com.google.android.exoplayer2.util.ParsableBitArray Java Examples

/**
 * Returns the DTS format given {@code data} containing the DTS frame according to ETSI TS 102 114
 * subsections 5.3/5.4.
 *
 * @param frame The DTS frame to parse.
 * @param trackId The track identifier to set on the format, or null.
 * @param language The language to set on the format.
 * @param drmInitData {@link DrmInitData} to be included in the format.
 * @return The DTS format parsed from data in the header.
 */
public static Format parseDtsFormat(byte[] frame, String trackId, String language,
    DrmInitData drmInitData) {
  ParsableBitArray frameBits = new ParsableBitArray(frame);
  frameBits.skipBits(4 * 8 + 1 + 5 + 1 + 7 + 14); // SYNC, FTYPE, SHORT, CPF, NBLKS, FSIZE
  int amode = frameBits.readBits(6);
  int channelCount = CHANNELS_BY_AMODE[amode];
  int sfreq = frameBits.readBits(4);
  int sampleRate = SAMPLE_RATE_BY_SFREQ[sfreq];
  int rate = frameBits.readBits(5);
  int bitrate = rate >= TWICE_BITRATE_KBPS_BY_RATE.length ? Format.NO_VALUE
      : TWICE_BITRATE_KBPS_BY_RATE[rate] * 1000 / 2;
  frameBits.skipBits(10); // MIX, DYNF, TIMEF, AUXF, HDCD, EXT_AUDIO_ID, EXT_AUDIO, ASPF
  channelCount += frameBits.readBits(2) > 0 ? 1 : 0; // LFF
  return Format.createAudioSampleFormat(trackId, MimeTypes.AUDIO_DTS, null, bitrate,
      Format.NO_VALUE, channelCount, sampleRate, null, drmInitData, 0, language);
}
 

/**
 * Parses a page composition segment, as defined by ETSI EN 300 743 7.2.2.
 */
private static PageComposition parsePageComposition(ParsableBitArray data, int length) {
  int timeoutSecs = data.readBits(8);
  int version = data.readBits(4);
  int state = data.readBits(2);
  data.skipBits(2);
  int remainingLength = length - 2;

  SparseArray<PageRegion> regions = new SparseArray<>();
  while (remainingLength > 0) {
    int regionId = data.readBits(8);
    data.skipBits(8); // Skip reserved.
    int regionHorizontalAddress = data.readBits(16);
    int regionVerticalAddress = data.readBits(16);
    remainingLength -= 6;
    regions.put(regionId, new PageRegion(regionHorizontalAddress, regionVerticalAddress));
  }

  return new PageComposition(timeoutSecs, version, state, regions);
}
 

/**
 * Returns the AC-3 format given {@code data} containing a syncframe. The reading position of
 * {@code data} will be modified.
 *
 * @param data The data to parse, positioned at the start of the syncframe.
 * @param trackId The track identifier to set on the format, or null.
 * @param language The language to set on the format.
 * @param drmInitData {@link DrmInitData} to be included in the format.
 * @return The AC-3 format parsed from data in the header.
 */
public static Format parseAc3SyncframeFormat(ParsableBitArray data, String trackId,
    String language, DrmInitData drmInitData) {
  data.skipBits(16 + 16); // syncword, crc1
  int fscod = data.readBits(2);
  data.skipBits(6 + 5 + 3); // frmsizecod, bsid, bsmod
  int acmod = data.readBits(3);
  if ((acmod & 0x01) != 0 && acmod != 1) {
    data.skipBits(2); // cmixlev
  }
  if ((acmod & 0x04) != 0) {
    data.skipBits(2); // surmixlev
  }
  if (acmod == 2) {
    data.skipBits(2); // dsurmod
  }
  boolean lfeon = data.readBit();
  return Format.createAudioSampleFormat(trackId, MimeTypes.AUDIO_AC3, null, Format.NO_VALUE,
      Format.NO_VALUE, CHANNEL_COUNT_BY_ACMOD[acmod] + (lfeon ? 1 : 0),
      SAMPLE_RATE_BY_FSCOD[fscod], null, drmInitData, 0, language);
}
 

/**
 * Returns the E-AC-3 format given {@code data} containing a syncframe. The reading position of
 * {@code data} will be modified.
 *
 * @param data The data to parse, positioned at the start of the syncframe.
 * @param trackId The track identifier to set on the format, or null.
 * @param language The language to set on the format.
 * @param drmInitData {@link DrmInitData} to be included in the format.
 * @return The E-AC-3 format parsed from data in the header.
 */
public static Format parseEac3SyncframeFormat(ParsableBitArray data, String trackId,
    String language, DrmInitData drmInitData) {
  data.skipBits(16 + 2 + 3 + 11); // syncword, strmtype, substreamid, frmsiz
  int sampleRate;
  int fscod = data.readBits(2);
  if (fscod == 3) {
    sampleRate = SAMPLE_RATE_BY_FSCOD2[data.readBits(2)];
  } else {
    data.skipBits(2); // numblkscod
    sampleRate = SAMPLE_RATE_BY_FSCOD[fscod];
  }
  int acmod = data.readBits(3);
  boolean lfeon = data.readBit();
  return Format.createAudioSampleFormat(trackId, MimeTypes.AUDIO_E_AC3, null, Format.NO_VALUE,
      Format.NO_VALUE, CHANNEL_COUNT_BY_ACMOD[acmod] + (lfeon ? 1 : 0), sampleRate, null,
      drmInitData, 0, language);
}
 

private void parseFrameLength(ParsableBitArray data) {
  frameLengthType = data.readBits(3);
  switch (frameLengthType) {
    case 0:
      data.skipBits(8); // latmBufferFullness.
      break;
    case 1:
      data.skipBits(9); // frameLength.
      break;
    case 3:
    case 4:
    case 5:
      data.skipBits(6); // CELPframeLengthTableIndex.
      break;
    case 6:
    case 7:
      data.skipBits(1); // HVXCframeLengthTableIndex.
      break;
    default:
      throw new IllegalStateException();
  }
}
 

/**
 * Parses an AudioMuxElement as defined in 14496-3:2009, Section 1.7.3.1, Table 1.41.
 *
 * @param data A {@link ParsableBitArray} containing the AudioMuxElement's bytes.
 */
private void parseAudioMuxElement(ParsableBitArray data) throws ParserException {
  boolean useSameStreamMux = data.readBit();
  if (!useSameStreamMux) {
    streamMuxRead = true;
    parseStreamMuxConfig(data);
  } else if (!streamMuxRead) {
    return; // Parsing cannot continue without StreamMuxConfig information.
  }

  if (audioMuxVersionA == 0) {
    if (numSubframes != 0) {
      throw new ParserException();
    }
    int muxSlotLengthBytes = parsePayloadLengthInfo(data);
    parsePayloadMux(data, muxSlotLengthBytes);
    if (otherDataPresent) {
      data.skipBits((int) otherDataLenBits);
    }
  } else {
    throw new ParserException(); // Not defined by ISO/IEC 14496-3:2009.
  }
}
 

/**
 * Returns the DTS format given {@code data} containing the DTS frame according to ETSI TS 102 114
 * subsections 5.3/5.4.
 *
 * @param frame The DTS frame to parse.
 * @param trackId The track identifier to set on the format.
 * @param language The language to set on the format.
 * @param drmInitData {@link DrmInitData} to be included in the format.
 * @return The DTS format parsed from data in the header.
 */
public static Format parseDtsFormat(
    byte[] frame, String trackId, String language, DrmInitData drmInitData) {
  ParsableBitArray frameBits = getNormalizedFrameHeader(frame);
  frameBits.skipBits(32 + 1 + 5 + 1 + 7 + 14); // SYNC, FTYPE, SHORT, CPF, NBLKS, FSIZE
  int amode = frameBits.readBits(6);
  int channelCount = CHANNELS_BY_AMODE[amode];
  int sfreq = frameBits.readBits(4);
  int sampleRate = SAMPLE_RATE_BY_SFREQ[sfreq];
  int rate = frameBits.readBits(5);
  int bitrate = rate >= TWICE_BITRATE_KBPS_BY_RATE.length ? Format.NO_VALUE
      : TWICE_BITRATE_KBPS_BY_RATE[rate] * 1000 / 2;
  frameBits.skipBits(10); // MIX, DYNF, TIMEF, AUXF, HDCD, EXT_AUDIO_ID, EXT_AUDIO, ASPF
  channelCount += frameBits.readBits(2) > 0 ? 1 : 0; // LFF
  return Format.createAudioSampleFormat(trackId, MimeTypes.AUDIO_DTS, null, bitrate,
      Format.NO_VALUE, channelCount, sampleRate, null, drmInitData, 0, language);
}
 

private void parsePayloadMux(ParsableBitArray data, int muxLengthBytes) {
  // The start of sample data in
  int bitPosition = data.getPosition();
  if ((bitPosition & 0x07) == 0) {
    // Sample data is byte-aligned. We can output it directly.
    sampleDataBuffer.setPosition(bitPosition >> 3);
  } else {
    // Sample data is not byte-aligned and we need align it ourselves before outputting.
    // Byte alignment is needed because LATM framing is not supported by MediaCodec.
    data.readBits(sampleDataBuffer.data, 0, muxLengthBytes * 8);
    sampleDataBuffer.setPosition(0);
  }
  output.sampleData(sampleDataBuffer, muxLengthBytes);
  output.sampleMetadata(timeUs, C.BUFFER_FLAG_KEY_FRAME, muxLengthBytes, 0, null);
  timeUs += sampleDurationUs;
}
 

/**
 * Returns the DTS format given {@code data} containing the DTS frame according to ETSI TS 102 114
 * subsections 5.3/5.4.
 *
 * @param frame The DTS frame to parse.
 * @param trackId The track identifier to set on the format.
 * @param language The language to set on the format.
 * @param drmInitData {@link DrmInitData} to be included in the format.
 * @return The DTS format parsed from data in the header.
 */
public static Format parseDtsFormat(
    byte[] frame, String trackId, @Nullable String language, @Nullable DrmInitData drmInitData) {
  ParsableBitArray frameBits = getNormalizedFrameHeader(frame);
  frameBits.skipBits(32 + 1 + 5 + 1 + 7 + 14); // SYNC, FTYPE, SHORT, CPF, NBLKS, FSIZE
  int amode = frameBits.readBits(6);
  int channelCount = CHANNELS_BY_AMODE[amode];
  int sfreq = frameBits.readBits(4);
  int sampleRate = SAMPLE_RATE_BY_SFREQ[sfreq];
  int rate = frameBits.readBits(5);
  int bitrate = rate >= TWICE_BITRATE_KBPS_BY_RATE.length ? Format.NO_VALUE
      : TWICE_BITRATE_KBPS_BY_RATE[rate] * 1000 / 2;
  frameBits.skipBits(10); // MIX, DYNF, TIMEF, AUXF, HDCD, EXT_AUDIO_ID, EXT_AUDIO, ASPF
  channelCount += frameBits.readBits(2) > 0 ? 1 : 0; // LFF
  return Format.createAudioSampleFormat(trackId, MimeTypes.AUDIO_DTS, null, bitrate,
      Format.NO_VALUE, channelCount, sampleRate, null, drmInitData, 0, language);
}
 

/**
 * Returns the DTS format given {@code data} containing the DTS frame according to ETSI TS 102 114
 * subsections 5.3/5.4.
 *
 * @param frame The DTS frame to parse.
 * @param trackId The track identifier to set on the format.
 * @param language The language to set on the format.
 * @param drmInitData {@link DrmInitData} to be included in the format.
 * @return The DTS format parsed from data in the header.
 */
public static Format parseDtsFormat(
    byte[] frame, String trackId, String language, DrmInitData drmInitData) {
  ParsableBitArray frameBits = getNormalizedFrameHeader(frame);
  frameBits.skipBits(32 + 1 + 5 + 1 + 7 + 14); // SYNC, FTYPE, SHORT, CPF, NBLKS, FSIZE
  int amode = frameBits.readBits(6);
  int channelCount = CHANNELS_BY_AMODE[amode];
  int sfreq = frameBits.readBits(4);
  int sampleRate = SAMPLE_RATE_BY_SFREQ[sfreq];
  int rate = frameBits.readBits(5);
  int bitrate = rate >= TWICE_BITRATE_KBPS_BY_RATE.length ? Format.NO_VALUE
      : TWICE_BITRATE_KBPS_BY_RATE[rate] * 1000 / 2;
  frameBits.skipBits(10); // MIX, DYNF, TIMEF, AUXF, HDCD, EXT_AUDIO_ID, EXT_AUDIO, ASPF
  channelCount += frameBits.readBits(2) > 0 ? 1 : 0; // LFF
  return Format.createAudioSampleFormat(trackId, MimeTypes.AUDIO_DTS, null, bitrate,
      Format.NO_VALUE, channelCount, sampleRate, null, drmInitData, 0, language);
}
 

private void parsePayloadMux(ParsableBitArray data, int muxLengthBytes) {
  // The start of sample data in
  int bitPosition = data.getPosition();
  if ((bitPosition & 0x07) == 0) {
    // Sample data is byte-aligned. We can output it directly.
    sampleDataBuffer.setPosition(bitPosition >> 3);
  } else {
    // Sample data is not byte-aligned and we need align it ourselves before outputting.
    // Byte alignment is needed because LATM framing is not supported by MediaCodec.
    data.readBits(sampleDataBuffer.data, 0, muxLengthBytes * 8);
    sampleDataBuffer.setPosition(0);
  }
  output.sampleData(sampleDataBuffer, muxLengthBytes);
  output.sampleMetadata(timeUs, C.BUFFER_FLAG_KEY_FRAME, muxLengthBytes, 0, null);
  timeUs += sampleDurationUs;
}
 

/**
 * Parses an AudioMuxElement as defined in 14496-3:2009, Section 1.7.3.1, Table 1.41.
 *
 * @param data A {@link ParsableBitArray} containing the AudioMuxElement's bytes.
 */
private void parseAudioMuxElement(ParsableBitArray data) throws ParserException {
  boolean useSameStreamMux = data.readBit();
  if (!useSameStreamMux) {
    streamMuxRead = true;
    parseStreamMuxConfig(data);
  } else if (!streamMuxRead) {
    return; // Parsing cannot continue without StreamMuxConfig information.
  }

  if (audioMuxVersionA == 0) {
    if (numSubframes != 0) {
      throw new ParserException();
    }
    int muxSlotLengthBytes = parsePayloadLengthInfo(data);
    parsePayloadMux(data, muxSlotLengthBytes);
    if (otherDataPresent) {
      data.skipBits((int) otherDataLenBits);
    }
  } else {
    throw new ParserException(); // Not defined by ISO/IEC 14496-3:2009.
  }
}
 

/**
 * Parses a page composition segment, as defined by ETSI EN 300 743 7.2.2.
 */
private static PageComposition parsePageComposition(ParsableBitArray data, int length) {
  int timeoutSecs = data.readBits(8);
  int version = data.readBits(4);
  int state = data.readBits(2);
  data.skipBits(2);
  int remainingLength = length - 2;

  SparseArray<PageRegion> regions = new SparseArray<>();
  while (remainingLength > 0) {
    int regionId = data.readBits(8);
    data.skipBits(8); // Skip reserved.
    int regionHorizontalAddress = data.readBits(16);
    int regionVerticalAddress = data.readBits(16);
    remainingLength -= 6;
    regions.put(regionId, new PageRegion(regionHorizontalAddress, regionVerticalAddress));
  }

  return new PageComposition(timeoutSecs, version, state, regions);
}
 

private int parseAudioSpecificConfig(ParsableBitArray data) throws ParserException {
  int bitsLeft = data.bitsLeft();
  Pair<Integer, Integer> config = CodecSpecificDataUtil.parseAacAudioSpecificConfig(data, true);
  sampleRateHz = config.first;
  channelCount = config.second;
  return bitsLeft - data.bitsLeft();
}
 

private int parseAudioSpecificConfig(ParsableBitArray data) throws ParserException {
  int bitsLeft = data.bitsLeft();
  Pair<Integer, Integer> config = CodecSpecificDataUtil.parseAacAudioSpecificConfig(data, true);
  sampleRateHz = config.first;
  channelCount = config.second;
  return bitsLeft - data.bitsLeft();
}
 

/**
 * Creates a new extractor for ADTS bitstreams.
 *
 * @param flags Flags that control the extractor's behavior.
 */
public AdtsExtractor(@Flags int flags) {
  this.flags = flags;
  reader = new AdtsReader(true);
  packetBuffer = new ParsableByteArray(MAX_PACKET_SIZE);
  averageFrameSize = C.LENGTH_UNSET;
  firstFramePosition = C.POSITION_UNSET;
  // Allocate scratch space for an ID3 header. The same buffer is also used to read 4 byte values.
  scratch = new ParsableByteArray(ID3_HEADER_LENGTH);
  scratchBits = new ParsableBitArray(scratch.data);
}
 

/**
 * Reads the number of audio samples represented by the given AC-4 syncframe. The buffer's
 * position is not modified.
 *
 * @param buffer The {@link ByteBuffer} from which to read the syncframe.
 * @return The number of audio samples represented by the syncframe.
 */
public static int parseAc4SyncframeAudioSampleCount(ByteBuffer buffer) {
  byte[] bufferBytes = new byte[HEADER_SIZE_FOR_PARSER];
  int position = buffer.position();
  buffer.get(bufferBytes);
  buffer.position(position);
  return parseAc4SyncframeInfo(new ParsableBitArray(bufferBytes)).sampleCount;
}
 

/**
 * Paint an 8-bit/pixel code string, as defined by ETSI EN 300 743 7.2.5.2, to a canvas.
 */
private static int paint8BitPixelCodeString(ParsableBitArray data, int[] clutEntries,
    byte[] clutMapTable, int column, int line, Paint paint, Canvas canvas) {
  boolean endOfPixelCodeString = false;
  do {
    int runLength = 0;
    int clutIndex = 0;
    int peek = data.readBits(8);
    if (peek != 0x00) {
      runLength = 1;
      clutIndex = peek;
    } else {
      if (!data.readBit()) {
        peek = data.readBits(7);
        if (peek != 0x00) {
          runLength = peek;
          clutIndex = 0x00;
        } else {
          endOfPixelCodeString = true;
        }
      } else {
        runLength = data.readBits(7);
        clutIndex = data.readBits(8);
      }
    }

    if (runLength != 0 && paint != null) {
      paint.setColor(clutEntries[clutMapTable != null ? clutMapTable[clutIndex] : clutIndex]);
      canvas.drawRect(column, line, column + runLength, line + 1, paint);
    }
    column += runLength;
  } while (!endOfPixelCodeString);

  return column;
}
 

/**
 * Reads the number of audio samples represented by the given AC-4 syncframe. The buffer's
 * position is not modified.
 *
 * @param buffer The {@link ByteBuffer} from which to read the syncframe.
 * @return The number of audio samples represented by the syncframe.
 */
public static int parseAc4SyncframeAudioSampleCount(ByteBuffer buffer) {
  byte[] bufferBytes = new byte[HEADER_SIZE_FOR_PARSER];
  int position = buffer.position();
  buffer.get(bufferBytes);
  buffer.position(position);
  return parseAc4SyncframeInfo(new ParsableBitArray(bufferBytes)).sampleCount;
}
 

private int parsePayloadLengthInfo(ParsableBitArray data) throws ParserException {
  int muxSlotLengthBytes = 0;
  // Assuming single program and single layer.
  if (frameLengthType == 0) {
    int tmp;
    do {
      tmp = data.readBits(8);
      muxSlotLengthBytes += tmp;
    } while (tmp == 255);
    return muxSlotLengthBytes;
  } else {
    throw new ParserException();
  }
}
 

/**
 * Parses an object data segment, as defined by ETSI EN 300 743 7.2.5.
 *
 * @return The parsed object data.
 */
private static ObjectData parseObjectData(ParsableBitArray data) {
  int objectId = data.readBits(16);
  data.skipBits(4); // Skip object_version_number
  int objectCodingMethod = data.readBits(2);
  boolean nonModifyingColorFlag = data.readBit();
  data.skipBits(1); // Skip reserved.

  byte[] topFieldData = null;
  byte[] bottomFieldData = null;

  if (objectCodingMethod == OBJECT_CODING_STRING) {
    int numberOfCodes = data.readBits(8);
    // TODO: Parse and use character_codes.
    data.skipBits(numberOfCodes * 16); // Skip character_codes.
  } else if (objectCodingMethod == OBJECT_CODING_PIXELS) {
    int topFieldDataLength = data.readBits(16);
    int bottomFieldDataLength = data.readBits(16);
    if (topFieldDataLength > 0) {
      topFieldData = new byte[topFieldDataLength];
      data.readBytes(topFieldData, 0, topFieldDataLength);
    }
    if (bottomFieldDataLength > 0) {
      bottomFieldData = new byte[bottomFieldDataLength];
      data.readBytes(bottomFieldData, 0, bottomFieldDataLength);
    } else {
      bottomFieldData = topFieldData;
    }
  }

  return new ObjectData(objectId, nonModifyingColorFlag, topFieldData, bottomFieldData);
}
 

private static byte[] buildClutMapTable(int length, int bitsPerEntry, ParsableBitArray data) {
  byte[] clutMapTable = new byte[length];
  for (int i = 0; i < length; i++) {
    clutMapTable[i] = (byte) data.readBits(bitsPerEntry);
  }
  return clutMapTable;
}
 

public Cea708Decoder(int accessibilityChannel, List<byte[]> initializationData) {
  ccData = new ParsableByteArray();
  serviceBlockPacket = new ParsableBitArray();
  selectedServiceNumber = accessibilityChannel == Format.NO_VALUE ? 1 : accessibilityChannel;

  cueBuilders = new CueBuilder[NUM_WINDOWS];
  for (int i = 0; i < NUM_WINDOWS; i++) {
    cueBuilders[i] = new CueBuilder();
  }

  currentCueBuilder = cueBuilders[0];
  resetCueBuilders();
}
 

/**
 * Parses an object data segment, as defined by ETSI EN 300 743 7.2.5.
 *
 * @return The parsed object data.
 */
private static ObjectData parseObjectData(ParsableBitArray data) {
  int objectId = data.readBits(16);
  data.skipBits(4); // Skip object_version_number
  int objectCodingMethod = data.readBits(2);
  boolean nonModifyingColorFlag = data.readBit();
  data.skipBits(1); // Skip reserved.

  byte[] topFieldData = null;
  byte[] bottomFieldData = null;

  if (objectCodingMethod == OBJECT_CODING_STRING) {
    int numberOfCodes = data.readBits(8);
    // TODO: Parse and use character_codes.
    data.skipBits(numberOfCodes * 16); // Skip character_codes.
  } else if (objectCodingMethod == OBJECT_CODING_PIXELS) {
    int topFieldDataLength = data.readBits(16);
    int bottomFieldDataLength = data.readBits(16);
    if (topFieldDataLength > 0) {
      topFieldData = new byte[topFieldDataLength];
      data.readBytes(topFieldData, 0, topFieldDataLength);
    }
    if (bottomFieldDataLength > 0) {
      bottomFieldData = new byte[bottomFieldDataLength];
      data.readBytes(bottomFieldData, 0, bottomFieldDataLength);
    } else {
      bottomFieldData = topFieldData;
    }
  }

  return new ObjectData(objectId, nonModifyingColorFlag, topFieldData, bottomFieldData);
}
 

private static ParsableBitArray getNormalizedFrameHeader(byte[] frameHeader) {
  if (frameHeader[0] == FIRST_BYTE_BE) {
    // The frame is already 16-bit mode, big endian.
    return new ParsableBitArray(frameHeader);
  }
  // Data is not normalized, but we don't want to modify frameHeader.
  frameHeader = Arrays.copyOf(frameHeader, frameHeader.length);
  if (isLittleEndianFrameHeader(frameHeader)) {
    // Change endianness.
    for (int i = 0; i < frameHeader.length - 1; i += 2) {
      byte temp = frameHeader[i];
      frameHeader[i] = frameHeader[i + 1];
      frameHeader[i + 1] = temp;
    }
  }
  ParsableBitArray frameBits = new ParsableBitArray(frameHeader);
  if (frameHeader[0] == (byte) (SYNC_VALUE_14B_BE >> 24)) {
    // Discard the 2 most significant bits of each 16 bit word.
    ParsableBitArray scratchBits = new ParsableBitArray(frameHeader);
    while (scratchBits.bitsLeft() >= 16) {
      scratchBits.skipBits(2);
      frameBits.putInt(scratchBits.readBits(14), 14);
    }
  }
  frameBits.reset(frameHeader);
  return frameBits;
}
 

/**
 * Constructs a new reader for (E-)AC-3 elementary streams.
 *
 * @param language Track language.
 */
public Ac3Reader(String language) {
  headerScratchBits = new ParsableBitArray(new byte[HEADER_SIZE]);
  headerScratchBytes = new ParsableByteArray(headerScratchBits.data);
  state = STATE_FINDING_SYNC;
  this.language = language;
}
 

/**
 * @param exposeId3 True if the reader should expose ID3 information.
 * @param language Track language.
 */
public AdtsReader(boolean exposeId3, String language) {
  adtsScratch = new ParsableBitArray(new byte[HEADER_SIZE + CRC_SIZE]);
  id3HeaderBuffer = new ParsableByteArray(Arrays.copyOf(ID3_IDENTIFIER, ID3_HEADER_SIZE));
  setFindingSampleState();
  firstFrameVersion = VERSION_UNSET;
  firstFrameSampleRateIndex = C.INDEX_UNSET;
  sampleDurationUs = C.TIME_UNSET;
  this.exposeId3 = exposeId3;
  this.language = language;
}
 

private int parsePayloadLengthInfo(ParsableBitArray data) throws ParserException {
  int muxSlotLengthBytes = 0;
  // Assuming single program and single layer.
  if (frameLengthType == 0) {
    int tmp;
    do {
      tmp = data.readBits(8);
      muxSlotLengthBytes += tmp;
    } while (tmp == 255);
    return muxSlotLengthBytes;
  } else {
    throw new ParserException();
  }
}
 

/**
 * Constructs a new reader for (E-)AC-3 elementary streams.
 *
 * @param language Track language.
 */
public Ac3Reader(String language) {
  headerScratchBits = new ParsableBitArray(new byte[HEADER_SIZE]);
  headerScratchBytes = new ParsableByteArray(headerScratchBits.data);
  state = STATE_FINDING_SYNC;
  this.language = language;
}
 

/**
 * Parses a display definition segment, as defined by ETSI EN 300 743 7.2.1.
 */
private static DisplayDefinition parseDisplayDefinition(ParsableBitArray data) {
  data.skipBits(4); // dds_version_number (4).
  boolean displayWindowFlag = data.readBit();
  data.skipBits(3); // Skip reserved.
  int width = data.readBits(16);
  int height = data.readBits(16);

  int horizontalPositionMinimum;
  int horizontalPositionMaximum;
  int verticalPositionMinimum;
  int verticalPositionMaximum;
  if (displayWindowFlag) {
    horizontalPositionMinimum = data.readBits(16);
    horizontalPositionMaximum = data.readBits(16);
    verticalPositionMinimum = data.readBits(16);
    verticalPositionMaximum = data.readBits(16);
  } else {
    horizontalPositionMinimum = 0;
    horizontalPositionMaximum = width;
    verticalPositionMinimum = 0;
    verticalPositionMaximum = height;
  }

  return new DisplayDefinition(width, height, horizontalPositionMinimum,
      horizontalPositionMaximum, verticalPositionMinimum, verticalPositionMaximum);
}