diff --git a/services/oboeservice/AAudioMixer.cpp b/services/oboeservice/AAudioMixer.cpp
new file mode 100644
index 0000000..70da339
--- /dev/null
+++ b/services/oboeservice/AAudioMixer.cpp
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+#define LOG_TAG "AAudioService"
+//#define LOG_NDEBUG 0
+#include <utils/Log.h>
+
+#include <cstring>
+#include "AAudioMixer.h"
+
+using android::WrappingBuffer;
+using android::FifoBuffer;
+using android::fifo_frames_t;
+
+AAudioMixer::~AAudioMixer() {
+    delete[] mOutputBuffer;
+}
+
+void AAudioMixer::allocate(int32_t samplesPerFrame, int32_t framesPerBurst) {
+    mSamplesPerFrame = samplesPerFrame;
+    mFramesPerBurst = framesPerBurst;
+    int32_t samplesPerBuffer = samplesPerFrame * framesPerBurst;
+    mOutputBuffer = new float[samplesPerBuffer];
+    mBufferSizeInBytes = samplesPerBuffer * sizeof(float);
+}
+
+void AAudioMixer::clear() {
+    memset(mOutputBuffer, 0, mBufferSizeInBytes);
+}
+
+void AAudioMixer::mix(FifoBuffer *fifo, float volume) {
+    WrappingBuffer wrappingBuffer;
+    float *destination = mOutputBuffer;
+    fifo_frames_t framesLeft = mFramesPerBurst;
+
+    // Gather the data from the client. May be in two parts.
+    fifo->getFullDataAvailable(&wrappingBuffer);
+
+    // Mix data in one or two parts.
+    int partIndex = 0;
+    while (framesLeft > 0 && partIndex < WrappingBuffer::SIZE) {
+        fifo_frames_t framesToMix = framesLeft;
+        fifo_frames_t framesAvailable = wrappingBuffer.numFrames[partIndex];
+        if (framesAvailable > 0) {
+            if (framesToMix > framesAvailable) {
+                framesToMix = framesAvailable;
+            }
+            mixPart(destination, (float *)wrappingBuffer.data[partIndex], framesToMix, volume);
+
+            destination += framesToMix * mSamplesPerFrame;
+            framesLeft -= framesToMix;
+        }
+        partIndex++;
+    }
+    fifo->getFifoControllerBase()->advanceReadIndex(mFramesPerBurst - framesLeft);
+    if (framesLeft > 0) {
+        ALOGW("AAudioMixer::mix() UNDERFLOW by %d / %d frames ----- UNDERFLOW !!!!!!!!!!",
+              framesLeft, mFramesPerBurst);
+    }
+}
+
+void AAudioMixer::mixPart(float *destination, float *source, int32_t numFrames, float volume) {
+    int32_t numSamples = numFrames * mSamplesPerFrame;
+    // TODO maybe optimize using SIMD
+    for (int sampleIndex = 0; sampleIndex < numSamples; sampleIndex++) {
+        *destination++ += *source++ * volume;
+    }
+}
+
+float *AAudioMixer::getOutputBuffer() {
+    return mOutputBuffer;
+}