com.pixelmed.scpecg
Class HuffmanDecoder

java.lang.Object
  com.pixelmed.scpecg.HuffmanDecoder

public class HuffmanDecoder
extends Object

A class to implement Huffman decoding as used by the SCP-ECG standard.

See Also:

DefaultHuffmanTable, HuffmanTable

Constructor Summary

HuffmanDecoder(byte[] bytesToDecompress, int differenceDataUsed, int multiplier, int numberOfHuffmanTables, ArrayList huffmanTablesList)
Construct a Huffman decoder for the supplied encoded data, as read from an SCP-ECG file.

Method Summary

short	decode() Decode a single value.
short[]	decode(int nValuesWanted) Decode a specified number of values.
static void	main(String[] arg) For testing.
String	toString() Dump the current decoder state as a String.

Methods inherited from class java.lang.Object

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

Constructor Detail

HuffmanDecoder

public HuffmanDecoder(byte[] bytesToDecompress,
                      int differenceDataUsed,
                      int multiplier,
                      int numberOfHuffmanTables,
                      ArrayList huffmanTablesList)

Construct a Huffman decoder for the supplied encoded data, as read from an SCP-ECG file.

Parameters:

bytesToDecompress - the compressed data

differenceDataUsed - 0 = no, 1 = 1 difference value, 2 = 2 difference values

multiplier - a value by which to scale the decoded values

numberOfHuffmanTables - how many tables are available for use

huffmanTablesList - the Huffman tables themselves

Method Detail

decode

public final short decode()
                   throws Exception

Decode a single value.

Returns:

the decoded value

Throws:

Exception

decode

public final short[] decode(int nValuesWanted)
                     throws Exception

Decode a specified number of values.

Parameters:

nValuesWanted - the number of decoded values wanted

Returns:

the decoded values

Throws:

Exception

toString

public String toString()

Dump the current decoder state as a String.

Overrides:

toString in class Object

Returns:

the current decoder state as a String

main

public static void main(String[] arg)

For testing.

Decodes the byte stream in the example specified in the SCP-ECG standard.

Parameters:

arg - none