diff --git a/include/media/stagefright/MediaCodecSource.h b/include/media/stagefright/MediaCodecSource.h
index d147b57..e3f3f5e 100644
--- a/include/media/stagefright/MediaCodecSource.h
+++ b/include/media/stagefright/MediaCodecSource.h
@@ -19,6 +19,7 @@
 
 #include <media/stagefright/foundation/ABase.h>
 #include <media/stagefright/foundation/AHandlerReflector.h>
+#include <media/stagefright/foundation/Mutexed.h>
 #include <media/stagefright/MediaSource.h>
 
 #include <gui/IGraphicBufferConsumer.h>
@@ -79,6 +80,7 @@
         kWhatStop,
         kWhatPause,
         kWhatSetInputBufferTimeOffset,
+        kWhatStopStalled,
     };
 
     MediaCodecSource(
@@ -127,12 +129,16 @@
     int64_t mFirstSampleTimeUs;
     List<int64_t> mDriftTimeQueue;
 
-    // following variables are protected by mOutputBufferLock
-    Mutex mOutputBufferLock;
-    Condition mOutputBufferCond;
-    List<MediaBuffer*> mOutputBufferQueue;
-    bool mEncoderReachedEOS;
-    status_t mErrorCode;
+    struct Output {
+        Output();
+        List<MediaBuffer*> mBufferQueue;
+        bool mEncoderReachedEOS;
+        status_t mErrorCode;
+        Condition mCond;
+    };
+    Mutexed<Output> mOutput;
+
+    int32_t mGeneration;
 
     DISALLOW_EVIL_CONSTRUCTORS(MediaCodecSource);
 };
diff --git a/media/libstagefright/MediaCodecSource.cpp b/media/libstagefright/MediaCodecSource.cpp
index a148d55..3a3a538 100644
--- a/media/libstagefright/MediaCodecSource.cpp
+++ b/media/libstagefright/MediaCodecSource.cpp
@@ -43,15 +43,19 @@
 const int kDefaultSwVideoEncoderFormat = HAL_PIXEL_FORMAT_YCbCr_420_888;
 const int kDefaultSwVideoEncoderDataSpace = HAL_DATASPACE_BT709;
 
+const int kStopTimeoutUs = 300000; // allow 1 sec for shutting down encoder
+
 struct MediaCodecSource::Puller : public AHandler {
     Puller(const sp<MediaSource> &source);
 
     status_t start(const sp<MetaData> &meta, const sp<AMessage> &notify);
     void stop();
-
+    void stopSource();
     void pause();
     void resume();
 
+    bool readBuffer(MediaBuffer **buffer);
+
 protected:
     virtual void onMessageReceived(const sp<AMessage> &msg);
     virtual ~Puller();
@@ -61,17 +65,31 @@
         kWhatStart = 'msta',
         kWhatStop,
         kWhatPull,
-        kWhatPause,
-        kWhatResume,
     };
 
     sp<MediaSource> mSource;
     sp<AMessage> mNotify;
     sp<ALooper> mLooper;
-    int32_t mPullGeneration;
     bool mIsAudio;
-    bool mPaused;
-    bool mReachedEOS;
+
+    struct Queue {
+        Queue()
+            : mReadPendingSince(0),
+              mPaused(false),
+              mPulling(false) { }
+        int64_t mReadPendingSince;
+        bool mPaused;
+        bool mPulling;
+        Vector<MediaBuffer *> mReadBuffers;
+
+        void flush();
+        // if queue is empty, return false and set *|buffer| to NULL . Otherwise, pop
+        // buffer from front of the queue, place it into *|buffer| and return true. 
+        bool readBuffer(MediaBuffer **buffer);
+        // add a buffer to the back of the queue 
+        void pushBuffer(MediaBuffer *mbuf);
+    };
+    Mutexed<Queue> mQueue;
 
     status_t postSynchronouslyAndReturnError(const sp<AMessage> &msg);
     void schedulePull();
@@ -83,10 +101,8 @@
 MediaCodecSource::Puller::Puller(const sp<MediaSource> &source)
     : mSource(source),
       mLooper(new ALooper()),
-      mPullGeneration(0),
-      mIsAudio(false),
-      mPaused(false),
-      mReachedEOS(false) {
+      mIsAudio(false)
+{
     sp<MetaData> meta = source->getFormat();
     const char *mime;
     CHECK(meta->findCString(kKeyMIMEType, &mime));
@@ -101,6 +117,33 @@
     mLooper->stop();
 }
 
+void MediaCodecSource::Puller::Queue::pushBuffer(MediaBuffer *mbuf) {
+    mReadBuffers.push_back(mbuf);
+}
+
+bool MediaCodecSource::Puller::Queue::readBuffer(MediaBuffer **mbuf) {
+    if (mReadBuffers.empty()) {
+        *mbuf = NULL;
+        return false;
+    }
+    *mbuf = *mReadBuffers.begin();
+    mReadBuffers.erase(mReadBuffers.begin());
+    return true;
+}
+
+void MediaCodecSource::Puller::Queue::flush() {
+    MediaBuffer *mbuf;
+    while (readBuffer(&mbuf)) {
+        // there are no null buffers in the queue
+        mbuf->release();
+    }
+}
+
+bool MediaCodecSource::Puller::readBuffer(MediaBuffer **mbuf) {
+    Mutexed<Queue>::Locked queue(mQueue);
+    return queue->readBuffer(mbuf);
+}
+
 status_t MediaCodecSource::Puller::postSynchronouslyAndReturnError(
         const sp<AMessage> &msg) {
     sp<AMessage> response;
@@ -117,8 +160,7 @@
     return err;
 }
 
-status_t MediaCodecSource::Puller::start(const sp<MetaData> &meta,
-        const sp<AMessage> &notify) {
+status_t MediaCodecSource::Puller::start(const sp<MetaData> &meta, const sp<AMessage> &notify) {
     ALOGV("puller (%s) start", mIsAudio ? "audio" : "video");
     mLooper->start(
             false /* runOnCallingThread */,
@@ -133,41 +175,46 @@
 }
 
 void MediaCodecSource::Puller::stop() {
-    // Stop source from caller's thread instead of puller's looper.
-    // mSource->stop() is thread-safe, doing it outside the puller's
-    // looper allows us to at least stop if source gets stuck.
-    // If source gets stuck in read(), the looper would never
-    // be able to process the stop(), which could lead to ANR.
+    bool interrupt = false;
+    {
+        // mark stopping before actually reaching kWhatStop on the looper, so the pulling will
+        // stop.
+        Mutexed<Queue>::Locked queue(mQueue);
+        queue->mPulling = false;
+        interrupt = queue->mReadPendingSince && (queue->mReadPendingSince < ALooper::GetNowUs() - 1000000);
+        queue->flush(); // flush any unprocessed pulled buffers
+    }
 
-    ALOGV("source (%s) stopping", mIsAudio ? "audio" : "video");
-    mSource->stop();
-    ALOGV("source (%s) stopped", mIsAudio ? "audio" : "video");
+    if (interrupt) {
+        // call source->stop if read has been pending for over a second
+        // TODO: we should really call this if kWhatStop has not returned for more than a second.
+        mSource->stop();
+    }
+}
 
+void MediaCodecSource::Puller::stopSource() {
     (new AMessage(kWhatStop, this))->post();
 }
 
 void MediaCodecSource::Puller::pause() {
-    (new AMessage(kWhatPause, this))->post();
+    Mutexed<Queue>::Locked queue(mQueue);
+    queue->mPaused = true;
 }
 
 void MediaCodecSource::Puller::resume() {
-    (new AMessage(kWhatResume, this))->post();
+    Mutexed<Queue>::Locked queue(mQueue);
+    queue->mPaused = false;
 }
 
 void MediaCodecSource::Puller::schedulePull() {
-    sp<AMessage> msg = new AMessage(kWhatPull, this);
-    msg->setInt32("generation", mPullGeneration);
-    msg->post();
+    (new AMessage(kWhatPull, this))->post();
 }
 
 void MediaCodecSource::Puller::handleEOS() {
-    if (!mReachedEOS) {
-        ALOGV("puller (%s) posting EOS", mIsAudio ? "audio" : "video");
-        mReachedEOS = true;
-        sp<AMessage> notify = mNotify->dup();
-        notify->setPointer("accessUnit", NULL);
-        notify->post();
-    }
+    ALOGV("puller (%s) posting EOS", mIsAudio ? "audio" : "video");
+    sp<AMessage> msg = mNotify->dup();
+    msg->setInt32("eos", 1);
+    msg->post();
 }
 
 void MediaCodecSource::Puller::onMessageReceived(const sp<AMessage> &msg) {
@@ -177,7 +224,10 @@
             sp<RefBase> obj;
             CHECK(msg->findObject("meta", &obj));
 
-            mReachedEOS = false;
+            {
+                Mutexed<Queue>::Locked queue(mQueue);
+                queue->mPulling = true;
+            }
 
             status_t err = mSource->start(static_cast<MetaData *>(obj.get()));
 
@@ -196,61 +246,52 @@
 
         case kWhatStop:
         {
-            ++mPullGeneration;
-
-            handleEOS();
+            mSource->stop();
             break;
         }
 
         case kWhatPull:
         {
-            int32_t generation;
-            CHECK(msg->findInt32("generation", &generation));
-
-            if (generation != mPullGeneration) {
+            Mutexed<Queue>::Locked queue(mQueue);
+            queue->mReadPendingSince = ALooper::GetNowUs();
+            if (!queue->mPulling) {
+                handleEOS();
                 break;
             }
 
-            MediaBuffer *mbuf;
+            queue.unlock();
+            MediaBuffer *mbuf = NULL;
             status_t err = mSource->read(&mbuf);
+            queue.lock();
 
-            if (mPaused) {
-                if (err == OK) {
+            queue->mReadPendingSince = 0;
+            // if we need to discard buffer
+            if (!queue->mPulling || queue->mPaused || err != OK) {
+                if (mbuf != NULL) {
                     mbuf->release();
                     mbuf = NULL;
                 }
-
-                msg->post();
-                break;
-            }
-
-            if (err != OK) {
-                if (err == ERROR_END_OF_STREAM) {
+                if (queue->mPulling && err == OK) {
+                    msg->post(); // if simply paused, keep pulling source
+                } else if (err == ERROR_END_OF_STREAM) {
                     ALOGV("stream ended, mbuf %p", mbuf);
-                } else {
+                } else if (err != OK) {
                     ALOGE("error %d reading stream.", err);
                 }
-                handleEOS();
-            } else {
-                sp<AMessage> notify = mNotify->dup();
-
-                notify->setPointer("accessUnit", mbuf);
-                notify->post();
-
-                msg->post();
             }
-            break;
-        }
 
-        case kWhatPause:
-        {
-            mPaused = true;
-            break;
-        }
+            if (mbuf != NULL) {
+                queue->pushBuffer(mbuf);
+            }
 
-        case kWhatResume:
-        {
-            mPaused = false;
+            queue.unlock();
+
+            if (mbuf != NULL) {
+                mNotify->post();
+                msg->post();
+            } else {
+                handleEOS();
+            }
             break;
         }
 
@@ -259,6 +300,11 @@
     }
 }
 
+MediaCodecSource::Output::Output()
+    : mEncoderReachedEOS(false),
+      mErrorCode(OK) {
+}
+
 // static
 sp<MediaCodecSource> MediaCodecSource::Create(
         const sp<ALooper> &looper,
@@ -289,21 +335,7 @@
 
 status_t MediaCodecSource::stop() {
     sp<AMessage> msg = new AMessage(kWhatStop, mReflector);
-    status_t err = postSynchronouslyAndReturnError(msg);
-
-    // mPuller->stop() needs to be done outside MediaCodecSource's looper,
-    // as it contains a synchronous call to stop the underlying MediaSource,
-    // which often waits for all outstanding MediaBuffers to return, but
-    // MediaBuffers are only returned when MediaCodecSource looper gets
-    // to process them.
-
-    if (mPuller != NULL) {
-        ALOGI("puller (%s) stopping", mIsVideo ? "video" : "audio");
-        mPuller->stop();
-        ALOGI("puller (%s) stopped", mIsVideo ? "video" : "audio");
-    }
-
-    return err;
+    return postSynchronouslyAndReturnError(msg);
 }
 
 status_t MediaCodecSource::pause() {
@@ -318,18 +350,18 @@
 
 status_t MediaCodecSource::read(
         MediaBuffer** buffer, const ReadOptions* /* options */) {
-    Mutex::Autolock autolock(mOutputBufferLock);
+    Mutexed<Output>::Locked output(mOutput);
 
     *buffer = NULL;
-    while (mOutputBufferQueue.size() == 0 && !mEncoderReachedEOS) {
-        mOutputBufferCond.wait(mOutputBufferLock);
+    while (output->mBufferQueue.size() == 0 && !output->mEncoderReachedEOS) {
+        output.waitForCondition(output->mCond);
     }
-    if (!mEncoderReachedEOS) {
-        *buffer = *mOutputBufferQueue.begin();
-        mOutputBufferQueue.erase(mOutputBufferQueue.begin());
+    if (!output->mEncoderReachedEOS) {
+        *buffer = *output->mBufferQueue.begin();
+        output->mBufferQueue.erase(output->mBufferQueue.begin());
         return OK;
     }
-    return mErrorCode;
+    return output->mErrorCode;
 }
 
 void MediaCodecSource::signalBufferReturned(MediaBuffer *buffer) {
@@ -357,8 +389,7 @@
       mGraphicBufferConsumer(consumer),
       mInputBufferTimeOffsetUs(0),
       mFirstSampleTimeUs(-1ll),
-      mEncoderReachedEOS(false),
-      mErrorCode(OK) {
+      mGeneration(0) {
     CHECK(mLooper != NULL);
 
     AString mime;
@@ -485,8 +516,11 @@
         return err;
     }
 
-    mEncoderReachedEOS = false;
-    mErrorCode = OK;
+    {
+        Mutexed<Output>::Locked output(mOutput);
+        output->mEncoderReachedEOS = false;
+        output->mErrorCode = OK;
+    }
 
     return OK;
 }
@@ -498,14 +532,6 @@
 
     mEncoder->release();
     mEncoder.clear();
-
-    while (!mInputBufferQueue.empty()) {
-        MediaBuffer *mbuf = *mInputBufferQueue.begin();
-        mInputBufferQueue.erase(mInputBufferQueue.begin());
-        if (mbuf != NULL) {
-            mbuf->release();
-        }
-    }
 }
 
 status_t MediaCodecSource::postSynchronouslyAndReturnError(
@@ -525,25 +551,32 @@
 }
 
 void MediaCodecSource::signalEOS(status_t err) {
-    if (!mEncoderReachedEOS) {
-        ALOGV("encoder (%s) reached EOS", mIsVideo ? "video" : "audio");
-        {
-            Mutex::Autolock autoLock(mOutputBufferLock);
+    bool reachedEOS = false;
+    {
+        Mutexed<Output>::Locked output(mOutput);
+        reachedEOS = output->mEncoderReachedEOS;
+        if (!reachedEOS) {
+            ALOGV("encoder (%s) reached EOS", mIsVideo ? "video" : "audio");
             // release all unread media buffers
-            for (List<MediaBuffer*>::iterator it = mOutputBufferQueue.begin();
-                    it != mOutputBufferQueue.end(); it++) {
+            for (List<MediaBuffer*>::iterator it = output->mBufferQueue.begin();
+                    it != output->mBufferQueue.end(); it++) {
                 (*it)->release();
             }
-            mOutputBufferQueue.clear();
-            mEncoderReachedEOS = true;
-            mErrorCode = err;
-            mOutputBufferCond.signal();
-        }
+            output->mBufferQueue.clear();
+            output->mEncoderReachedEOS = true;
+            output->mErrorCode = err;
+            output->mCond.signal();
 
-        releaseEncoder();
+            reachedEOS = true;
+            output.unlock();
+            releaseEncoder();
+        }
     }
-    if (mStopping && mEncoderReachedEOS) {
+
+    if (mStopping && reachedEOS) {
         ALOGI("encoder (%s) stopped", mIsVideo ? "video" : "audio");
+        mPuller->stopSource();
+        ALOGV("source (%s) stopped", mIsVideo ? "video" : "audio");
         // posting reply to everyone that's waiting
         List<sp<AReplyToken>>::iterator it;
         for (it = mStopReplyIDQueue.begin();
@@ -552,6 +585,7 @@
         }
         mStopReplyIDQueue.clear();
         mStopping = false;
+        ++mGeneration;
     }
 }
 
@@ -577,11 +611,8 @@
 }
 
 status_t MediaCodecSource::feedEncoderInputBuffers() {
-    while (!mInputBufferQueue.empty()
-            && !mAvailEncoderInputIndices.empty()) {
-        MediaBuffer* mbuf = *mInputBufferQueue.begin();
-        mInputBufferQueue.erase(mInputBufferQueue.begin());
-
+    MediaBuffer* mbuf = NULL;
+    while (!mAvailEncoderInputIndices.empty() && mPuller->readBuffer(&mbuf)) {
         size_t bufferIndex = *mAvailEncoderInputIndices.begin();
         mAvailEncoderInputIndices.erase(mAvailEncoderInputIndices.begin());
 
@@ -700,30 +731,19 @@
     switch (msg->what()) {
     case kWhatPullerNotify:
     {
-        MediaBuffer *mbuf;
-        CHECK(msg->findPointer("accessUnit", (void**)&mbuf));
-
-        if (mbuf == NULL) {
-            ALOGV("puller (%s) reached EOS",
-                    mIsVideo ? "video" : "audio");
+        int32_t eos = 0;
+        if (msg->findInt32("eos", &eos) && eos) {
+            ALOGV("puller (%s) reached EOS", mIsVideo ? "video" : "audio");
             signalEOS();
-        }
-
-        if (mEncoder == NULL) {
-            ALOGV("got msg '%s' after encoder shutdown.",
-                  msg->debugString().c_str());
-
-            if (mbuf != NULL) {
-                mbuf->release();
-            }
-
             break;
         }
 
-        mInputBufferQueue.push_back(mbuf);
+        if (mEncoder == NULL) {
+            ALOGV("got msg '%s' after encoder shutdown.", msg->debugString().c_str());
+            break;
+        }
 
         feedEncoderInputBuffers();
-
         break;
     }
     case kWhatEncoderActivity:
@@ -815,9 +835,9 @@
             mbuf->add_ref();
 
             {
-                Mutex::Autolock autoLock(mOutputBufferLock);
-                mOutputBufferQueue.push_back(mbuf);
-                mOutputBufferCond.signal();
+                Mutexed<Output>::Locked output(mOutput);
+                output->mBufferQueue.push_back(mbuf);
+                output->mCond.signal();
             }
 
             mEncoder->releaseOutputBuffer(index);
@@ -851,7 +871,7 @@
         sp<AReplyToken> replyID;
         CHECK(msg->senderAwaitsResponse(&replyID));
 
-        if (mEncoderReachedEOS) {
+        if (mOutput.lock()->mEncoderReachedEOS) {
             // if we already reached EOS, reply and return now
             ALOGI("encoder (%s) already stopped",
                     mIsVideo ? "video" : "audio");
@@ -869,14 +889,38 @@
         mStopping = true;
 
         // if using surface, signal source EOS and wait for EOS to come back.
-        // otherwise, release encoder and post EOS if haven't done already
+        // otherwise, stop puller (which also clears the input buffer queue)
+        // and wait for the EOS message. We cannot call source->stop() because
+        // the encoder may still be processing input buffers.
         if (mFlags & FLAG_USE_SURFACE_INPUT) {
             mEncoder->signalEndOfInputStream();
         } else {
-            signalEOS();
+            mPuller->stop();
         }
+
+        // complete stop even if encoder/puller stalled
+        sp<AMessage> timeoutMsg = new AMessage(kWhatStopStalled, mReflector);
+        timeoutMsg->setInt32("generation", mGeneration);
+        timeoutMsg->post(kStopTimeoutUs);
         break;
     }
+
+    case kWhatStopStalled:
+    {
+        int32_t generation;
+        CHECK(msg->findInt32("generation", &generation));
+        if (generation != mGeneration) {
+             break;
+        }
+
+        if (!(mFlags & FLAG_USE_SURFACE_INPUT)) {
+            ALOGV("source (%s) stopping", mIsVideo ? "video" : "audio");
+            mPuller->stopSource();
+            ALOGV("source (%s) stopped", mIsVideo ? "video" : "audio");
+        }
+        signalEOS();
+    }
+
     case kWhatPause:
     {
         if (mFlags & FLAG_USE_SURFACE_INPUT) {