jj2000.j2k.encoder

Class Encoder

java.lang.Object

jj2000.j2k.encoder.Encoder

All Implemented Interfaces:

Runnable

public class Encoder
extends Object
implements Runnable

This class is the main class of JJ2000's encoder. It instantiates all objects of the chain and launchs the encoding process. It then writes the header and the compressed bit stream to the output file. Finally, packed packet headers (through codestream post-manipulation) and file-format may be created if needed.

First the encoder should be initialized with a ParameterList object provided through the constructor. Then, the run() method is invoked and the encoder executes. The exit code of the class can be obtained with the getExitCode() method, after the constructor and after the run method. A non-zero value indicates that an error has occurred.

The modules are inserted in the encoding chain with the following order:

• ImgReader
• ImgDataJoiner (if multiple image readers)
• Tiler
• ForwCompTransf
• ImgDataConverter
• ForwardWT
• Quantizer
• ROIScaler
• EntropyCoder
• PostCompRateAllocator

The encoder uses a pull model. This means that the last module (PostCompRateAllocator) requests data from its source (EntropyCoder), ...

Writing of the codestream writing (header+bit stream) is realized by HeaderEncoder and CodestreamWriter modules.

Packed packet headers and file-format creation are carried out by CodestreamManipulator and FileFormatWriter modules respectively.

Many modules of the encoder may behave differently depending on the tile-component. The specifications of their behaviour are kept in specialized modules extending ModuleSpec class. All these modules are accessible through an instance of EncoderSpecs class.

See Also:

ImgReader, ImgDataJoiner, ForwCompTransf, Tiler, ImgDataConverter, ForwardWT, Quantizer, ROIScaler, EntropyCoder, PostCompRateAllocator, HeaderEncoder, CodestreamWriter, CodestreamManipulator, FileFormatWriter, ModuleSpec, EncoderSpecs

Field Summary

Fields

Modifier and Type	Field and Description
static char[]	vprfxs The valid list of options prefixes

Constructor Summary

Constructors

Constructor and Description
Encoder(ParameterList pl) Instantiates an encoder object, width the ParameterList object given as argument.

Method Summary

Methods

Modifier and Type	Method and Description
static String[][]	getAllParameters() Returns all the parameters used in the encoding chain.
int	getExitCode() Returns the exit code of the class.
static String[][]	getParameterInfo() Returns the parameters that are used in this class and implementing classes.
void	run() Runs the encoder.

Methods inherited from class java.lang.Object

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

Field Detail

vprfxs

public static final char[] vprfxs

The valid list of options prefixes

Constructor Detail

Encoder

public Encoder(ParameterList pl)

Instantiates an encoder object, width the ParameterList object given as argument. It also retrieves the default ParameterList.

Parameters:

pl - The ParameterList for this decoder (contains also defaults values);

Method Detail

getExitCode

public int getExitCode()

Returns the exit code of the class. This is only initialized after the constructor and when the run method returns.

Returns:

The exit code of the constructor and the run() method.

run

public void run()

Runs the encoder. After completion the exit code is set, a non-zero value indicates that an error occurred.

Specified by:

run in interface Runnable

See Also:

getExitCode()

getParameterInfo

public static String[][] getParameterInfo()

Returns the parameters that are used in this class and implementing classes. It returns a 2D String array. Each of the 1D arrays is for a different option, and they have 4 elements. The first element is the option name, the second one is the synopsis, the third one is a long description of what the parameter is and the fourth is its default value. The synopsis or description may be 'null', in which case it is assumed that there is no synopsis or description of the option, respectively. Null may be returned if no options are supported.

Returns:

the options name, their synopsis and their explanation, or null if no options are supported.

getAllParameters

public static String[][] getAllParameters()

Returns all the parameters used in the encoding chain. It calls parameter from each module and store them in one array (one row per parameter and 4 columns).

Returns:

All encoding parameters

See Also:

getParameterInfo()