/*
* 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.Container;
import com.coremedia.iso.boxes.UserBox;
import java.io.EOFException;
import java.io.IOException;
import java.nio.ByteBuffer;
import com.googlecode.mp4parser.DataSource;
import java.util.logging.Logger;
/**
* 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);
ThreadLocal<ByteBuffer> header = new ThreadLocal<ByteBuffer>() {
@Override
protected ByteBuffer initialValue() {
return ByteBuffer.allocate(32);
}
};
/**
* Parses the next size and type, creates a box instance and parses the box's content.
*
* @param byteChannel the DataSource 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(DataSource byteChannel, Container parent) throws IOException {
header.get().rewind().limit(8);
int bytesRead = 0;
while ((bytesRead += byteChannel.read(header.get())) != 8) {
if (bytesRead < 0) {
throw new EOFException();
}
}
header.get().rewind();
long size = IsoTypeReader.readUInt32(header.get());
// 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.get());
//System.err.println(type);
byte[] usertype = null;
long contentSize;
if (size == 1) {
header.get().limit(16);
byteChannel.read(header.get());
header.get().position(8);
size = IsoTypeReader.readUInt64(header.get());
contentSize = size - 16;
} else if (size == 0) {
size = byteChannel.size() - byteChannel.position() - 8;
contentSize = size - 8;
throw new RuntimeException( "'" + type + "' with '" + (parent instanceof Box?((Box) parent).getType():"IsoFile") + "' as parent has length == 0. That's not supported");
} else {
contentSize = size - 8;
}
if (UserBox.TYPE.equals(type)) {
header.get().limit(header.get().limit() + 16);
byteChannel.read(header.get());
usertype = new byte[16];
for (int i = header.get().position() - 16; i < header.get().position(); i++) {
usertype[i - (header.get().position() - 16)] = header.get().get(i);
}
contentSize -= 16;
}
Box box = createBox(type, usertype, (parent instanceof Box) ? ((Box) parent).getType() : "");
box.setParent(parent);
//LOG.finest("Parsing " + box.getType());
// System.out.println("parsing " + Arrays.toString(box.getType()) + " " + box.getClass().getName() + " size=" + size);
header.get().rewind();
box.parse(byteChannel, header.get(), contentSize, this);
return box;
}
}