Java Code Examples for com.google.android.exoplayer2.util.ParsableBitArray#readBits()

/**
 * 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);
}
 

/**
 * 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);
}
 

/**
 * 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 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();
  }
}
 

private static int readVariableBits(ParsableBitArray data, int bitsPerRead) {
  int value = 0;
  while (true) {
    value += data.readBits(bitsPerRead);
    if (!data.readBit()) {
      break;
    }
    value++;
    value <<= bitsPerRead;
  }
  return value;
}
 

/**
 * 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 MlltFrame decodeMlltFrame(ParsableByteArray id3Data, int frameSize) {
  // See ID3v2.4.0 native frames subsection 4.6.
  int mpegFramesBetweenReference = id3Data.readUnsignedShort();
  int bytesBetweenReference = id3Data.readUnsignedInt24();
  int millisecondsBetweenReference = id3Data.readUnsignedInt24();
  int bitsForBytesDeviation = id3Data.readUnsignedByte();
  int bitsForMillisecondsDeviation = id3Data.readUnsignedByte();

  ParsableBitArray references = new ParsableBitArray();
  references.reset(id3Data);
  int referencesBits = 8 * (frameSize - 10);
  int bitsPerReference = bitsForBytesDeviation + bitsForMillisecondsDeviation;
  int referencesCount = referencesBits / bitsPerReference;
  int[] bytesDeviations = new int[referencesCount];
  int[] millisecondsDeviations = new int[referencesCount];
  for (int i = 0; i < referencesCount; i++) {
    int bytesDeviation = references.readBits(bitsForBytesDeviation);
    int millisecondsDeviation = references.readBits(bitsForMillisecondsDeviation);
    bytesDeviations[i] = bytesDeviation;
    millisecondsDeviations[i] = millisecondsDeviation;
  }

  return new MlltFrame(
      mpegFramesBetweenReference,
      bytesBetweenReference,
      millisecondsBetweenReference,
      bytesDeviations,
      millisecondsDeviations);
}
 

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 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);
}
 

/**
 * 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;
}
 

private static MlltFrame decodeMlltFrame(ParsableByteArray id3Data, int frameSize) {
  // See ID3v2.4.0 native frames subsection 4.6.
  int mpegFramesBetweenReference = id3Data.readUnsignedShort();
  int bytesBetweenReference = id3Data.readUnsignedInt24();
  int millisecondsBetweenReference = id3Data.readUnsignedInt24();
  int bitsForBytesDeviation = id3Data.readUnsignedByte();
  int bitsForMillisecondsDeviation = id3Data.readUnsignedByte();

  ParsableBitArray references = new ParsableBitArray();
  references.reset(id3Data);
  int referencesBits = 8 * (frameSize - 10);
  int bitsPerReference = bitsForBytesDeviation + bitsForMillisecondsDeviation;
  int referencesCount = referencesBits / bitsPerReference;
  int[] bytesDeviations = new int[referencesCount];
  int[] millisecondsDeviations = new int[referencesCount];
  for (int i = 0; i < referencesCount; i++) {
    int bytesDeviation = references.readBits(bitsForBytesDeviation);
    int millisecondsDeviation = references.readBits(bitsForMillisecondsDeviation);
    bytesDeviations[i] = bytesDeviation;
    millisecondsDeviations[i] = millisecondsDeviation;
  }

  return new MlltFrame(
      mpegFramesBetweenReference,
      bytesBetweenReference,
      millisecondsBetweenReference,
      bytesDeviations,
      millisecondsDeviations);
}
 

/** Paint a 2-bit/pixel code string, as defined by ETSI EN 300 743 7.2.5.2, to a canvas. */
private static int paint2BitPixelCodeString(
    ParsableBitArray data,
    int[] clutEntries,
    @Nullable byte[] clutMapTable,
    int column,
    int line,
    @Nullable Paint paint,
    Canvas canvas) {
  boolean endOfPixelCodeString = false;
  do {
    int runLength = 0;
    int clutIndex = 0;
    int peek = data.readBits(2);
    if (peek != 0x00) {
      runLength = 1;
      clutIndex = peek;
    } else if (data.readBit()) {
      runLength = 3 + data.readBits(3);
      clutIndex = data.readBits(2);
    } else if (data.readBit()) {
      runLength = 1;
    } else {
      switch (data.readBits(2)) {
        case 0x00:
          endOfPixelCodeString = true;
          break;
        case 0x01:
          runLength = 2;
          break;
        case 0x02:
          runLength = 12 + data.readBits(4);
          clutIndex = data.readBits(2);
          break;
        case 0x03:
          runLength = 29 + data.readBits(8);
          clutIndex = data.readBits(2);
          break;
      }
    }

    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;
}
 

/**
 * Draws a pixel data sub-block, as defined by ETSI EN 300 743 7.2.5.1, into a canvas.
 */
private static void paintPixelDataSubBlock(byte[] pixelData, int[] clutEntries, int regionDepth,
    int horizontalAddress, int verticalAddress, Paint paint, Canvas canvas) {
  ParsableBitArray data = new ParsableBitArray(pixelData);
  int column = horizontalAddress;
  int line = verticalAddress;
  byte[] clutMapTable2To4 = null;
  byte[] clutMapTable2To8 = null;
  byte[] clutMapTable4To8 = null;

  while (data.bitsLeft() != 0) {
    int dataType = data.readBits(8);
    switch (dataType) {
      case DATA_TYPE_2BP_CODE_STRING:
        byte[] clutMapTable2ToX;
        if (regionDepth == REGION_DEPTH_8_BIT) {
          clutMapTable2ToX = clutMapTable2To8 == null ? defaultMap2To8 : clutMapTable2To8;
        } else if (regionDepth == REGION_DEPTH_4_BIT) {
          clutMapTable2ToX = clutMapTable2To4 == null ? defaultMap2To4 : clutMapTable2To4;
        } else {
          clutMapTable2ToX = null;
        }
        column = paint2BitPixelCodeString(data, clutEntries, clutMapTable2ToX, column, line,
            paint, canvas);
        data.byteAlign();
        break;
      case DATA_TYPE_4BP_CODE_STRING:
        byte[] clutMapTable4ToX;
        if (regionDepth == REGION_DEPTH_8_BIT) {
          clutMapTable4ToX = clutMapTable4To8 == null ? defaultMap4To8 : clutMapTable4To8;
        } else {
          clutMapTable4ToX = null;
        }
        column = paint4BitPixelCodeString(data, clutEntries, clutMapTable4ToX, column, line,
            paint, canvas);
        data.byteAlign();
        break;
      case DATA_TYPE_8BP_CODE_STRING:
        column = paint8BitPixelCodeString(data, clutEntries, null, column, line, paint, canvas);
        break;
      case DATA_TYPE_24_TABLE_DATA:
        clutMapTable2To4 = buildClutMapTable(4, 4, data);
        break;
      case DATA_TYPE_28_TABLE_DATA:
        clutMapTable2To8 = buildClutMapTable(4, 8, data);
        break;
      case DATA_TYPE_48_TABLE_DATA:
        clutMapTable2To8 = buildClutMapTable(16, 8, data);
        break;
      case DATA_TYPE_END_LINE:
        column = horizontalAddress;
        line += 2;
        break;
      default:
        // Do nothing.
        break;
    }
  }
}
 

/**
 * Returns AC-4 format information 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.
 * @return The AC-4 format data parsed from the header.
 */
public static SyncFrameInfo parseAc4SyncframeInfo(ParsableBitArray data) {
  int headerSize = 0;
  int syncWord = data.readBits(16);
  headerSize += 2;
  int frameSize = data.readBits(16);
  headerSize += 2;
  if (frameSize == 0xFFFF) {
    frameSize = data.readBits(24);
    headerSize += 3; // Extended frame_size
  }
  frameSize += headerSize;
  if (syncWord == AC41_SYNCWORD) {
    frameSize += 2; // crc_word
  }
  int bitstreamVersion = data.readBits(2);
  if (bitstreamVersion == 3) {
    bitstreamVersion += readVariableBits(data, /* bitsPerRead= */ 2);
  }
  int sequenceCounter = data.readBits(10);
  if (data.readBit()) { // b_wait_frames
    if (data.readBits(3) > 0) { // wait_frames
      data.skipBits(2); // reserved
    }
  }
  int sampleRate = data.readBit() ? 48000 : 44100;
  int frameRateIndex = data.readBits(4);
  int sampleCount = 0;
  if (sampleRate == 44100 && frameRateIndex == 13) {
    sampleCount = SAMPLE_COUNT[frameRateIndex];
  } else if (sampleRate == 48000 && frameRateIndex < SAMPLE_COUNT.length) {
    sampleCount = SAMPLE_COUNT[frameRateIndex];
    switch (sequenceCounter % 5) {
      case 1: // fall through
      case 3:
        if (frameRateIndex == 3 || frameRateIndex == 8) {
          sampleCount++;
        }
        break;
      case 2:
        if (frameRateIndex == 8 || frameRateIndex == 11) {
          sampleCount++;
        }
        break;
      case 4:
        if (frameRateIndex == 3 || frameRateIndex == 8 || frameRateIndex == 11) {
          sampleCount++;
        }
        break;
      default:
        break;
    }
  }
  return new SyncFrameInfo(bitstreamVersion, CHANNEL_COUNT_2, sampleRate, frameSize, sampleCount);
}
 

/**
 * Parses a region composition segment, as defined by ETSI EN 300 743 7.2.3.
 */
private static RegionComposition parseRegionComposition(ParsableBitArray data, int length) {
  int id = data.readBits(8);
  data.skipBits(4); // Skip region_version_number
  boolean fillFlag = data.readBit();
  data.skipBits(3); // Skip reserved.
  int width = data.readBits(16);
  int height = data.readBits(16);
  int levelOfCompatibility = data.readBits(3);
  int depth = data.readBits(3);
  data.skipBits(2); // Skip reserved.
  int clutId = data.readBits(8);
  int pixelCode8Bit = data.readBits(8);
  int pixelCode4Bit = data.readBits(4);
  int pixelCode2Bit = data.readBits(2);
  data.skipBits(2); // Skip reserved
  int remainingLength = length - 10;

  SparseArray<RegionObject> regionObjects = new SparseArray<>();
  while (remainingLength > 0) {
    int objectId = data.readBits(16);
    int objectType = data.readBits(2);
    int objectProvider = data.readBits(2);
    int objectHorizontalPosition = data.readBits(12);
    data.skipBits(4); // Skip reserved.
    int objectVerticalPosition = data.readBits(12);
    remainingLength -= 6;

    int foregroundPixelCode = 0;
    int backgroundPixelCode = 0;
    if (objectType == 0x01 || objectType == 0x02) { // Only seems to affect to char subtitles.
      foregroundPixelCode = data.readBits(8);
      backgroundPixelCode = data.readBits(8);
      remainingLength -= 2;
    }

    regionObjects.put(objectId, new RegionObject(objectType, objectProvider,
        objectHorizontalPosition, objectVerticalPosition, foregroundPixelCode,
        backgroundPixelCode));
  }

  return new RegionComposition(id, fillFlag, width, height, levelOfCompatibility, depth, clutId,
      pixelCode8Bit, pixelCode4Bit, pixelCode2Bit, regionObjects);
}
 

/**
 * Paint a 2-bit/pixel code string, as defined by ETSI EN 300 743 7.2.5.2, to a canvas.
 */
private static int paint2BitPixelCodeString(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(2);
    if (peek != 0x00) {
      runLength = 1;
      clutIndex = peek;
    } else if (data.readBit()) {
      runLength = 3 + data.readBits(3);
      clutIndex = data.readBits(2);
    } else if (data.readBit()) {
      runLength = 1;
    } else {
      switch (data.readBits(2)) {
        case 0x00:
          endOfPixelCodeString = true;
          break;
        case 0x01:
          runLength = 2;
          break;
        case 0x02:
          runLength = 12 + data.readBits(4);
          clutIndex = data.readBits(2);
          break;
        case 0x03:
          runLength = 29 + data.readBits(8);
          clutIndex = data.readBits(2);
          break;
      }
    }

    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;
}
 

/**
 * Parses a region composition segment, as defined by ETSI EN 300 743 7.2.3.
 */
private static RegionComposition parseRegionComposition(ParsableBitArray data, int length) {
  int id = data.readBits(8);
  data.skipBits(4); // Skip region_version_number
  boolean fillFlag = data.readBit();
  data.skipBits(3); // Skip reserved.
  int width = data.readBits(16);
  int height = data.readBits(16);
  int levelOfCompatibility = data.readBits(3);
  int depth = data.readBits(3);
  data.skipBits(2); // Skip reserved.
  int clutId = data.readBits(8);
  int pixelCode8Bit = data.readBits(8);
  int pixelCode4Bit = data.readBits(4);
  int pixelCode2Bit = data.readBits(2);
  data.skipBits(2); // Skip reserved
  int remainingLength = length - 10;

  SparseArray<RegionObject> regionObjects = new SparseArray<>();
  while (remainingLength > 0) {
    int objectId = data.readBits(16);
    int objectType = data.readBits(2);
    int objectProvider = data.readBits(2);
    int objectHorizontalPosition = data.readBits(12);
    data.skipBits(4); // Skip reserved.
    int objectVerticalPosition = data.readBits(12);
    remainingLength -= 6;

    int foregroundPixelCode = 0;
    int backgroundPixelCode = 0;
    if (objectType == 0x01 || objectType == 0x02) { // Only seems to affect to char subtitles.
      foregroundPixelCode = data.readBits(8);
      backgroundPixelCode = data.readBits(8);
      remainingLength -= 2;
    }

    regionObjects.put(objectId, new RegionObject(objectType, objectProvider,
        objectHorizontalPosition, objectVerticalPosition, foregroundPixelCode,
        backgroundPixelCode));
  }

  return new RegionComposition(id, fillFlag, width, height, levelOfCompatibility, depth, clutId,
      pixelCode8Bit, pixelCode4Bit, pixelCode2Bit, regionObjects);
}
 

/**
 * Parses a region composition segment, as defined by ETSI EN 300 743 7.2.3.
 */
private static RegionComposition parseRegionComposition(ParsableBitArray data, int length) {
  int id = data.readBits(8);
  data.skipBits(4); // Skip region_version_number
  boolean fillFlag = data.readBit();
  data.skipBits(3); // Skip reserved.
  int width = data.readBits(16);
  int height = data.readBits(16);
  int levelOfCompatibility = data.readBits(3);
  int depth = data.readBits(3);
  data.skipBits(2); // Skip reserved.
  int clutId = data.readBits(8);
  int pixelCode8Bit = data.readBits(8);
  int pixelCode4Bit = data.readBits(4);
  int pixelCode2Bit = data.readBits(2);
  data.skipBits(2); // Skip reserved
  int remainingLength = length - 10;

  SparseArray<RegionObject> regionObjects = new SparseArray<>();
  while (remainingLength > 0) {
    int objectId = data.readBits(16);
    int objectType = data.readBits(2);
    int objectProvider = data.readBits(2);
    int objectHorizontalPosition = data.readBits(12);
    data.skipBits(4); // Skip reserved.
    int objectVerticalPosition = data.readBits(12);
    remainingLength -= 6;

    int foregroundPixelCode = 0;
    int backgroundPixelCode = 0;
    if (objectType == 0x01 || objectType == 0x02) { // Only seems to affect to char subtitles.
      foregroundPixelCode = data.readBits(8);
      backgroundPixelCode = data.readBits(8);
      remainingLength -= 2;
    }

    regionObjects.put(objectId, new RegionObject(objectType, objectProvider,
        objectHorizontalPosition, objectVerticalPosition, foregroundPixelCode,
        backgroundPixelCode));
  }

  return new RegionComposition(id, fillFlag, width, height, levelOfCompatibility, depth, clutId,
      pixelCode8Bit, pixelCode4Bit, pixelCode2Bit, regionObjects);
}
 

private static long latmGetValue(ParsableBitArray data) {
  int bytesForValue = data.readBits(2);
  return data.readBits((bytesForValue + 1) * 8);
}
 

private static long latmGetValue(ParsableBitArray data) {
  int bytesForValue = data.readBits(2);
  return data.readBits((bytesForValue + 1) * 8);
}