[WIP] Updates the LTR-Standard and LTR-Net decoders to use a new LTR

decoder with a zero-crossing symbol timing error detector.  The new
decoder is optimized for 8 kHz FM demodulated audio produced by the
AudioModule.

src/main/java/io/github/dsheirer/dsp/fsk/SampleBufferInstrumented.java

@@ -0,0 +1,98 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 Dennis Sheirer
+ *
+ * This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public
+ * License as published by  the Free Software Foundation, either version 3 of the License, or  (at your option) any
+ * later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License  along with this program.
+ * If not, see <http://www.gnu.org/licenses/>
+ *
+ ******************************************************************************/
+package io.github.dsheirer.dsp.fsk;
+
+public class SampleBufferInstrumented extends SampleBuffer
+{
+    public boolean mLastSymbol;
+
+    /**
+     * Buffer to store complex sample data and produce interpolated samples.
+     *
+     * @param samplesPerSymbol
+     * @param symbolTimingGain
+     */
+    public SampleBufferInstrumented(float samplesPerSymbol, float symbolTimingGain)
+    {
+        super(samplesPerSymbol, symbolTimingGain);
+    }
+
+    /**
+     * Sample delay buffer containing boolean (ie positive or negative) samples.
+     */
+    public boolean[] getDelayLine()
+    {
+        return mDelayLine;
+    }
+
+    /**
+     * Current delay buffer pointer which points to where the next sample will be stored and/or the oldest sample in
+     * the buffer.
+     */
+    public int getDelayLinePointer()
+    {
+        return mDelayLinePointer;
+    }
+
+    public int getDelayLineSecondPointer()
+    {
+        return mDelayLinePointer + mTwiceSamplesPerSymbol;
+    }
+
+    /**
+     * Current symbol timing gain value
+     * @return
+     */
+    public float getSymbolTimingGain()
+    {
+        return mSymbolTimingGain;
+    }
+
+    /**
+     * Current mid-symbol sampling point
+     */
+    public float getMidSymbolSamplingPoint()
+    {
+        return mMidSymbolSamplingPoint;
+    }
+
+    public float getSamplesPerSymbol()
+    {
+        return mSamplesPerSymbol;
+    }
+
+    @Override
+    public boolean getSymbol()
+    {
+        mLastSymbol = super.getSymbol();
+        return mLastSymbol;
+    }
+
+    public boolean getLastSymbol()
+    {
+        return mLastSymbol;
+    }
+
+    public int getSymbolStart()
+    {
+        return mSymbolStart;
+    }
+
+    public int getSymbolEnd()
+    {
+        return mSymbolEnd;
+    }
+}