diff --git a/services/audioflinger/MonoPipe.cpp b/services/audioflinger/MonoPipe.cpp
index f3fc19a..bd876b4 100644
--- a/services/audioflinger/MonoPipe.cpp
+++ b/services/audioflinger/MonoPipe.cpp
@@ -17,17 +17,22 @@
 #define LOG_TAG "MonoPipe"
 //#define LOG_NDEBUG 0
 
+#include <common_time/cc_helper.h>
 #include <cutils/atomic.h>
 #include <cutils/compiler.h>
+#include <utils/LinearTransform.h>
 #include <utils/Log.h>
 #include <utils/Trace.h>
+#include "AudioBufferProvider.h"
 #include "MonoPipe.h"
 #include "roundup.h"
 
+
 namespace android {
 
 MonoPipe::MonoPipe(size_t reqFrames, NBAIO_Format format, bool writeCanBlock) :
         NBAIO_Sink(format),
+        mUpdateSeq(0),
         mReqFrames(reqFrames),
         mMaxFrames(roundup(reqFrames)),
         mBuffer(malloc(mMaxFrames * Format_frameSize(format))),
@@ -38,6 +43,37 @@
         mSetpoint((reqFrames * 11) / 16),
         mWriteCanBlock(writeCanBlock)
 {
+    CCHelper tmpHelper;
+    status_t res;
+    uint64_t N, D;
+
+    mNextRdPTS = AudioBufferProvider::kInvalidPTS;
+
+    mSamplesToLocalTime.a_zero = 0;
+    mSamplesToLocalTime.b_zero = 0;
+    mSamplesToLocalTime.a_to_b_numer = 0;
+    mSamplesToLocalTime.a_to_b_denom = 0;
+
+    D = Format_sampleRate(format);
+    if (OK != (res = tmpHelper.getLocalFreq(&N))) {
+        ALOGE("Failed to fetch local time frequency when constructing a"
+              " MonoPipe (res = %d).  getNextWriteTimestamp calls will be"
+              " non-functional", res);
+        return;
+    }
+
+    LinearTransform::reduce(&N, &D);
+    static const uint64_t kSignedHiBitsMask   = ~(0x7FFFFFFFull);
+    static const uint64_t kUnsignedHiBitsMask = ~(0xFFFFFFFFull);
+    if ((N & kSignedHiBitsMask) || (D & kUnsignedHiBitsMask)) {
+        ALOGE("Cannot reduce sample rate to local clock frequency ratio to fit"
+              " in a 32/32 bit rational.  (max reduction is 0x%016llx/0x%016llx"
+              ").  getNextWriteTimestamp calls will be non-functional", N, D);
+        return;
+    }
+
+    mSamplesToLocalTime.a_to_b_numer = static_cast<int32_t>(N);
+    mSamplesToLocalTime.a_to_b_denom = static_cast<uint32_t>(D);
 }
 
 MonoPipe::~MonoPipe()
@@ -162,4 +198,102 @@
     mSetpoint = setpoint;
 }
 
+status_t MonoPipe::getNextWriteTimestamp(int64_t *timestamp)
+{
+    int32_t front;
+
+    ALOG_ASSERT(NULL != timestamp);
+
+    if (0 == mSamplesToLocalTime.a_to_b_denom)
+        return UNKNOWN_ERROR;
+
+    observeFrontAndNRPTS(&front, timestamp);
+
+    if (AudioBufferProvider::kInvalidPTS != *timestamp) {
+        // If we have a valid read-pointer and next read timestamp pair, then
+        // use the current value of the write pointer to figure out how many
+        // frames are in the buffer, and offset the timestamp by that amt.  Then
+        // next time we write to the MonoPipe, the data will hit the speakers at
+        // the next read timestamp plus the current amount of data in the
+        // MonoPipe.
+        size_t pendingFrames = (mRear - front) & (mMaxFrames - 1);
+        *timestamp = offsetTimestampByAudioFrames(*timestamp, pendingFrames);
+    }
+
+    return OK;
+}
+
+void MonoPipe::updateFrontAndNRPTS(int32_t newFront, int64_t newNextRdPTS)
+{
+    // Set the MSB of the update sequence number to indicate that there is a
+    // multi-variable update in progress.  Use an atomic store with an "acquire"
+    // barrier to make sure that the next operations cannot be re-ordered and
+    // take place before the change to mUpdateSeq is commited..
+    int32_t tmp = mUpdateSeq | 0x80000000;
+    android_atomic_acquire_store(tmp, &mUpdateSeq);
+
+    // Update mFront and mNextRdPTS
+    mFront = newFront;
+    mNextRdPTS = newNextRdPTS;
+
+    // We are finished with the update.  Compute the next sequnce number (which
+    // should be the old sequence number, plus one, and with the MSB cleared)
+    // and then store it in mUpdateSeq using an atomic store with a "release"
+    // barrier so our update operations cannot be re-ordered past the update of
+    // the sequence number.
+    tmp = (tmp + 1) & 0x7FFFFFFF;
+    android_atomic_release_store(tmp, &mUpdateSeq);
+}
+
+void MonoPipe::observeFrontAndNRPTS(int32_t *outFront, int64_t *outNextRdPTS)
+{
+    // Perform an atomic observation of mFront and mNextRdPTS.  Basically,
+    // atomically observe the sequence number, then observer the variables, then
+    // atomically observe the sequence number again.  If the two observations of
+    // the sequence number match, and the update-in-progress bit was not set,
+    // then we know we have a successful atomic observation.  Otherwise, we loop
+    // around and try again.
+    //
+    // Note, it is very important that the observer be a lower priority thread
+    // than the updater.  If the updater is lower than the observer, or they are
+    // the same priority and running with SCHED_FIFO (implying that quantum
+    // based premption is disabled) then we run the risk of deadlock.
+    int32_t seqOne, seqTwo;
+
+    do {
+        seqOne        = android_atomic_acquire_load(&mUpdateSeq);
+        *outFront     = mFront;
+        *outNextRdPTS = mNextRdPTS;
+        seqTwo        = android_atomic_release_load(&mUpdateSeq);
+    } while ((seqOne != seqTwo) || (seqOne & 0x80000000));
+}
+
+int64_t MonoPipe::offsetTimestampByAudioFrames(int64_t ts, size_t audFrames)
+{
+    if (0 == mSamplesToLocalTime.a_to_b_denom)
+        return AudioBufferProvider::kInvalidPTS;
+
+    if (ts == AudioBufferProvider::kInvalidPTS)
+        return AudioBufferProvider::kInvalidPTS;
+
+    int64_t frame_lt_duration;
+    if (!mSamplesToLocalTime.doForwardTransform(audFrames,
+                                                &frame_lt_duration)) {
+        // This should never fail, but if there is a bug which is causing it
+        // to fail, this message would probably end up flooding the logs
+        // because the conversion would probably fail forever.  Log the
+        // error, but then zero out the ratio in the linear transform so
+        // that we don't try to do any conversions from now on.  This
+        // MonoPipe's getNextWriteTimestamp is now broken for good.
+        ALOGE("Overflow when attempting to convert %d audio frames to"
+              " duration in local time.  getNextWriteTimestamp will fail from"
+              " now on.", audFrames);
+        mSamplesToLocalTime.a_to_b_numer = 0;
+        mSamplesToLocalTime.a_to_b_denom = 0;
+        return AudioBufferProvider::kInvalidPTS;
+    }
+
+    return ts + frame_lt_duration;
+}
+
 }   // namespace android