001: /*
002: * $RCSfile: EntropyDecoder.java,v $
003: * $Revision: 1.1 $
004: * $Date: 2005/02/11 05:02:06 $
005: * $State: Exp $
006: *
007: * Class: EntropyDecoder
008: *
009: * Description: The abstract class for all entropy decoders.
010: *
011: *
012: *
013: * COPYRIGHT:
014: *
015: * This software module was originally developed by Raphaël Grosbois and
016: * Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel
017: * Askelöf (Ericsson Radio Systems AB); and Bertrand Berthelot, David
018: * Bouchard, Félix Henry, Gerard Mozelle and Patrice Onno (Canon Research
019: * Centre France S.A) in the course of development of the JPEG2000
020: * standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This
021: * software module is an implementation of a part of the JPEG 2000
022: * Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio
023: * Systems AB and Canon Research Centre France S.A (collectively JJ2000
024: * Partners) agree not to assert against ISO/IEC and users of the JPEG
025: * 2000 Standard (Users) any of their rights under the copyright, not
026: * including other intellectual property rights, for this software module
027: * with respect to the usage by ISO/IEC and Users of this software module
028: * or modifications thereof for use in hardware or software products
029: * claiming conformance to the JPEG 2000 Standard. Those intending to use
030: * this software module in hardware or software products are advised that
031: * their use may infringe existing patents. The original developers of
032: * this software module, JJ2000 Partners and ISO/IEC assume no liability
033: * for use of this software module or modifications thereof. No license
034: * or right to this software module is granted for non JPEG 2000 Standard
035: * conforming products. JJ2000 Partners have full right to use this
036: * software module for his/her own purpose, assign or donate this
037: * software module to any third party and to inhibit third parties from
038: * using this software module for non JPEG 2000 Standard conforming
039: * products. This copyright notice must be included in all copies or
040: * derivative works of this software module.
041: *
042: * Copyright (c) 1999/2000 JJ2000 Partners.
043: * */
044: package jj2000.j2k.entropy.decoder;
045:
046: import jj2000.j2k.quantization.dequantizer.*;
047: import jj2000.j2k.codestream.reader.*;
048: import jj2000.j2k.wavelet.synthesis.*;
049: import jj2000.j2k.codestream.*;
050: import jj2000.j2k.entropy.*;
051: import jj2000.j2k.image.*;
052: import jj2000.j2k.io.*;
053: import jj2000.j2k.*;
054: import java.io.*;
055:
056: /**
057: * This is the abstract class from which all entropy decoders must
058: * inherit. This class implements the 'MultiResImgData', therefore it has the
059: * concept of a current tile and all operations are performed on the current
060: * tile.
061: *
062: * <P>Default implementations of the methods in 'MultiResImgData' are provided
063: * through the 'MultiResImgDataAdapter' abstract class.
064: *
065: * <P>Sign magnitude representation is used (instead of two's complement) for
066: * the output data. The most significant bit is used for the sign (0 if
067: * positive, 1 if negative). Then the magnitude of the quantized coefficient
068: * is stored in the next most significat bits. The most significant magnitude
069: * bit corresponds to the most significant bit-plane and so on.
070: *
071: * @see MultiResImgData
072: * @see MultiResImgDataAdapter
073: * */
074: public abstract class EntropyDecoder extends MultiResImgDataAdapter
075: implements CBlkQuantDataSrcDec {
076:
077: /** The prefix for entropy decoder optiojns: 'C' */
078: public final static char OPT_PREFIX = 'C';
079:
080: /** The list of parameters that is accepted by the entropy
081: * decoders. They start with 'C'. */
082: private final static String[][] pinfo = {
083: {
084: "Cverber",
085: "[true|false]",
086: "Specifies if the entropy decoder should be verbose about detected "
087: + "errors. If 'true' a message is printed whenever an error is detected.",
088: "true" },
089: {
090: "Cer",
091: "[true|false]",
092: "Specifies if error detection should be performed by the entropy "
093: + "decoder engine. If errors are detected they will be concealed and "
094: + "the resulting distortion will be less important. Note that errors "
095: + "can only be detected if the encoder that generated the data "
096: + "included error resilience information.",
097: "true" }, };
098:
099: /** The bit stream transport from where to get the compressed data
100: * (the source) */
101: protected CodedCBlkDataSrcDec src;
102:
103: /**
104: * Initializes the source of compressed data.
105: *
106: * @param src From where to obtain the compressed data.
107: * */
108: public EntropyDecoder(CodedCBlkDataSrcDec src) {
109: super (src);
110: this .src = src;
111: }
112:
113: /**
114: * Returns the subband tree, for the specified tile-component. This method
115: * returns the root element of the subband tree structure, see Subband and
116: * SubbandSyn. The tree comprises all the available resolution levels.
117: *
118: * <P>The number of magnitude bits ('magBits' member variable) for
119: * each subband is not initialized.
120: *
121: * @param t The index of the tile, from 0 to T-1.
122: *
123: * @param c The index of the component, from 0 to C-1.
124: *
125: * @return The root of the tree structure.
126: * */
127:
128: public SubbandSyn getSynSubbandTree(int t, int c) {
129: return src.getSynSubbandTree(t, c);
130: }
131:
132: /**
133: * Returns the horizontal code-block partition origin. Allowable values
134: * are 0 and 1, nothing else.
135: * */
136: public int getCbULX() {
137: return src.getCbULX();
138: }
139:
140: /**
141: * Returns the vertical code-block partition origin. Allowable values are
142: * 0 and 1, nothing else.
143: * */
144: public int getCbULY() {
145: return src.getCbULY();
146: }
147:
148: /**
149: * Returns the parameters that are used in this class and
150: * implementing classes. It returns a 2D String array. Each of the
151: * 1D arrays is for a different option, and they have 3
152: * elements. The first element is the option name, the second one
153: * is the synopsis and the third one is a long description of what
154: * the parameter is. The synopsis or description may be 'null', in
155: * which case it is assumed that there is no synopsis or
156: * description of the option, respectively. Null may be returned
157: * if no options are supported.
158: *
159: * @return the options name, their synopsis and their explanation,
160: * or null if no options are supported.
161: * */
162: public static String[][] getParameterInfo() {
163: return pinfo;
164: }
165:
166: }
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