com.colloquial.arithcode
Class TokenStreamEncoder

java.lang.Object
  |
  +--com.colloquial.arithcode.TokenStreamEncoder

public final class TokenStreamEncoder

extends java.lang.Object

Model of a sequence of tokens. Limited to 256 distinct tokens (to enable coding as PPM).

Field Summary

private ArithEncoder	_encoder Arithmetic encoder used for encoding symbols and the bytes making them up.
private int[]	_interval Interval used for coding ranges.
private int	_nextTokenIndex Index of next token, which must fall between 0 and 255 inclusive.
private PPMModel	_tokenBytesModel MOdel for the bytes making up the tokens.
private PPMModel	_tokenSequenceModel Model for the sequence of tokens, encoded as bytes, making up the token stream.
private java.util.HashMap	_tokenToSymbolMap Maps each token string to an Integer used to encode it.
private static java.lang.String	LATIN1
private static ByteSet	LATIN1_UNUSED_BYTES

Constructor Summary

TokenStreamEncoder(ArithEncoder encoder, int tokenSequenceOrder, PPMModel tokenBytesModel)

Method Summary

private void	encode(PPMModel model, int symbol)
void	encode(java.lang.String token)
private void	encodeBytes(byte[] bytes)
private void	encodeToken(int symbol)

Methods inherited from class java.lang.Object

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

Field Detail

_encoder

private final ArithEncoder _encoder

Arithmetic encoder used for encoding symbols and the bytes making them up.

_interval

private final int[] _interval

Interval used for coding ranges.

_nextTokenIndex

private int _nextTokenIndex

Index of next token, which must fall between 0 and 255 inclusive.

_tokenBytesModel

private final PPMModel _tokenBytesModel

MOdel for the bytes making up the tokens.

_tokenSequenceModel

private final PPMModel _tokenSequenceModel

Model for the sequence of tokens, encoded as bytes, making up the token stream.

_tokenToSymbolMap

private final java.util.HashMap _tokenToSymbolMap

Maps each token string to an Integer used to encode it.

LATIN1

private static final java.lang.String LATIN1

See Also:

Constant Field Values

LATIN1_UNUSED_BYTES

private static final ByteSet LATIN1_UNUSED_BYTES

Constructor Detail

TokenStreamEncoder

public TokenStreamEncoder(ArithEncoder encoder,
                          int tokenSequenceOrder,
                          PPMModel tokenBytesModel)

Method Detail

encode

public void encode(java.lang.String token)
            throws java.io.IOException

java.io.IOException

encodeToken

private void encodeToken(int symbol)
                  throws java.io.IOException

java.io.IOException

encodeBytes

private void encodeBytes(byte[] bytes)
                  throws java.io.IOException

java.io.IOException

encode

private void encode(PPMModel model,
                    int symbol)
             throws java.io.IOException

java.io.IOException