    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.read2Bytes;
    020import static org.apache.commons.imaging.common.BinaryFunctions.readByte;
    021
    022import java.io.ByteArrayInputStream;
    023import java.io.IOException;
    024import java.io.InputStream;
    025import java.util.logging.Level;
    026import java.util.logging.Logger;
    027
    028import org.apache.commons.imaging.ImagingException;
    029import org.apache.commons.imaging.common.Allocator;
    030import org.apache.commons.imaging.formats.jpeg.JpegConstants;
    031
    032public final class SofnSegment extends AbstractSegment {
    033
    034    public static class Component {
    035        static final int SHALLOW_SIZE = 32;
    036        public final int componentIdentifier;
    037        public final int horizontalSamplingFactor;
    038        public final int verticalSamplingFactor;
    039        public final int quantTabDestSelector;
    040
    041        public Component(final int componentIdentifier, final int horizontalSamplingFactor, final int veritcalSamplingFactor, final int quantTabDestSelector) {
    042            this.componentIdentifier = componentIdentifier;
    043            this.horizontalSamplingFactor = horizontalSamplingFactor;
    044            this.verticalSamplingFactor = veritcalSamplingFactor;
    045            this.quantTabDestSelector = quantTabDestSelector;
    046        }
    047    }
    048
    049    private static final Logger LOGGER = Logger.getLogger(SofnSegment.class.getName());
    050    public final int width;
    051    public final int height;
    052    public final int numberOfComponents;
    053    public final int precision;
    054
    055    private final Component[] components;
    056
    057    public SofnSegment(final int marker, final byte[] segmentData) throws IOException, ImagingException {
    058        this(marker, segmentData.length, new ByteArrayInputStream(segmentData));
    059    }
    060
    061    public SofnSegment(final int marker, final int markerLength, final InputStream is) throws IOException, ImagingException {
    062        super(marker, markerLength);
    063
    064        if (LOGGER.isLoggable(Level.FINEST)) {
    065            LOGGER.finest("SOF0Segment markerLength: " + markerLength);
    066        }
    067
    068        precision = readByte("precision", is, "Not a Valid JPEG File");
    069        height = read2Bytes("height", is, "Not a Valid JPEG File", getByteOrder());
    070        width = read2Bytes("width", is, "Not a Valid JPEG File", getByteOrder());
    071        numberOfComponents = readByte("numberOfComponents", is, "Not a Valid JPEG File");
    072        if (numberOfComponents < 0) {
    073            throw new ImagingException("The number of components in a SOF0Segment cannot be less than 0!");
    074        }
    075        components = Allocator.array(numberOfComponents, Component[]::new, Component.SHALLOW_SIZE);
    076        for (int i = 0; i < numberOfComponents; i++) {
    077            final int componentIdentifier = readByte("ComponentIdentifier", is, "Not a Valid JPEG File");
    078
    079            final int hvSamplingFactors = readByte("SamplingFactors", is, "Not a Valid JPEG File");
    080            final int horizontalSamplingFactor = hvSamplingFactors >> 4 & 0xf;
    081            final int verticalSamplingFactor = hvSamplingFactors & 0xf;
    082            final int quantTabDestSelector = readByte("QuantTabDestSel", is, "Not a Valid JPEG File");
    083            components[i] = new Component(componentIdentifier, horizontalSamplingFactor, verticalSamplingFactor, quantTabDestSelector);
    084        }
    085    }
    086
    087    /**
    088     * Returns a copy of all the components.
    089     *
    090     * @return the components
    091     */
    092    public Component[] getComponents() {
    093        return components.clone();
    094    }
    095
    096    /**
    097     * Returns the component at the specified index.
    098     *
    099     * @param index the array index
    100     * @return the component
    101     */
    102    public Component getComponents(final int index) {
    103        return components[index];
    104    }
    105
    106    @Override
    107    public String getDescription() {
    108        return "SOFN (SOF" + (marker - JpegConstants.SOF0_MARKER) + ") (" + getSegmentType() + ")";
    109    }
    110
    111}