/*
* Entagged Audio Tag library
* Copyright (c) 2004-2005 Christian Laireiter <liree@web.de>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package org.jaudiotagger.audio.asf.data;
import org.jaudiotagger.audio.asf.util.Utils;
import java.math.BigInteger;
import java.nio.charset.Charset;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
/**
* Each ASF file starts with a so called header. <br>
* This header contains other chunks. Each chunk starts with a 16 byte GUID
* followed by the length (in bytes) of the chunk (including GUID). The length
* number takes 8 bytes and is unsigned. Finally the chunk's data appears. <br>
*
* @author Christian Laireiter
*/
public final class AsfHeader extends ChunkContainer {
/**
* The charset "UTF-16LE" is mandatory for ASF handling.
*/
public final static Charset ASF_CHARSET = Charset.forName("UTF-16LE"); //$NON-NLS-1$
/**
* Byte sequence representing the zero term character.
*/
public final static byte[] ZERO_TERM = { 0, 0 };
static {
Set<GUID> MULTI_CHUNKS = new HashSet<GUID>();
MULTI_CHUNKS.add(GUID.GUID_STREAM);
}
/**
* An ASF header contains multiple chunks. <br>
* The count of those is stored here.
*/
private final long chunkCount;
/**
* Creates an instance.
*
* @param pos
* see {@link Chunk#position}
* @param chunkLen
* see {@link Chunk#chunkLength}
* @param chunkCnt
*/
public AsfHeader(final long pos, final BigInteger chunkLen,
final long chunkCnt) {
super(GUID.GUID_HEADER, pos, chunkLen);
this.chunkCount = chunkCnt;
}
/**
* This method looks for an content description object in this header
* instance, if not found there, it tries to get one from a contained ASF
* header extension object.
*
* @return content description if found, <code>null</code> otherwise.
*/
public ContentDescription findContentDescription() {
ContentDescription result = getContentDescription();
if (result == null && getExtendedHeader() != null) {
result = getExtendedHeader().getContentDescription();
}
return result;
}
/**
* This method looks for an extended content description object in this
* header instance, if not found there, it tries to get one from a contained
* ASF header extension object.
*
* @return extended content description if found, <code>null</code>
* otherwise.
*/
public MetadataContainer findExtendedContentDescription() {
MetadataContainer result = getExtendedContentDescription();
if (result == null && getExtendedHeader() != null) {
result = getExtendedHeader().getExtendedContentDescription();
}
return result;
}
/**
* This method searches for a metadata container of the given type.<br>
*
* @param type
* the type of the container to look up.
* @return a container of specified type, of <code>null</code> if not
* contained.
*/
public MetadataContainer findMetadataContainer(final ContainerType type) {
MetadataContainer result = (MetadataContainer) getFirst(type
.getContainerGUID(), MetadataContainer.class);
if (result == null) {
result = (MetadataContainer) getExtendedHeader().getFirst(
type.getContainerGUID(), MetadataContainer.class);
}
return result;
}
/**
* This method returns the first audio stream chunk found in the asf file or
* stream.
*
* @return Returns the audioStreamChunk.
*/
public AudioStreamChunk getAudioStreamChunk() {
AudioStreamChunk result = null;
final List<Chunk> streamChunks = assertChunkList(GUID.GUID_STREAM);
for (int i = 0; i < streamChunks.size() && result == null; i++) {
if (streamChunks.get(i) instanceof AudioStreamChunk) {
result = (AudioStreamChunk) streamChunks.get(i);
}
}
return result;
}
/**
* Returns the amount of chunks, when this instance was created.<br>
* If chunks have been added, this won'timer be reflected with this call.<br>
* For that use {@link #getChunks()}.
*
* @return Chunkcount at instance creation.
*/
public long getChunkCount() {
return this.chunkCount;
}
/**
* @return Returns the contentDescription.
*/
public ContentDescription getContentDescription() {
return (ContentDescription) getFirst(GUID.GUID_CONTENTDESCRIPTION,
ContentDescription.class);
}
/**
* @return Returns the encodingChunk.
*/
public EncodingChunk getEncodingChunk() {
return (EncodingChunk) getFirst(GUID.GUID_ENCODING, EncodingChunk.class);
}
/**
* @return Returns the encodingChunk.
*/
public EncryptionChunk getEncryptionChunk() {
return (EncryptionChunk) getFirst(GUID.GUID_CONTENT_ENCRYPTION,
EncryptionChunk.class);
}
/**
* @return Returns the tagHeader.
*/
public MetadataContainer getExtendedContentDescription() {
return (MetadataContainer) getFirst(
GUID.GUID_EXTENDED_CONTENT_DESCRIPTION, MetadataContainer.class);
}
/**
* @return Returns the extended header.
*/
public AsfExtendedHeader getExtendedHeader() {
return (AsfExtendedHeader) getFirst(GUID.GUID_HEADER_EXTENSION,
AsfExtendedHeader.class);
}
/**
* @return Returns the fileHeader.
*/
public FileHeader getFileHeader() {
return (FileHeader) getFirst(GUID.GUID_FILE, FileHeader.class);
}
/**
* @return Returns the streamBitratePropertiesChunk.
*/
public StreamBitratePropertiesChunk getStreamBitratePropertiesChunk() {
return (StreamBitratePropertiesChunk) getFirst(
GUID.GUID_STREAM_BITRATE_PROPERTIES,
StreamBitratePropertiesChunk.class);
}
/**
*
* {@inheritDoc}
*/
@Override
public String prettyPrint(final String prefix) {
final StringBuilder result = new StringBuilder(super.prettyPrint(prefix,
prefix + " | : Contains: \"" + getChunkCount() + "\" chunks"
+ Utils.LINE_SEPARATOR));
return result.toString();
}
}