org.javaseis.compress
Class TraceCompressor

java.lang.Object
  org.javaseis.compress.TraceCompressor

All Implemented Interfaces:

java.io.Serializable

public class TraceCompressor
extends java.lang.Object
implements java.io.Serializable

The jsTraceCompressor class provides compression support for (trace) data. For 16 or -8bit compression, the trace is divided into sample windows. The maximum value in each window is used to scale trace samples to 16 or 8-bits. The floating point scalars are stored in the buffer first, followed by the 16 or 8-bit trace samples. Methods are provided to position the buffer for compression or decompression in trace units.

Author:

Chuck Mosher.

See Also:

Serialized Form

Field Summary

protected byte[]	_buffer08
protected int	_buffer08LengthInFloats
protected char[]	_buffer16
protected int	_buffer16LengthInFloats
protected java.nio.ByteBuffer	_bufferViewByte
protected java.nio.FloatBuffer	_bufferViewFloat
protected java.nio.ShortBuffer	_bufferViewShort
protected int	_bytesPerSample
protected int	_numSamples
protected int	_numSamplesX
protected int	_numWindows
protected int	_recordLengthInBytes
protected int	_recordLengthInFloats
protected int	_recordLengthInShorts
protected float[]	_scalars
protected int	_scalarsLengthInBytes
protected int	_scalarsLengthInShorts
protected byte[]	_traceDataByte
protected short[]	_traceDataShort
protected DataFormat	_traceFormat
protected int	_tracePosition
protected static int	CLIPPING_MAX_INT08
protected static int	CLIPPING_MAX_INT16
protected static int	CLIPPING_MIN_INT08
protected static int	CLIPPING_MIN_INT16
protected static int	WNDWLEN08
protected static int	WNDWLEN16

Constructor Summary

TraceCompressor(DataFormat traceFormat, int numSamples, java.nio.ByteBuffer bufferByte)
Constructs an instace of jsTraceCompressor.

Method Summary

protected void	arrayCopyByteToFloat(int numSamples, byte[] traceIn, float[] traceOut) Copies trace data from byte array to float array.
protected void	arrayCopyFloatToByte(int numSamples, float[] traceIn, byte[] traceOut) Copies trace data from float array to byte array (clipping if necessary).
protected void	arrayCopyFloatToShort(int numSamples, float[] traceIn, short[] traceOut) Copies trac edata from byte array to float array.
protected void	arrayCopyShortToFloat(int numSamples, short[] traceIn, float[] traceOut) Copies trace data from short array to float array.
int	getPosition() Gets the buffer position in trace units.
static int	getRecordLength(DataFormat traceFormat, int numSamples) Gets the record length in bytes.
static void	main(java.lang.String[] args) The "main" method used for testing.
void	packFrame(int numTraces, float[][] traceData) Packs frame data into compression buffer.
void	packTrace(float[] traceData) Packs trace data into DataFormat.FLOAT,INT16,INT08 buffer.
void	packTrace08(float[] traceData) Packs trace data into DataFormat.COMPRESSED_INT08 buffer.
void	packTrace16(float[] traceData) Packs trace data into DataFormat.COMPRESSED_INT16 buffer.
int	setPosition(int tracePosition) Sets the buffer position in trace units.
void	unpackFrame(int numTraces, float[][] traceData) Unpacks frame data from compression buffer.
void	unpackTrace(float[] traceData) Unpacks trace data from DataFormat.FLOAT,INT16,INT08 buffer.
void	unpackTrace08(float[] traceData) Unpacks trace data from DataFormat.COMPRESSED_INT08 buffer.
void	unpackTrace16(float[] traceData) Unpacks trace data from DataFormat.COMPRESSED_INT16 buffer.

Methods inherited from class java.lang.Object

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

Field Detail

_buffer08

protected byte[] _buffer08

_buffer08LengthInFloats

protected int _buffer08LengthInFloats

_buffer16

protected char[] _buffer16

_buffer16LengthInFloats

protected int _buffer16LengthInFloats

_bufferViewByte

protected java.nio.ByteBuffer _bufferViewByte

_bufferViewFloat

protected java.nio.FloatBuffer _bufferViewFloat

_bufferViewShort

protected java.nio.ShortBuffer _bufferViewShort

_bytesPerSample

protected int _bytesPerSample

_numSamples

protected int _numSamples

_numSamplesX

protected int _numSamplesX

_numWindows

protected int _numWindows

_recordLengthInBytes

protected int _recordLengthInBytes

_recordLengthInFloats

protected int _recordLengthInFloats

_recordLengthInShorts

protected int _recordLengthInShorts

_scalars

protected float[] _scalars

_scalarsLengthInBytes

protected int _scalarsLengthInBytes

_scalarsLengthInShorts

protected int _scalarsLengthInShorts

_traceDataByte

protected byte[] _traceDataByte

_traceDataShort

protected short[] _traceDataShort

_traceFormat

protected DataFormat _traceFormat

_tracePosition

protected int _tracePosition

CLIPPING_MAX_INT08

protected static final int CLIPPING_MAX_INT08

See Also:

Constant Field Values

CLIPPING_MAX_INT16

protected static final int CLIPPING_MAX_INT16

See Also:

Constant Field Values

CLIPPING_MIN_INT08

protected static final int CLIPPING_MIN_INT08

See Also:

Constant Field Values

CLIPPING_MIN_INT16

protected static final int CLIPPING_MIN_INT16

See Also:

Constant Field Values

WNDWLEN08

protected static int WNDWLEN08

WNDWLEN16

protected static int WNDWLEN16

Constructor Detail

TraceCompressor

public TraceCompressor(DataFormat traceFormat,
                       int numSamples,
                       java.nio.ByteBuffer bufferByte)

Constructs an instace of jsTraceCompressor.

Parameters:

traceFormat - The format type (i.e. DataFormat.INT16, etc).

numSamples - The number of samples per trace.

bufferByte - The buffer used to store compressed trace data.

Method Detail

arrayCopyByteToFloat

protected void arrayCopyByteToFloat(int numSamples,
                                    byte[] traceIn,
                                    float[] traceOut)

Copies trace data from byte array to float array.

Parameters:

numSamples - The number of samples in the arrays.

traceIn - The input byte array.

traceOut - The output float array.

arrayCopyFloatToByte

protected void arrayCopyFloatToByte(int numSamples,
                                    float[] traceIn,
                                    byte[] traceOut)

Copies trace data from float array to byte array (clipping if necessary).

Parameters:

numSamples - The number of samples in the arrays.

traceIn - The input float array.

traceOut - The output byte array.

arrayCopyFloatToShort

protected void arrayCopyFloatToShort(int numSamples,
                                     float[] traceIn,
                                     short[] traceOut)

Copies trac edata from byte array to float array.

Parameters:

numSamples - The number of samples in the arrays.

traceIn - The input byte array.

traceOut - The output float array.

arrayCopyShortToFloat

protected void arrayCopyShortToFloat(int numSamples,
                                     short[] traceIn,
                                     float[] traceOut)

Copies trace data from short array to float array.

Parameters:

numSamples - The number of samples in the arrays.

traceIn - The input short array.

traceOut - The output float array.

getPosition

public int getPosition()

Gets the buffer position in trace units.

Returns:

The buffer position in trace units.

getRecordLength

public static int getRecordLength(DataFormat traceFormat,
                                  int numSamples)
                           throws SeisException

Gets the record length in bytes.

Parameters:

traceFormat - The trace format.

numSamples - The number of samples per trace.

Returns:

The record length in bytes.

Throws:

SeisException

main

public static void main(java.lang.String[] args)
                 throws SeisException

The "main" method used for testing.

Parameters:

args - The arguments for testing.

Throws:

SeisException - Thrown on testing errors.

packFrame

public void packFrame(int numTraces,
                      float[][] traceData)

Packs frame data into compression buffer.

Parameters:

traceData - The array of frame data to compress.

packTrace

public void packTrace(float[] traceData)

Packs trace data into DataFormat.FLOAT,INT16,INT08 buffer.

Parameters:

traceData - The array of trace data to compress.

packTrace08

public void packTrace08(float[] traceData)

Packs trace data into DataFormat.COMPRESSED_INT08 buffer.

Parameters:

traceData - The array of trace data to compress.

packTrace16

public void packTrace16(float[] traceData)

Packs trace data into DataFormat.COMPRESSED_INT16 buffer.

Parameters:

traceData - The array of trace data to compress.

setPosition

public int setPosition(int tracePosition)

Sets the buffer position in trace units.

Parameters:

tracePosition - The desired buffer position in trace units.

Returns:

The buffer position in trace units.

unpackFrame

public void unpackFrame(int numTraces,
                        float[][] traceData)

Unpacks frame data from compression buffer.

Parameters:

traceData - The array to contain decompressed frame data.

unpackTrace

public void unpackTrace(float[] traceData)

Unpacks trace data from DataFormat.FLOAT,INT16,INT08 buffer.

Parameters:

traceData - The array to contain decompressed trace data.

unpackTrace08

public void unpackTrace08(float[] traceData)

Unpacks trace data from DataFormat.COMPRESSED_INT08 buffer.

Parameters:

traceData - The array to contain decompressed trace data.

unpackTrace16

public void unpackTrace16(float[] traceData)

Unpacks trace data from DataFormat.COMPRESSED_INT16 buffer.

Parameters:

traceData - The array to contain decompressed trace data.