com.drew.metadata.heif.boxes.ItemLocationBox Maven / Gradle / Ivy

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Java library for extracting EXIF, IPTC, XMP, ICC and other metadata from image files.
There is a newer version: 2.19.0
/*
 * Copyright 2002-2019 Drew Noakes and contributors
 *
 *    Licensed 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.
 *
 * More information about this project is available at:
 *
 *    https://drewnoakes.com/code/exif/
 *    https://github.com/drewnoakes/metadata-extractor
 */
package com.drew.metadata.heif.boxes;

import com.drew.lang.SequentialReader;

import java.io.IOException;

/**
 * ISO/IEC 14496-12:2015 pg.77-80
 */
public class ItemLocationBox extends FullBox
{
    int indexSize;
    int offsetSize;
    int lengthSize;
    int baseOffsetSize;
    long itemCount;
    long itemID;
    int constructionMethod;
    int dataReferenceIndex;
    byte[] baseOffset;
    int extentCount;
    Extent[] extents;

    public ItemLocationBox(SequentialReader reader, Box box) throws IOException
    {
        super(reader, box);

        int holder = reader.getUInt8();
        offsetSize = (holder & 0xF0) >> 4;
        lengthSize = (holder & 0x0F);

        holder = reader.getUInt8();
        baseOffsetSize = (holder & 0xF0) >> 4;
        if ((version == 1) || (version == 2)) {
            indexSize = (holder & 0x0F);
        } else {
            // Reserved
        }
        if (version < 2) {
            itemCount = reader.getUInt16();
        } else if (version == 2) {
            itemCount = reader.getUInt32();
        }
        for (int i = 0; i < itemCount; i++) {
            if (version < 2) {
                itemID = reader.getUInt16();
            } else if (version == 2) {
                itemID = reader.getUInt32();
            }
            if ((version == 1) || (version == 2)) {
                holder = reader.getUInt16();
                constructionMethod = (holder & 0x000F);
            }
            dataReferenceIndex = reader.getUInt16();
            baseOffset = reader.getBytes(baseOffsetSize);
            extentCount = reader.getUInt16();

            Long extentIndex = null;
            long extentOffset;
            long extentLength;
            extents = new Extent[extentCount];
            for (int j = 0; j < extentCount; j++) {
                if ((version == 1) || (version == 2) && (indexSize > 0)) {
                    extentIndex = getIntFromUnknownByte(indexSize, reader);
                }
                extentOffset = getIntFromUnknownByte(offsetSize, reader);
                extentLength = getIntFromUnknownByte(lengthSize, reader);
                extents[j] = new Extent(extentIndex == null ? null : extentIndex, extentOffset, extentLength);
            }
        }
    }

    public Long getIntFromUnknownByte(int variable, SequentialReader reader) throws IOException
    {
        switch(variable) {
            case (1):
                return (long)reader.getUInt8();
            case (2):
                return (long)reader.getUInt16();
            case (4):
                return (long)reader.getUInt32();
            case (8):
                return reader.getInt64();
            default:
                return null;
        }
    }

    class Extent
    {
        Long index;
        long offset;
        long length;

        public Extent(Long index, long offset, long length) {
            this.index = index;
            this.offset = offset;
            this.length = length;
        }
    }
}