Added DC filter option to offline audio file loading

src/Acquisition/AcquisitionProcess.java

@@ -496,13 +496,7 @@ public class AcquisitionProcess extends PamProcess {
 		lastStallCheckSamples = 0;
 		lastStallState = false;
 
-		if (acquisitionControl.acquisitionParameters.subtractDC) {
-			dcFilter = new DCFilter(acquisitionControl.acquisitionParameters.sampleRate,
-					acquisitionControl.acquisitionParameters.dcTimeConstant, PamConstants.MAX_CHANNELS);
-		}
-		else {
-			dcFilter = null;
-		}
+		dcFilter = createDCFilter();
 
 		setSampleRate(acquisitionControl.acquisitionParameters.sampleRate, true);
 
@@ -526,6 +520,22 @@ public class AcquisitionProcess extends PamProcess {
 	}
 
 
+	public DCFilter createDCFilter() {
+		if (acquisitionControl.acquisitionParameters.subtractDC) {
+			if (dcFilter == null) {
+				dcFilter = new DCFilter(acquisitionControl.acquisitionParameters.sampleRate,
+						acquisitionControl.acquisitionParameters.dcTimeConstant, PamConstants.MAX_CHANNELS);
+			}
+			else {
+				dcFilter.setTimeContant(acquisitionControl.acquisitionParameters.sampleRate, acquisitionControl.acquisitionParameters.dcTimeConstant);
+			}
+		}
+		else {
+			dcFilter = null;
+		}
+		return dcFilter;
+	}
+
 	@Override
 	public void setSampleRate(float sampleRate, boolean notify) {
 		acquisitionControl.acquisitionParameters.sampleRate = sampleRate;
@@ -1159,6 +1169,10 @@ public class AcquisitionProcess extends PamProcess {
 
 //		System.out.println("AquisitionProcess: GetofflineData: " + offlineLoadDataInfo.getCurrentObserver().getObserverName())
 
+		// set the DC filter so that offline data benefit from it too
+		dcFilter = createDCFilter();
+		rawDataBlock.setDcFilter(dcFilter);
+		
 		if (acquisitionControl.getOfflineFileServer() == null) {
 			return PamDataBlock.REQUEST_NO_DATA;
 		}

src/Acquisition/DCFilter.java

@@ -12,15 +12,34 @@ public class DCFilter {
 	private int nChannels;
 	private double[] background;
 	private double alpha;
+	private int[] channelCallCount;
 
 	public DCFilter(double sampleRate, double timeConstant, int nChannels) {
 		this.sampleRate = sampleRate;
 		this.timeConstant = timeConstant;
 		this.nChannels = nChannels;
 		background = new double[nChannels];
+		setTimeContant(sampleRate, timeConstant);
+		channelCallCount = new int[nChannels];
+	}
+	
+	/**
+	 * Set the time constant
+	 * @param timeConstant 
+	 * @param timeConstant2
+	 * @param timeConstant 
+	 */
+	public void setTimeContant(double sampleRate, double timeConstant) {
+		this.sampleRate = sampleRate;
+		this.timeConstant = timeConstant;
 		alpha = 1-1./(sampleRate*timeConstant);
 	}
 
+	/**
+	 * Filter data in place. 
+	 * @param channel
+	 * @param data
+	 */
 	public void filterData(int channel, double[] data) {
 		double x;
 		double b = background[channel];
@@ -33,5 +52,30 @@ public class DCFilter {
 //			data[i] = x;
 		}
 		background[channel] = b;
+		channelCallCount[channel] ++;
+	}
+	
+	public int getChannelCallCount(int channel) {
+		return channelCallCount[channel];
+	}
+
+	public double getSampleRate() {
+		return sampleRate;
+	}
+
+	public double getTimeConstant() {
+		return timeConstant;
+	}
+
+	public int getnChannels() {
+		return nChannels;
+	}
+
+	public double[] getBackground() {
+		return background;
+	}
+
+	public double getAlpha() {
+		return alpha;
 	}
 }

src/Acquisition/pamAudio/WavAudioFile.java

@@ -283,18 +283,18 @@ public class WavAudioFile implements PamAudioFileLoader {
 	}
 	
 	
-	public static void main(String args[]) {
-		
-		File wavFile = new File("E:\\SoundNet\\1chan_analysis\\pamguard\\67150826\\mf_wav\\20180529\\PAM_20180529_055114_000.wav");
-		try {
-			WavFileInputStream.openInputStream(wavFile);
-			System.out.println("Wav file opened successfully: " + isSoundFile(wavFile));
-			
-		} catch (UnsupportedAudioFileException | IOException e) {
-			// TODO Auto-generated catch block
-			e.printStackTrace();
-		}
-	}
+//	public static void main(String args[]) {
+//		
+//		File wavFile = new File("E:\\SoundNet\\1chan_analysis\\pamguard\\67150826\\mf_wav\\20180529\\PAM_20180529_055114_000.wav");
+//		try {
+//			WavFileInputStream.openInputStream(wavFile);
+//			System.out.println("Wav file opened successfully: " + isSoundFile(wavFile));
+//			
+//		} catch (UnsupportedAudioFileException | IOException e) {
+//			// TODO Auto-generated catch block
+//			e.printStackTrace();
+//		}
+//	}
 
 	@Override
 	public PamAudioSettingsPane getSettingsPane() {

src/PamguardMVC/PamRawDataBlock.java

@@ -30,6 +30,7 @@ package PamguardMVC;
 import java.util.ListIterator;
 
 import Acquisition.AcquisitionProcess;
+import Acquisition.DCFilter;
 import Acquisition.RawDataBinaryDataSource;
 import PamController.PamController;
 import PamDetection.RawDataUnit;
@@ -56,6 +57,8 @@ public class PamRawDataBlock extends AcousticDataBlock<RawDataUnit> {
 	private double[] summaryTotals2 = new double[PamConstants.MAX_CHANNELS];
 	private double[] summaryMaxVal = new double[PamConstants.MAX_CHANNELS];
 	private int[] summaryCount = new int[PamConstants.MAX_CHANNELS];
+	
+	private DCFilter dcFilter;
 
 	/**
 	 * Keep a record of the last sample added. 
@@ -183,6 +186,14 @@ public class PamRawDataBlock extends AcousticDataBlock<RawDataUnit> {
 //			return; add the data anyway, may get back into synch !!!! 
 		}
 		prevChannelSample[thisChannel] = pamDataUnit.getStartSample();
+		if (dcFilter != null) {
+			int callCount = dcFilter.getChannelCallCount(thisChannel);
+			dcFilter.filterData(thisChannel, pamDataUnit.getRawData());
+			if (callCount == 0) {
+				// run again for luck now that it should have settled. 
+				dcFilter.filterData(thisChannel, pamDataUnit.getRawData());
+			}
+		}
 //		System.out.println(String.format("Sample %d channel %d in %s is in  synch - expected sample %d",
 //				pamDataUnit.getStartSample(), thisChannel, getDataName(), desiredSample));
 		addSummaryData(thisChannel, pamDataUnit);
@@ -609,6 +620,28 @@ public class PamRawDataBlock extends AcousticDataBlock<RawDataUnit> {
 		return null;
 	}
 
+	/**
+	 * DC filter to use on all incoming data. Don't probably want this in 
+	 * normal mode since it's already done in the acquisition thread, but 
+	 * have option to do it in viewer mode if it's set from the 
+	 * process owning this data block. 
+	 * @param dcFilter
+	 */
+	public void setDcFilter(DCFilter dcFilter) {
+		this.dcFilter = dcFilter;
+	}
+
+	/**	 
+	 * DC filter to use on all incoming data. Don't probably want this in 
+	 * normal mode since it's already done in the acquisition thread, but 
+	 * have option to do it in viewer mode if it's set from the 
+	 * process owning this data block. 
+	 * @return
+	 */
+	public DCFilter getDcFilter() {
+		return dcFilter;
+	}
+
 
 
 //	@Override