/*
* Copyright (C) 2011 in-somnia
*
* This file is part of JAAD.
*
* JAAD 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 3 of the
* License, or (at your option) any later version.
*
* JAAD 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, see <http://www.gnu.org/licenses/>.
*/
package net.sourceforge.jaad.mp4.boxes.impl.sampleentries.codec;
import java.io.IOException;
import net.sourceforge.jaad.mp4.MP4InputStream;
/**
* This box contains parameters for Extended AC-3 decoders. For more information
* see the AC-3 specification "<code>ETSI TS 102 366 V1.2.1 (2008-08)</code>" at
* <a href="http://www.etsi.org/deliver/etsi_ts/102300_102399/102366/01.02.01_60/ts_102366v010201p.pdf>
* http://www.etsi.org/deliver/etsi_ts/102300_102399/102366/01.02.01_60/ts_102366v010201p.pdf</a>.
*
* @author in-somnia
*/
public class EAC3SpecificBox extends CodecSpecificBox {
private int dataRate, independentSubstreamCount;
private int[] fscods, bsids, bsmods, acmods, dependentSubstreamCount, dependentSubstreamLocation;
private boolean[] lfeons;
public EAC3SpecificBox() {
super("EAC-3 Specific Box");
}
@Override
public void decode(MP4InputStream in) throws IOException {
long l = in.readBytes(2);
//13 bits dataRate
dataRate = (int) ((l>>3)&0x1FFF);
//3 bits number of independent substreams
independentSubstreamCount = (int) (l&0x7);
for(int i = 0; i<independentSubstreamCount; i++) {
l = in.readBytes(3);
//2 bits fscod
fscods[i] = (int) ((l>>22)&0x3);
//5 bits bsid
bsids[i] = (int) ((l>>17)&0x1F);
//5 bits bsmod
bsmods[i] = (int) ((l>>12)&0x1F);
//3 bits acmod
acmods[i] = (int) ((l>>9)&0x7);
//3 bits reserved
//1 bit lfeon
lfeons[i] = ((l>>5)&0x1)==1;
//4 bits number of dependent substreams
dependentSubstreamCount[i] = (int) ((l>>1)&0xF);
if(dependentSubstreamCount[i]>0) {
//9 bits dependent substream location
l = (l<<8)|in.read();
dependentSubstreamLocation[i] = (int) (l&0x1FF);
}
//else: 1 bit reserved
}
}
/**
* This value indicates the data rate of the Enhanced AC-3 bitstream in
* kbit/s. If the Enhanced AC-3 stream is variable bit rate, then this value
* indicates the maximum data rate of the stream.
*
* @return the data rate
*/
public int getDataRate() {
return dataRate;
}
/**
* This field indicates the number of independent substreams that are
* present in the Enhanced AC-3 bitstream.
*
* @return the number of independent substreams
*/
public int getIndependentSubstreamCount() {
return independentSubstreamCount;
}
/**
* This field has the same meaning and is set to the same value as the fscod
* field in the independent substream.
*
* @return the 'fscod' values for all independent substreams
*/
public int[] getFscods() {
return fscods;
}
/**
* This field has the same meaning and is set to the same value as the bsid
* field in the independent substream.
*
* @return the 'bsid' values for all independent substreams
*/
public int[] getBsids() {
return bsids;
}
/**
* This field has the same meaning and is set to the same value as the bsmod
* field in the independent substream. If the bsmod field is not present in
* the independent substream, this field shall be set to 0.
*
* @return the 'bsmod' values for all independent substreams
*/
public int[] getBsmods() {
return bsmods;
}
/**
* This field has the same meaning and is set to the same value as the acmod
* field in the independent substream.
*
* @return the 'acmod' values for all independent substreams
*/
public int[] getAcmods() {
return acmods;
}
/**
* This field has the same meaning and is set to the same value as the lfeon
* field in the independent substream.
*
* @return the 'lfeon' values for all independent substreams
*/
public boolean[] getLfeons() {
return lfeons;
}
/**
* This field indicates the number of dependent substreams that are
* associated with an independent substream.
*
* @return the number of dependent substreams for all independent substreams
*/
public int[] getDependentSubstreamCount() {
return dependentSubstreamCount;
}
/**
* If there are one or more dependent substreams associated with an
* independent substream, this bit field is used to identify channel
* locations beyond those identified using the 'acmod' field that are
* present in the bitstream. The lowest 9 bits of the returned integer are
* flags indicating if a channel location is present. The flags are used
* according to the following table, where index 0 is the most significant
* bit of all 9 used bits:
* <table>
* <tr><th>Bit</th><th>Location</th></tr>
* <tr><td>0</td><td>Lc/Rc pair</td></tr>
* <tr><td>1</td><td>Lrs/Rrs pair</td></tr>
* <tr><td>2</td><td>Cs</td></tr>
* <tr><td>3</td><td>Ts</td></tr>
* <tr><td>4</td><td>Lsd/Rsd pair</td></tr>
* <tr><td>5</td><td>Lw/Rw pair</td></tr>
* <tr><td>6</td><td>Lvh/Rvh pair </td></tr>
* <tr><td>7</td><td>Cvh</td></tr>
* <tr><td>8</td><td>LFE2</td></tr>
* </table>
*
* @return the dependent substream locations for all independent substreams
*/
public int[] getDependentSubstreamLocation() {
return dependentSubstreamLocation;
}
}