/*
* Entagged Audio Tag library
* Copyright (c) 2003-2005 Raphaƫl Slinckx <raphael@slinckx.net>
*
* 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.mp4.atom;
import org.jaudiotagger.audio.generic.Utils;
import java.nio.ByteBuffer;
/**
* MvhdBox (movie (presentation) header box)
* <p/>
* <p>This MP4Box contains important audio information we need. It can be used to calculate track length,
* depending on the version field this can be in either short or long format
*/
public class Mp4MvhdBox extends AbstractMp4Box {
public static final int VERSION_FLAG_POS = 0;
public static final int OTHER_FLAG_POS = 1;
public static final int CREATED_DATE_SHORT_POS = 4;
public static final int MODIFIED_DATE_SHORT_POS = 8;
public static final int TIMESCALE_SHORT_POS = 12;
public static final int DURATION_SHORT_POS = 16;
public static final int CREATED_DATE_LONG_POS = 4;
public static final int MODIFIED_DATE_LONG_POS = 12;
public static final int TIMESCALE_LONG_POS = 20;
public static final int DURATION_LONG_POS = 24;
public static final int VERSION_FLAG_LENGTH = 1;
public static final int OTHER_FLAG_LENGTH = 3;
public static final int CREATED_DATE_SHORT_LENGTH = 4;
public static final int MODIFIED_DATE_SHORT_LENGTH = 4;
public static final int CREATED_DATE_LONG_LENGTH = 8;
public static final int MODIFIED_DATE_LONG_LENGTH = 8;
public static final int TIMESCALE_LENGTH = 4;
public static final int DURATION_SHORT_LENGTH = 4;
public static final int DURATION_LONG_LENGTH = 8;
private static final int LONG_FORMAT = 1;
private int timeScale;
private long timeLength;
/**
* @param header header info
* @param dataBuffer data of box (doesnt include header data)
*/
public Mp4MvhdBox(Mp4BoxHeader header, ByteBuffer dataBuffer) {
this.header = header;
byte version = dataBuffer.get(VERSION_FLAG_POS);
if (version == LONG_FORMAT) {
this.timeScale = Utils.getIntBE(dataBuffer, TIMESCALE_LONG_POS, (TIMESCALE_LONG_POS + TIMESCALE_LENGTH - 1));
this.timeLength = Utils.getLongBE(dataBuffer, DURATION_LONG_POS, (DURATION_LONG_POS + DURATION_LONG_LENGTH - 1));
} else {
this.timeScale = Utils.getIntBE(dataBuffer, TIMESCALE_SHORT_POS, (TIMESCALE_SHORT_POS + TIMESCALE_LENGTH - 1));
this.timeLength = Utils.getIntBE(dataBuffer, DURATION_SHORT_POS, (DURATION_SHORT_POS + DURATION_SHORT_LENGTH - 1));
}
}
public double getLength() {
return (double) this.timeLength / (double) this.timeScale;
}
}