src/main/java/org/apache/commons/sanselan/formats/jpeg/segments/Segment.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.sanselan.formats.jpeg.segments;

import java.io.PrintWriter;

import org.apache.commons.sanselan.common.BinaryFileParser;

public abstract class Segment extends BinaryFileParser
{
    public final int marker;
    public final int length;

    public Segment(int marker, int length)
    {
        //        super();

        this.marker = marker;
        this.length = length;
    }

    public void dump(PrintWriter pw)
    {
    }

    public abstract String getDescription();

    @Override
    public String toString()
    {
        return "[Segment: " + getDescription() + "]";
    }

    public String getSegmentType()
    {

        switch (marker)
        {
            case 0xffc0 :
                return "Start Of Frame, Baseline Dct, Huffman coding";
            case 0xffc1 :
                return "Start Of Frame, Extended sequential Dct, Huffman coding";
            case 0xffc2 :
                return "Start Of Frame, Progressive Dct, Huffman coding";
            case 0xffc3 :
                return "Start Of Frame, Lossless (sequential), Huffman coding";

            case 0xffc5 :
                return "Start Of Frame, Differential sequential Dct, Huffman coding";
            case 0xffc6 :
                return "Start Of Frame, Differential progressive Dct, Huffman coding";
            case 0xffc7 :
                return "Start Of Frame, Differential lossless (sequential), Huffman coding";

            case 0xffc8 :
                return "Start Of Frame, Reserved for JPEG extensions, arithmetic coding";
            case 0xffc9 :
                return "Start Of Frame, Extended sequential Dct, arithmetic coding";
            case 0xffca :
                return "Start Of Frame, Progressive Dct, arithmetic coding";
            case 0xffcb :
                return "Start Of Frame, Lossless (sequential), arithmetic coding";

            case 0xffcd :
                return "Start Of Frame, Differential sequential Dct, arithmetic coding";
            case 0xffce :
                return "Start Of Frame, Differential progressive Dct, arithmetic coding";
            case 0xffcf :
                return "Start Of Frame, Differential lossless (sequential), arithmetic coding";

            case 0xffc4 :
                return "Define Huffman table(s)";
            case 0xffcc :
                return "Define arithmetic coding conditioning(s)";

            case 0xffd0 :
                return "Restart with modulo 8 count 0";
            case 0xffd1 :
                return "Restart with modulo 8 count 1";
            case 0xffd2 :
                return "Restart with modulo 8 count 2";
            case 0xffd3 :
                return "Restart with modulo 8 count 3";
            case 0xffd4 :
                return "Restart with modulo 8 count 4";
            case 0xffd5 :
                return "Restart with modulo 8 count 5";
            case 0xffd6 :
                return "Restart with modulo 8 count 6";
            case 0xffd7 :
                return "Restart with modulo 8 count 7";

            case 0xffd8 :
                return "Start of image";
            case 0xffd9 :
                return "End of image";
            case 0xffda :
                return "Start of scan";
            case 0xffdb :
                return "Define quantization table(s)";
            case 0xffdc :
                return "Define number of lines";
            case 0xffdd :
                return "Define restart interval";
            case 0xffde :
                return "Define hierarchical progression";
            case 0xffdf :
                return "Expand reference component(s)";
                //            case 0xffd8 :
                //                return "Reserved for application segments";
                //            case 0xffd8 :
                //                return "Reserved for JPEG extensions";
            case 0xfffe :
                return "Comment";
            case 0xff01 :
                return "For temporary private use in arithmetic coding";
                //            case 0xffd8 :
                //                return "Reserved";

            default :
        }

        if ((marker >= 0xff02) && (marker <= 0xffbf))
            return "Reserved";
        if ((marker >= 0xffe0) && (marker <= 0xffef))
            return "APP" + (marker - 0xffe0);
        if ((marker >= 0xfff0) && (marker <= 0xfffd))
            return "JPG" + (marker - 0xffe0);

        return "Unknown";

    }

}