    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.formats.jpeg.JpegConstants;
    029
    030public class SofnSegment extends Segment {
    031
    032    private static final Logger LOGGER = Logger.getLogger(SofnSegment.class.getName());
    033
    034    public final int width;
    035    public final int height;
    036    public final int numberOfComponents;
    037    public final int precision;
    038    private final Component[] components;
    039
    040    public static class Component {
    041        public final int componentIdentifier;
    042        public final int horizontalSamplingFactor;
    043        public final int verticalSamplingFactor;
    044        public final int quantTabDestSelector;
    045
    046        public Component(final int componentIdentifier, final int horizontalSamplingFactor,
    047                final int veritcalSamplingFactor, final int quantTabDestSelector) {
    048            this.componentIdentifier = componentIdentifier;
    049            this.horizontalSamplingFactor = horizontalSamplingFactor;
    050            this.verticalSamplingFactor = veritcalSamplingFactor;
    051            this.quantTabDestSelector = quantTabDestSelector;
    052        }
    053    }
    054
    055    public SofnSegment(final int marker, final byte[] segmentData) throws IOException {
    056        this(marker, segmentData.length, new ByteArrayInputStream(segmentData));
    057    }
    058
    059    public SofnSegment(final int marker, final int markerLength, final InputStream is)
    060            throws IOException {
    061        super(marker, markerLength);
    062
    063        if (LOGGER.isLoggable(Level.FINEST)) {
    064            LOGGER.finest("SOF0Segment marker_length: " + markerLength);
    065        }
    066
    067        precision = readByte("Data_precision", is, "Not a Valid JPEG File");
    068        height = read2Bytes("Image_height", is, "Not a Valid JPEG File", getByteOrder());
    069        width = read2Bytes("Image_Width", is, "Not a Valid JPEG File", getByteOrder());
    070        numberOfComponents = readByte("Number_of_components", is,
    071                "Not a Valid JPEG File");
    072        components = new Component[numberOfComponents];
    073        for (int i = 0; i < numberOfComponents; i++) {
    074            final int componentIdentifier = readByte("ComponentIdentifier", is,
    075                    "Not a Valid JPEG File");
    076
    077            final int hvSamplingFactors = readByte("SamplingFactors", is,
    078                    "Not a Valid JPEG File");
    079            final int horizontalSamplingFactor = (hvSamplingFactors >> 4) & 0xf;
    080            final int verticalSamplingFactor = hvSamplingFactors & 0xf;
    081            final int quantTabDestSelector = readByte("QuantTabDestSel", is,
    082                    "Not a Valid JPEG File");
    083            components[i] = new Component(componentIdentifier,
    084                    horizontalSamplingFactor, verticalSamplingFactor,
    085                    quantTabDestSelector);
    086        }
    087    }
    088
    089    /**
    090     * Returns a copy of all the components.
    091     * @return the components
    092     */
    093    public Component[] getComponents() {
    094        return components.clone();
    095    }
    096
    097    /**
    098     * Returns the component at the specified index.
    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
    107    @Override
    108    public String getDescription() {
    109        return "SOFN (SOF" + (marker - JpegConstants.SOF0_MARKER) + ") ("
    110                + getSegmentType() + ")";
    111    }
    112
    113}