/** Parses a sidx atom (defined in 14496-12). */
  private static ChunkIndex parseSidx(ParsableByteArray atom, long inputPosition)
      throws ParserException {
    atom.setPosition(Atom.HEADER_SIZE);
    int fullAtom = atom.readInt();
    int version = Atom.parseFullAtomVersion(fullAtom);

    atom.skipBytes(4);
    long timescale = atom.readUnsignedInt();
    long earliestPresentationTime;
    long offset = inputPosition;
    if (version == 0) {
      earliestPresentationTime = atom.readUnsignedInt();
      offset += atom.readUnsignedInt();
    } else {
      earliestPresentationTime = atom.readUnsignedLongToLong();
      offset += atom.readUnsignedLongToLong();
    }

    atom.skipBytes(2);

    int referenceCount = atom.readUnsignedShort();
    int[] sizes = new int[referenceCount];
    long[] offsets = new long[referenceCount];
    long[] durationsUs = new long[referenceCount];
    long[] timesUs = new long[referenceCount];

    long time = earliestPresentationTime;
    long timeUs = Util.scaleLargeTimestamp(time, C.MICROS_PER_SECOND, timescale);
    for (int i = 0; i < referenceCount; i++) {
      int firstInt = atom.readInt();

      int type = 0x80000000 & firstInt;
      if (type != 0) {
        throw new ParserException("Unhandled indirect reference");
      }
      long referenceDuration = atom.readUnsignedInt();

      sizes[i] = 0x7fffffff & firstInt;
      offsets[i] = offset;

      // Calculate time and duration values such that any rounding errors are consistent. i.e. That
      // timesUs[i] + durationsUs[i] == timesUs[i + 1].
      timesUs[i] = timeUs;
      time += referenceDuration;
      timeUs = Util.scaleLargeTimestamp(time, C.MICROS_PER_SECOND, timescale);
      durationsUs[i] = timeUs - timesUs[i];

      atom.skipBytes(4);
      offset += sizes[i];
    }

    return new ChunkIndex(sizes, offsets, durationsUs, timesUs);
  }
  private static void parseSaiz(
      TrackEncryptionBox encryptionBox, ParsableByteArray saiz, TrackFragment out)
      throws ParserException {
    int vectorSize = encryptionBox.initializationVectorSize;
    saiz.setPosition(Atom.HEADER_SIZE);
    int fullAtom = saiz.readInt();
    int flags = Atom.parseFullAtomFlags(fullAtom);
    if ((flags & 0x01) == 1) {
      saiz.skipBytes(8);
    }
    int defaultSampleInfoSize = saiz.readUnsignedByte();

    int sampleCount = saiz.readUnsignedIntToInt();
    if (sampleCount != out.length) {
      throw new ParserException("Length mismatch: " + sampleCount + ", " + out.length);
    }

    int totalSize = 0;
    if (defaultSampleInfoSize == 0) {
      boolean[] sampleHasSubsampleEncryptionTable = out.sampleHasSubsampleEncryptionTable;
      for (int i = 0; i < sampleCount; i++) {
        int sampleInfoSize = saiz.readUnsignedByte();
        totalSize += sampleInfoSize;
        sampleHasSubsampleEncryptionTable[i] = sampleInfoSize > vectorSize;
      }
    } else {
      boolean subsampleEncryption = defaultSampleInfoSize > vectorSize;
      totalSize += defaultSampleInfoSize * sampleCount;
      Arrays.fill(out.sampleHasSubsampleEncryptionTable, 0, sampleCount, subsampleEncryption);
    }
    out.initEncryptionData(totalSize);
  }
 /** Parses a trex atom (defined in 14496-12). */
 private static DefaultSampleValues parseTrex(ParsableByteArray trex) {
   trex.setPosition(Atom.FULL_HEADER_SIZE + 4);
   int defaultSampleDescriptionIndex = trex.readUnsignedIntToInt() - 1;
   int defaultSampleDuration = trex.readUnsignedIntToInt();
   int defaultSampleSize = trex.readUnsignedIntToInt();
   int defaultSampleFlags = trex.readInt();
   return new DefaultSampleValues(
       defaultSampleDescriptionIndex,
       defaultSampleDuration,
       defaultSampleSize,
       defaultSampleFlags);
 }
  /**
   * Parses a saio atom (defined in 14496-12).
   *
   * @param saio The saio atom to parse.
   * @param out The track fragment to populate with data from the saio atom.
   */
  private static void parseSaio(ParsableByteArray saio, TrackFragment out) throws ParserException {
    saio.setPosition(Atom.HEADER_SIZE);
    int fullAtom = saio.readInt();
    int flags = Atom.parseFullAtomFlags(fullAtom);
    if ((flags & 0x01) == 1) {
      saio.skipBytes(8);
    }

    int entryCount = saio.readUnsignedIntToInt();
    if (entryCount != 1) {
      // We only support one trun element currently, so always expect one entry.
      throw new ParserException("Unexpected saio entry count: " + entryCount);
    }

    int version = Atom.parseFullAtomVersion(fullAtom);
    out.auxiliaryDataPosition +=
        version == 0 ? saio.readUnsignedInt() : saio.readUnsignedLongToLong();
  }
  private static void parseSenc(ParsableByteArray senc, int offset, TrackFragment out)
      throws ParserException {
    senc.setPosition(Atom.HEADER_SIZE + offset);
    int fullAtom = senc.readInt();
    int flags = Atom.parseFullAtomFlags(fullAtom);

    if ((flags & 0x01 /* override_track_encryption_box_parameters */) != 0) {
      // TODO: Implement this.
      throw new ParserException("Overriding TrackEncryptionBox parameters is unsupported.");
    }

    boolean subsampleEncryption = (flags & 0x02 /* use_subsample_encryption */) != 0;
    int sampleCount = senc.readUnsignedIntToInt();
    if (sampleCount != out.length) {
      throw new ParserException("Length mismatch: " + sampleCount + ", " + out.length);
    }

    Arrays.fill(out.sampleHasSubsampleEncryptionTable, 0, sampleCount, subsampleEncryption);
    out.initEncryptionData(senc.bytesLeft());
    out.fillEncryptionData(senc);
  }
  /**
   * Parses a tfhd atom (defined in 14496-12).
   *
   * @param extendsDefaults Default sample values from the trex atom.
   * @param tfhd The tfhd atom to parse.
   * @param out The track fragment to populate with data from the tfhd atom.
   */
  private static void parseTfhd(
      DefaultSampleValues extendsDefaults, ParsableByteArray tfhd, TrackFragment out) {
    tfhd.setPosition(Atom.HEADER_SIZE);
    int fullAtom = tfhd.readInt();
    int flags = Atom.parseFullAtomFlags(fullAtom);

    tfhd.skipBytes(4); // trackId
    if ((flags & 0x01 /* base_data_offset_present */) != 0) {
      long baseDataPosition = tfhd.readUnsignedLongToLong();
      out.dataPosition = baseDataPosition;
      out.auxiliaryDataPosition = baseDataPosition;
    }

    int defaultSampleDescriptionIndex =
        ((flags & 0x02 /* default_sample_description_index_present */) != 0)
            ? tfhd.readUnsignedIntToInt() - 1
            : extendsDefaults.sampleDescriptionIndex;
    int defaultSampleDuration =
        ((flags & 0x08 /* default_sample_duration_present */) != 0)
            ? tfhd.readUnsignedIntToInt()
            : extendsDefaults.duration;
    int defaultSampleSize =
        ((flags & 0x10 /* default_sample_size_present */) != 0)
            ? tfhd.readUnsignedIntToInt()
            : extendsDefaults.size;
    int defaultSampleFlags =
        ((flags & 0x20 /* default_sample_flags_present */) != 0)
            ? tfhd.readUnsignedIntToInt()
            : extendsDefaults.flags;
    out.header =
        new DefaultSampleValues(
            defaultSampleDescriptionIndex,
            defaultSampleDuration,
            defaultSampleSize,
            defaultSampleFlags);
  }
  /**
   * Parses a trun atom (defined in 14496-12).
   *
   * @param track The corresponding track.
   * @param defaultSampleValues Default sample values.
   * @param decodeTime The decode time.
   * @param trun The trun atom to parse.
   * @param out The {@TrackFragment} into which parsed data should be placed.
   */
  private static void parseTrun(
      Track track,
      DefaultSampleValues defaultSampleValues,
      long decodeTime,
      int workaroundFlags,
      ParsableByteArray trun,
      TrackFragment out) {
    trun.setPosition(Atom.HEADER_SIZE);
    int fullAtom = trun.readInt();
    int flags = Atom.parseFullAtomFlags(fullAtom);

    int sampleCount = trun.readUnsignedIntToInt();
    if ((flags & 0x01 /* data_offset_present */) != 0) {
      out.dataPosition += trun.readInt();
    }

    boolean firstSampleFlagsPresent = (flags & 0x04 /* first_sample_flags_present */) != 0;
    int firstSampleFlags = defaultSampleValues.flags;
    if (firstSampleFlagsPresent) {
      firstSampleFlags = trun.readUnsignedIntToInt();
    }

    boolean sampleDurationsPresent = (flags & 0x100 /* sample_duration_present */) != 0;
    boolean sampleSizesPresent = (flags & 0x200 /* sample_size_present */) != 0;
    boolean sampleFlagsPresent = (flags & 0x400 /* sample_flags_present */) != 0;
    boolean sampleCompositionTimeOffsetsPresent =
        (flags & 0x800 /* sample_composition_time_offsets_present */) != 0;

    out.initTables(sampleCount);
    int[] sampleSizeTable = out.sampleSizeTable;
    int[] sampleCompositionTimeOffsetTable = out.sampleCompositionTimeOffsetTable;
    long[] sampleDecodingTimeTable = out.sampleDecodingTimeTable;
    boolean[] sampleIsSyncFrameTable = out.sampleIsSyncFrameTable;

    long timescale = track.timescale;
    long cumulativeTime = decodeTime;
    boolean workaroundEveryVideoFrameIsSyncFrame =
        track.type == Track.TYPE_vide
            && (workaroundFlags & WORKAROUND_EVERY_VIDEO_FRAME_IS_SYNC_FRAME) != 0;
    for (int i = 0; i < sampleCount; i++) {
      // Use trun values if present, otherwise tfhd, otherwise trex.
      int sampleDuration =
          sampleDurationsPresent ? trun.readUnsignedIntToInt() : defaultSampleValues.duration;
      int sampleSize = sampleSizesPresent ? trun.readUnsignedIntToInt() : defaultSampleValues.size;
      int sampleFlags =
          (i == 0 && firstSampleFlagsPresent)
              ? firstSampleFlags
              : sampleFlagsPresent ? trun.readInt() : defaultSampleValues.flags;
      if (sampleCompositionTimeOffsetsPresent) {
        // The BMFF spec (ISO 14496-12) states that sample offsets should be unsigned integers in
        // version 0 trun boxes, however a significant number of streams violate the spec and use
        // signed integers instead. It's safe to always parse sample offsets as signed integers
        // here, because unsigned integers will still be parsed correctly (unless their top bit is
        // set, which is never true in practice because sample offsets are always small).
        int sampleOffset = trun.readInt();
        sampleCompositionTimeOffsetTable[i] = (int) ((sampleOffset * 1000) / timescale);
      } else {
        sampleCompositionTimeOffsetTable[i] = 0;
      }
      sampleDecodingTimeTable[i] = Util.scaleLargeTimestamp(cumulativeTime, 1000, timescale);
      sampleSizeTable[i] = sampleSize;
      sampleIsSyncFrameTable[i] =
          ((sampleFlags >> 16) & 0x1) == 0 && (!workaroundEveryVideoFrameIsSyncFrame || i == 0);
      cumulativeTime += sampleDuration;
    }
  }
 /**
  * Parses a tfdt atom (defined in 14496-12).
  *
  * @return baseMediaDecodeTime The sum of the decode durations of all earlier samples in the
  *     media, expressed in the media's timescale.
  */
 private static long parseTfdt(ParsableByteArray tfdt) {
   tfdt.setPosition(Atom.HEADER_SIZE);
   int fullAtom = tfdt.readInt();
   int version = Atom.parseFullAtomVersion(fullAtom);
   return version == 1 ? tfdt.readUnsignedLongToLong() : tfdt.readUnsignedInt();
 }
  private boolean readAtomHeader(ExtractorInput input) throws IOException, InterruptedException {
    if (atomHeaderBytesRead == 0) {
      // Read the standard length atom header.
      if (!input.readFully(atomHeader.data, 0, Atom.HEADER_SIZE, true)) {
        return false;
      }
      atomHeaderBytesRead = Atom.HEADER_SIZE;
      atomHeader.setPosition(0);
      atomSize = atomHeader.readUnsignedInt();
      atomType = atomHeader.readInt();
    }

    if (atomSize == Atom.LONG_SIZE_PREFIX) {
      // Read the extended atom size.
      int headerBytesRemaining = Atom.LONG_HEADER_SIZE - Atom.HEADER_SIZE;
      input.readFully(atomHeader.data, Atom.HEADER_SIZE, headerBytesRemaining);
      atomHeaderBytesRead += headerBytesRemaining;
      atomSize = atomHeader.readUnsignedLongToLong();
    }

    long atomPosition = input.getPosition() - atomHeaderBytesRead;
    if (atomType == Atom.TYPE_moof) {
      // The data positions may be updated when parsing the tfhd/trun.
      fragmentRun.auxiliaryDataPosition = atomPosition;
      fragmentRun.dataPosition = atomPosition;
    }

    if (atomType == Atom.TYPE_mdat) {
      endOfMdatPosition = atomPosition + atomSize;
      if (!haveOutputSeekMap) {
        extractorOutput.seekMap(SeekMap.UNSEEKABLE);
        haveOutputSeekMap = true;
      }
      if (fragmentRun.sampleEncryptionDataNeedsFill) {
        parserState = STATE_READING_ENCRYPTION_DATA;
      } else {
        parserState = STATE_READING_SAMPLE_START;
      }
      return true;
    }

    if (shouldParseContainerAtom(atomType)) {
      long endPosition = input.getPosition() + atomSize - Atom.HEADER_SIZE;
      containerAtoms.add(new ContainerAtom(atomType, endPosition));
      enterReadingAtomHeaderState();
    } else if (shouldParseLeafAtom(atomType)) {
      // We don't support parsing of leaf atoms that define extended atom sizes, or that have
      // lengths greater than Integer.MAX_VALUE.
      checkState(atomHeaderBytesRead == Atom.HEADER_SIZE);
      checkState(atomSize <= Integer.MAX_VALUE);
      atomData = new ParsableByteArray((int) atomSize);
      System.arraycopy(atomHeader.data, 0, atomData.data, 0, Atom.HEADER_SIZE);
      parserState = STATE_READING_ATOM_PAYLOAD;
    } else {
      // We don't support skipping of atoms that have lengths greater than Integer.MAX_VALUE.
      checkState(atomSize <= Integer.MAX_VALUE);
      atomData = null;
      parserState = STATE_READING_ATOM_PAYLOAD;
    }

    return true;
  }