org.mp4parser.AbstractBoxParser Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of isoparser Show documentation
Show all versions of isoparser Show documentation
A generic parser and writer for all ISO 14496 based files (MP4, Quicktime, DCF, PDCF, ...)
/*
* 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 org.mp4parser;
import org.mp4parser.boxes.UserBox;
import org.mp4parser.tools.Hex;
import org.mp4parser.tools.IsoTypeReader;
import java.io.EOFException;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.ReadableByteChannel;
import java.util.logging.Level;
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());
ThreadLocal header = new ThreadLocal() {
@Override
protected ByteBuffer initialValue() {
return ByteBuffer.allocate(32);
}
};
public abstract ParsableBox 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 DataSource pointing to the ISO file
* @param parentType the current box's parent's type (null if no parent)
* @return the box just parsed
* @throws java.io.IOException if reading from in
fails
*/
public ParsableBox parseBox(ReadableByteChannel byteChannel, String parentType) throws IOException {
header.get().rewind().limit(8);
int bytesRead = 0;
int b;
while ((b = byteChannel.read(header.get())) + bytesRead < 8) {
if (b < 0) {
throw new EOFException();
} else {
bytesRead += b;
}
}
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) {
throw new RuntimeException("box size of zero means 'till end of file. That is not yet 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;
}
if (LOG.isLoggable(Level.FINER)) {
LOG.finer("Creating " + type + " " + Hex.encodeHex(new byte[]{header.get().get(4), header.get().get(5), header.get().get(6), header.get().get(7)}));
}
ParsableBox parsableBox = createBox(type, usertype, parentType);
//LOG.finest("Parsing " + box.getType());
// System.out.println("parsing " + Mp4Arrays.toString(box.getType()) + " " + box.getClass().getName() + " size=" + size);
header.get().rewind();
parsableBox.parse(byteChannel, header.get(), contentSize, this);
return parsableBox;
}
}