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diff --git a/externals/oboe/apps/OboeTester/app/src/main/cpp/analyzer/ManchesterEncoder.h b/externals/oboe/apps/OboeTester/app/src/main/cpp/analyzer/ManchesterEncoder.h
new file mode 100644
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+++ b/externals/oboe/apps/OboeTester/app/src/main/cpp/analyzer/ManchesterEncoder.h
@@ -0,0 +1,97 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANALYZER_MANCHESTER_ENCODER_H
+#define ANALYZER_MANCHESTER_ENCODER_H
+
+#include <cstdint>
+
+/**
+ * Encode bytes using Manchester Coding scheme.
+ *
+ * Manchester Code is self clocking.
+ * There is a transition in the middle of every bit.
+ * Zero is high then low.
+ * One is low then high.
+ *
+ * This avoids having long DC sections that would droop when
+ * passed though analog circuits with AC coupling.
+ *
+ * IEEE 802.3 compatible.
+ */
+
+class ManchesterEncoder {
+public:
+    ManchesterEncoder(int samplesPerPulse)
+            : mSamplesPerPulse(samplesPerPulse)
+            , mSamplesPerPulseHalf(samplesPerPulse / 2)
+            , mCursor(samplesPerPulse) {
+    }
+
+    virtual ~ManchesterEncoder() = default;
+
+    /**
+     * This will be called when the next byte is needed.
+     * @return next byte
+     */
+    virtual uint8_t onNextByte() = 0;
+
+    /**
+     * Generate the next floating point sample.
+     * @return next float
+     */
+    virtual float nextFloat() {
+        advanceSample();
+        if (mCurrentBit) {
+            return (mCursor < mSamplesPerPulseHalf) ? -1.0f : 1.0f; // one
+        } else {
+            return (mCursor < mSamplesPerPulseHalf) ? 1.0f : -1.0f; // zero
+        }
+    }
+
+protected:
+    /**
+     * This will be called when a new bit is ready to be encoded.
+     * It can be used to prepare the encoded samples.
+     */
+    virtual void onNextBit(bool /* current */) {};
+
+    void advanceSample() {
+        // Are we ready for a new bit?
+        if (++mCursor >= mSamplesPerPulse) {
+            mCursor = 0;
+            if (mBitsLeft == 0) {
+                mCurrentByte = onNextByte();
+                mBitsLeft = 8;
+            }
+            --mBitsLeft;
+            mCurrentBit = (mCurrentByte >> mBitsLeft) & 1;
+            onNextBit(mCurrentBit);
+        }
+    }
+
+    bool getCurrentBit() {
+        return mCurrentBit;
+    }
+
+    const int mSamplesPerPulse;
+    const int mSamplesPerPulseHalf;
+    int       mCursor;
+    int       mBitsLeft = 0;
+    uint8_t   mCurrentByte = 0;
+    bool      mCurrentBit = false;
+};
+#endif //ANALYZER_MANCHESTER_ENCODER_H