Camera3: Add ZSL stream support

Bug: 8563838

Change-Id: I2feda142ff5172aba17ade5c8d502f9bb5d5b766

19 files changed, 1751 insertions, 66 deletions

diff --git a/services/camera/libcameraservice/Android.mk b/services/camera/libcameraservice/Android.mk
index e1c36d5..8ae414f 100644
--- a/services/camera/libcameraservice/Android.mk
+++ b/services/camera/libcameraservice/Android.mk
@@ -25,6 +25,7 @@ LOCAL_SRC_FILES:=               \
     camera2/JpegCompressor.cpp \
     camera2/CaptureSequencer.cpp \
     camera2/ProFrameProcessor.cpp \
+    camera2/ZslProcessor3.cpp \
     camera3/Camera3Stream.cpp \
     camera3/Camera3InputStream.cpp \
     camera3/Camera3OutputStream.cpp \
diff --git a/services/camera/libcameraservice/Camera2Client.cpp b/services/camera/libcameraservice/Camera2Client.cpp
index eae7461..48f3606 100644
--- a/services/camera/libcameraservice/Camera2Client.cpp
+++ b/services/camera/libcameraservice/Camera2Client.cpp
@@ -28,6 +28,9 @@
 #include "Camera2Device.h"
 #include "Camera3Device.h"
 
+#include "camera2/ZslProcessor.h"
+#include "camera2/ZslProcessor3.h"
+
 #define ALOG1(...) ALOGD_IF(gLogLevel >= 1, __VA_ARGS__);
 #define ALOG2(...) ALOGD_IF(gLogLevel >= 2, __VA_ARGS__);
 
@@ -51,12 +54,13 @@ Camera2Client::Camera2Client(const sp<CameraService>& cameraService,
         int deviceVersion):
         Camera2ClientBase(cameraService, cameraClient, clientPackageName,
                 cameraId, cameraFacing, clientPid, clientUid, servicePid),
-        mParameters(cameraId, cameraFacing)
+        mParameters(cameraId, cameraFacing),
+        mDeviceVersion(deviceVersion)
 {
     ATRACE_CALL();
     ALOGI("Camera %d: Opened", cameraId);
 
-    switch (deviceVersion) {
+    switch (mDeviceVersion) {
         case CAMERA_DEVICE_API_VERSION_2_0:
             mDevice = new Camera2Device(cameraId);
             break;
@@ -65,7 +69,7 @@ Camera2Client::Camera2Client(const sp<CameraService>& cameraService,
             break;
         default:
             ALOGE("Camera %d: Unknown HAL device version %d",
-                    cameraId, deviceVersion);
+                    cameraId, mDeviceVersion);
             mDevice = NULL;
             break;
     }
@@ -114,10 +118,27 @@ status_t Camera2Client::initialize(camera_module_t *module)
             mCameraId);
     mJpegProcessor->run(threadName.string());
 
-    mZslProcessor = new ZslProcessor(this, mCaptureSequencer);
+    switch (mDeviceVersion) {
+        case CAMERA_DEVICE_API_VERSION_2_0: {
+            sp<ZslProcessor> zslProc =
+                    new ZslProcessor(this, mCaptureSequencer);
+            mZslProcessor = zslProc;
+            mZslProcessorThread = zslProc;
+            break;
+        }
+        case CAMERA_DEVICE_API_VERSION_3_0:{
+            sp<ZslProcessor3> zslProc =
+                    new ZslProcessor3(this, mCaptureSequencer);
+            mZslProcessor = zslProc;
+            mZslProcessorThread = zslProc;
+            break;
+        }
+        default:
+            break;
+    }
     threadName = String8::format("C2-%d-ZslProc",
             mCameraId);
-    mZslProcessor->run(threadName.string());
+    mZslProcessorThread->run(threadName.string());
 
     mCallbackProcessor = new CallbackProcessor(this);
     threadName = String8::format("C2-%d-CallbkProc",
@@ -393,7 +414,7 @@ void Camera2Client::disconnect() {
     mFrameProcessor->requestExit();
     mCaptureSequencer->requestExit();
     mJpegProcessor->requestExit();
-    mZslProcessor->requestExit();
+    mZslProcessorThread->requestExit();
     mCallbackProcessor->requestExit();
 
     ALOGV("Camera %d: Waiting for threads", mCameraId);
@@ -401,7 +422,7 @@ void Camera2Client::disconnect() {
     mFrameProcessor->join();
     mCaptureSequencer->join();
     mJpegProcessor->join();
-    mZslProcessor->join();
+    mZslProcessorThread->join();
     mCallbackProcessor->join();
 
     ALOGV("Camera %d: Disconnecting device", mCameraId);
diff --git a/services/camera/libcameraservice/Camera2Client.h b/services/camera/libcameraservice/Camera2Client.h
index 713fab3..af72ab2 100644
--- a/services/camera/libcameraservice/Camera2Client.h
+++ b/services/camera/libcameraservice/Camera2Client.h
@@ -23,7 +23,7 @@
 #include "camera2/FrameProcessor.h"
 #include "camera2/StreamingProcessor.h"
 #include "camera2/JpegProcessor.h"
-#include "camera2/ZslProcessor.h"
+#include "camera2/ZslProcessorInterface.h"
 #include "camera2/CaptureSequencer.h"
 #include "camera2/CallbackProcessor.h"
 #include "Camera2ClientBase.h"
@@ -154,6 +154,7 @@ private:
 
     void     setPreviewCallbackFlagL(Parameters &params, int flag);
     status_t updateRequests(Parameters &params);
+    int mDeviceVersion;
 
     // Used with stream IDs
     static const int NO_STREAM = -1;
@@ -173,7 +174,8 @@ private:
 
     sp<camera2::CaptureSequencer> mCaptureSequencer;
     sp<camera2::JpegProcessor> mJpegProcessor;
-    sp<camera2::ZslProcessor> mZslProcessor;
+    sp<camera2::ZslProcessorInterface> mZslProcessor;
+    sp<Thread> mZslProcessorThread;
 
     /** Notification-related members */
 
diff --git a/services/camera/libcameraservice/Camera3Device.cpp b/services/camera/libcameraservice/Camera3Device.cpp
index 3437130..748f3a7 100644
--- a/services/camera/libcameraservice/Camera3Device.cpp
+++ b/services/camera/libcameraservice/Camera3Device.cpp
@@ -433,6 +433,81 @@ status_t Camera3Device::createInputStream(
     return OK;
 }
 
+
+status_t Camera3Device::createZslStream(
+            uint32_t width, uint32_t height,
+            int depth,
+            /*out*/
+            int *id,
+            sp<Camera3ZslStream>* zslStream) {
+    ATRACE_CALL();
+    Mutex::Autolock l(mLock);
+
+    status_t res;
+    bool wasActive = false;
+
+    switch (mStatus) {
+        case STATUS_ERROR:
+            ALOGE("%s: Device has encountered a serious error", __FUNCTION__);
+            return INVALID_OPERATION;
+        case STATUS_UNINITIALIZED:
+            ALOGE("%s: Device not initialized", __FUNCTION__);
+            return INVALID_OPERATION;
+        case STATUS_IDLE:
+            // OK
+            break;
+        case STATUS_ACTIVE:
+            ALOGV("%s: Stopping activity to reconfigure streams", __FUNCTION__);
+            mRequestThread->setPaused(true);
+            res = waitUntilDrainedLocked();
+            if (res != OK) {
+                ALOGE("%s: Can't pause captures to reconfigure streams!",
+                        __FUNCTION__);
+                mStatus = STATUS_ERROR;
+                return res;
+            }
+            wasActive = true;
+            break;
+        default:
+            ALOGE("%s: Unexpected status: %d", __FUNCTION__, mStatus);
+            return INVALID_OPERATION;
+    }
+    assert(mStatus == STATUS_IDLE);
+
+    if (mInputStream != 0) {
+        ALOGE("%s: Cannot create more than 1 input stream", __FUNCTION__);
+        return INVALID_OPERATION;
+    }
+
+    sp<Camera3ZslStream> newStream = new Camera3ZslStream(mNextStreamId,
+                width, height, depth);
+
+    res = mOutputStreams.add(mNextStreamId, newStream);
+    if (res < 0) {
+        ALOGE("%s: Can't add new stream to set: %s (%d)",
+                __FUNCTION__, strerror(-res), res);
+        return res;
+    }
+    mInputStream = newStream;
+
+    *id = mNextStreamId++;
+    *zslStream = newStream;
+
+    // Continue captures if active at start
+    if (wasActive) {
+        ALOGV("%s: Restarting activity to reconfigure streams", __FUNCTION__);
+        res = configureStreamsLocked();
+        if (res != OK) {
+            ALOGE("%s: Can't reconfigure device for new stream %d: %s (%d)",
+                    __FUNCTION__, mNextStreamId, strerror(-res), res);
+            return res;
+        }
+        mRequestThread->setPaused(false);
+    }
+
+    return OK;
+}
+
 status_t Camera3Device::createStream(sp<ANativeWindow> consumer,
         uint32_t width, uint32_t height, int format, size_t size, int *id) {
     ATRACE_CALL();
@@ -588,7 +663,7 @@ status_t Camera3Device::deleteStream(int id) {
         return INVALID_OPERATION;
     }
 
-    sp<Camera3Stream> deletedStream;
+    sp<Camera3StreamInterface> deletedStream;
     if (mInputStream != NULL && id == mInputStream->getId()) {
         deletedStream = mInputStream;
         mInputStream.clear();
@@ -881,7 +956,8 @@ sp<Camera3Device::CaptureRequest> Camera3Device::createCaptureRequest(
                     __FUNCTION__, streams.data.u8[i]);
             return NULL;
         }
-        sp<Camera3OutputStream> stream = mOutputStreams.editValueAt(idx);
+        sp<Camera3OutputStreamInterface> stream =
+                mOutputStreams.editValueAt(idx);
 
         // Lazy completion of stream configuration (allocation/registration)
         // on first use
@@ -932,6 +1008,15 @@ status_t Camera3Device::configureStreamsLocked() {
     }
 
     for (size_t i = 0; i < mOutputStreams.size(); i++) {
+
+        // Don't configure bidi streams twice, nor add them twice to the list
+        if (mOutputStreams[i].get() ==
+            static_cast<Camera3StreamInterface*>(mInputStream.get())) {
+
+            config.num_streams--;
+            continue;
+        }
+
         camera3_stream_t *outputStream;
         outputStream = mOutputStreams.editValueAt(i)->startConfiguration();
         if (outputStream == NULL) {
diff --git a/services/camera/libcameraservice/Camera3Device.h b/services/camera/libcameraservice/Camera3Device.h
index 5c5faeb..9b26f06 100644
--- a/services/camera/libcameraservice/Camera3Device.h
+++ b/services/camera/libcameraservice/Camera3Device.h
@@ -26,6 +26,7 @@
 #include "CameraDeviceBase.h"
 #include "camera3/Camera3Stream.h"
 #include "camera3/Camera3OutputStream.h"
+#include "camera3/Camera3ZslStream.h"
 
 #include "hardware/camera3.h"
 
@@ -85,6 +86,12 @@ class Camera3Device :
     virtual status_t createInputStream(
             uint32_t width, uint32_t height, int format,
             int *id);
+    virtual status_t createZslStream(
+            uint32_t width, uint32_t height,
+            int depth,
+            /*out*/
+            int *id,
+            sp<camera3::Camera3ZslStream>* zslStream);
     virtual status_t createReprocessStreamFromStream(int outputId, int *id);
 
     virtual status_t getStreamInfo(int id,
@@ -132,14 +139,15 @@ class Camera3Device :
     }                          mStatus;
 
     // Mapping of stream IDs to stream instances
-    typedef KeyedVector<int, sp<camera3::Camera3OutputStream> > StreamSet;
+    typedef KeyedVector<int, sp<camera3::Camera3OutputStreamInterface> >
+            StreamSet;
 
     StreamSet                  mOutputStreams;
     sp<camera3::Camera3Stream> mInputStream;
     int                        mNextStreamId;
 
     // Need to hold on to stream references until configure completes.
-    Vector<sp<camera3::Camera3Stream> > mDeletedStreams;
+    Vector<sp<camera3::Camera3StreamInterface> > mDeletedStreams;
 
     /**** End scope for mLock ****/
 
@@ -147,7 +155,8 @@ class Camera3Device :
       public:
         CameraMetadata                      mSettings;
         sp<camera3::Camera3Stream>          mInputStream;
-        Vector<sp<camera3::Camera3Stream> > mOutputStreams;
+        Vector<sp<camera3::Camera3OutputStreamInterface> >
+                                            mOutputStreams;
     };
     typedef List<sp<CaptureRequest> > RequestList;
 
diff --git a/services/camera/libcameraservice/camera2/CaptureSequencer.cpp b/services/camera/libcameraservice/camera2/CaptureSequencer.cpp
index ee03329..266e516 100644
--- a/services/camera/libcameraservice/camera2/CaptureSequencer.cpp
+++ b/services/camera/libcameraservice/camera2/CaptureSequencer.cpp
@@ -27,6 +27,7 @@
 #include "../Camera2Device.h"
 #include "../Camera2Client.h"
 #include "Parameters.h"
+#include "ZslProcessorInterface.h"
 
 namespace android {
 namespace camera2 {
@@ -54,7 +55,7 @@ CaptureSequencer::~CaptureSequencer() {
     ALOGV("%s: Exit", __FUNCTION__);
 }
 
-void CaptureSequencer::setZslProcessor(wp<ZslProcessor> processor) {
+void CaptureSequencer::setZslProcessor(wp<ZslProcessorInterface> processor) {
     Mutex::Autolock l(mInputMutex);
     mZslProcessor = processor;
 }
@@ -265,8 +266,10 @@ CaptureSequencer::CaptureState CaptureSequencer::manageDone(sp<Camera2Client> &c
                 res = INVALID_OPERATION;
         }
     }
-    sp<ZslProcessor> processor = mZslProcessor.promote();
+    sp<ZslProcessorInterface> processor = mZslProcessor.promote();
     if (processor != 0) {
+        ALOGV("%s: Memory optimization, clearing ZSL queue",
+              __FUNCTION__);
         processor->clearZslQueue();
     }
 
@@ -324,7 +327,7 @@ CaptureSequencer::CaptureState CaptureSequencer::manageZslStart(
         sp<Camera2Client> &client) {
     ALOGV("%s", __FUNCTION__);
     status_t res;
-    sp<ZslProcessor> processor = mZslProcessor.promote();
+    sp<ZslProcessorInterface> processor = mZslProcessor.promote();
     if (processor == 0) {
         ALOGE("%s: No ZSL queue to use!", __FUNCTION__);
         return DONE;
diff --git a/services/camera/libcameraservice/camera2/CaptureSequencer.h b/services/camera/libcameraservice/camera2/CaptureSequencer.h
index 7db8007..76750aa 100644
--- a/services/camera/libcameraservice/camera2/CaptureSequencer.h
+++ b/services/camera/libcameraservice/camera2/CaptureSequencer.h
@@ -33,7 +33,7 @@ class Camera2Client;
 
 namespace camera2 {
 
-class ZslProcessor;
+class ZslProcessorInterface;
 class BurstCapture;
 
 /**
@@ -48,7 +48,7 @@ class CaptureSequencer:
     ~CaptureSequencer();
 
     // Get reference to the ZslProcessor, which holds the ZSL buffers and frames
-    void setZslProcessor(wp<ZslProcessor> processor);
+    void setZslProcessor(wp<ZslProcessorInterface> processor);
 
     // Begin still image capture
     status_t startCapture(int msgType);
@@ -105,7 +105,7 @@ class CaptureSequencer:
     static const int kMaxTimeoutsForCaptureEnd    = 40;  // 4 sec
 
     wp<Camera2Client> mClient;
-    wp<ZslProcessor> mZslProcessor;
+    wp<ZslProcessorInterface> mZslProcessor;
     sp<BurstCapture> mBurstCapture;
 
     enum CaptureState {
diff --git a/services/camera/libcameraservice/camera2/ZslProcessor.cpp b/services/camera/libcameraservice/camera2/ZslProcessor.cpp
index 2c12fb0..94059cd 100644
--- a/services/camera/libcameraservice/camera2/ZslProcessor.cpp
+++ b/services/camera/libcameraservice/camera2/ZslProcessor.cpp
@@ -248,11 +248,6 @@ int ZslProcessor::getStreamId() const {
     return mZslStreamId;
 }
 
-int ZslProcessor::getReprocessStreamId() const {
-    Mutex::Autolock l(mInputMutex);
-    return mZslReprocessStreamId;
-}
-
 status_t ZslProcessor::pushToReprocess(int32_t requestId) {
     ALOGV("%s: Send in reprocess request with id %d",
             __FUNCTION__, requestId);
diff --git a/services/camera/libcameraservice/camera2/ZslProcessor.h b/services/camera/libcameraservice/camera2/ZslProcessor.h
index ee3bcd6..27b597e 100644
--- a/services/camera/libcameraservice/camera2/ZslProcessor.h
+++ b/services/camera/libcameraservice/camera2/ZslProcessor.h
@@ -28,6 +28,7 @@
 #include "camera/CameraMetadata.h"
 #include "Camera2Heap.h"
 #include "../CameraDeviceBase.h"
+#include "ZslProcessorInterface.h"
 
 namespace android {
 
@@ -44,7 +45,8 @@ class ZslProcessor:
             virtual public Thread,
             virtual public BufferItemConsumer::FrameAvailableListener,
             virtual public FrameProcessor::FilteredListener,
-            virtual public CameraDeviceBase::BufferReleasedListener {
+            virtual public CameraDeviceBase::BufferReleasedListener,
+                    public ZslProcessorInterface {
   public:
     ZslProcessor(sp<Camera2Client> client, wp<CaptureSequencer> sequencer);
     ~ZslProcessor();
@@ -56,10 +58,15 @@ class ZslProcessor:
 
     virtual void onBufferReleased(buffer_handle_t *handle);
 
+    /**
+     ****************************************
+     * ZslProcessorInterface implementation *
+     ****************************************
+     */
+
     status_t updateStream(const Parameters &params);
     status_t deleteStream();
     int getStreamId() const;
-    int getReprocessStreamId() const;
 
     status_t pushToReprocess(int32_t requestId);
     status_t clearZslQueue();
diff --git a/services/camera/libcameraservice/camera2/ZslProcessor3.cpp b/services/camera/libcameraservice/camera2/ZslProcessor3.cpp
new file mode 100644
index 0000000..88bcefb
--- /dev/null
+++ b/services/camera/libcameraservice/camera2/ZslProcessor3.cpp
@@ -0,0 +1,442 @@
+/*
+ * Copyright (C) 2013 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 "Camera2-ZslProcessor3"
+#define ATRACE_TAG ATRACE_TAG_CAMERA
+//#define LOG_NDEBUG 0
+//#define LOG_NNDEBUG 0
+
+#ifdef LOG_NNDEBUG
+#define ALOGVV(...) ALOGV(__VA_ARGS__)
+#else
+#define ALOGVV(...) ((void)0)
+#endif
+
+#include <utils/Log.h>
+#include <utils/Trace.h>
+
+#include "ZslProcessor3.h"
+#include <gui/Surface.h>
+#include "../CameraDeviceBase.h"
+#include "../Camera3Device.h"
+#include "../Camera2Client.h"
+
+
+namespace android {
+namespace camera2 {
+
+ZslProcessor3::ZslProcessor3(
+    sp<Camera2Client> client,
+    wp<CaptureSequencer> sequencer):
+        Thread(false),
+        mState(RUNNING),
+        mClient(client),
+        mSequencer(sequencer),
+        mId(client->getCameraId()),
+        mZslStreamId(NO_STREAM),
+        mFrameListHead(0),
+        mZslQueueHead(0),
+        mZslQueueTail(0) {
+    mZslQueue.insertAt(0, kZslBufferDepth);
+    mFrameList.insertAt(0, kFrameListDepth);
+    sp<CaptureSequencer> captureSequencer = mSequencer.promote();
+    if (captureSequencer != 0) captureSequencer->setZslProcessor(this);
+}
+
+ZslProcessor3::~ZslProcessor3() {
+    ALOGV("%s: Exit", __FUNCTION__);
+    deleteStream();
+}
+
+void ZslProcessor3::onFrameAvailable(int32_t /*frameId*/,
+                                     const CameraMetadata &frame) {
+    Mutex::Autolock l(mInputMutex);
+    camera_metadata_ro_entry_t entry;
+    entry = frame.find(ANDROID_SENSOR_TIMESTAMP);
+    nsecs_t timestamp = entry.data.i64[0];
+    (void)timestamp;
+    ALOGVV("Got preview metadata for timestamp %lld", timestamp);
+
+    if (mState != RUNNING) return;
+
+    mFrameList.editItemAt(mFrameListHead) = frame;
+    mFrameListHead = (mFrameListHead + 1) % kFrameListDepth;
+}
+
+status_t ZslProcessor3::updateStream(const Parameters &params) {
+    ATRACE_CALL();
+    ALOGV("%s: Configuring ZSL streams", __FUNCTION__);
+    status_t res;
+
+    Mutex::Autolock l(mInputMutex);
+
+    sp<Camera2Client> client = mClient.promote();
+    if (client == 0) {
+        ALOGE("%s: Camera %d: Client does not exist", __FUNCTION__, mId);
+        return INVALID_OPERATION;
+    }
+    sp<Camera3Device> device =
+        static_cast<Camera3Device*>(client->getCameraDevice().get());
+    if (device == 0) {
+        ALOGE("%s: Camera %d: Device does not exist", __FUNCTION__, mId);
+        return INVALID_OPERATION;
+    }
+
+    if (mZslStreamId != NO_STREAM) {
+        // Check if stream parameters have to change
+        uint32_t currentWidth, currentHeight;
+        res = device->getStreamInfo(mZslStreamId,
+                &currentWidth, &currentHeight, 0);
+        if (res != OK) {
+            ALOGE("%s: Camera %d: Error querying capture output stream info: "
+                    "%s (%d)", __FUNCTION__,
+                    client->getCameraId(), strerror(-res), res);
+            return res;
+        }
+        if (currentWidth != (uint32_t)params.fastInfo.arrayWidth ||
+                currentHeight != (uint32_t)params.fastInfo.arrayHeight) {
+            ALOGV("%s: Camera %d: Deleting stream %d since the buffer "
+                  "dimensions changed",
+                __FUNCTION__, client->getCameraId(), mZslStreamId);
+            res = device->deleteStream(mZslStreamId);
+            if (res != OK) {
+                ALOGE("%s: Camera %d: Unable to delete old output stream "
+                        "for ZSL: %s (%d)", __FUNCTION__,
+                        client->getCameraId(), strerror(-res), res);
+                return res;
+            }
+            mZslStreamId = NO_STREAM;
+        }
+    }
+
+    if (mZslStreamId == NO_STREAM) {
+        // Create stream for HAL production
+        // TODO: Sort out better way to select resolution for ZSL
+
+        // Note that format specified internally in Camera3ZslStream
+        res = device->createZslStream(
+                params.fastInfo.arrayWidth, params.fastInfo.arrayHeight,
+                kZslBufferDepth,
+                &mZslStreamId,
+                &mZslStream);
+        if (res != OK) {
+            ALOGE("%s: Camera %d: Can't create ZSL stream: "
+                    "%s (%d)", __FUNCTION__, client->getCameraId(),
+                    strerror(-res), res);
+            return res;
+        }
+    }
+    client->registerFrameListener(Camera2Client::kPreviewRequestIdStart,
+            Camera2Client::kPreviewRequestIdEnd,
+            this);
+
+    return OK;
+}
+
+status_t ZslProcessor3::deleteStream() {
+    ATRACE_CALL();
+    status_t res;
+
+    Mutex::Autolock l(mInputMutex);
+
+    if (mZslStreamId != NO_STREAM) {
+        sp<Camera2Client> client = mClient.promote();
+        if (client == 0) {
+            ALOGE("%s: Camera %d: Client does not exist", __FUNCTION__, mId);
+            return INVALID_OPERATION;
+        }
+
+        sp<Camera3Device> device =
+            reinterpret_cast<Camera3Device*>(client->getCameraDevice().get());
+        if (device == 0) {
+            ALOGE("%s: Camera %d: Device does not exist", __FUNCTION__, mId);
+            return INVALID_OPERATION;
+        }
+
+        res = device->deleteStream(mZslStreamId);
+        if (res != OK) {
+            ALOGE("%s: Camera %d: Cannot delete ZSL output stream %d: "
+                    "%s (%d)", __FUNCTION__, client->getCameraId(),
+                    mZslStreamId, strerror(-res), res);
+            return res;
+        }
+
+        mZslStreamId = NO_STREAM;
+    }
+    return OK;
+}
+
+int ZslProcessor3::getStreamId() const {
+    Mutex::Autolock l(mInputMutex);
+    return mZslStreamId;
+}
+
+status_t ZslProcessor3::pushToReprocess(int32_t requestId) {
+    ALOGV("%s: Send in reprocess request with id %d",
+            __FUNCTION__, requestId);
+    Mutex::Autolock l(mInputMutex);
+    status_t res;
+    sp<Camera2Client> client = mClient.promote();
+
+    if (client == 0) {
+        ALOGE("%s: Camera %d: Client does not exist", __FUNCTION__, mId);
+        return INVALID_OPERATION;
+    }
+
+    IF_ALOGV() {
+        dumpZslQueue(-1);
+    }
+
+    size_t metadataIdx;
+    nsecs_t candidateTimestamp = getCandidateTimestampLocked(&metadataIdx);
+
+    if (candidateTimestamp == -1) {
+        ALOGE("%s: Could not find good candidate for ZSL reprocessing",
+              __FUNCTION__);
+        return NOT_ENOUGH_DATA;
+    }
+
+    res = mZslStream->enqueueInputBufferByTimestamp(candidateTimestamp,
+                                                    /*actualTimestamp*/NULL);
+
+    if (res == mZslStream->NO_BUFFER_AVAILABLE) {
+        ALOGV("%s: No ZSL buffers yet", __FUNCTION__);
+        return NOT_ENOUGH_DATA;
+    } else if (res != OK) {
+        ALOGE("%s: Unable to push buffer for reprocessing: %s (%d)",
+                __FUNCTION__, strerror(-res), res);
+        return res;
+    }
+
+    {
+        CameraMetadata request = mFrameList[metadataIdx];
+
+        // Verify that the frame is reasonable for reprocessing
+
+        camera_metadata_entry_t entry;
+        entry = request.find(ANDROID_CONTROL_AE_STATE);
+        if (entry.count == 0) {
+            ALOGE("%s: ZSL queue frame has no AE state field!",
+                    __FUNCTION__);
+            return BAD_VALUE;
+        }
+        if (entry.data.u8[0] != ANDROID_CONTROL_AE_STATE_CONVERGED &&
+                entry.data.u8[0] != ANDROID_CONTROL_AE_STATE_LOCKED) {
+            ALOGV("%s: ZSL queue frame AE state is %d, need full capture",
+                    __FUNCTION__, entry.data.u8[0]);
+            return NOT_ENOUGH_DATA;
+        }
+
+        uint8_t requestType = ANDROID_REQUEST_TYPE_REPROCESS;
+        res = request.update(ANDROID_REQUEST_TYPE,
+                &requestType, 1);
+        uint8_t inputStreams[1] =
+                { static_cast<uint8_t>(mZslStreamId) };
+        if (res == OK) request.update(ANDROID_REQUEST_INPUT_STREAMS,
+                inputStreams, 1);
+        // TODO: Shouldn't we also update the latest preview frame?
+        uint8_t outputStreams[1] =
+                { static_cast<uint8_t>(client->getCaptureStreamId()) };
+        if (res == OK) request.update(ANDROID_REQUEST_OUTPUT_STREAMS,
+                outputStreams, 1);
+        res = request.update(ANDROID_REQUEST_ID,
+                &requestId, 1);
+
+        if (res != OK ) {
+            ALOGE("%s: Unable to update frame to a reprocess request",
+                  __FUNCTION__);
+            return INVALID_OPERATION;
+        }
+
+        res = client->stopStream();
+        if (res != OK) {
+            ALOGE("%s: Camera %d: Unable to stop preview for ZSL capture: "
+                "%s (%d)",
+                __FUNCTION__, client->getCameraId(), strerror(-res), res);
+            return INVALID_OPERATION;
+        }
+
+        // Update JPEG settings
+        {
+            SharedParameters::Lock l(client->getParameters());
+            res = l.mParameters.updateRequestJpeg(&request);
+            if (res != OK) {
+                ALOGE("%s: Camera %d: Unable to update JPEG entries of ZSL "
+                        "capture request: %s (%d)", __FUNCTION__,
+                        client->getCameraId(),
+                        strerror(-res), res);
+                return res;
+            }
+        }
+
+        mLatestCapturedRequest = request;
+        res = client->getCameraDevice()->capture(request);
+        if (res != OK ) {
+            ALOGE("%s: Unable to send ZSL reprocess request to capture: %s"
+                  " (%d)", __FUNCTION__, strerror(-res), res);
+            return res;
+        }
+
+        mState = LOCKED;
+    }
+
+    return OK;
+}
+
+status_t ZslProcessor3::clearZslQueue() {
+    Mutex::Autolock l(mInputMutex);
+    // If in middle of capture, can't clear out queue
+    if (mState == LOCKED) return OK;
+
+    return clearZslQueueLocked();
+}
+
+status_t ZslProcessor3::clearZslQueueLocked() {
+    return mZslStream->clearInputRingBuffer();
+}
+
+void ZslProcessor3::dump(int fd, const Vector<String16>& /*args*/) const {
+    Mutex::Autolock l(mInputMutex);
+    if (!mLatestCapturedRequest.isEmpty()) {
+        String8 result("    Latest ZSL capture request:\n");
+        write(fd, result.string(), result.size());
+        mLatestCapturedRequest.dump(fd, 2, 6);
+    } else {
+        String8 result("    Latest ZSL capture request: none yet\n");
+        write(fd, result.string(), result.size());
+    }
+    dumpZslQueue(fd);
+}
+
+bool ZslProcessor3::threadLoop() {
+    // TODO: remove dependency on thread
+    return true;
+}
+
+void ZslProcessor3::dumpZslQueue(int fd) const {
+    String8 header("ZSL queue contents:");
+    String8 indent("    ");
+    ALOGV("%s", header.string());
+    if (fd != -1) {
+        header = indent + header + "\n";
+        write(fd, header.string(), header.size());
+    }
+    for (size_t i = 0; i < mZslQueue.size(); i++) {
+        const ZslPair &queueEntry = mZslQueue[i];
+        nsecs_t bufferTimestamp = queueEntry.buffer.mTimestamp;
+        camera_metadata_ro_entry_t entry;
+        nsecs_t frameTimestamp = 0;
+        int frameAeState = -1;
+        if (!queueEntry.frame.isEmpty()) {
+            entry = queueEntry.frame.find(ANDROID_SENSOR_TIMESTAMP);
+            if (entry.count > 0) frameTimestamp = entry.data.i64[0];
+            entry = queueEntry.frame.find(ANDROID_CONTROL_AE_STATE);
+            if (entry.count > 0) frameAeState = entry.data.u8[0];
+        }
+        String8 result =
+                String8::format("   %d: b: %lld\tf: %lld, AE state: %d", i,
+                        bufferTimestamp, frameTimestamp, frameAeState);
+        ALOGV("%s", result.string());
+        if (fd != -1) {
+            result = indent + result + "\n";
+            write(fd, result.string(), result.size());
+        }
+
+    }
+}
+
+nsecs_t ZslProcessor3::getCandidateTimestampLocked(size_t* metadataIdx) const {
+    /**
+     * Find the smallest timestamp we know about so far
+     * - ensure that aeState is either converged or locked
+     */
+
+    size_t idx = 0;
+    nsecs_t minTimestamp = -1;
+    for (size_t j = 0; j < mFrameList.size(); j++) {
+        const CameraMetadata &frame = mFrameList[j];
+        if (!frame.isEmpty()) {
+            camera_metadata_ro_entry_t entry;
+            entry = frame.find(ANDROID_SENSOR_TIMESTAMP);
+            if (entry.count == 0) {
+                ALOGE("%s: Can't find timestamp in frame!",
+                        __FUNCTION__);
+                continue;
+            }
+            nsecs_t frameTimestamp = entry.data.i64[0];
+            if (minTimestamp > frameTimestamp) {
+
+                entry = frame.find(ANDROID_CONTROL_AE_STATE);
+                if (entry.count == 0) {
+                    ALOGW("%s: ZSL queue frame has no AE state field!",
+                            __FUNCTION__);
+                    continue;
+                }
+                if (entry.data.u8[0] != ANDROID_CONTROL_AE_STATE_CONVERGED &&
+                        entry.data.u8[0] != ANDROID_CONTROL_AE_STATE_LOCKED) {
+                    ALOGVV("%s: ZSL queue frame AE state is %d, need "
+                           "full capture",  __FUNCTION__, entry.data.u8[0]);
+                    continue;
+                }
+
+                minTimestamp = frameTimestamp;
+                idx = j;
+            }
+        }
+    }
+
+    if (metadataIdx) {
+        *metadataIdx = idx;
+    }
+
+    return minTimestamp;
+}
+
+void ZslProcessor3::onBufferAcquired(const BufferInfo& /*bufferInfo*/) {
+    // Intentionally left empty
+    // Although theoretically we could use this to get better dump info
+}
+
+void ZslProcessor3::onBufferReleased(const BufferInfo& bufferInfo) {
+    Mutex::Autolock l(mInputMutex);
+
+    // ignore output buffers
+    if (bufferInfo.mOutput) {
+        return;
+    }
+
+    // TODO: Verify that the buffer is in our queue by looking at timestamp
+    // theoretically unnecessary unless we change the following assumptions:
+    // -- only 1 buffer reprocessed at a time (which is the case now)
+
+    // Erase entire ZSL queue since we've now completed the capture and preview
+    // is stopped.
+    //
+    // We need to guarantee that if we do two back-to-back captures,
+    // the second won't use a buffer that's older/the same as the first, which
+    // is theoretically possible if we don't clear out the queue and the
+    // selection criteria is something like 'newest'. Clearing out the queue
+    // on a completed capture ensures we'll only use new data.
+    ALOGV("%s: Memory optimization, clearing ZSL queue",
+          __FUNCTION__);
+    clearZslQueueLocked();
+
+    // Required so we accept more ZSL requests
+    mState = RUNNING;
+}
+
+}; // namespace camera2
+}; // namespace android
diff --git a/services/camera/libcameraservice/camera2/ZslProcessor3.h b/services/camera/libcameraservice/camera2/ZslProcessor3.h
new file mode 100644
index 0000000..cb98b99
--- /dev/null
+++ b/services/camera/libcameraservice/camera2/ZslProcessor3.h
@@ -0,0 +1,137 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+
+#ifndef ANDROID_SERVERS_CAMERA_CAMERA2_ZSLPROCESSOR3_H
+#define ANDROID_SERVERS_CAMERA_CAMERA2_ZSLPROCESSOR3_H
+
+#include <utils/Thread.h>
+#include <utils/String16.h>
+#include <utils/Vector.h>
+#include <utils/Mutex.h>
+#include <utils/Condition.h>
+#include <gui/BufferItemConsumer.h>
+#include "Parameters.h"
+#include "FrameProcessor.h"
+#include "camera/CameraMetadata.h"
+#include "Camera2Heap.h"
+#include "../CameraDeviceBase.h"
+#include "ZslProcessorInterface.h"
+#include "../camera3/Camera3ZslStream.h"
+
+namespace android {
+
+class Camera2Client;
+
+namespace camera2 {
+
+class CaptureSequencer;
+
+/***
+ * ZSL queue processing
+ */
+class ZslProcessor3 :
+                    public ZslProcessorInterface,
+                    public camera3::Camera3StreamBufferListener,
+            virtual public Thread,
+            virtual public FrameProcessor::FilteredListener {
+  public:
+    ZslProcessor3(sp<Camera2Client> client, wp<CaptureSequencer> sequencer);
+    ~ZslProcessor3();
+
+    // From FrameProcessor
+    virtual void onFrameAvailable(int32_t frameId, const CameraMetadata &frame);
+
+    /**
+     ****************************************
+     * ZslProcessorInterface implementation *
+     ****************************************
+     */
+
+    virtual status_t updateStream(const Parameters &params);
+    virtual status_t deleteStream();
+    virtual int getStreamId() const;
+
+    virtual status_t pushToReprocess(int32_t requestId);
+    virtual status_t clearZslQueue();
+
+    void dump(int fd, const Vector<String16>& args) const;
+
+  protected:
+    /**
+     **********************************************
+     * Camera3StreamBufferListener implementation *
+     **********************************************
+     */
+    typedef camera3::Camera3StreamBufferListener::BufferInfo BufferInfo;
+    // Buffer was acquired by the HAL
+    virtual void onBufferAcquired(const BufferInfo& bufferInfo);
+    // Buffer was released by the HAL
+    virtual void onBufferReleased(const BufferInfo& bufferInfo);
+
+  private:
+    static const nsecs_t kWaitDuration = 10000000; // 10 ms
+
+    enum {
+        RUNNING,
+        LOCKED
+    } mState;
+
+    wp<Camera2Client> mClient;
+    wp<CaptureSequencer> mSequencer;
+
+    const int mId;
+
+    mutable Mutex mInputMutex;
+
+    enum {
+        NO_STREAM = -1
+    };
+
+    int mZslStreamId;
+    sp<camera3::Camera3ZslStream> mZslStream;
+
+    struct ZslPair {
+        BufferItemConsumer::BufferItem buffer;
+        CameraMetadata frame;
+    };
+
+    static const size_t kZslBufferDepth = 4;
+    static const size_t kFrameListDepth = kZslBufferDepth * 2;
+    Vector<CameraMetadata> mFrameList;
+    size_t mFrameListHead;
+
+    ZslPair mNextPair;
+
+    Vector<ZslPair> mZslQueue;
+    size_t mZslQueueHead;
+    size_t mZslQueueTail;
+
+    CameraMetadata mLatestCapturedRequest;
+
+    virtual bool threadLoop();
+
+    status_t clearZslQueueLocked();
+
+    void dumpZslQueue(int id) const;
+
+    nsecs_t getCandidateTimestampLocked(size_t* metadataIdx) const;
+};
+
+
+}; //namespace camera2
+}; //namespace android
+
+#endif
diff --git a/services/camera/libcameraservice/camera2/ZslProcessorInterface.h b/services/camera/libcameraservice/camera2/ZslProcessorInterface.h
new file mode 100644
index 0000000..183c0c2
--- /dev/null
+++ b/services/camera/libcameraservice/camera2/ZslProcessorInterface.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+
+#ifndef ANDROID_SERVERS_CAMERA_CAMERA2_ZSLPROCESSORINTERFACE_H
+#define ANDROID_SERVERS_CAMERA_CAMERA2_ZSLPROCESSORINTERFACE_H
+
+#include <utils/Errors.h>
+#include <utils/RefBase.h>
+
+namespace android {
+namespace camera2 {
+
+class Parameters;
+
+class ZslProcessorInterface : virtual public RefBase {
+public:
+
+    // Get ID for use with android.request.outputStreams / inputStreams
+    virtual int getStreamId() const = 0;
+
+    // Update the streams by recreating them if the size/format has changed
+    virtual status_t updateStream(const Parameters& params) = 0;
+
+    // Delete the underlying CameraDevice streams
+    virtual status_t deleteStream() = 0;
+
+    /**
+     * Submits a ZSL capture request (id = requestId)
+     *
+     * An appropriate ZSL buffer is selected by the closest timestamp,
+     * then we push that buffer to be reprocessed by the HAL.
+     * A capture request is created and submitted on behalf of the client.
+     */
+    virtual status_t pushToReprocess(int32_t requestId) = 0;
+
+    // Flush the ZSL buffer queue, freeing up all the buffers
+    virtual status_t clearZslQueue() = 0;
+
+    // (Debugging only) Dump the current state to the specified file descriptor
+    virtual void dump(int fd, const Vector<String16>& args) const = 0;
+};
+
+}; //namespace camera2
+}; //namespace android
+
+#endif
diff --git a/services/camera/libcameraservice/camera3/Camera3OutputStream.h b/services/camera/libcameraservice/camera3/Camera3OutputStream.h
index d331a94..2464dce 100644
--- a/services/camera/libcameraservice/camera3/Camera3OutputStream.h
+++ b/services/camera/libcameraservice/camera3/Camera3OutputStream.h
@@ -21,6 +21,7 @@
 #include <gui/Surface.h>
 
 #include "Camera3Stream.h"
+#include "Camera3OutputStreamInterface.h"
 
 namespace android {
 
@@ -29,7 +30,9 @@ namespace camera3 {
 /**
  * A class for managing a single stream of output data from the camera device.
  */
-class Camera3OutputStream : public Camera3Stream {
+class Camera3OutputStream :
+        public Camera3Stream,
+        public Camera3OutputStreamInterface {
   public:
     /**
      * Set up a stream for formats that have 2 dimensions, such as RAW and YUV.
diff --git a/services/camera/libcameraservice/camera3/Camera3OutputStreamInterface.h b/services/camera/libcameraservice/camera3/Camera3OutputStreamInterface.h
new file mode 100644
index 0000000..aae72cf
--- /dev/null
+++ b/services/camera/libcameraservice/camera3/Camera3OutputStreamInterface.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+
+#ifndef ANDROID_SERVERS_CAMERA3_OUTPUT_STREAM_INTERFACE_H
+#define ANDROID_SERVERS_CAMERA3_OUTPUT_STREAM_INTERFACE_H
+
+#include "Camera3StreamInterface.h"
+
+namespace android {
+
+namespace camera3 {
+
+/**
+ * An interface for managing a single stream of output data from the camera
+ * device.
+ */
+class Camera3OutputStreamInterface : public virtual Camera3StreamInterface {
+  public:
+    /**
+     * Set the transform on the output stream; one of the
+     * HAL_TRANSFORM_* / NATIVE_WINDOW_TRANSFORM_* constants.
+     */
+    virtual status_t setTransform(int transform) = 0;
+};
+
+} // namespace camera3
+
+} // namespace android
+
+#endif
diff --git a/services/camera/libcameraservice/camera3/Camera3Stream.cpp b/services/camera/libcameraservice/camera3/Camera3Stream.cpp
index bc259b6..f137227 100644
--- a/services/camera/libcameraservice/camera3/Camera3Stream.cpp
+++ b/services/camera/libcameraservice/camera3/Camera3Stream.cpp
@@ -178,26 +178,75 @@ status_t Camera3Stream::finishConfiguration(camera3_device *hal3Device) {
 status_t Camera3Stream::getBuffer(camera3_stream_buffer *buffer) {
     ATRACE_CALL();
     Mutex::Autolock l(mLock);
-    return getBufferLocked(buffer);
+
+    status_t res = getBufferLocked(buffer);
+    if (res == OK) {
+        fireBufferListenersLocked(*buffer, /*acquired*/true, /*output*/true);
+    }
+
+    return res;
 }
 
 status_t Camera3Stream::returnBuffer(const camera3_stream_buffer &buffer,
         nsecs_t timestamp) {
     ATRACE_CALL();
     Mutex::Autolock l(mLock);
-    return returnBufferLocked(buffer, timestamp);
+
+    status_t res = returnBufferLocked(buffer, timestamp);
+    if (res == OK) {
+        fireBufferListenersLocked(buffer, /*acquired*/false, /*output*/true);
+    }
+
+    return res;
 }
 
 status_t Camera3Stream::getInputBuffer(camera3_stream_buffer *buffer) {
     ATRACE_CALL();
     Mutex::Autolock l(mLock);
-    return getInputBufferLocked(buffer);
+
+    status_t res = getInputBufferLocked(buffer);
+    if (res == OK) {
+        fireBufferListenersLocked(*buffer, /*acquired*/true, /*output*/false);
+    }
+
+    return res;
 }
 
 status_t Camera3Stream::returnInputBuffer(const camera3_stream_buffer &buffer) {
     ATRACE_CALL();
     Mutex::Autolock l(mLock);
-    return returnInputBufferLocked(buffer);
+
+    status_t res = returnInputBufferLocked(buffer);
+    if (res == OK) {
+        fireBufferListenersLocked(buffer, /*acquired*/false, /*output*/false);
+    }
+    return res;
+}
+
+void Camera3Stream::fireBufferListenersLocked(
+        const camera3_stream_buffer& /*buffer*/, bool acquired, bool output) {
+    List<wp<Camera3StreamBufferListener> >::iterator it, end;
+
+    // TODO: finish implementing
+
+    Camera3StreamBufferListener::BufferInfo info =
+        Camera3StreamBufferListener::BufferInfo();
+    info.mOutput = output;
+    // TODO: rest of fields
+
+    for (it = mBufferListenerList.begin(), end = mBufferListenerList.end();
+         it != end;
+         ++it) {
+
+        sp<Camera3StreamBufferListener> listener = it->promote();
+        if (listener != 0) {
+            if (acquired) {
+                listener->onBufferAcquired(info);
+            } else {
+                listener->onBufferReleased(info);
+            }
+        }
+    }
 }
 
 bool Camera3Stream::hasOutstandingBuffers() const {
@@ -290,6 +339,36 @@ status_t Camera3Stream::returnInputBufferLocked(
     return INVALID_OPERATION;
 }
 
+void Camera3Stream::addBufferListener(
+        wp<Camera3StreamBufferListener> listener) {
+    Mutex::Autolock l(mLock);
+    mBufferListenerList.push_back(listener);
+}
+
+void Camera3Stream::removeBufferListener(
+        const sp<Camera3StreamBufferListener>& listener) {
+    Mutex::Autolock l(mLock);
+
+    bool erased = true;
+    List<wp<Camera3StreamBufferListener> >::iterator it, end;
+    for (it = mBufferListenerList.begin(), end = mBufferListenerList.end();
+         it != end;
+         ) {
+
+        if (*it == listener) {
+            it = mBufferListenerList.erase(it);
+            erased = true;
+        } else {
+            ++it;
+        }
+    }
+
+    if (!erased) {
+        ALOGW("%s: Could not find listener to remove, already removed",
+              __FUNCTION__);
+    }
+}
+
 }; // namespace camera3
 
 }; // namespace android
diff --git a/services/camera/libcameraservice/camera3/Camera3Stream.h b/services/camera/libcameraservice/camera3/Camera3Stream.h
index 46a3872..d992cfe 100644
--- a/services/camera/libcameraservice/camera3/Camera3Stream.h
+++ b/services/camera/libcameraservice/camera3/Camera3Stream.h
@@ -21,9 +21,13 @@
 #include <utils/RefBase.h>
 #include <utils/String8.h>
 #include <utils/String16.h>
+#include <utils/List.h>
 
 #include "hardware/camera3.h"
 
+#include "Camera3StreamBufferListener.h"
+#include "Camera3StreamInterface.h"
+
 namespace android {
 
 namespace camera3 {
@@ -81,7 +85,8 @@ namespace camera3 {
  */
 class Camera3Stream :
         protected camera3_stream,
-        public LightRefBase<Camera3Stream> {
+        public virtual Camera3StreamInterface,
+        public virtual RefBase {
   public:
 
     virtual ~Camera3Stream();
@@ -205,6 +210,11 @@ class Camera3Stream :
      */
     virtual void     dump(int fd, const Vector<String16> &args) const = 0;
 
+    void             addBufferListener(
+            wp<Camera3StreamBufferListener> listener);
+    void             removeBufferListener(
+            const sp<Camera3StreamBufferListener>& listener);
+
   protected:
     const int mId;
     const String8 mName;
@@ -261,6 +271,10 @@ class Camera3Stream :
     // Gets all buffers from endpoint and registers them with the HAL.
     status_t registerBuffersLocked(camera3_device *hal3Device);
 
+    void fireBufferListenersLocked(const camera3_stream_buffer& buffer,
+                                  bool acquired, bool output);
+    List<wp<Camera3StreamBufferListener> > mBufferListenerList;
+
 }; // class Camera3Stream
 
 }; // namespace camera3
diff --git a/services/camera/libcameraservice/camera3/Camera3StreamInterface.h b/services/camera/libcameraservice/camera3/Camera3StreamInterface.h
new file mode 100644
index 0000000..4768536
--- /dev/null
+++ b/services/camera/libcameraservice/camera3/Camera3StreamInterface.h
@@ -0,0 +1,162 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+
+#ifndef ANDROID_SERVERS_CAMERA3_STREAM_INTERFACE_H
+#define ANDROID_SERVERS_CAMERA3_STREAM_INTERFACE_H
+
+#include <utils/RefBase.h>
+#include "Camera3StreamBufferListener.h"
+
+struct camera3_stream_buffer;
+
+namespace android {
+
+namespace camera3 {
+
+/**
+ * An interface for managing a single stream of input and/or output data from
+ * the camera device.
+ */
+class Camera3StreamInterface : public virtual RefBase {
+  public:
+    /**
+     * Get the stream's ID
+     */
+    virtual int      getId() const = 0;
+
+    /**
+     * Get the stream's dimensions and format
+     */
+    virtual uint32_t getWidth() const = 0;
+    virtual uint32_t getHeight() const = 0;
+    virtual int      getFormat() const = 0;
+
+    /**
+     * Start the stream configuration process. Returns a handle to the stream's
+     * information to be passed into the HAL device's configure_streams call.
+     *
+     * Until finishConfiguration() is called, no other methods on the stream may
+     * be called. The usage and max_buffers fields of camera3_stream may be
+     * modified between start/finishConfiguration, but may not be changed after
+     * that. The priv field of camera3_stream may be modified at any time after
+     * startConfiguration.
+     *
+     * Returns NULL in case of error starting configuration.
+     */
+    virtual camera3_stream* startConfiguration() = 0;
+
+    /**
+     * Check if the stream is mid-configuration (start has been called, but not
+     * finish).  Used for lazy completion of configuration.
+     */
+    virtual bool    isConfiguring() const = 0;
+
+    /**
+     * Completes the stream configuration process. During this call, the stream
+     * may call the device's register_stream_buffers() method. The stream
+     * information structure returned by startConfiguration() may no longer be
+     * modified after this call, but can still be read until the destruction of
+     * the stream.
+     *
+     * Returns:
+     *   OK on a successful configuration
+     *   NO_INIT in case of a serious error from the HAL device
+     *   NO_MEMORY in case of an error registering buffers
+     *   INVALID_OPERATION in case connecting to the consumer failed
+     */
+    virtual status_t finishConfiguration(camera3_device *hal3Device) = 0;
+
+    /**
+     * Fill in the camera3_stream_buffer with the next valid buffer for this
+     * stream, to hand over to the HAL.
+     *
+     * This method may only be called once finishConfiguration has been called.
+     * For bidirectional streams, this method applies to the output-side
+     * buffers.
+     *
+     */
+    virtual status_t getBuffer(camera3_stream_buffer *buffer) = 0;
+
+    /**
+     * Return a buffer to the stream after use by the HAL.
+     *
+     * This method may only be called for buffers provided by getBuffer().
+     * For bidirectional streams, this method applies to the output-side buffers
+     */
+    virtual status_t returnBuffer(const camera3_stream_buffer &buffer,
+            nsecs_t timestamp) = 0;
+
+    /**
+     * Fill in the camera3_stream_buffer with the next valid buffer for this
+     * stream, to hand over to the HAL.
+     *
+     * This method may only be called once finishConfiguration has been called.
+     * For bidirectional streams, this method applies to the input-side
+     * buffers.
+     *
+     */
+    virtual status_t getInputBuffer(camera3_stream_buffer *buffer) = 0;
+
+    /**
+     * Return a buffer to the stream after use by the HAL.
+     *
+     * This method may only be called for buffers provided by getBuffer().
+     * For bidirectional streams, this method applies to the input-side buffers
+     */
+    virtual status_t returnInputBuffer(const camera3_stream_buffer &buffer) = 0;
+
+    /**
+     * Whether any of the stream's buffers are currently in use by the HAL,
+     * including buffers that have been returned but not yet had their
+     * release fence signaled.
+     */
+    virtual bool     hasOutstandingBuffers() const = 0;
+
+    enum {
+        TIMEOUT_NEVER = -1
+    };
+    /**
+     * Wait until the HAL is done with all of this stream's buffers, including
+     * signalling all release fences. Returns TIMED_OUT if the timeout is
+     * exceeded, OK on success. Pass in TIMEOUT_NEVER for timeout to indicate
+     * an indefinite wait.
+     */
+    virtual status_t waitUntilIdle(nsecs_t timeout) = 0;
+
+    /**
+     * Disconnect stream from its non-HAL endpoint. After this,
+     * start/finishConfiguration must be called before the stream can be used
+     * again. This cannot be called if the stream has outstanding dequeued
+     * buffers.
+     */
+    virtual status_t disconnect() = 0;
+
+    /**
+     * Debug dump of the stream's state.
+     */
+    virtual void     dump(int fd, const Vector<String16> &args) const = 0;
+
+    virtual void     addBufferListener(
+            wp<Camera3StreamBufferListener> listener) = 0;
+    virtual void     removeBufferListener(
+            const sp<Camera3StreamBufferListener>& listener) = 0;
+};
+
+} // namespace camera3
+
+} // namespace android
+
+#endif
diff --git a/services/camera/libcameraservice/camera3/Camera3ZslStream.cpp b/services/camera/libcameraservice/camera3/Camera3ZslStream.cpp
index e8a5ca6..0345d5b 100644
--- a/services/camera/libcameraservice/camera3/Camera3ZslStream.cpp
+++ b/services/camera/libcameraservice/camera3/Camera3ZslStream.cpp
@@ -18,70 +18,652 @@
 #define ATRACE_TAG ATRACE_TAG_CAMERA
 //#define LOG_NDEBUG 0
 
+// This is needed for stdint.h to define INT64_MAX in C++
+#define __STDC_LIMIT_MACROS
+
 #include <utils/Log.h>
 #include <utils/Trace.h>
 #include "Camera3ZslStream.h"
 
+#ifndef container_of
+#define container_of(ptr, type, member) \
+    (type *)((char*)(ptr) - offsetof(type, member))
+#endif
+
+typedef android::RingBufferConsumer::PinnedBufferItem PinnedBufferItem;
+
 namespace android {
 
 namespace camera3 {
 
+namespace {
+struct TimestampFinder : public RingBufferConsumer::RingBufferComparator {
+    typedef RingBufferConsumer::BufferInfo BufferInfo;
+
+    enum {
+        SELECT_I1 = -1,
+        SELECT_I2 = 1,
+        SELECT_NEITHER = 0,
+    };
+
+    TimestampFinder(nsecs_t timestamp) : mTimestamp(timestamp) {}
+    ~TimestampFinder() {}
+
+    template <typename T>
+    static void swap(T& a, T& b) {
+        T tmp = a;
+        a = b;
+        b = tmp;
+    }
+
+    /**
+     * Try to find the best candidate for a ZSL buffer.
+     * Match priority from best to worst:
+     *  1) Timestamps match.
+     *  2) Timestamp is closest to the needle (and lower).
+     *  3) Timestamp is closest to the needle (and higher).
+     *
+     */
+    virtual int compare(const BufferInfo *i1,
+                        const BufferInfo *i2) const {
+        // Try to select non-null object first.
+        if (i1 == NULL) {
+            return SELECT_I2;
+        } else if (i2 == NULL) {
+            return SELECT_I1;
+        }
+
+        // Best result: timestamp is identical
+        if (i1->mTimestamp == mTimestamp) {
+            return SELECT_I1;
+        } else if (i2->mTimestamp == mTimestamp) {
+            return SELECT_I2;
+        }
+
+        const BufferInfo* infoPtrs[2] = {
+            i1,
+            i2
+        };
+        int infoSelectors[2] = {
+            SELECT_I1,
+            SELECT_I2
+        };
+
+        // Order i1,i2 so that always i1.timestamp < i2.timestamp
+        if (i1->mTimestamp > i2->mTimestamp) {
+            swap(infoPtrs[0], infoPtrs[1]);
+            swap(infoSelectors[0], infoSelectors[1]);
+        }
+
+        // Second best: closest (lower) timestamp
+        if (infoPtrs[1]->mTimestamp < mTimestamp) {
+            return infoSelectors[1];
+        } else if (infoPtrs[0]->mTimestamp < mTimestamp) {
+            return infoSelectors[0];
+        }
+
+        // Worst: closest (higher) timestamp
+        return infoSelectors[0];
+
+        /**
+         * The above cases should cover all the possibilities,
+         * and we get an 'empty' result only if the ring buffer
+         * was empty itself
+         */
+    }
+
+    const nsecs_t mTimestamp;
+}; // struct TimestampFinder
+} // namespace anonymous
+
 Camera3ZslStream::Camera3ZslStream(int id, uint32_t width, uint32_t height,
         int depth) :
         Camera3Stream(id, CAMERA3_STREAM_BIDIRECTIONAL, width, height, 0,
                 HAL_PIXEL_FORMAT_IMPLEMENTATION_DEFINED),
-        mDepth(depth) {
+        mDepth(depth),
+        mProducer(new RingBufferConsumer(GRALLOC_USAGE_HW_CAMERA_ZSL,
+                                         depth)),
+        mConsumer(new Surface(mProducer->getProducerInterface())),
+        //mTransform(0),
+        mTotalBufferCount(0),
+        mDequeuedBufferCount(0),
+        mFrameCount(0),
+        mLastTimestamp(0),
+        mCombinedFence(new Fence()) {
+}
+
+Camera3ZslStream::~Camera3ZslStream() {
+    disconnectLocked();
 }
 
 status_t Camera3ZslStream::getBufferLocked(camera3_stream_buffer *buffer) {
-    (void) buffer;
-    ALOGE("%s: Not implemented", __FUNCTION__);
-    return INVALID_OPERATION;
+    // same as output stream code
+    ATRACE_CALL();
+    status_t res;
+
+    // Allow dequeue during IN_[RE]CONFIG for registration
+    if (mState != STATE_CONFIGURED &&
+            mState != STATE_IN_CONFIG && mState != STATE_IN_RECONFIG) {
+        ALOGE("%s: Stream %d: Can't get buffers in unconfigured state %d",
+                __FUNCTION__, mId, mState);
+        return INVALID_OPERATION;
+    }
+
+    // Only limit dequeue amount when fully configured
+    if (mState == STATE_CONFIGURED &&
+            mDequeuedBufferCount == camera3_stream::max_buffers) {
+        ALOGE("%s: Stream %d: Already dequeued maximum number of simultaneous"
+                " buffers (%d)", __FUNCTION__, mId,
+                camera3_stream::max_buffers);
+        return INVALID_OPERATION;
+    }
+
+    ANativeWindowBuffer* anb;
+    int fenceFd;
+
+    res = mConsumer->dequeueBuffer(mConsumer.get(), &anb, &fenceFd);
+    if (res != OK) {
+        ALOGE("%s: Stream %d: Can't dequeue next output buffer: %s (%d)",
+                __FUNCTION__, mId, strerror(-res), res);
+        return res;
+    }
+
+    // Handing out a raw pointer to this object. Increment internal refcount.
+    incStrong(this);
+    buffer->stream = this;
+    buffer->buffer = &(anb->handle);
+    buffer->acquire_fence = fenceFd;
+    buffer->release_fence = -1;
+    buffer->status = CAMERA3_BUFFER_STATUS_OK;
+
+    mDequeuedBufferCount++;
+
+    return OK;
 }
 
 status_t Camera3ZslStream::returnBufferLocked(
         const camera3_stream_buffer &buffer,
         nsecs_t timestamp) {
-    (void) buffer;
-    (void) timestamp;
-    ALOGE("%s: Not implemented", __FUNCTION__);
-    return INVALID_OPERATION;
+    // same as output stream code
+    ATRACE_CALL();
+    status_t res;
+
+    // returnBuffer may be called from a raw pointer, not a sp<>, and we'll be
+    // decrementing the internal refcount next. In case this is the last ref, we
+    // might get destructed on the decStrong(), so keep an sp around until the
+    // end of the call - otherwise have to sprinkle the decStrong on all exit
+    // points.
+    sp<Camera3ZslStream> keepAlive(this);
+    decStrong(this);
+
+    // Allow buffers to be returned in the error state, to allow for disconnect
+    // and in the in-config states for registration
+    if (mState == STATE_CONSTRUCTED) {
+        ALOGE("%s: Stream %d: Can't return buffers in unconfigured state %d",
+                __FUNCTION__, mId, mState);
+        return INVALID_OPERATION;
+    }
+    if (mDequeuedBufferCount == 0) {
+        ALOGE("%s: Stream %d: No buffers outstanding to return", __FUNCTION__,
+                mId);
+        return INVALID_OPERATION;
+    }
+    if (buffer.status == CAMERA3_BUFFER_STATUS_ERROR) {
+        res = mConsumer->cancelBuffer(mConsumer.get(),
+                container_of(buffer.buffer, ANativeWindowBuffer, handle),
+                buffer.release_fence);
+        if (res != OK) {
+            ALOGE("%s: Stream %d: Error cancelling buffer to native window:"
+                    " %s (%d)", __FUNCTION__, mId, strerror(-res), res);
+            return res;
+        }
+    } else {
+        res = native_window_set_buffers_timestamp(mConsumer.get(), timestamp);
+        if (res != OK) {
+            ALOGE("%s: Stream %d: Error setting timestamp: %s (%d)",
+                    __FUNCTION__, mId, strerror(-res), res);
+            return res;
+        }
+
+        sp<Fence> releaseFence = new Fence(buffer.release_fence);
+        int anwReleaseFence = releaseFence->dup();
+
+        res = mConsumer->queueBuffer(mConsumer.get(),
+                container_of(buffer.buffer, ANativeWindowBuffer, handle),
+                anwReleaseFence);
+        if (res != OK) {
+            ALOGE("%s: Stream %d: Error queueing buffer to native window: %s (%d)",
+                    __FUNCTION__, mId, strerror(-res), res);
+            close(anwReleaseFence);
+            return res;
+        }
+
+        mCombinedFence = Fence::merge(mName, mCombinedFence, releaseFence);
+    }
+
+    mDequeuedBufferCount--;
+    mBufferReturnedSignal.signal();
+    mLastTimestamp = timestamp;
+
+    return OK;
 }
 
 bool Camera3ZslStream::hasOutstandingBuffersLocked() const {
-    ALOGE("%s: Not implemented", __FUNCTION__);
+    // same as output stream
+    nsecs_t signalTime = mCombinedFence->getSignalTime();
+    ALOGV("%s: Stream %d: Has %d outstanding buffers,"
+            " buffer signal time is %lld",
+            __FUNCTION__, mId, mDequeuedBufferCount, signalTime);
+    if (mDequeuedBufferCount > 0 || signalTime == INT64_MAX) {
+        return true;
+    }
     return false;
 }
 
 status_t Camera3ZslStream::waitUntilIdle(nsecs_t timeout) {
-    (void) timeout;
-    ALOGE("%s: Not implemented", __FUNCTION__);
-    return INVALID_OPERATION;
+    // same as output stream
+    status_t res;
+    {
+        Mutex::Autolock l(mLock);
+        while (mDequeuedBufferCount > 0) {
+            if (timeout != TIMEOUT_NEVER) {
+                nsecs_t startTime = systemTime();
+                res = mBufferReturnedSignal.waitRelative(mLock, timeout);
+                if (res == TIMED_OUT) {
+                    return res;
+                } else if (res != OK) {
+                    ALOGE("%s: Error waiting for outstanding buffers: %s (%d)",
+                            __FUNCTION__, strerror(-res), res);
+                    return res;
+                }
+                nsecs_t deltaTime = systemTime() - startTime;
+                if (timeout <= deltaTime) {
+                    timeout = 0;
+                } else {
+                    timeout -= deltaTime;
+                }
+            } else {
+                res = mBufferReturnedSignal.wait(mLock);
+                if (res != OK) {
+                    ALOGE("%s: Error waiting for outstanding buffers: %s (%d)",
+                            __FUNCTION__, strerror(-res), res);
+                    return res;
+                }
+            }
+        }
+    }
+
+    // No lock
+
+    unsigned int timeoutMs;
+    if (timeout == TIMEOUT_NEVER) {
+        timeoutMs = Fence::TIMEOUT_NEVER;
+    } else if (timeout == 0) {
+        timeoutMs = 0;
+    } else {
+        // Round up to wait at least 1 ms
+        timeoutMs = (timeout + 999999) / 1000000;
+    }
+
+    return mCombinedFence->wait(timeoutMs);
+}
+
+status_t Camera3ZslStream::configureQueueLocked() {
+    status_t res;
+
+    switch (mState) {
+        case STATE_IN_RECONFIG:
+            res = disconnectLocked();
+            if (res != OK) {
+                return res;
+            }
+            break;
+        case STATE_IN_CONFIG:
+            // OK
+            break;
+        default:
+            ALOGE("%s: Bad state: %d", __FUNCTION__, mState);
+            return INVALID_OPERATION;
+    }
+
+    // Configure consumer-side ANativeWindow interface
+    res = native_window_api_connect(mConsumer.get(),
+            NATIVE_WINDOW_API_CAMERA);
+    if (res != OK) {
+        ALOGE("%s: Unable to connect to native window for stream %d",
+                __FUNCTION__, mId);
+        return res;
+    }
+
+    res = native_window_set_usage(mConsumer.get(), camera3_stream::usage);
+    if (res != OK) {
+        ALOGE("%s: Unable to configure usage %08x for stream %d",
+                __FUNCTION__, camera3_stream::usage, mId);
+        return res;
+    }
+
+    res = native_window_set_scaling_mode(mConsumer.get(),
+            NATIVE_WINDOW_SCALING_MODE_SCALE_TO_WINDOW);
+    if (res != OK) {
+        ALOGE("%s: Unable to configure stream scaling: %s (%d)",
+                __FUNCTION__, strerror(-res), res);
+        return res;
+    }
+
+    if (mMaxSize == 0) {
+        // For buffers of known size
+        res = native_window_set_buffers_geometry(mConsumer.get(),
+                camera3_stream::width, camera3_stream::height,
+                camera3_stream::format);
+    } else {
+        // For buffers with bounded size
+        res = native_window_set_buffers_geometry(mConsumer.get(),
+                mMaxSize, 1,
+                camera3_stream::format);
+    }
+    if (res != OK) {
+        ALOGE("%s: Unable to configure stream buffer geometry"
+                " %d x %d, format %x for stream %d",
+                __FUNCTION__, camera3_stream::width, camera3_stream::height,
+                camera3_stream::format, mId);
+        return res;
+    }
+
+    int maxConsumerBuffers;
+    res = mConsumer->query(mConsumer.get(),
+            NATIVE_WINDOW_MIN_UNDEQUEUED_BUFFERS, &maxConsumerBuffers);
+    if (res != OK) {
+        ALOGE("%s: Unable to query consumer undequeued"
+                " buffer count for stream %d", __FUNCTION__, mId);
+        return res;
+    }
+
+    ALOGV("%s: Consumer wants %d buffers", __FUNCTION__,
+            maxConsumerBuffers);
+
+    mTotalBufferCount = maxConsumerBuffers + camera3_stream::max_buffers;
+    mDequeuedBufferCount = 0;
+    mFrameCount = 0;
+    mLastTimestamp = 0;
+
+    res = native_window_set_buffer_count(mConsumer.get(),
+            mTotalBufferCount);
+    if (res != OK) {
+        ALOGE("%s: Unable to set buffer count for stream %d",
+                __FUNCTION__, mId);
+        return res;
+    }
+
+    return OK;
+}
+
+size_t Camera3ZslStream::getBufferCountLocked() {
+    return mTotalBufferCount;
 }
 
 status_t Camera3ZslStream::disconnectLocked() {
-    ALOGE("%s: Not implemented", __FUNCTION__);
-    return INVALID_OPERATION;
+    status_t res;
+
+    switch (mState) {
+        case STATE_IN_RECONFIG:
+        case STATE_CONFIGURED:
+            // OK
+            break;
+        default:
+            // No connection, nothing to do
+            return OK;
+    }
+
+    if (mDequeuedBufferCount > 0) {
+        ALOGE("%s: Can't disconnect with %d buffers still dequeued!",
+                __FUNCTION__, mDequeuedBufferCount);
+        return INVALID_OPERATION;
+    }
+
+    res = native_window_api_disconnect(mConsumer.get(), NATIVE_WINDOW_API_CAMERA);
+
+    /**
+     * This is not an error. if client calling process dies, the window will
+     * also die and all calls to it will return DEAD_OBJECT, thus it's already
+     * "disconnected"
+     */
+    if (res == DEAD_OBJECT) {
+        ALOGW("%s: While disconnecting stream %d from native window, the"
+                " native window died from under us", __FUNCTION__, mId);
+    }
+    else if (res != OK) {
+        ALOGE("%s: Unable to disconnect stream %d from native window (error %d %s)",
+                __FUNCTION__, mId, res, strerror(-res));
+        mState = STATE_ERROR;
+        return res;
+    }
+
+    mState = (mState == STATE_IN_RECONFIG) ? STATE_IN_CONFIG : STATE_CONSTRUCTED;
+    return OK;
 }
 
-status_t Camera3ZslStream::getInputBuffer(camera3_stream_buffer *buffer,
-        nsecs_t timestamp) {
-    (void) buffer;
-    (void) timestamp;
-    ALOGE("%s: Not implemented", __FUNCTION__);
-    return INVALID_OPERATION;
+status_t Camera3ZslStream::getInputBufferLocked(camera3_stream_buffer *buffer) {
+    ATRACE_CALL();
+
+    // TODO: potentially register from inputBufferLocked
+    // this should be ok, registerBuffersLocked only calls getBuffer for now
+    // register in output mode instead of input mode for ZSL streams.
+    if (mState == STATE_IN_CONFIG || mState == STATE_IN_RECONFIG) {
+        ALOGE("%s: Stream %d: Buffer registration for input streams"
+              " not implemented (state %d)",
+              __FUNCTION__, mId, mState);
+        return INVALID_OPERATION;
+    }
+
+    // Allow dequeue during IN_[RE]CONFIG for registration
+    if (mState != STATE_CONFIGURED &&
+            mState != STATE_IN_CONFIG && mState != STATE_IN_RECONFIG) {
+        ALOGE("%s: Stream %d: Can't get buffers in unconfigured state %d",
+                __FUNCTION__, mId, mState);
+        return INVALID_OPERATION;
+    }
+
+    // Only limit dequeue amount when fully configured
+    if (mState == STATE_CONFIGURED &&
+            mDequeuedBufferCount == camera3_stream::max_buffers) {
+        ALOGE("%s: Stream %d: Already dequeued maximum number of simultaneous"
+                " buffers (%d)", __FUNCTION__, mId,
+                camera3_stream::max_buffers);
+        return INVALID_OPERATION;
+    }
+
+    ANativeWindowBuffer* anb;
+    int fenceFd;
+
+    assert(mProducer != 0);
+
+    sp<PinnedBufferItem> bufferItem;
+    {
+        List<sp<RingBufferConsumer::PinnedBufferItem> >::iterator it, end;
+        it = mInputBufferQueue.begin();
+        end = mInputBufferQueue.end();
+
+        // Need to call enqueueInputBufferByTimestamp as a prerequisite
+        if (it == end) {
+            ALOGE("%s: Stream %d: No input buffer was queued",
+                    __FUNCTION__, mId);
+            return INVALID_OPERATION;
+        }
+        bufferItem = *it;
+        mInputBufferQueue.erase(it);
+    }
+
+    anb = bufferItem->getBufferItem().mGraphicBuffer->getNativeBuffer();
+    assert(anb != NULL);
+    fenceFd = bufferItem->getBufferItem().mFence->dup();
+
+    /**
+     * FenceFD now owned by HAL except in case of error,
+     * in which case we reassign it to acquire_fence
+     */
+
+    // Handing out a raw pointer to this object. Increment internal refcount.
+    incStrong(this);
+    buffer->stream = this;
+    buffer->buffer = &(anb->handle);
+    buffer->acquire_fence = fenceFd;
+    buffer->release_fence = -1;
+    buffer->status = CAMERA3_BUFFER_STATUS_OK;
+
+    mDequeuedBufferCount++;
+
+    mBuffersInFlight.push_back(bufferItem);
+
+    return OK;
 }
 
-status_t Camera3ZslStream::returnInputBuffer(const camera3_stream_buffer &buffer) {
-    (void) buffer;
-    ALOGE("%s: Not implemented", __FUNCTION__);
-    return INVALID_OPERATION;
+status_t Camera3ZslStream::returnInputBufferLocked(
+        const camera3_stream_buffer &buffer) {
+    ATRACE_CALL();
+
+    // returnBuffer may be called from a raw pointer, not a sp<>, and we'll be
+    // decrementing the internal refcount next. In case this is the last ref, we
+    // might get destructed on the decStrong(), so keep an sp around until the
+    // end of the call - otherwise have to sprinkle the decStrong on all exit
+    // points.
+    sp<Camera3ZslStream> keepAlive(this);
+    decStrong(this);
+
+    // Allow buffers to be returned in the error state, to allow for disconnect
+    // and in the in-config states for registration
+    if (mState == STATE_CONSTRUCTED) {
+        ALOGE("%s: Stream %d: Can't return buffers in unconfigured state %d",
+                __FUNCTION__, mId, mState);
+        return INVALID_OPERATION;
+    }
+    if (mDequeuedBufferCount == 0) {
+        ALOGE("%s: Stream %d: No buffers outstanding to return", __FUNCTION__,
+                mId);
+        return INVALID_OPERATION;
+    }
+
+    bool bufferFound = false;
+    sp<PinnedBufferItem> bufferItem;
+    {
+        // Find the buffer we are returning
+        Vector<sp<PinnedBufferItem> >::iterator it, end;
+        for (it = mBuffersInFlight.begin(), end = mBuffersInFlight.end();
+             it != end;
+             ++it) {
+
+            const sp<PinnedBufferItem>& tmp = *it;
+            ANativeWindowBuffer *anb =
+                    tmp->getBufferItem().mGraphicBuffer->getNativeBuffer();
+            if (anb != NULL && &(anb->handle) == buffer.buffer) {
+                bufferFound = true;
+                bufferItem = tmp;
+                mBuffersInFlight.erase(it);
+                mDequeuedBufferCount--;
+            }
+        }
+    }
+    if (!bufferFound) {
+        ALOGE("%s: Stream %d: Can't return buffer that wasn't sent to HAL",
+              __FUNCTION__, mId);
+        return INVALID_OPERATION;
+    }
+
+    int releaseFenceFd = buffer.release_fence;
+
+    if (buffer.status == CAMERA3_BUFFER_STATUS_ERROR) {
+        if (buffer.release_fence != -1) {
+            ALOGE("%s: Stream %d: HAL should not set release_fence(%d) when "
+                  "there is an error", __FUNCTION__, mId, buffer.release_fence);
+            close(buffer.release_fence);
+        }
+
+        /**
+         * Reassign release fence as the acquire fence incase of error
+         */
+        releaseFenceFd = buffer.acquire_fence;
+    }
+
+    /**
+     * Unconditionally return buffer to the buffer queue.
+     * - Fwk takes over the release_fence ownership
+     */
+    sp<Fence> releaseFence = new Fence(releaseFenceFd);
+    bufferItem->getBufferItem().mFence = releaseFence;
+    bufferItem.clear(); // dropping last reference unpins buffer
+
+    mCombinedFence = Fence::merge(mName, mCombinedFence, releaseFence);
+
+    mBufferReturnedSignal.signal();
+
+    return OK;
+
 }
 
 void Camera3ZslStream::dump(int fd, const Vector<String16> &args) const {
-    (void) fd;
     (void) args;
-    ALOGE("%s: Not implemented", __FUNCTION__);
+
+    String8 lines;
+    lines.appendFormat("    Stream[%d]: ZSL\n", mId);
+    lines.appendFormat("      State: %d\n", mState);
+    lines.appendFormat("      Dims: %d x %d, format 0x%x\n",
+            camera3_stream::width, camera3_stream::height,
+            camera3_stream::format);
+    lines.appendFormat("      Usage: %d, max HAL buffers: %d\n",
+            camera3_stream::usage, camera3_stream::max_buffers);
+    lines.appendFormat("      Frames produced: %d, last timestamp: %lld ns\n",
+            mFrameCount, mLastTimestamp);
+    lines.appendFormat("      Total buffers: %d, currently dequeued: %d\n",
+            mTotalBufferCount, mDequeuedBufferCount);
+    lines.appendFormat("      Input buffers pending: %d, in flight %d\n",
+            mInputBufferQueue.size(), mBuffersInFlight.size());
+    write(fd, lines.string(), lines.size());
+}
+
+status_t Camera3ZslStream::enqueueInputBufferByTimestamp(
+        nsecs_t timestamp,
+        nsecs_t* actualTimestamp) {
+
+    Mutex::Autolock l(mLock);
+
+    TimestampFinder timestampFinder = TimestampFinder(timestamp);
+
+    sp<RingBufferConsumer::PinnedBufferItem> pinnedBuffer =
+            mProducer->pinSelectedBuffer(timestampFinder,
+                                        /*waitForFence*/false);
+
+    if (pinnedBuffer == 0) {
+        ALOGE("%s: No ZSL buffers were available yet", __FUNCTION__);
+        return NO_BUFFER_AVAILABLE;
+    }
+
+    nsecs_t actual = pinnedBuffer->getBufferItem().mTimestamp;
+
+    if (actual != timestamp) {
+        ALOGW("%s: ZSL buffer candidate search didn't find an exact match --"
+              " requested timestamp = %lld, actual timestamp = %lld",
+              __FUNCTION__, timestamp, actual);
+    }
+
+    mInputBufferQueue.push_back(pinnedBuffer);
+
+    if (actualTimestamp != NULL) {
+        *actualTimestamp = actual;
+    }
+
+    return OK;
+}
+
+status_t Camera3ZslStream::clearInputRingBuffer() {
+    Mutex::Autolock l(mLock);
+
+    mInputBufferQueue.clear();
+
+    return mProducer->clear();
+}
+
+status_t Camera3ZslStream::setTransform(int /*transform*/) {
+    ALOGV("%s: Not implemented", __FUNCTION__);
+    return INVALID_OPERATION;
 }
 
 }; // namespace camera3
diff --git a/services/camera/libcameraservice/camera3/Camera3ZslStream.h b/services/camera/libcameraservice/camera3/Camera3ZslStream.h
index 39d5995..b863e7f 100644
--- a/services/camera/libcameraservice/camera3/Camera3ZslStream.h
+++ b/services/camera/libcameraservice/camera3/Camera3ZslStream.h
@@ -19,8 +19,10 @@
 
 #include <utils/RefBase.h>
 #include <gui/Surface.h>
+#include <gui/RingBufferConsumer.h>
 
 #include "Camera3Stream.h"
+#include "Camera3OutputStreamInterface.h"
 
 namespace android {
 
@@ -32,32 +34,62 @@ namespace camera3 {
  * most output buffers, and when directed, pushes a buffer back to the HAL for
  * processing.
  */
-class Camera3ZslStream: public Camera3Stream {
+class Camera3ZslStream :
+        public Camera3Stream,
+        public Camera3OutputStreamInterface {
   public:
     /**
      * Set up a ZSL stream of a given resolution. Depth is the number of buffers
      * cached within the stream that can be retrieved for input.
      */
     Camera3ZslStream(int id, uint32_t width, uint32_t height, int depth);
+    ~Camera3ZslStream();
 
     virtual status_t waitUntilIdle(nsecs_t timeout);
     virtual void     dump(int fd, const Vector<String16> &args) const;
 
+    enum { NO_BUFFER_AVAILABLE = BufferQueue::NO_BUFFER_AVAILABLE };
+
+    /**
+     * Locate a buffer matching this timestamp in the RingBufferConsumer,
+     * and mark it to be queued at the next getInputBufferLocked invocation.
+     *
+     * Errors: Returns NO_BUFFER_AVAILABLE if we could not find a match.
+     *
+     */
+    status_t enqueueInputBufferByTimestamp(nsecs_t timestamp,
+                                           nsecs_t* actualTimestamp);
+
     /**
-     * Get an input buffer matching a specific timestamp. If no buffer matching
-     * the timestamp is available, NO_MEMORY is returned.
+     * Clears the buffers that can be used by enqueueInputBufferByTimestamp
      */
-    status_t getInputBuffer(camera3_stream_buffer *buffer, nsecs_t timestamp);
+    status_t clearInputRingBuffer();
 
     /**
-     * Return input buffer from HAL. The buffer is then marked as unfilled, and
-     * returned to the output-side stream for refilling.
+     * Camera3OutputStreamInterface implementation
      */
-    status_t returnInputBuffer(const camera3_stream_buffer &buffer);
+    status_t setTransform(int transform);
 
   private:
 
     int mDepth;
+    // Input buffers pending to be queued into HAL
+    List<sp<RingBufferConsumer::PinnedBufferItem> > mInputBufferQueue;
+    sp<RingBufferConsumer>                          mProducer;
+    sp<ANativeWindow>                               mConsumer;
+
+    // Input buffers in flight to HAL
+    Vector<sp<RingBufferConsumer::PinnedBufferItem> > mBuffersInFlight;
+    size_t                                          mTotalBufferCount;
+    // sum of input and output buffers that are currently acquired by HAL
+    size_t                                          mDequeuedBufferCount;
+    Condition                                       mBufferReturnedSignal;
+    uint32_t                                        mFrameCount;
+    // Last received output buffer's timestamp
+    nsecs_t                                         mLastTimestamp;
+
+    // The merged release fence for all returned buffers
+    sp<Fence>                                       mCombinedFence;
 
     /**
      * Camera3Stream interface
@@ -67,9 +99,18 @@ class Camera3ZslStream: public Camera3Stream {
     virtual status_t getBufferLocked(camera3_stream_buffer *buffer);
     virtual status_t returnBufferLocked(const camera3_stream_buffer &buffer,
             nsecs_t timestamp);
+    // getInputBuffer/returnInputBuffer operate the input stream side of the
+    // ZslStream.
+    virtual status_t getInputBufferLocked(camera3_stream_buffer *buffer);
+    virtual status_t returnInputBufferLocked(
+            const camera3_stream_buffer &buffer);
+
     virtual bool     hasOutstandingBuffersLocked() const;
     virtual status_t disconnectLocked();
 
+    virtual status_t configureQueueLocked();
+    virtual size_t   getBufferCountLocked();
+
 }; // class Camera3ZslStream
 
 }; // namespace camera3