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/*
* Copyright 2012 Sebastian Annies, Hamburg
*
* 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.
*/
package com.coremedia.iso;
import com.coremedia.iso.boxes.Box;
import com.coremedia.iso.boxes.ContainerBox;
import com.coremedia.iso.boxes.UserBox;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.ReadableByteChannel;
import java.util.logging.Logger;
import static com.googlecode.mp4parser.util.CastUtils.l2i;
/**
* This BoxParser handles the basic stuff like reading size and extracting box type.
*/
public abstract class AbstractBoxParser implements BoxParser {
private static Logger LOG = Logger.getLogger(AbstractBoxParser.class.getName());
public abstract Box createBox(String type, byte[] userType, String parent);
/**
* Parses the next size and type, creates a box instance and parses the box's content.
*
* @param byteChannel the FileChannel pointing to the ISO file
* @param parent the current box's parent (null if no parent)
* @return the box just parsed
* @throws java.io.IOException if reading from <code>in</code> fails
*/
public Box parseBox(ReadableByteChannel byteChannel, ContainerBox parent) throws IOException {
ByteBuffer header = ChannelHelper.readFully(byteChannel, 8);
long size = IsoTypeReader.readUInt32(header);
// do plausibility check
if (size < 8 && size > 1) {
LOG.severe("Plausibility check failed: size < 8 (size = " + size + "). Stop parsing!");
return null;
}
String type = IsoTypeReader.read4cc(header);
byte[] usertype = null;
long contentSize;
if (size == 1) {
ByteBuffer bb = ByteBuffer.allocate(8);
byteChannel.read(bb);
bb.rewind();
size = IsoTypeReader.readUInt64(bb);
contentSize = size - 16;
} else if (size == 0) {
if (byteChannel instanceof FileChannel) {
size = ((FileChannel) byteChannel).size() - ((FileChannel) byteChannel).position() - 8;
} else {
throw new RuntimeException("Only FileChannel inputs may use size == 0 (box reaches to the end of file)");
}
contentSize = size - 8;
} else {
contentSize = size - 8;
}
if (UserBox.TYPE.equals(type)) {
ByteBuffer bb = ByteBuffer.allocate(16);
byteChannel.read(bb);
bb.rewind();
usertype = bb.array();
contentSize -= 16;
}
Box box = createBox(type, usertype, parent.getType());
box.setParent(parent);
LOG.finest("Parsing " + box.getType());
// System.out.println("parsing " + Arrays.toString(box.getType()) + " " + box.getClass().getName() + " size=" + size);
if (l2i(size - contentSize) == 8) {
// default - no large box - no uuid
// do nothing header's already correct
header.rewind();
} else if (l2i(size - contentSize) == 16) {
header = ByteBuffer.allocate(16);
IsoTypeWriter.writeUInt32(header, 1);
header.put(IsoFile.fourCCtoBytes(type));
IsoTypeWriter.writeUInt64(header, size);
} else if (l2i(size - contentSize) == 24) {
header = ByteBuffer.allocate(24);
IsoTypeWriter.writeUInt32(header, size);
header.put(IsoFile.fourCCtoBytes(type));
header.put(usertype);
} else if (l2i(size - contentSize) == 32) {
header = ByteBuffer.allocate(32);
IsoTypeWriter.writeUInt32(header, size);
header.put(IsoFile.fourCCtoBytes(type));
IsoTypeWriter.writeUInt64(header, size);
header.put(usertype);
} else {
throw new RuntimeException("I didn't expect that");
}
box.parse(byteChannel, header, contentSize, this);
// System.out.println("box = " + box);
assert size == box.getSize() :
"Reconstructed Size is not x to the number of parsed bytes! (" +
box.getType() + ")"
+ " Actual Box size: " + size + " Calculated size: " + box.getSize();
return box;
}
}
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