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/* Copyright (c) 2014, David A. Clunie DBA Pixelmed Publishing. All rights reserved. */
package com.pixelmed.codec.jpeg;
/**
* <p>A JPEG SOF Marker Segment.</p>
*
* @author dclunie
*/
public class MarkerSegmentSOF {
private static final String identString = "@(#) $Header: /userland/cvs/codec/com/pixelmed/codec/jpeg/MarkerSegmentSOF.java,v 1.2 2014/03/22 09:06:13 dclunie Exp $";
private int SamplePrecision;
private int nLines;
private int nSamplesPerLine;
private int nComponentsInFrame;
private int[] ComponentIdentifier;
private int[] HorizontalSamplingFactor;
private int[] VerticalSamplingFactor;
private int[] QuantizationTableDestinationSelector;
public int getNLines() { return nLines; }
public int getNSamplesPerLine() { return nSamplesPerLine; }
public int[] getHorizontalSamplingFactor() { return HorizontalSamplingFactor; }
public int[] getVerticalSamplingFactor() { return VerticalSamplingFactor; }
public MarkerSegmentSOF(byte[] b,int length) throws Exception {
SamplePrecision = Utilities.extract8(b,0);
nLines = Utilities.extract16be(b,1);
nSamplesPerLine = Utilities.extract16be(b,3);
nComponentsInFrame = Utilities.extract8(b,5);
int lengthExpected = 6+nComponentsInFrame*3;
if (length != lengthExpected) {
throw new Exception("Incorrect length of SOF Parameters Marker Segment, expected "+lengthExpected+" (based on nComponentsInFrame "+nComponentsInFrame+") but was "+length);
}
ComponentIdentifier = new int[nComponentsInFrame];
HorizontalSamplingFactor = new int[nComponentsInFrame];
VerticalSamplingFactor = new int[nComponentsInFrame];
QuantizationTableDestinationSelector= new int[nComponentsInFrame];
for (int i=0; i<nComponentsInFrame; ++i) {
ComponentIdentifier[i] = Utilities.extract8(b,6+i*3);
HorizontalSamplingFactor[i] = Utilities.extract8(b,6+i*3+1) >> 4;
VerticalSamplingFactor[i] = Utilities.extract8(b,6+i*3+1) & 0x0f;
QuantizationTableDestinationSelector[i] = Utilities.extract8(b,6+i*3+2);
}
}
public String toString() {
StringBuffer buf = new StringBuffer();
buf.append("\n\tSOF:\n");
buf.append("\t\t SamplePrecision = " +SamplePrecision+"\n");
buf.append("\t\t nLines = " +nLines+"\n");
buf.append("\t\t nSamplesPerLine = " +nSamplesPerLine+"\n");
buf.append("\t\t nComponentsInFrame = " +nComponentsInFrame+"\n");
for (int i=0; i<nComponentsInFrame; ++i) {
buf.append("\t\t component " +i+"\n");
buf.append("\t\t\t ComponentIdentifier = " +ComponentIdentifier[i]+"\n");
buf.append("\t\t\t HorizontalSamplingFactor = " +HorizontalSamplingFactor[i]+"\n");
buf.append("\t\t\t VerticalSamplingFactor = " +VerticalSamplingFactor[i]+"\n");
buf.append("\t\t\t QuantizationTableDestinationSelector = " +QuantizationTableDestinationSelector[i]+"\n");
}
return buf.toString();
}
}
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