diff --git a/services/audioflinger/NBAIO.cpp b/services/audioflinger/NBAIO.cpp
new file mode 100644
index 0000000..9d71eae
--- /dev/null
+++ b/services/audioflinger/NBAIO.cpp
@@ -0,0 +1,189 @@
+/*
+ * Copyright (C) 2012 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 "NBAIO"
+//#define LOG_NDEBUG 0
+
+#include <utils/Log.h>
+#include "NBAIO.h"
+
+namespace android {
+
+size_t Format_frameSize(NBAIO_Format format)
+{
+    switch (format) {
+    case Format_SR44_1_C2_I16:
+    case Format_SR48_C2_I16:
+        return 2 * sizeof(short);
+    case Format_SR44_1_C1_I16:
+    case Format_SR48_C1_I16:
+        return 1 * sizeof(short);
+    case Format_Invalid:
+    default:
+        return 0;
+    }
+}
+
+size_t Format_frameBitShift(NBAIO_Format format)
+{
+    switch (format) {
+    case Format_SR44_1_C2_I16:
+    case Format_SR48_C2_I16:
+        return 2;   // 1 << 2 == 2 * sizeof(short)
+    case Format_SR44_1_C1_I16:
+    case Format_SR48_C1_I16:
+        return 1;   // 1 << 1 == 1 * sizeof(short)
+    case Format_Invalid:
+    default:
+        return 0;
+    }
+}
+
+unsigned Format_sampleRate(NBAIO_Format format)
+{
+    switch (format) {
+    case Format_SR44_1_C1_I16:
+    case Format_SR44_1_C2_I16:
+        return 44100;
+    case Format_SR48_C1_I16:
+    case Format_SR48_C2_I16:
+        return 48000;
+    case Format_Invalid:
+    default:
+        return 0;
+    }
+}
+
+unsigned Format_channelCount(NBAIO_Format format)
+{
+    switch (format) {
+    case Format_SR44_1_C1_I16:
+    case Format_SR48_C1_I16:
+        return 1;
+    case Format_SR44_1_C2_I16:
+    case Format_SR48_C2_I16:
+        return 2;
+    case Format_Invalid:
+    default:
+        return 0;
+    }
+}
+
+NBAIO_Format Format_from_SR_C(unsigned sampleRate, unsigned channelCount)
+{
+    if (sampleRate == 44100 && channelCount == 2) return Format_SR44_1_C2_I16;
+    if (sampleRate == 48000 && channelCount == 2) return Format_SR48_C2_I16;
+    if (sampleRate == 44100 && channelCount == 1) return Format_SR44_1_C1_I16;
+    if (sampleRate == 48000 && channelCount == 1) return Format_SR48_C1_I16;
+    return Format_Invalid;
+}
+
+// This is a default implementation; it is expected that subclasses will optimize this.
+ssize_t NBAIO_Sink::writeVia(writeVia_t via, size_t total, void *user, size_t block)
+{
+    if (!mNegotiated) {
+        return (ssize_t) NEGOTIATE;
+    }
+    static const size_t maxBlock = 32;
+    size_t frameSize = Format_frameSize(mFormat);
+    ALOG_ASSERT(frameSize > 0 && frameSize <= 8);
+    // double guarantees alignment for stack similar to what malloc() gives for heap
+    if (block == 0 || block > maxBlock) {
+        block = maxBlock;
+    }
+    double buffer[((frameSize * block) + sizeof(double) - 1) / sizeof(double)];
+    size_t accumulator = 0;
+    while (accumulator < total) {
+        size_t count = total - accumulator;
+        if (count > block) {
+            count = block;
+        }
+        ssize_t ret = via(user, buffer, count);
+        if (ret > 0) {
+            ALOG_ASSERT((size_t) ret <= count);
+            size_t maxRet = ret;
+            ret = write(buffer, maxRet);
+            if (ret > 0) {
+                ALOG_ASSERT((size_t) ret <= maxRet);
+                accumulator += ret;
+                continue;
+            }
+        }
+        return accumulator > 0 ? accumulator : ret;
+    }
+    return accumulator;
+}
+
+// This is a default implementation; it is expected that subclasses will optimize this.
+ssize_t NBAIO_Source::readVia(readVia_t via, size_t total, void *user, size_t block)
+{
+    if (!mNegotiated) {
+        return (ssize_t) NEGOTIATE;
+    }
+    static const size_t maxBlock = 32;
+    size_t frameSize = Format_frameSize(mFormat);
+    ALOG_ASSERT(frameSize > 0 && frameSize <= 8);
+    // double guarantees alignment for stack similar to what malloc() gives for heap
+    if (block == 0 || block > maxBlock) {
+        block = maxBlock;
+    }
+    double buffer[((frameSize * block) + sizeof(double) - 1) / sizeof(double)];
+    size_t accumulator = 0;
+    while (accumulator < total) {
+        size_t count = total - accumulator;
+        if (count > block) {
+            count = block;
+        }
+        ssize_t ret = read(buffer, count);
+        if (ret > 0) {
+            ALOG_ASSERT((size_t) ret <= count);
+            size_t maxRet = ret;
+            ret = via(user, buffer, maxRet);
+            if (ret > 0) {
+                ALOG_ASSERT((size_t) ret <= maxRet);
+                accumulator += ret;
+                continue;
+            }
+        }
+        return accumulator > 0 ? accumulator : ret;
+    }
+    return accumulator;
+}
+
+// Default implementation that only accepts my mFormat
+ssize_t NBAIO_Port::negotiate(const NBAIO_Format offers[], size_t numOffers,
+                                  NBAIO_Format counterOffers[], size_t& numCounterOffers)
+{
+    ALOGV("negotiate offers=%p numOffers=%u countersOffers=%p numCounterOffers=%u",
+            offers, numOffers, counterOffers, numCounterOffers);
+    if (mFormat != Format_Invalid) {
+        for (size_t i = 0; i < numOffers; ++i) {
+            if (offers[i] == mFormat) {
+                mNegotiated = true;
+                return i;
+            }
+        }
+        if (numCounterOffers > 0) {
+            counterOffers[0] = mFormat;
+        }
+        numCounterOffers = 1;
+    } else {
+        numCounterOffers = 0;
+    }
+    return (ssize_t) NEGOTIATE;
+}
+
+}   // namespace android