CADI.Common.LogicalTarget.JPEG2000.Codestream
Class PacketHeadersDecoder

java.lang.Object
  CADI.Common.LogicalTarget.JPEG2000.Codestream.PacketHeadersDecoder

public class PacketHeadersDecoder
extends java.lang.Object

This class performs the packet header decoding.

Usage: example:
construct
[reset]
packetHeaderDecoding

Version:

1.1.0 2008/12/05

Author:

Group on Interactive Coding of Images (GICI)

Field Summary

private boolean	EPH Indicates whether the End of Packet marker is in the codestream and it must be read.
private int[][][]	firstLayer Definition in PacketHeaderDataDecoder.firstLayer.
private int[][][][][][]	imageStructure Is the image structure.
private int[][][]	lBlock Definition in PacketHeaderDataDecoder.lBlock.
private int	Nsop Packet sequence number.
private int	NsopInHeader
private java.util.Hashtable<java.lang.Long,PacketHeaderDataDecoder>	packetHeaders This object is used to save the packet headers data objects.
private PacketHeaderDataInputStream	PHDataInputStream Is a input stream where bits of packet headers will be read from.
private boolean	SOP Indicates whether the Start of Packet marker is in the codestream and it must be read.
private TagTreeDecoder[]	TTInclusionInformation Definition in PacketHeaderDataDecoder.TTInclusionInformation.
private TagTreeDecoder[]	TTZeroBitPlanes Definition in PacketHeaderDataDecoder.TTZeroBitPlanes.
private int[][][]	zeroBitPlanes

Constructor Summary

PacketHeadersDecoder(int[][][][][][] imageStructure)
Constructor.

PacketHeadersDecoder(int[][][][][][] imageStructure, boolean sop, boolean eph)
Constructor.

Method Summary

private int	DecodeCodingPasses() Decodify the coding passes
private int	DecodeLblock() Decodify the Lblock value
private int[]	DecodeLengths(int lblock, int codingPasses) Decodify the length of codeword segment
private int	getBit() Returns the bit readed from the file.
int[][][]	getZeroBitPlanes(long inClassIdentifier) Returns the zero bit planes for a tile-component-resolution-precinct.
void	list(java.io.PrintStream out) Prints this Packet headers Decoder's fields to the specified output stream.
int[][][][]	packetHeaderDecoding(BufferedDataInputStream PHDataInputStream, long inClassIdentifier, int z, int rLevel, int precinct) Decodes the packet header for a precinct of a given layer, z, rLevel, precinct
private void	readEPH(BufferedDataInputStream PHDataInputStream) To read EPH marker if it is used
private void	readSOP(BufferedDataInputStream PHDataInputStream) To position the file pointer just before the first PacketHeader
void	reset() Sets the internal attributes (states) to its initial values.
java.lang.String	toString() (non-Javadoc)

Methods inherited from class java.lang.Object

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

Field Detail

imageStructure

private int[][][][][][] imageStructure

Is the image structure. Indices means:
z: image component
resolutionLevel: 0 is the LL subband, and 1, 2, ... represents next starting with the little one
precinct: precinct in the resolution level
subband: 0 - HL, 1 - LH, 2 - HH (ifresolutionLevel == 0 --> 0 - LL)
yBlock: block row in the subband
xBlock: block column in the subband

PHDataInputStream

private PacketHeaderDataInputStream PHDataInputStream

Is a input stream where bits of packet headers will be read from.

SOP

private boolean SOP

Indicates whether the Start of Packet marker is in the codestream and it must be read.

EPH

private boolean EPH

Indicates whether the End of Packet marker is in the codestream and it must be read.

packetHeaders

private java.util.Hashtable<java.lang.Long,PacketHeaderDataDecoder> packetHeaders

This object is used to save the packet headers data objects. It uses the inClassIdentififer (see JPIPMessageHeader.inClassIdentifier) as a key.

TTInclusionInformation

private TagTreeDecoder[] TTInclusionInformation

Definition in PacketHeaderDataDecoder.TTInclusionInformation.

TTZeroBitPlanes

private TagTreeDecoder[] TTZeroBitPlanes

Definition in PacketHeaderDataDecoder.TTZeroBitPlanes.

lBlock

private int[][][] lBlock

Definition in PacketHeaderDataDecoder.lBlock.

firstLayer

private int[][][] firstLayer

Definition in PacketHeaderDataDecoder.firstLayer.

zeroBitPlanes

private int[][][] zeroBitPlanes

Nsop

private int Nsop

Packet sequence number. The first packet in a coded tile is assigned the value 0. When the maximum number -65535- is reached, the number rolls over to zero.

Valid values between 0 to 65535.

NsopInHeader

private int NsopInHeader

Constructor Detail

PacketHeadersDecoder

public PacketHeadersDecoder(int[][][][][][] imageStructure)

Constructor.

This constructor assumes Start Of Packet (SOP) and End of Packet Headers (EPH) are not used.

Parameters:

imageStructure - definition in imageStructure

PacketHeadersDecoder

public PacketHeadersDecoder(int[][][][][][] imageStructure,
                            boolean sop,
                            boolean eph)

Constructor.

Parameters:

imageStructure - definition in imageStructure

sop - definition in SOP

eph - definition in EPH

Method Detail

reset

public void reset()
           throws ErrorException

Sets the internal attributes (states) to its initial values.

Throws:

ErrorException - when the internal attributes cannot be reseted.

packetHeaderDecoding

public int[][][][] packetHeaderDecoding(BufferedDataInputStream PHDataInputStream,
                                        long inClassIdentifier,
                                        int z,
                                        int rLevel,
                                        int precinct)
                                 throws ErrorException,
                                        java.io.EOFException,
                                        java.io.IOException

Decodes the packet header for a precinct of a given layer, z, rLevel, precinct

Parameters:

PHDataInputStream - a input stream where packet header is read from.

inClassIdentifier - definition in JPIPMessageHeader.inClassIdentifier.

layer - Layer

z - Component

rLevel - Resolution level

precinct - Precinct

Returns:

A vector which will contain the data length for a given subband, yBlock, xBlock and coding pass The index are: [subband][yBlock][xBlock][codingPasses] = data length

Throws:

ErrorException - when the packet header is corrupted

java.io.EOFException - if the end of the input stream has been reached.

java.io.IOException - if a I/O error has ocurred.

getZeroBitPlanes

public int[][][] getZeroBitPlanes(long inClassIdentifier)
                           throws java.lang.IllegalAccessException

Returns the zero bit planes for a tile-component-resolution-precinct.

Parameters:

inClassIdentifier -

Returns:

definition in PacketHeaderDataDecoder.zeroBitPlanes

Throws:

java.lang.IllegalAccessException

toString

public java.lang.String toString()

(non-Javadoc)

Overrides:

toString in class java.lang.Object

See Also:

Object.toString()

list

public void list(java.io.PrintStream out)

Prints this Packet headers Decoder's fields to the specified output stream. This method is useful for debugging.

Parameters:

out - an output stream.

DecodeLblock

private int DecodeLblock()
                  throws java.io.EOFException,
                         java.io.IOException

Decodify the Lblock value

Returns:

lblock value

Throws:

ErrorException - when the packet header is corrupted

java.io.EOFException

java.io.IOException

DecodeLengths

private int[] DecodeLengths(int lblock,
                            int codingPasses)
                     throws java.io.EOFException,
                            java.io.IOException

Decodify the length of codeword segment

Parameters:

lblock - current value

codingPasses - coding passes number of the codeblock

Returns:

length of code-block

Throws:

ErrorException - when the packet header is corrupted

java.io.EOFException

java.io.IOException

DecodeCodingPasses

private int DecodeCodingPasses()
                        throws java.io.EOFException,
                               java.io.IOException

Decodify the coding passes

Returns:

coding passes

Throws:

ErrorException - when the packet header is corrupted

java.io.EOFException

java.io.IOException

readSOP

private void readSOP(BufferedDataInputStream PHDataInputStream)
              throws ErrorException,
                     java.io.EOFException,
                     java.io.IOException

To position the file pointer just before the first PacketHeader

Throws:

ErrorException - when the file cannot be load

java.io.EOFException

java.io.IOException

readEPH

private void readEPH(BufferedDataInputStream PHDataInputStream)
              throws ErrorException,
                     java.io.EOFException,
                     java.io.IOException

To read EPH marker if it is used

Throws:

ErrorException - when the file cannot be load

java.io.EOFException

java.io.IOException

getBit

private int getBit()
            throws java.io.EOFException,
                   java.io.IOException

Returns the bit readed from the file.

Returns:

an integer that represents the bit readed from the file

Throws:

java.io.EOFException

java.io.IOException