edu.harvard.hul.ois.jhove.module.jpeg2000
Class MarkerSegment

java.lang.Object
  edu.harvard.hul.ois.jhove.module.jpeg2000.MarkerSegment

Direct Known Subclasses:

COCMarkerSegment, CODMarkerSegment, CommentMarkerSegment, CRGMarkerSegment, DefaultMarkerSegment, Marker, PLMMarkerSegment, PLTMarkerSegment, POCMarkerSegment, PPMMarkerSegment, PPTMarkerSegment, QCCMarkerSegment, QCDMarkerSegment, RGNMarkerSegment, SIZMarkerSegment, SOTMarkerSegment, TLMMarkerSegment

public abstract class MarkerSegment
extends java.lang.Object

Abstract superclass for marker segments.

Author:

Gary McGath

Field Summary

protected ContCodestream	_ccs
protected Codestream	_cs
protected java.io.DataInputStream	_dstream
protected Jpeg2000Module	_module
protected RepInfo	_repInfo
protected static int	COC
protected static int	COD
protected static int	COM
protected static int	CRG
protected static int	EOC
protected static int	EPH
protected static int	PLM
protected static int	PLT
protected static int	POC
protected static int	PPM
protected static int	PPT
protected static int	QCC
protected static int	QCD
protected static int	RGN
protected static int	SIZ
protected static int	SOC
protected static int	SOD
protected static int	SOP
protected static int	SOT
protected static int	TLM

Constructor Summary

MarkerSegment()
Constructor.

Method Summary

protected MainOrTile	getMainOrTile() Returns the MainOrTile object which is currently applicable in the Contiguous Codestream.
boolean	isMarker() Returns true if this segment is a Marker.
protected static MarkerSegment	markerSegmentMaker(int markerCode) Static factory method for generating an object of the appropriate subclass of MarkerSegment, based on the marker code.
protected int	nCompBytes() Determines size of fields indexed by number of components.
protected abstract boolean	process(int bytesToEat) Process the marker or marker segment.
protected int	readMarkLen() Reads and returns the length field of the marker segment.
void	setCodestream(Codestream cs) Sets the Codestream object being built.
void	setContCodestream(ContCodestream ccs) Sets the Continuous Codestream from which this marker was obtained.
void	setDataInputStream(java.io.DataInputStream dstream) Sets the DataInputStream over which this marker is being read.
void	setModule(Jpeg2000Module module) Sets the Module under which all this is happening.
void	setRepInfo(RepInfo repInfo) Sets the RepInfo into which messages may be placed.

Methods inherited from class java.lang.Object

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

Field Detail

SOC

protected static final int SOC

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Constant Field Values

COD

protected static final int COD

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Constant Field Values

COC

protected static final int COC

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Constant Field Values

TLM

protected static final int TLM

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Constant Field Values

PLM

protected static final int PLM

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Constant Field Values

PLT

protected static final int PLT

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Constant Field Values

QCD

protected static final int QCD

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Constant Field Values

QCC

protected static final int QCC

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Constant Field Values

RGN

protected static final int RGN

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Constant Field Values

POC

protected static final int POC

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Constant Field Values

PPM

protected static final int PPM

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Constant Field Values

PPT

protected static final int PPT

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Constant Field Values

CRG

protected static final int CRG

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Constant Field Values

COM

protected static final int COM

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Constant Field Values

SOT

protected static final int SOT

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Constant Field Values

SOP

protected static final int SOP

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Constant Field Values

EPH

protected static final int EPH

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Constant Field Values

SOD

protected static final int SOD

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Constant Field Values

EOC

protected static final int EOC

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Constant Field Values

SIZ

protected static final int SIZ

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Constant Field Values

_ccs

protected ContCodestream _ccs

_cs

protected Codestream _cs

_module

protected Jpeg2000Module _module

_dstream

protected java.io.DataInputStream _dstream

_repInfo

protected RepInfo _repInfo

Constructor Detail

MarkerSegment

public MarkerSegment()

Constructor. After an instance of a MarkerSegment is created, the setter methods setContCodestream, setCodestream, setModule, and setDataInputStream must all be called as part of the setup before process is called.

Method Detail

setContCodestream

public void setContCodestream(ContCodestream ccs)

Sets the Continuous Codestream from which this marker was obtained.

setCodestream

public void setCodestream(Codestream cs)

Sets the Codestream object being built.

setModule

public void setModule(Jpeg2000Module module)

Sets the Module under which all this is happening.

setDataInputStream

public void setDataInputStream(java.io.DataInputStream dstream)

Sets the DataInputStream over which this marker is being read.

setRepInfo

public void setRepInfo(RepInfo repInfo)

Sets the RepInfo into which messages may be placed.

isMarker

public boolean isMarker()

Returns true if this segment is a Marker. Will return false unless overridden.

markerSegmentMaker

protected static MarkerSegment markerSegmentMaker(int markerCode)

Static factory method for generating an object of the appropriate subclass of MarkerSegment, based on the marker code.

Parameters:

markerCode - The 8-bit marker code (ignoring the FF).

readMarkLen

protected int readMarkLen()
                   throws java.io.IOException

Reads and returns the length field of the marker segment. The setter methods setModule and setDataInputStream must be called as part of the setup before readMarkLen is called.

Throws:

java.io.IOException

nCompBytes

protected int nCompBytes()

Determines size of fields indexed by number of components. Some marker segments have fields which are 1 byte long if the number of components is 1-255, and 2 bytes long if the number of components is 256-65535.

Returns:

0 if number of components not yet set, otherwise 1 or 2

getMainOrTile

protected MainOrTile getMainOrTile()

Returns the MainOrTile object which is currently applicable in the Contiguous Codestream. If the Contiguous Codestream has a current Tile, that is returned; otherwise the Codestream object established by setCodestream is returned.

process

protected abstract boolean process(int bytesToEat)
                            throws java.io.IOException

Process the marker or marker segment. The DataInputStream will be at the point of having read the marker code. The process method must consume exactly the number of bytes remaining in the marker segment; for a marker, this number will always be 0.

Parameters:

bytesToEat - The number of bytes that must be consumed. For a Marker, this number will always be 0. If it is 0 for a MarkerSegment, the number of bytes to consume is unknown.

Returns:

true if segment is well-formed, false otherwise.

Throws:

java.io.IOException