64,17 +62,13 @@ import java.util.List;
  public final static class LeafAtom extends Atom {
-    private final ParsableByteArray data;
+    public final ParsableByteArray data;
    public LeafAtom(int type, ParsableByteArray data) {
      super(type);
      this.data = data;
    }
-    public ParsableByteArray getData() {
-      return data;
-    }
  }
  public final static class ContainerAtom extends Atom {
@@ -91,7 +85,8 @@ import java.util.List;
    }
    public LeafAtom getLeafAtomOfType(int type) {
-      for (int i = 0; i < children.size(); i++) {
+      int childrenSize = children.size();
+      for (int i = 0; i < childrenSize; i++) {
        Atom atom = children.get(i);
        if (atom.type == type) {
          return (LeafAtom) atom;
@@ -101,7 +96,8 @@ import java.util.List;
    }
    public ContainerAtom getContainerAtomOfType(int type) {
-      for (int i = 0; i < children.size(); i++) {
+      int childrenSize = children.size();
+      for (int i = 0; i < childrenSize; i++) {
        Atom atom = children.get(i);
        if (atom.type == type) {
          return (ContainerAtom) atom;
@@ -110,10 +106,6 @@ import java.util.List;
      return null;
    }
-    public List<Atom> getChildren() {
-      return children;
-    }
  }
 }
--- a/library/src/main/java/com/google/android/exoplayer/parser/mp4/CodecSpecificDataUtil.java
+++ b/library/src/main/java/com/google/android/exoplayer/parser/mp4/CodecSpecificDataUtil.java
@@ -27,7 +27,7 @@ import java.util.List;
 /**
 * Provides static utility methods for manipulating various types of codec specific data.
 */
-public class CodecSpecificDataUtil {
+public final class CodecSpecificDataUtil {
  private static final byte[] NAL_START_CODE = new byte[] {0, 0, 0, 1};

--- a/library/src/main/java/com/google/android/exoplayer/parser/mp4/FragmentedMp4Extractor.java
+++ b/library/src/main/java/com/google/android/exoplayer/parser/mp4/FragmentedMp4Extractor.java
@@ -110,7 +110,6 @@ public final class FragmentedMp4Extractor {
    parsedAtoms.add(Atom.TYPE_hdlr);
    parsedAtoms.add(Atom.TYPE_mdat);
    parsedAtoms.add(Atom.TYPE_mdhd);
-    parsedAtoms.add(Atom.TYPE_mfhd);
    parsedAtoms.add(Atom.TYPE_moof);
    parsedAtoms.add(Atom.TYPE_moov);
    parsedAtoms.add(Atom.TYPE_mp4a);
@@ -154,8 +153,10 @@ public final class FragmentedMp4Extractor {
  // Parser state
  private final ParsableByteArray atomHeader;
+  private final byte[] extendedTypeScratch;
  private final Stack<ContainerAtom> containerAtoms;
  private final Stack<Integer> containerAtomEndPoints;
+  private final TrackFragment fragmentRun;
  private int parserState;
  private int atomBytesRead;
@@ -175,9 +176,6 @@ public final class FragmentedMp4Extractor {
  private Track track;
  private DefaultSampleValues extendsDefaults;
-  // Data parsed from the most recent moof atom
-  private TrackFragment fragmentRun;
  public FragmentedMp4Extractor() {
    this(0);
  }
@@ -190,8 +188,10 @@ public final class FragmentedMp4Extractor {
    this.workaroundFlags = workaroundFlags;
    parserState = STATE_READING_ATOM_HEADER;
    atomHeader = new ParsableByteArray(ATOM_HEADER_SIZE);
+    extendedTypeScratch = new byte[16];
    containerAtoms = new Stack<ContainerAtom>();
    containerAtomEndPoints = new Stack<Integer>();
+    fragmentRun = new TrackFragment();
    psshData = new HashMap<UUID, byte[]>();
  }
@@ -335,7 +335,7 @@ public final class FragmentedMp4Extractor {
  private int readAtomHeader(NonBlockingInputStream inputStream) {
    int remainingBytes = ATOM_HEADER_SIZE - atomBytesRead;
-    int bytesRead = inputStream.read(atomHeader.getData(), atomBytesRead, remainingBytes);
+    int bytesRead = inputStream.read(atomHeader.data, atomBytesRead, remainingBytes);
    if (bytesRead == -1) {
      return RESULT_END_OF_STREAM;
    }
@@ -365,7 +365,7 @@ public final class FragmentedMp4Extractor {
        containerAtomEndPoints.add(rootAtomBytesRead + atomSize - ATOM_HEADER_SIZE);
      } else {
        atomData = new ParsableByteArray(atomSize);
-        System.arraycopy(atomHeader.getData(), 0, atomData.getData(), 0, ATOM_HEADER_SIZE);
+        System.arraycopy(atomHeader.data, 0, atomData.data, 0, ATOM_HEADER_SIZE);
        enterState(STATE_READING_ATOM_PAYLOAD);
      }
    } else {
@@ -379,7 +379,7 @@ public final class FragmentedMp4Extractor {
  private int readAtomPayload(NonBlockingInputStream inputStream) {
    int bytesRead;
    if (atomData != null) {
-      bytesRead = inputStream.read(atomData.getData(), atomBytesRead, atomSize - atomBytesRead);
+      bytesRead = inputStream.read(atomData.data, atomBytesRead, atomSize - atomBytesRead);
    } else {
      bytesRead = inputStream.skip(atomSize - atomBytesRead);
    }
@@ -411,7 +411,7 @@ public final class FragmentedMp4Extractor {
    if (!containerAtoms.isEmpty()) {
      containerAtoms.peek().add(leaf);
    } else if (leaf.type == Atom.TYPE_sidx) {
-      segmentIndex = parseSidx(leaf.getData());
+      segmentIndex = parseSidx(leaf.data);
      return RESULT_READ_INDEX;
    }
    return 0;
@@ -430,11 +430,12 @@ public final class FragmentedMp4Extractor {
  }
  private void onMoovContainerAtomRead(ContainerAtom moov) {
-    List<Atom> moovChildren = moov.getChildren();
+    List<Atom> moovChildren = moov.children;
-    for (int i = 0; i < moovChildren.size(); i++) {
+    int moovChildrenSize = moovChildren.size();
+    for (int i = 0; i < moovChildrenSize; i++) {
      Atom child = moovChildren.get(i);
      if (child.type == Atom.TYPE_pssh) {
-        ParsableByteArray psshAtom = ((LeafAtom) child).getData();
+        ParsableByteArray psshAtom = ((LeafAtom) child).data;
        psshAtom.setPosition(FULL_ATOM_HEADER_SIZE);
        UUID uuid = new UUID(psshAtom.readLong(), psshAtom.readLong());
        int dataSize = psshAtom.readInt();
@@ -444,13 +445,13 @@ public final class FragmentedMp4Extractor {
      }
    }
    ContainerAtom mvex = moov.getContainerAtomOfType(Atom.TYPE_mvex);
-    extendsDefaults = parseTrex(mvex.getLeafAtomOfType(Atom.TYPE_trex).getData());
+    extendsDefaults = parseTrex(mvex.getLeafAtomOfType(Atom.TYPE_trex).data);
    track = parseTrak(moov.getContainerAtomOfType(Atom.TYPE_trak));
  }
  private void onMoofContainerAtomRead(ContainerAtom moof) {
-    fragmentRun = new TrackFragment();
+    fragmentRun.reset();
-    parseMoof(track, extendsDefaults, moof, fragmentRun, workaroundFlags);
+    parseMoof(track, extendsDefaults, moof, fragmentRun, workaroundFlags, extendedTypeScratch);
    sampleIndex = 0;
    lastSyncSampleIndex = 0;
    pendingSeekSyncSampleIndex = 0;
@@ -484,21 +485,21 @@ public final class FragmentedMp4Extractor {
   */
  private static Track parseTrak(ContainerAtom trak) {
    ContainerAtom mdia = trak.getContainerAtomOfType(Atom.TYPE_mdia);
-    int trackType = parseHdlr(mdia.getLeafAtomOfType(Atom.TYPE_hdlr).getData());
+    int trackType = parseHdlr(mdia.getLeafAtomOfType(Atom.TYPE_hdlr).data);
    Assertions.checkState(trackType == Track.TYPE_AUDIO || trackType == Track.TYPE_VIDEO);
-    Pair<Integer, Long> header = parseTkhd(trak.getLeafAtomOfType(Atom.TYPE_tkhd).getData());
+    Pair<Integer, Long> header = parseTkhd(trak.getLeafAtomOfType(Atom.TYPE_tkhd).data);
    int id = header.first;
    // TODO: This value should be used to set a duration field on the Track object
    // instantiated below, however we've found examples where the value is 0. Revisit whether we
    // should set it anyway (and just have it be wrong for bad media streams).
    // long duration = header.second;
-    long timescale = parseMdhd(mdia.getLeafAtomOfType(Atom.TYPE_mdhd).getData());
+    long timescale = parseMdhd(mdia.getLeafAtomOfType(Atom.TYPE_mdhd).data);
    ContainerAtom stbl = mdia.getContainerAtomOfType(Atom.TYPE_minf)
        .getContainerAtomOfType(Atom.TYPE_stbl);
    Pair<MediaFormat, TrackEncryptionBox[]> sampleDescriptions =
-        parseStsd(stbl.getLeafAtomOfType(Atom.TYPE_stsd).getData());
+        parseStsd(stbl.getLeafAtomOfType(Atom.TYPE_stsd).data);
    return new Track(id, trackType, timescale, sampleDescriptions.first, sampleDescriptions.second);
  }
@@ -667,7 +668,7 @@ public final class FragmentedMp4Extractor {
    int length = atom.readUnsignedShort();
    int offset = atom.getPosition();
    atom.skip(length);
-    return CodecSpecificDataUtil.buildNalUnit(atom.getData(), offset, length);
+    return CodecSpecificDataUtil.buildNalUnit(atom.data, offset, length);
  }
  private static TrackEncryptionBox parseSinfFromParent(ParsableByteArray parent, int position,
@@ -759,55 +760,41 @@ public final class FragmentedMp4Extractor {
  }
  private static void parseMoof(Track track, DefaultSampleValues extendsDefaults,
-      ContainerAtom moof, TrackFragment out, int workaroundFlags) {
+      ContainerAtom moof, TrackFragment out, int workaroundFlags, byte[] extendedTypeScratch) {
-    // TODO: Consider checking that the sequence number returned by parseMfhd is as expected.
-    parseMfhd(moof.getLeafAtomOfType(Atom.TYPE_mfhd).getData());
    parseTraf(track, extendsDefaults, moof.getContainerAtomOfType(Atom.TYPE_traf),
-        out, workaroundFlags);
+        out, workaroundFlags, extendedTypeScratch);
-  }
-  /**
-   * Parses an mfhd atom (defined in 14496-12).
-   *
-   * @param mfhd The mfhd atom to parse.
-   * @return The sequence number of the fragment.
-   */
-  private static int parseMfhd(ParsableByteArray mfhd) {
-    mfhd.setPosition(FULL_ATOM_HEADER_SIZE);
-    return mfhd.readUnsignedIntToInt();
  }
  /**
   * Parses a traf atom (defined in 14496-12).
   */
  private static void parseTraf(Track track, DefaultSampleValues extendsDefaults,
-      ContainerAtom traf, TrackFragment out, int workaroundFlags) {
+      ContainerAtom traf, TrackFragment out, int workaroundFlags, byte[] extendedTypeScratch) {
    LeafAtom tfdtAtom = traf.getLeafAtomOfType(Atom.TYPE_tfdt);
-    long decodeTime = tfdtAtom == null ? 0
+    long decodeTime = tfdtAtom == null ? 0 : parseTfdt(traf.getLeafAtomOfType(Atom.TYPE_tfdt).data);
-        : parseTfdt(traf.getLeafAtomOfType(Atom.TYPE_tfdt).getData());
    LeafAtom tfhd = traf.getLeafAtomOfType(Atom.TYPE_tfhd);
-    DefaultSampleValues fragmentHeader = parseTfhd(extendsDefaults, tfhd.getData());
+    DefaultSampleValues fragmentHeader = parseTfhd(extendsDefaults, tfhd.data);
-    out.setSampleDescriptionIndex(fragmentHeader.sampleDescriptionIndex);
+    out.sampleDescriptionIndex = fragmentHeader.sampleDescriptionIndex;
    LeafAtom trun = traf.getLeafAtomOfType(Atom.TYPE_trun);
-    parseTrun(track, fragmentHeader, decodeTime, workaroundFlags, trun.getData(), out);
+    parseTrun(track, fragmentHeader, decodeTime, workaroundFlags, trun.data, out);
    TrackEncryptionBox trackEncryptionBox =
        track.sampleDescriptionEncryptionBoxes[fragmentHeader.sampleDescriptionIndex];
    LeafAtom saiz = traf.getLeafAtomOfType(Atom.TYPE_saiz);
    if (saiz != null) {
-      parseSaiz(trackEncryptionBox, saiz.getData(), out);
+      parseSaiz(trackEncryptionBox, saiz.data, out);
    }
    LeafAtom senc = traf.getLeafAtomOfType(Atom.TYPE_senc);
    if (senc != null) {
-      parseSenc(senc.getData(), out);
+      parseSenc(senc.data, out);
    }
    LeafAtom uuid = traf.getLeafAtomOfType(Atom.TYPE_uuid);
    if (uuid != null) {
-      parseUuid(uuid.getData(), out);
+      parseUuid(uuid.data, out, extendedTypeScratch);
    }
  }
@@ -821,10 +808,15 @@ public final class FragmentedMp4Extractor {
      saiz.skip(8);
    }
    int defaultSampleInfoSize = saiz.readUnsignedByte();
    int sampleCount = saiz.readUnsignedIntToInt();
+    if (sampleCount != out.length) {
+      throw new IllegalStateException("Length mismatch: " + sampleCount + ", " + out.length);
+    }
    int totalSize = 0;
-    boolean[] sampleHasSubsampleEncryptionTable = new boolean[sampleCount];
    if (defaultSampleInfoSize == 0) {
+      boolean[] sampleHasSubsampleEncryptionTable = out.sampleHasSubsampleEncryptionTable;
      for (int i = 0; i < sampleCount; i++) {
        int sampleInfoSize = saiz.readUnsignedByte();
        totalSize += sampleInfoSize;
@@ -833,10 +825,9 @@ public final class FragmentedMp4Extractor {
    } else {
      boolean subsampleEncryption = defaultSampleInfoSize > vectorSize;
      totalSize += defaultSampleInfoSize * sampleCount;
-      Arrays.fill(sampleHasSubsampleEncryptionTable, subsampleEncryption);
+      Arrays.fill(out.sampleHasSubsampleEncryptionTable, 0, sampleCount, subsampleEncryption);
    }
-    out.setSampleEncryptionData(sampleHasSubsampleEncryptionTable,
+    out.initEncryptionData(totalSize);
-        new ParsableByteArray(totalSize), true);
  }
  /**
@@ -895,10 +886,9 @@ public final class FragmentedMp4Extractor {
      long decodeTime, int workaroundFlags, ParsableByteArray trun, TrackFragment out) {
    trun.setPosition(ATOM_HEADER_SIZE);
    int fullAtom = trun.readInt();
-    int version = parseFullAtomVersion(fullAtom);
    int flags = parseFullAtomFlags(fullAtom);
-    int numberOfEntries = trun.readUnsignedIntToInt();
+    int sampleCount = trun.readUnsignedIntToInt();
    if ((flags & 0x01 /* data_offset_present */) != 0) {
      trun.skip(4);
    }
@@ -915,17 +905,18 @@ public final class FragmentedMp4Extractor {
    boolean sampleCompositionTimeOffsetsPresent =
        (flags & 0x800 /* sample_composition_time_offsets_present */) != 0;
-    int[] sampleSizeTable = new int[numberOfEntries];
+    out.initTables(sampleCount);
-    int[] sampleDecodingTimeTable = new int[numberOfEntries];
+    int[] sampleSizeTable = out.sampleSizeTable;
-    int[] sampleCompositionTimeOffsetTable = new int[numberOfEntries];
+    int[] sampleDecodingTimeTable = out.sampleDecodingTimeTable;
-    boolean[] sampleIsSyncFrameTable = new boolean[numberOfEntries];
+    int[] sampleCompositionTimeOffsetTable = out.sampleCompositionTimeOffsetTable;
+    boolean[] sampleIsSyncFrameTable = out.sampleIsSyncFrameTable;
    long timescale = track.timescale;
    long cumulativeTime = decodeTime;
    boolean workaroundEveryVideoFrameIsSyncFrame = track.type == Track.TYPE_VIDEO
        && ((workaroundFlags & WORKAROUND_EVERY_VIDEO_FRAME_IS_SYNC_FRAME)
        == WORKAROUND_EVERY_VIDEO_FRAME_IS_SYNC_FRAME);
-    for (int i = 0; i < numberOfEntries; i++) {
+    for (int i = 0; i < sampleCount; i++) {
      // Use trun values if present, otherwise tfhd, otherwise trex.
      int sampleDuration = sampleDurationsPresent ? trun.readUnsignedIntToInt()
          : defaultSampleValues.duration;
@@ -933,18 +924,15 @@ public final class FragmentedMp4Extractor {
      int sampleFlags = (i == 0 && firstSampleFlagsPresent) ? firstSampleFlags
          : sampleFlagsPresent ? trun.readInt() : defaultSampleValues.flags;
      if (sampleCompositionTimeOffsetsPresent) {
-        int sampleOffset;
+        // The BMFF spec (ISO 14496-12) states that sample offsets should be unsigned integers in
-        if (version == 0) {
+        // version 0 trun boxes, however a significant number of streams violate the spec and use
-          // The BMFF spec (ISO 14496-12) states that sample offsets should be unsigned integers in
+        // signed integers instead. It's safe to always parse sample offsets as signed integers
-          // version 0 trun boxes, however a significant number of streams violate the spec and use
+        // here, because unsigned integers will still be parsed correctly (unless their top bit is
-          // signed integers instead. It's safe to always parse sample offsets as signed integers
+        // set, which is never true in practice because sample offsets are always small).
-          // here, because unsigned integers will still be parsed correctly (unless their top bit is
+        int sampleOffset = trun.readInt();
-          // set, which is never true in practice because sample offsets are always small).
-          sampleOffset = trun.readInt();
-        } else {
-          sampleOffset = trun.readInt();
-        }
        sampleCompositionTimeOffsetTable[i] = (int) ((sampleOffset * 1000) / timescale);
+      } else {
+        sampleCompositionTimeOffsetTable[i] = 0;
      }
      sampleDecodingTimeTable[i] = (int) ((cumulativeTime * 1000) / timescale);
      sampleSizeTable[i] = sampleSize;
@@ -952,18 +940,15 @@ public final class FragmentedMp4Extractor {
          && (!workaroundEveryVideoFrameIsSyncFrame || i == 0);
      cumulativeTime += sampleDuration;
    }
-    out.setSampleTables(sampleSizeTable, sampleDecodingTimeTable, sampleCompositionTimeOffsetTable,
-        sampleIsSyncFrameTable);
  }
-  private static void parseUuid(ParsableByteArray uuid, TrackFragment out) {
+  private static void parseUuid(ParsableByteArray uuid, TrackFragment out,
+      byte[] extendedTypeScratch) {
    uuid.setPosition(ATOM_HEADER_SIZE);
-    byte[] extendedType = new byte[16];
+    uuid.readBytes(extendedTypeScratch, 0, 16);
-    uuid.readBytes(extendedType, 0, 16);
    // Currently this parser only supports Microsoft's PIFF SampleEncryptionBox.
-    if (!Arrays.equals(extendedType, PIFF_SAMPLE_ENCRYPTION_BOX_EXTENDED_TYPE)) {
+    if (!Arrays.equals(extendedTypeScratch, PIFF_SAMPLE_ENCRYPTION_BOX_EXTENDED_TYPE)) {
      return;
    }
@@ -993,14 +978,9 @@ public final class FragmentedMp4Extractor {
      throw new IllegalStateException("Length mismatch: " + sampleCount + ", " + out.length);
    }
-    boolean[] sampleHasSubsampleEncryptionTable = new boolean[sampleCount];
+    Arrays.fill(out.sampleHasSubsampleEncryptionTable, 0, sampleCount, subsampleEncryption);
-    Arrays.fill(sampleHasSubsampleEncryptionTable, subsampleEncryption);
+    out.initEncryptionData(senc.length() - senc.getPosition());
+    out.fillEncryptionData(senc);
-    int sampleEncryptionDataLength = senc.length() - senc.getPosition();
-    ParsableByteArray sampleEncryptionData = new ParsableByteArray(sampleEncryptionDataLength);
-    senc.readBytes(sampleEncryptionData.getData(), 0, sampleEncryptionDataLength);
-    out.setSampleEncryptionData(sampleHasSubsampleEncryptionTable, sampleEncryptionData, false);
  }
  /**
@@ -1060,13 +1040,10 @@ public final class FragmentedMp4Extractor {
  }
  private int readEncryptionData(NonBlockingInputStream inputStream) {
-    ParsableByteArray sampleEncryptionData = fragmentRun.sampleEncryptionData;
+    boolean success = fragmentRun.fillEncryptionData(inputStream);
-    int sampleEncryptionDataLength = sampleEncryptionData.length();
+    if (!success) {
-    if (inputStream.getAvailableByteCount() < sampleEncryptionDataLength) {
      return RESULT_NEED_MORE_DATA;
    }
-    inputStream.read(sampleEncryptionData.getData(), 0, sampleEncryptionDataLength);
-    fragmentRun.sampleEncryptionDataNeedsFill = false;
    enterState(STATE_READING_SAMPLE);
    return 0;
  }
@@ -1105,8 +1082,8 @@ public final class FragmentedMp4Extractor {
  }
  private int skipSample(NonBlockingInputStream inputStream, int sampleSize) {
-    ParsableByteArray sampleEncryptionData = fragmentRun.sampleEncryptionData;
+    if (fragmentRun.definesEncryptionData) {
-    if (sampleEncryptionData != null) {
+      ParsableByteArray sampleEncryptionData = fragmentRun.sampleEncryptionData;
      TrackEncryptionBox encryptionBox =
          track.sampleDescriptionEncryptionBoxes[fragmentRun.sampleDescriptionIndex];
      int vectorSize = encryptionBox.initializationVectorSize;
@@ -1141,9 +1118,8 @@ public final class FragmentedMp4Extractor {
      outputData = ByteBuffer.allocate(sampleSize);
      out.data = outputData;
    }
-    ParsableByteArray sampleEncryptionData = fragmentRun.sampleEncryptionData;
+    if (fragmentRun.definesEncryptionData) {
-    if (sampleEncryptionData != null) {
+      readSampleEncryptionData(fragmentRun.sampleEncryptionData, out);
-      readSampleEncryptionData(sampleEncryptionData, out);
    }
    if (outputData == null) {

--- a/library/src/main/java/com/google/android/exoplayer/parser/mp4/ParsableByteArray.java
+++ b/library/src/main/java/com/google/android/exoplayer/parser/mp4/ParsableByteArray.java
@@ -23,17 +23,14 @@ import java.nio.ByteBuffer;
 */
 /* package */ final class ParsableByteArray {
-  private final byte[] data;
+  public byte[] data;
  private int position;
  public ParsableByteArray(int length) {
    this.data = new byte[length];
  }
-  public byte[] getData() {
-    return data;
-  }
  public int length() {
    return data.length;
  }

--- a/library/src/main/java/com/google/android/exoplayer/parser/mp4/TrackEncryptionBox.java
+++ b/library/src/main/java/com/google/android/exoplayer/parser/mp4/TrackEncryptionBox.java
@@ -18,7 +18,7 @@ package com.google.android.exoplayer.parser.mp4;
 /**
 * Encapsulates information parsed from a track encryption (tenc) box in an MP4 stream.
 */
-public class TrackEncryptionBox {
+public final class TrackEncryptionBox {
  /**
   * Indicates the encryption state of the samples in the sample group.

--- a/library/src/main/java/com/google/android/exoplayer/parser/mp4/TrackFragment.java
+++ b/library/src/main/java/com/google/android/exoplayer/parser/mp4/TrackFragment.java
@@ -15,41 +15,136 @@
 */
 package com.google.android.exoplayer.parser.mp4;
+import com.google.android.exoplayer.upstream.NonBlockingInputStream;
 /**
 * A holder for information corresponding to a single fragment of an mp4 file.
 */
-/* package */ class TrackFragment {
+/* package */ final class TrackFragment {
  public int sampleDescriptionIndex;
+  /**
+   * The number of samples contained by the fragment.
+   */
  public int length;
+  /**
+   * The size of each sample in the run.
+   */
  public int[] sampleSizeTable;
+  /**
+   * The decoding time of each sample in the run.
+   */
  public int[] sampleDecodingTimeTable;
+  /**
+   * The composition time offset of each sample in the run.
+   */
  public int[] sampleCompositionTimeOffsetTable;
+  /**
+   * Indicates which samples are sync frames.
+   */
  public boolean[] sampleIsSyncFrameTable;
+  /**
+   * True if the fragment defines encryption data. False otherwise.
+   */
+  public boolean definesEncryptionData;
+  /**
+   * If {@link #definesEncryptionData} is true, indicates which samples use sub-sample encryption.
+   * Undefined otherwise.
+   */
  public boolean[] sampleHasSubsampleEncryptionTable;
+  /**
+   * 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;
+  /**
+   * Whether {@link #sampleEncryptionData} needs populating with the actual encryption data.
+   */
  public boolean sampleEncryptionDataNeedsFill;
-  public void setSampleDescriptionIndex(int sampleDescriptionIndex) {
+  /**
-    this.sampleDescriptionIndex = sampleDescriptionIndex;
+   * Resets the fragment.
+   * <p>
+   * The {@link #length} is set to 0, and both {@link #definesEncryptionData} and
+   * {@link #sampleEncryptionDataNeedsFill} is set to false.
+   */
+  public void reset() {
+    length = 0;
+    definesEncryptionData = false;
+    sampleEncryptionDataNeedsFill = false;
+  }
+  /**
+   * Configures the fragment for the specified number of samples.
+   * <p>
+   * The {@link #length} of the fragment is set to the specified sample count, and the contained
+   * tables are resized if necessary such that they are at least this length.
+   *
+   * @param sampleCount The number of samples in the new run.
+   */
+  public void initTables(int sampleCount) {
+    length = sampleCount;
+    if (sampleSizeTable == null || sampleSizeTable.length < length) {
+      // 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;
+      sampleSizeTable = new int[tableSize];
+      sampleDecodingTimeTable = new int[tableSize];
+      sampleCompositionTimeOffsetTable = new int[tableSize];
+      sampleIsSyncFrameTable = new boolean[tableSize];
+      sampleHasSubsampleEncryptionTable = new boolean[tableSize];
+    }
+  }
+  /**
+   * 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
+   * the specified length, and {@link #sampleEncryptionData} is resized if necessary such that it
+   * is at least this length.
+   *
+   * @param length The length in bytes of the encryption data.
+   */
+  public void initEncryptionData(int length) {
+    if (sampleEncryptionData == null || sampleEncryptionData.length() < length) {
+      sampleEncryptionData = new ParsableByteArray(length);
+    }
+    sampleEncryptionDataLength = length;
+    definesEncryptionData = true;
+    sampleEncryptionDataNeedsFill = true;
  }
-  public void setSampleTables(int[] sampleSizeTable, int[] sampleDecodingTimeTable,
+  /**
-      int[] sampleCompositionTimeOffsetTable, boolean[] sampleIsSyncFrameTable) {
+   * Fills {@link #sampleEncryptionData} from the provided source.
-    this.sampleSizeTable = sampleSizeTable;
+   *
-    this.sampleDecodingTimeTable = sampleDecodingTimeTable;
+   * @param source A source from which to read the encryption data.
-    this.sampleCompositionTimeOffsetTable = sampleCompositionTimeOffsetTable;
+   */
-    this.sampleIsSyncFrameTable = sampleIsSyncFrameTable;
+  public void fillEncryptionData(ParsableByteArray source) {
-    this.length = sampleSizeTable.length;
+    source.readBytes(sampleEncryptionData.data, 0, sampleEncryptionDataLength);
+    sampleEncryptionData.setPosition(0);
+    sampleEncryptionDataNeedsFill = false;
  }
-  public void setSampleEncryptionData(boolean[] sampleHasSubsampleEncryptionTable,
+  /**
-      ParsableByteArray sampleEncryptionData, boolean sampleEncryptionDataNeedsFill) {
+   * Fills {@link #sampleEncryptionData} for the current run from the provided source.
-    this.sampleHasSubsampleEncryptionTable = sampleHasSubsampleEncryptionTable;
+   *
-    this.sampleEncryptionData = sampleEncryptionData;
+   * @param source A source from which to read the encryption data.
-    this.sampleEncryptionDataNeedsFill = sampleEncryptionDataNeedsFill;
+   * @return True if the encryption data was filled. False if the source had insufficient data.
+   */
+  public boolean fillEncryptionData(NonBlockingInputStream source) {
+    if (source.getAvailableByteCount() < sampleEncryptionDataLength) {
+      return false;
+    }
+    source.read(sampleEncryptionData.data, 0, sampleEncryptionDataLength);
+    sampleEncryptionData.setPosition(0);
+    sampleEncryptionDataNeedsFill = false;
+    return true;
  }
  public int getSamplePresentationTime(int index) {