    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.imaging.formats.jpeg.segments;
    018
    019import static org.apache.commons.imaging.common.BinaryFunctions.readByte;
    020
    021import java.io.ByteArrayInputStream;
    022import java.io.IOException;
    023import java.io.InputStream;
    024import java.util.logging.Level;
    025import java.util.logging.Logger;
    026
    027import org.apache.commons.imaging.common.Allocator;
    028
    029public final class SosSegment extends AbstractSegment {
    030
    031    public static class Component {
    032        static final int SHALLOW_SIZE = 24;
    033        public final int scanComponentSelector;
    034        public final int dcCodingTableSelector;
    035        public final int acCodingTableSelector;
    036
    037        public Component(final int scanComponentSelector, final int dcCodingTableSelector, final int acCodingTableSelector) {
    038            this.scanComponentSelector = scanComponentSelector;
    039            this.dcCodingTableSelector = dcCodingTableSelector;
    040            this.acCodingTableSelector = acCodingTableSelector;
    041        }
    042    }
    043
    044    private static final Logger LOGGER = Logger.getLogger(SosSegment.class.getName());
    045    public final int numberOfComponents;
    046    private final Component[] components;
    047    public final int startOfSpectralSelection;
    048    public final int endOfSpectralSelection;
    049    public final int successiveApproximationBitHigh;
    050
    051    public final int successiveApproximationBitLow;
    052
    053    public SosSegment(final int marker, final byte[] segmentData) throws IOException {
    054        this(marker, segmentData.length, new ByteArrayInputStream(segmentData));
    055    }
    056
    057    public SosSegment(final int marker, final int markerLength, final InputStream is) throws IOException {
    058        super(marker, markerLength);
    059
    060        if (LOGGER.isLoggable(Level.FINEST)) {
    061            LOGGER.finest("SosSegment markerLength: " + markerLength);
    062        }
    063
    064        // Debug.debug("SOS", marker_length);
    065
    066        numberOfComponents = readByte("numberOfComponents", is, "Not a Valid JPEG File");
    067        // Debug.debug("number_of_components_in_scan",
    068        // numberOfComponents);
    069
    070        components = Allocator.array(numberOfComponents, Component[]::new, Component.SHALLOW_SIZE);
    071        for (int i = 0; i < numberOfComponents; i++) {
    072            final int scanComponentSelector = readByte("scanComponentSelector", is, "Not a Valid JPEG File");
    073            // Debug.debug("scanComponentSelector", scanComponentSelector);
    074
    075            final int acDcEntropyCodingTableSelector = readByte("acDcEntropyCodingTableSelector", is, "Not a Valid JPEG File");
    076            // Debug.debug("ac_dc_entrooy_coding_table_selector",
    077            // acDcEntropyCodingTableSelector);
    078
    079            final int dcCodingTableSelector = acDcEntropyCodingTableSelector >> 4 & 0xf;
    080            final int acCodingTableSelector = acDcEntropyCodingTableSelector & 0xf;
    081            components[i] = new Component(scanComponentSelector, dcCodingTableSelector, acCodingTableSelector);
    082        }
    083
    084        startOfSpectralSelection = readByte("startOfSpectralSelection", is, "Not a Valid JPEG File");
    085        // Debug.debug("start_of_spectral_selection", startOfSpectralSelection);
    086        endOfSpectralSelection = readByte("endOfSpectralSelection", is, "Not a Valid JPEG File");
    087        // Debug.debug("end_of_spectral_selection", endOfSpectralSelection);
    088        final int successiveApproximationBitPosition = readByte("successiveApproximationBitPosition", is, "Not a Valid JPEG File");
    089        // Debug.debug("successive_approximation_bit_position",
    090        // successive_approximation_bit_position);
    091        successiveApproximationBitHigh = successiveApproximationBitPosition >> 4 & 0xf;
    092        successiveApproximationBitLow = successiveApproximationBitPosition & 0xf;
    093    }
    094
    095    /**
    096     * Returns a copy of all the components.
    097     *
    098     * @return all the components
    099     */
    100    public Component[] getComponents() {
    101        return components.clone();
    102    }
    103
    104    /**
    105     * Gets a component at the specified index.
    106     *
    107     * @param index the component index
    108     * @return the component
    109     */
    110    public Component getComponents(final int index) {
    111        return components[index];
    112    }
    113
    114    @Override
    115    public String getDescription() {
    116        return "SOS (" + getSegmentType() + ")";
    117    }
    118
    119}