diff --git a/media/libmediaplayerservice/nuplayer/NuPlayerDecoder.cpp b/media/libmediaplayerservice/nuplayer/NuPlayerDecoder.cpp
index e1d426a..1d62498 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayerDecoder.cpp
+++ b/media/libmediaplayerservice/nuplayer/NuPlayerDecoder.cpp
@@ -203,6 +203,18 @@
             break;
         }
 
+        case kWhatAudioOutputFormatChanged:
+        {
+            if (!isStaleReply(msg)) {
+                status_t err;
+                if (msg->findInt32("err", &err) && err != OK) {
+                    ALOGE("Renderer reported 0x%x when changing audio output format", err);
+                    handleError(err);
+                }
+            }
+            break;
+        }
+
         case kWhatSetVideoSurface:
         {
             sp<AReplyToken> replyID;
@@ -699,15 +711,10 @@
             flags = AUDIO_OUTPUT_FLAG_NONE;
         }
 
-        // TODO: This is a temporary fix to flush audio buffers in renderer. The real
-        // fix should be to wait for all buffers rendered normally, then open a new
-        // AudioSink.
-        mRenderer->flush(true /* audio */, false /* notifyComplete */);
-        status_t err = mRenderer->openAudioSink(
-                format, false /* offloadOnly */, hasVideo, flags, NULL /* isOffloaed */);
-        if (err != OK) {
-            handleError(err);
-        }
+        sp<AMessage> reply = new AMessage(kWhatAudioOutputFormatChanged, this);
+        reply->setInt32("generation", mBufferGeneration);
+        mRenderer->changeAudioFormat(
+                format, false /* offloadOnly */, hasVideo, flags, reply);
     }
 }
 
diff --git a/media/libmediaplayerservice/nuplayer/NuPlayerDecoder.h b/media/libmediaplayerservice/nuplayer/NuPlayerDecoder.h
index fcf601b..82db59c 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayerDecoder.h
+++ b/media/libmediaplayerservice/nuplayer/NuPlayerDecoder.h
@@ -56,7 +56,8 @@
     enum {
         kWhatCodecNotify         = 'cdcN',
         kWhatRenderBuffer        = 'rndr',
-        kWhatSetVideoSurface     = 'sSur'
+        kWhatSetVideoSurface     = 'sSur',
+        kWhatAudioOutputFormatChanged = 'aofc'
     };
 
     enum {
diff --git a/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.cpp b/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.cpp
index b78bdfb..42e95da 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.cpp
+++ b/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.cpp
@@ -144,9 +144,10 @@
 
     // Try to avoid racing condition in case callback is still on.
     Mutex::Autolock autoLock(mLock);
-    mUseAudioCallback = false;
-    flushQueue(&mAudioQueue);
-    flushQueue(&mVideoQueue);
+    if (mUseAudioCallback) {
+        flushQueue(&mAudioQueue);
+        flushQueue(&mVideoQueue);
+    }
     mWakeLock.clear();
     mMediaClock.clear();
     mVideoScheduler.clear();
@@ -297,7 +298,7 @@
             ++mVideoDrainGeneration;
         }
 
-        clearAnchorTime_l();
+        mMediaClock->clearAnchor();
         mVideoLateByUs = 0;
         mSyncQueues = false;
     }
@@ -374,7 +375,8 @@
     }
 }
 
-void NuPlayer::Renderer::clearAnchorTime_l() {
+// Called on renderer looper.
+void NuPlayer::Renderer::clearAnchorTime() {
     mMediaClock->clearAnchor();
     mAnchorTimeMediaUs = -1;
     mAnchorNumFramesWritten = -1;
@@ -423,6 +425,25 @@
     msg->postAndAwaitResponse(&response);
 }
 
+void NuPlayer::Renderer::changeAudioFormat(
+        const sp<AMessage> &format,
+        bool offloadOnly,
+        bool hasVideo,
+        uint32_t flags,
+        const sp<AMessage> &notify) {
+    sp<AMessage> meta = new AMessage;
+    meta->setMessage("format", format);
+    meta->setInt32("offload-only", offloadOnly);
+    meta->setInt32("has-video", hasVideo);
+    meta->setInt32("flags", flags);
+
+    sp<AMessage> msg = new AMessage(kWhatChangeAudioFormat, this);
+    msg->setInt32("queueGeneration", getQueueGeneration(true /* audio */));
+    msg->setMessage("notify", notify);
+    msg->setMessage("meta", meta);
+    msg->post();
+}
+
 void NuPlayer::Renderer::onMessageReceived(const sp<AMessage> &msg) {
     switch (msg->what()) {
         case kWhatOpenAudioSink:
@@ -470,6 +491,41 @@
             break;
         }
 
+        case kWhatChangeAudioFormat:
+        {
+            int32_t queueGeneration;
+            CHECK(msg->findInt32("queueGeneration", &queueGeneration));
+
+            sp<AMessage> notify;
+            CHECK(msg->findMessage("notify", &notify));
+
+            if (offloadingAudio()) {
+                ALOGW("changeAudioFormat should NOT be called in offload mode");
+                notify->setInt32("err", INVALID_OPERATION);
+                notify->post();
+                break;
+            }
+
+            sp<AMessage> meta;
+            CHECK(msg->findMessage("meta", &meta));
+
+            if (queueGeneration != getQueueGeneration(true /* audio */)
+                    || mAudioQueue.empty()) {
+                onChangeAudioFormat(meta, notify);
+                break;
+            }
+
+            QueueEntry entry;
+            entry.mNotifyConsumed = notify;
+            entry.mMeta = meta;
+
+            Mutex::Autolock autoLock(mLock);
+            mAudioQueue.push_back(entry);
+            postDrainAudioQueue_l();
+
+            break;
+        }
+
         case kWhatDrainAudioQueue:
         {
             mDrainAudioQueuePending = false;
@@ -869,7 +925,7 @@
     while (it != mAudioQueue.end()) {
         int32_t eos;
         QueueEntry *entry = &*it++;
-        if (entry->mBuffer == NULL
+        if ((entry->mBuffer == nullptr && entry->mNotifyConsumed == nullptr)
                 || (entry->mNotifyConsumed->findInt32("eos", &eos) && eos != 0)) {
             itEOS = it;
             foundEOS = true;
@@ -879,9 +935,14 @@
     if (foundEOS) {
         // post all replies before EOS and drop the samples
         for (it = mAudioQueue.begin(); it != itEOS; it++) {
-            if (it->mBuffer == NULL) {
-                // delay doesn't matter as we don't even have an AudioTrack
-                notifyEOS(true /* audio */, it->mFinalResult);
+            if (it->mBuffer == nullptr) {
+                if (it->mNotifyConsumed == nullptr) {
+                    // delay doesn't matter as we don't even have an AudioTrack
+                    notifyEOS(true /* audio */, it->mFinalResult);
+                } else {
+                    // TAG for re-opening audio sink.
+                    onChangeAudioFormat(it->mMeta, it->mNotifyConsumed);
+                }
             } else {
                 it->mNotifyConsumed->post();
             }
@@ -933,9 +994,14 @@
     while (!mAudioQueue.empty()) {
         QueueEntry *entry = &*mAudioQueue.begin();
 
-        mLastAudioBufferDrained = entry->mBufferOrdinal;
-
         if (entry->mBuffer == NULL) {
+            if (entry->mNotifyConsumed != nullptr) {
+                // TAG for re-open audio sink.
+                onChangeAudioFormat(entry->mMeta, entry->mNotifyConsumed);
+                mAudioQueue.erase(mAudioQueue.begin());
+                continue;
+            }
+
             // EOS
             int64_t postEOSDelayUs = 0;
             if (mAudioSink->needsTrailingPadding()) {
@@ -956,6 +1022,8 @@
             return false;
         }
 
+        mLastAudioBufferDrained = entry->mBufferOrdinal;
+
         // ignore 0-sized buffer which could be EOS marker with no data
         if (entry->mOffset == 0 && entry->mBuffer->size() > 0) {
             int64_t mediaTimeUs;
@@ -1291,8 +1359,7 @@
         if (!mVideoSampleReceived && !mHasAudio) {
             // This will ensure that the first frame after a flush won't be used as anchor
             // when renderer is in paused state, because resume can happen any time after seek.
-            Mutex::Autolock autoLock(mLock);
-            clearAnchorTime_l();
+            clearAnchorTime();
         }
     }
 
@@ -1502,8 +1569,8 @@
         // Therefore we'll stop syncing the queues if at least one of them
         // is flushed.
         syncQueuesDone_l();
-        clearAnchorTime_l();
     }
+    clearAnchorTime();
 
     ALOGV("flushing %s", audio ? "audio" : "video");
     if (audio) {
@@ -1574,6 +1641,9 @@
 
         if (entry->mBuffer != NULL) {
             entry->mNotifyConsumed->post();
+        } else if (entry->mNotifyConsumed != nullptr) {
+            // Is it needed to open audio sink now?
+            onChangeAudioFormat(entry->mMeta, entry->mNotifyConsumed);
         }
 
         queue->erase(queue->begin());
@@ -1611,10 +1681,7 @@
     }
     CHECK(!mDrainAudioQueuePending);
     mNumFramesWritten = 0;
-    {
-        Mutex::Autolock autoLock(mLock);
-        mAnchorNumFramesWritten = -1;
-    }
+    mAnchorNumFramesWritten = -1;
     uint32_t written;
     if (mAudioSink->getFramesWritten(&written) == OK) {
         mNumFramesWritten = written;
@@ -1962,5 +2029,27 @@
     mCurrentPcmInfo = AUDIO_PCMINFO_INITIALIZER;
 }
 
+void NuPlayer::Renderer::onChangeAudioFormat(
+        const sp<AMessage> &meta, const sp<AMessage> &notify) {
+    sp<AMessage> format;
+    CHECK(meta->findMessage("format", &format));
+
+    int32_t offloadOnly;
+    CHECK(meta->findInt32("offload-only", &offloadOnly));
+
+    int32_t hasVideo;
+    CHECK(meta->findInt32("has-video", &hasVideo));
+
+    uint32_t flags;
+    CHECK(meta->findInt32("flags", (int32_t *)&flags));
+
+    status_t err = onOpenAudioSink(format, offloadOnly, hasVideo, flags);
+
+    if (err != OK) {
+        notify->setInt32("err", err);
+    }
+    notify->post();
+}
+
 }  // namespace android
 
diff --git a/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.h b/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.h
index 0bd3aa1..385bb06 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.h
+++ b/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.h
@@ -60,8 +60,6 @@
 
     void signalTimeDiscontinuity();
 
-    void signalAudioSinkChanged();
-
     void signalDisableOffloadAudio();
     void signalEnableOffloadAudio();
 
@@ -81,6 +79,14 @@
             bool *isOffloaded);
     void closeAudioSink();
 
+    // re-open audio sink after all pending audio buffers played.
+    void changeAudioFormat(
+            const sp<AMessage> &format,
+            bool offloadOnly,
+            bool hasVideo,
+            uint32_t flags,
+            const sp<AMessage> &notify);
+
     enum {
         kWhatEOS                      = 'eos ',
         kWhatFlushComplete            = 'fluC',
@@ -118,14 +124,19 @@
         kWhatResume              = 'resm',
         kWhatOpenAudioSink       = 'opnA',
         kWhatCloseAudioSink      = 'clsA',
+        kWhatChangeAudioFormat   = 'chgA',
         kWhatStopAudioSink       = 'stpA',
         kWhatDisableOffloadAudio = 'noOA',
         kWhatEnableOffloadAudio  = 'enOA',
         kWhatSetVideoFrameRate   = 'sVFR',
     };
 
+    // if mBuffer != nullptr, it's a buffer containing real data.
+    // else if mNotifyConsumed == nullptr, it's EOS.
+    // else it's a tag for re-opening audio sink in different format.
     struct QueueEntry {
         sp<MediaCodecBuffer> mBuffer;
+        sp<AMessage> mMeta;
         sp<AMessage> mNotifyConsumed;
         size_t mOffset;
         status_t mFinalResult;
@@ -220,7 +231,7 @@
     int64_t getPendingAudioPlayoutDurationUs(int64_t nowUs);
     void postDrainAudioQueue_l(int64_t delayUs = 0);
 
-    void clearAnchorTime_l();
+    void clearAnchorTime();
     void clearAudioFirstAnchorTime_l();
     void setAudioFirstAnchorTimeIfNeeded_l(int64_t mediaUs);
     void setVideoLateByUs(int64_t lateUs);
@@ -258,6 +269,7 @@
             bool hasVideo,
             uint32_t flags);
     void onCloseAudioSink();
+    void onChangeAudioFormat(const sp<AMessage> &meta, const sp<AMessage> &notify);
 
     void notifyEOS(bool audio, status_t finalResult, int64_t delayUs = 0);
     void notifyFlushComplete(bool audio);