edu.harvard.hul.ois.jhove.module.iff

Class Chunk

java.lang.Object

edu.harvard.hul.ois.jhove.module.iff.Chunk

Direct Known Subclasses:

ApplicationChunk, AudioRecChunk, CommentsChunk, CommonChunk, FormatVersionChunk, InstrumentChunk, MarkerChunk, MidiChunk, SaxelChunk, SoundDataChunk, Superchunk, TextChunk

public abstract class Chunk
extends Object

Abstract superclass for IFF/AIFF chunks.

Author:

Gary McGath

Field Summary

Fields

Modifier and Type	Field and Description
protected DataInputStream	_dstream
protected ModuleBase	_module
protected long	bytesLeft
protected long	chunkOffset
protected long	chunkSize
static int	HEADER_LENGTH Length of chunk headers in bytes
static int	ID_LENGTH Length of chunk ID fields in bytes
static int	SIZE_LENGTH Length of chunk size fields in bytes

Constructor Summary

Constructors

Constructor and Description
Chunk(ModuleBase module, ChunkHeader hdr, DataInputStream dstrm) Class constructor.

Method Summary

Modifier and Type	Method and Description
protected String	byteBufString(byte[] byteArray) Converts a byte buffer cleanly into an ASCII string.
abstract boolean	readChunk(RepInfo info) Reads a chunk and puts appropriate information into the RepInfo object.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ID_LENGTH

public static final int ID_LENGTH

Length of chunk ID fields in bytes

See Also:

Constant Field Values

SIZE_LENGTH

public static final int SIZE_LENGTH

Length of chunk size fields in bytes

See Also:

Constant Field Values

HEADER_LENGTH

public static final int HEADER_LENGTH

Length of chunk headers in bytes

See Also:

Constant Field Values

_module

protected ModuleBase _module

_dstream

protected DataInputStream _dstream

bytesLeft

protected long bytesLeft

chunkSize

protected long chunkSize

chunkOffset

protected long chunkOffset

Constructor Detail

Chunk

public Chunk(ModuleBase module,
             ChunkHeader hdr,
             DataInputStream dstrm)

Class constructor.

Parameters:

module - The Module under which this was called

hdr - The header for this chunk

dstrm - The stream from which the data are being read

Method Detail

readChunk

public abstract boolean readChunk(RepInfo info)
                           throws IOException

Reads a chunk and puts appropriate information into the RepInfo object.

Parameters:

info - RepInfo object to receive information

Returns:

false if the chunk is structurally invalid, otherwise true

Throws:

IOException

byteBufString

protected String byteBufString(byte[] byteArray)

Converts a byte buffer cleanly into an ASCII string. This is used for fixed-allocation strings in Broadcast WAVE chunks, and might have uses elsewhere. If a string is shorter than its fixed allocation, we're guaranteed only that there is a null terminating the string, and noise could follow it. So we can't use the byte buffer constructor for a string.