diff --git a/camera/device/3.6/default/Android.bp b/camera/device/3.6/default/Android.bp
index ce51185..a2ddebd 100644
--- a/camera/device/3.6/default/Android.bp
+++ b/camera/device/3.6/default/Android.bp
@@ -28,6 +28,7 @@
     srcs: [
         "ExternalCameraDevice.cpp",
         "ExternalCameraDeviceSession.cpp",
+        "ExternalCameraOfflineSession.cpp",
     ],
     shared_libs: [
         "libhidlbase",
diff --git a/camera/device/3.6/default/ExternalCameraDeviceSession.cpp b/camera/device/3.6/default/ExternalCameraDeviceSession.cpp
index e14ae99..0cc81bb 100644
--- a/camera/device/3.6/default/ExternalCameraDeviceSession.cpp
+++ b/camera/device/3.6/default/ExternalCameraDeviceSession.cpp
@@ -73,12 +73,8 @@
 
     Status status = configureStreams(config_v32, &outStreams_v33, blobBufferSize);
 
-    outStreams.streams.resize(outStreams_v33.streams.size());
-    for (size_t i = 0; i < outStreams.streams.size(); i++) {
-        outStreams.streams[i].v3_4.v3_3 = outStreams_v33.streams[i];
-        // TODO: implement it later
-        outStreams.streams[i].supportOffline = false;
-    }
+    fillOutputStream3_6(outStreams_v33, &outStreams);
+
     _hidl_cb(status, outStreams);
     return Void();
 }
@@ -86,12 +82,273 @@
 Return<void> ExternalCameraDeviceSession::switchToOffline(
         const hidl_vec<int32_t>& streamsToKeep,
         ICameraDeviceSession::switchToOffline_cb _hidl_cb) {
-    // TODO: implement this
-    (void) streamsToKeep;
-    (void) _hidl_cb;
+    std::vector<NotifyMsg> msgs;
+    std::vector<CaptureResult> results;
+    CameraOfflineSessionInfo info;
+    sp<ICameraOfflineSession> session;
+
+    Status st = switchToOffline(streamsToKeep, &msgs, &results, &info, &session);
+
+    mCallback->notify(msgs);
+    hidl_vec<CaptureResult> hidlResults(std::move(results));
+    invokeProcessCaptureResultCallback(hidlResults, /* tryWriteFmq */true);
+    V3_4::implementation::freeReleaseFences(hidlResults);
+
+    _hidl_cb(st, info, session);
     return Void();
 }
 
+void ExternalCameraDeviceSession::fillOutputStream3_6(
+        const V3_3::HalStreamConfiguration& outStreams_v33,
+        /*out*/V3_6::HalStreamConfiguration* outStreams_v36) {
+    if (outStreams_v36 == nullptr) {
+        ALOGE("%s: outStreams_v36 must not be null!", __FUNCTION__);
+        return;
+    }
+    Mutex::Autolock _l(mLock);
+    outStreams_v36->streams.resize(outStreams_v33.streams.size());
+    for (size_t i = 0; i < outStreams_v36->streams.size(); i++) {
+        outStreams_v36->streams[i].v3_4.v3_3 = outStreams_v33.streams[i];
+        outStreams_v36->streams[i].supportOffline =
+                supportOfflineLocked(outStreams_v33.streams[i].v3_2.id);
+    }
+}
+
+bool ExternalCameraDeviceSession::supportOfflineLocked(int32_t streamId) {
+    const Stream& stream = mStreamMap[streamId];
+    if (stream.format == PixelFormat::BLOB &&
+            stream.dataSpace == static_cast<int32_t>(Dataspace::V0_JFIF)) {
+        return true;
+    }
+    // TODO: support YUV output stream?
+    return false;
+}
+
+bool ExternalCameraDeviceSession::canDropRequest(const hidl_vec<int32_t>& offlineStreams,
+        std::shared_ptr<V3_4::implementation::HalRequest> halReq) {
+    for (const auto& buffer : halReq->buffers) {
+        for (auto offlineStreamId : offlineStreams) {
+            if (buffer.streamId == offlineStreamId) {
+                return false;
+            }
+        }
+    }
+    // Only drop a request completely if it has no offline output
+    return true;
+}
+
+void ExternalCameraDeviceSession::fillOfflineSessionInfo(const hidl_vec<int32_t>& offlineStreams,
+        std::deque<std::shared_ptr<HalRequest>>& offlineReqs,
+        const std::map<int, CirculatingBuffers>& circulatingBuffers,
+        /*out*/CameraOfflineSessionInfo* info) {
+    if (info == nullptr) {
+        ALOGE("%s: output info must not be null!", __FUNCTION__);
+        return;
+    }
+
+    info->offlineStreams.resize(offlineStreams.size());
+    info->offlineRequests.resize(offlineReqs.size());
+
+    std::unordered_map<int32_t, uint32_t> outstandingBufs(offlineStreams.size());
+    for (const auto streamId : offlineStreams) {
+        outstandingBufs.insert({streamId, 0});
+    }
+    // Fill in offline reqs and count outstanding buffers
+    for (size_t i = 0; i < offlineReqs.size(); i++) {
+        info->offlineRequests[i].frameNumber = offlineReqs[i]->frameNumber;
+        info->offlineRequests[i].pendingStreams.resize(offlineReqs[i]->buffers.size());
+        for (size_t bIdx = 0; bIdx < offlineReqs[i]->buffers.size(); bIdx++) {
+            int32_t streamId = offlineReqs[i]->buffers[bIdx].streamId;
+            info->offlineRequests[i].pendingStreams[bIdx] = streamId;
+            outstandingBufs[streamId]++;
+        }
+    }
+
+    for (size_t i = 0; i < offlineStreams.size(); i++) {
+        int32_t streamId = offlineStreams[i];
+        info->offlineStreams[i].id = streamId;
+        info->offlineStreams[i].numOutstandingBuffers = outstandingBufs[streamId];
+        const CirculatingBuffers& bufIdMap = circulatingBuffers.at(streamId);
+        info->offlineStreams[i].circulatingBufferIds.resize(bufIdMap.size());
+        size_t bIdx = 0;
+        for (const auto& pair : bufIdMap) {
+            // Fill in bufferId
+            info->offlineStreams[i].circulatingBufferIds[bIdx++] = pair.first;
+        }
+
+    }
+}
+
+Status ExternalCameraDeviceSession::switchToOffline(const hidl_vec<int32_t>& offlineStreams,
+        /*out*/std::vector<NotifyMsg>* msgs,
+        /*out*/std::vector<CaptureResult>* results,
+        /*out*/CameraOfflineSessionInfo* info,
+        /*out*/sp<ICameraOfflineSession>* session) {
+    ATRACE_CALL();
+    if (offlineStreams.size() > 1) {
+        ALOGE("%s: more than one offline stream is not supported", __FUNCTION__);
+        return Status::ILLEGAL_ARGUMENT;
+    }
+
+    if (msgs == nullptr || results == nullptr || info == nullptr || session == nullptr) {
+        ALOGE("%s: output arguments (%p, %p, %p, %p) must not be null", __FUNCTION__,
+                msgs, results, info, session);
+        return Status::ILLEGAL_ARGUMENT;
+    }
+
+    msgs->clear();
+    results->clear();
+
+    Mutex::Autolock _il(mInterfaceLock);
+    Status status = initStatus();
+    if (status != Status::OK) {
+        return status;
+    }
+
+    Mutex::Autolock _l(mLock);
+    for (auto streamId : offlineStreams) {
+        if (!supportOfflineLocked(streamId)) {
+            return Status::ILLEGAL_ARGUMENT;
+        }
+    }
+
+    // pause output thread and get all remaining inflight requests
+    auto remainingReqs = mOutputThread->switchToOffline();
+    std::vector<std::shared_ptr<V3_4::implementation::HalRequest>> halReqs;
+
+    // Send out buffer/request error for remaining requests and filter requests
+    // to be handled in offline mode
+    for (auto& halReq : remainingReqs) {
+        bool dropReq = canDropRequest(offlineStreams, halReq);
+        if (dropReq) {
+            // Request is dropped completely. Just send request error and
+            // there is no need to send the request to offline session
+            processCaptureRequestError(halReq, msgs, results);
+            continue;
+        }
+
+        // All requests reach here must have at least one offline stream output
+        NotifyMsg shutter;
+        shutter.type = MsgType::SHUTTER;
+        shutter.msg.shutter.frameNumber = halReq->frameNumber;
+        shutter.msg.shutter.timestamp = halReq->shutterTs;
+        msgs->push_back(shutter);
+
+        std::vector<V3_4::implementation::HalStreamBuffer> offlineBuffers;
+        for (const auto& buffer : halReq->buffers) {
+            bool dropBuffer = true;
+            for (auto offlineStreamId : offlineStreams) {
+                if (buffer.streamId == offlineStreamId) {
+                    dropBuffer = false;
+                    break;
+                }
+            }
+            if (dropBuffer) {
+                NotifyMsg error;
+                error.type = MsgType::ERROR;
+                error.msg.error.frameNumber = halReq->frameNumber;
+                error.msg.error.errorStreamId = buffer.streamId;
+                error.msg.error.errorCode = ErrorCode::ERROR_BUFFER;
+                msgs->push_back(error);
+
+                CaptureResult result;
+                result.frameNumber = halReq->frameNumber;
+                result.partialResult = 0; // buffer only result
+                result.inputBuffer.streamId = -1;
+                result.outputBuffers.resize(1);
+                result.outputBuffers[0].streamId = buffer.streamId;
+                result.outputBuffers[0].bufferId = buffer.bufferId;
+                result.outputBuffers[0].status = BufferStatus::ERROR;
+                if (buffer.acquireFence >= 0) {
+                    native_handle_t* handle = native_handle_create(/*numFds*/1, /*numInts*/0);
+                    handle->data[0] = buffer.acquireFence;
+                    result.outputBuffers[0].releaseFence.setTo(handle, /*shouldOwn*/false);
+                }
+                results->push_back(result);
+            } else {
+                offlineBuffers.push_back(buffer);
+            }
+        }
+        halReq->buffers = offlineBuffers;
+        halReqs.push_back(halReq);
+    }
+
+    // convert hal requests to offline request
+    std::deque<std::shared_ptr<HalRequest>> offlineReqs(halReqs.size());
+    for (auto& v4lReq : halReqs) {
+        std::shared_ptr<HalRequest> halReq = std::make_shared<HalRequest>();
+        halReq->frameNumber = v4lReq->frameNumber;
+        halReq->setting = v4lReq->setting;
+        halReq->shutterTs = v4lReq->shutterTs;
+        halReq->buffers = v4lReq->buffers;
+        sp<V3_4::implementation::V4L2Frame> v4l2Frame =
+                static_cast<V3_4::implementation::V4L2Frame*>(v4lReq->frameIn.get());
+        halReq->frameIn = new AllocatedV4L2Frame(v4l2Frame);
+        offlineReqs.push_back(halReq);
+        // enqueue V4L2 frame
+        enqueueV4l2Frame(v4l2Frame);
+    }
+
+    // Collect buffer caches/streams
+    hidl_vec<Stream> streamInfos;
+    streamInfos.resize(offlineStreams.size());
+    std::map<int, CirculatingBuffers> circulatingBuffers;
+    {
+        Mutex::Autolock _l(mCbsLock);
+        size_t idx = 0;
+        for(auto streamId : offlineStreams) {
+            circulatingBuffers[streamId] = mCirculatingBuffers.at(streamId);
+            mCirculatingBuffers.erase(streamId);
+            streamInfos[idx++] = mStreamMap.at(streamId);
+            mStreamMap.erase(streamId);
+        }
+    }
+
+    fillOfflineSessionInfo(offlineStreams, offlineReqs, circulatingBuffers, info);
+
+    // create the offline session object
+    bool afTrigger;
+    {
+        std::lock_guard<std::mutex> lk(mAfTriggerLock);
+        afTrigger = mAfTrigger;
+    }
+    sp<ExternalCameraOfflineSession> sessionImpl = new ExternalCameraOfflineSession(
+            mCroppingType, mCameraCharacteristics, mCameraId,
+            mExifMake, mExifModel, mBlobBufferSize, afTrigger,
+            streamInfos, offlineReqs, circulatingBuffers);
+
+    bool initFailed = sessionImpl->initialize();
+    if (initFailed) {
+        ALOGE("%s: offline session initialize failed!", __FUNCTION__);
+        return Status::INTERNAL_ERROR;
+    }
+
+    // cleanup stream and buffer caches
+    {
+        Mutex::Autolock _l(mCbsLock);
+        for(auto pair : mStreamMap) {
+            cleanupBuffersLocked(/*Stream ID*/pair.first);
+        }
+        mCirculatingBuffers.clear();
+    }
+    mStreamMap.clear();
+
+    // update inflight records
+    {
+        std::lock_guard<std::mutex> lk(mInflightFramesLock);
+        mInflightFrames.clear();
+    }
+
+    // stop v4l2 streaming
+    if (v4l2StreamOffLocked() !=0) {
+        ALOGE("%s: stop V4L2 streaming failed!", __FUNCTION__);
+        return Status::INTERNAL_ERROR;
+    }
+
+    *session = sessionImpl->getInterface();
+    return Status::OK;
+}
+
 } // namespace implementation
 }  // namespace V3_6
 }  // namespace device
diff --git a/camera/device/3.6/default/ExternalCameraOfflineSession.cpp b/camera/device/3.6/default/ExternalCameraOfflineSession.cpp
new file mode 100644
index 0000000..e606fda
--- /dev/null
+++ b/camera/device/3.6/default/ExternalCameraOfflineSession.cpp
@@ -0,0 +1,554 @@
+/*
+ * Copyright (C) 2020 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 "ExtCamOfflnSsn@3.6"
+#define ATRACE_TAG ATRACE_TAG_CAMERA
+#include <android/log.h>
+
+#include <linux/videodev2.h>
+#include <sync/sync.h>
+
+#define HAVE_JPEG // required for libyuv.h to export MJPEG decode APIs
+#include <libyuv.h>
+
+#include <utils/Trace.h>
+#include "ExternalCameraOfflineSession.h"
+
+namespace {
+
+// Size of request/result metadata fast message queue. Change to 0 to always use hwbinder buffer.
+static constexpr size_t kMetadataMsgQueueSize = 1 << 18 /* 256kB */;
+
+} // anonymous namespace
+
+namespace android {
+namespace hardware {
+namespace camera {
+namespace device {
+namespace V3_6 {
+namespace implementation {
+
+// static instance
+HandleImporter ExternalCameraOfflineSession::sHandleImporter;
+
+using V3_5::implementation::ExternalCameraDeviceSession;
+
+ExternalCameraOfflineSession::ExternalCameraOfflineSession(
+        const CroppingType& croppingType,
+        const common::V1_0::helper::CameraMetadata& chars,
+        const std::string& cameraId,
+        const std::string& exifMake,
+        const std::string& exifModel,
+        const uint32_t blobBufferSize,
+        const bool afTrigger,
+        const hidl_vec<Stream>& offlineStreams,
+        std::deque<std::shared_ptr<HalRequest>>& offlineReqs,
+        const std::map<int, CirculatingBuffers>& circulatingBuffers) :
+        mCroppingType(croppingType), mChars(chars), mCameraId(cameraId),
+        mExifMake(exifMake), mExifModel(exifModel), mBlobBufferSize(blobBufferSize),
+        mAfTrigger(afTrigger), mOfflineStreams(offlineStreams), mOfflineReqs(offlineReqs),
+        mCirculatingBuffers(circulatingBuffers) {}
+
+ExternalCameraOfflineSession::~ExternalCameraOfflineSession() {
+    close();
+}
+
+bool ExternalCameraOfflineSession::initialize() {
+    mResultMetadataQueue = std::make_shared<ResultMetadataQueue>(
+            kMetadataMsgQueueSize, false /* non blocking */);
+    if (!mResultMetadataQueue->isValid()) {
+        ALOGE("%s: invalid result fmq", __FUNCTION__);
+        return true;
+    }
+    return false;
+}
+
+void ExternalCameraOfflineSession::initOutputThread() {
+    if (mOutputThread != nullptr) {
+        ALOGE("%s: OutputThread already exist!", __FUNCTION__);
+        return;
+    }
+
+    mBufferRequestThread = new ExternalCameraDeviceSession::BufferRequestThread(
+            this, mCallback);
+    mBufferRequestThread->run("ExtCamBufReq", PRIORITY_DISPLAY);
+
+    mOutputThread = new OutputThread(this, mCroppingType, mChars,
+            mBufferRequestThread, mOfflineReqs);
+
+    mOutputThread->setExifMakeModel(mExifMake, mExifModel);
+
+    Size inputSize = { mOfflineReqs[0]->frameIn->mWidth, mOfflineReqs[0]->frameIn->mHeight};
+    Size maxThumbSize = V3_4::implementation::getMaxThumbnailResolution(mChars);
+    mOutputThread->allocateIntermediateBuffers(
+            inputSize, maxThumbSize, mOfflineStreams, mBlobBufferSize);
+
+    mOutputThread->run("ExtCamOfflnOut", PRIORITY_DISPLAY);
+}
+
+bool ExternalCameraOfflineSession::OutputThread::threadLoop() {
+    auto parent = mParent.promote();
+    if (parent == nullptr) {
+       ALOGE("%s: session has been disconnected!", __FUNCTION__);
+       return false;
+    }
+
+    if (mOfflineReqs.empty()) {
+        ALOGI("%s: all offline requests are processed. Stopping.", __FUNCTION__);
+        return false;
+    }
+
+    std::shared_ptr<HalRequest> req = mOfflineReqs.front();
+    mOfflineReqs.pop_front();
+
+    auto onDeviceError = [&](auto... args) {
+        ALOGE(args...);
+        parent->notifyError(
+                req->frameNumber, /*stream*/-1, ErrorCode::ERROR_DEVICE);
+        signalRequestDone();
+        return false;
+    };
+
+    if (req->frameIn->mFourcc != V4L2_PIX_FMT_MJPEG && req->frameIn->mFourcc != V4L2_PIX_FMT_Z16) {
+        return onDeviceError("%s: do not support V4L2 format %c%c%c%c", __FUNCTION__,
+                req->frameIn->mFourcc & 0xFF,
+                (req->frameIn->mFourcc >> 8) & 0xFF,
+                (req->frameIn->mFourcc >> 16) & 0xFF,
+                (req->frameIn->mFourcc >> 24) & 0xFF);
+    }
+
+    int res = requestBufferStart(req->buffers);
+    if (res != 0) {
+        ALOGE("%s: send BufferRequest failed! res %d", __FUNCTION__, res);
+        return onDeviceError("%s: failed to send buffer request!", __FUNCTION__);
+    }
+
+    std::unique_lock<std::mutex> lk(mBufferLock);
+    // Convert input V4L2 frame to YU12 of the same size
+    // TODO: see if we can save some computation by converting to YV12 here
+    uint8_t* inData;
+    size_t inDataSize;
+    if (req->frameIn->getData(&inData, &inDataSize) != 0) {
+        lk.unlock();
+        return onDeviceError("%s: V4L2 buffer map failed", __FUNCTION__);
+    }
+
+    // TODO: in some special case maybe we can decode jpg directly to gralloc output?
+    if (req->frameIn->mFourcc == V4L2_PIX_FMT_MJPEG) {
+        ATRACE_BEGIN("MJPGtoI420");
+        int res = libyuv::MJPGToI420(
+            inData, inDataSize, static_cast<uint8_t*>(mYu12FrameLayout.y), mYu12FrameLayout.yStride,
+            static_cast<uint8_t*>(mYu12FrameLayout.cb), mYu12FrameLayout.cStride,
+            static_cast<uint8_t*>(mYu12FrameLayout.cr), mYu12FrameLayout.cStride,
+            mYu12Frame->mWidth, mYu12Frame->mHeight, mYu12Frame->mWidth, mYu12Frame->mHeight);
+        ATRACE_END();
+
+        if (res != 0) {
+            // For some webcam, the first few V4L2 frames might be malformed...
+            ALOGE("%s: Convert V4L2 frame to YU12 failed! res %d", __FUNCTION__, res);
+            lk.unlock();
+            Status st = parent->processCaptureRequestError(req);
+            if (st != Status::OK) {
+                return onDeviceError("%s: failed to process capture request error!", __FUNCTION__);
+            }
+            signalRequestDone();
+            return true;
+        }
+    }
+
+    ATRACE_BEGIN("Wait for BufferRequest done");
+    res = waitForBufferRequestDone(&req->buffers);
+    ATRACE_END();
+
+    if (res != 0) {
+        ALOGE("%s: wait for BufferRequest done failed! res %d", __FUNCTION__, res);
+        lk.unlock();
+        return onDeviceError("%s: failed to process buffer request error!", __FUNCTION__);
+    }
+
+    ALOGV("%s processing new request", __FUNCTION__);
+    const int kSyncWaitTimeoutMs = 500;
+    for (auto& halBuf : req->buffers) {
+        if (*(halBuf.bufPtr) == nullptr) {
+            ALOGW("%s: buffer for stream %d missing", __FUNCTION__, halBuf.streamId);
+            halBuf.fenceTimeout = true;
+        } else if (halBuf.acquireFence >= 0) {
+            int ret = sync_wait(halBuf.acquireFence, kSyncWaitTimeoutMs);
+            if (ret) {
+                halBuf.fenceTimeout = true;
+            } else {
+                ::close(halBuf.acquireFence);
+                halBuf.acquireFence = -1;
+            }
+        }
+
+        if (halBuf.fenceTimeout) {
+            continue;
+        }
+
+        // Gralloc lockYCbCr the buffer
+        switch (halBuf.format) {
+            case PixelFormat::BLOB: {
+                int ret = createJpegLocked(halBuf, req->setting);
+
+                if(ret != 0) {
+                    lk.unlock();
+                    return onDeviceError("%s: createJpegLocked failed with %d",
+                          __FUNCTION__, ret);
+                }
+            } break;
+            case PixelFormat::Y16: {
+                void* outLayout = sHandleImporter.lock(*(halBuf.bufPtr), halBuf.usage, inDataSize);
+
+                std::memcpy(outLayout, inData, inDataSize);
+
+                int relFence = sHandleImporter.unlock(*(halBuf.bufPtr));
+                if (relFence >= 0) {
+                    halBuf.acquireFence = relFence;
+                }
+            } break;
+            case PixelFormat::YCBCR_420_888:
+            case PixelFormat::YV12: {
+                IMapper::Rect outRect {0, 0,
+                        static_cast<int32_t>(halBuf.width),
+                        static_cast<int32_t>(halBuf.height)};
+                YCbCrLayout outLayout = sHandleImporter.lockYCbCr(
+                        *(halBuf.bufPtr), halBuf.usage, outRect);
+                ALOGV("%s: outLayout y %p cb %p cr %p y_str %d c_str %d c_step %d",
+                        __FUNCTION__, outLayout.y, outLayout.cb, outLayout.cr,
+                        outLayout.yStride, outLayout.cStride, outLayout.chromaStep);
+
+                // Convert to output buffer size/format
+                uint32_t outputFourcc = V3_4::implementation::getFourCcFromLayout(outLayout);
+                ALOGV("%s: converting to format %c%c%c%c", __FUNCTION__,
+                        outputFourcc & 0xFF,
+                        (outputFourcc >> 8) & 0xFF,
+                        (outputFourcc >> 16) & 0xFF,
+                        (outputFourcc >> 24) & 0xFF);
+
+                YCbCrLayout cropAndScaled;
+                ATRACE_BEGIN("cropAndScaleLocked");
+                int ret = cropAndScaleLocked(
+                        mYu12Frame,
+                        Size { halBuf.width, halBuf.height },
+                        &cropAndScaled);
+                ATRACE_END();
+                if (ret != 0) {
+                    lk.unlock();
+                    return onDeviceError("%s: crop and scale failed!", __FUNCTION__);
+                }
+
+                Size sz {halBuf.width, halBuf.height};
+                ATRACE_BEGIN("formatConvert");
+                ret = V3_4::implementation::formatConvert(cropAndScaled, outLayout, sz, outputFourcc);
+                ATRACE_END();
+                if (ret != 0) {
+                    lk.unlock();
+                    return onDeviceError("%s: format coversion failed!", __FUNCTION__);
+                }
+                int relFence = sHandleImporter.unlock(*(halBuf.bufPtr));
+                if (relFence >= 0) {
+                    halBuf.acquireFence = relFence;
+                }
+            } break;
+            default:
+                lk.unlock();
+                return onDeviceError("%s: unknown output format %x", __FUNCTION__, halBuf.format);
+        }
+    } // for each buffer
+    mScaledYu12Frames.clear();
+
+    // Don't hold the lock while calling back to parent
+    lk.unlock();
+    Status st = parent->processCaptureResult(req);
+    if (st != Status::OK) {
+        return onDeviceError("%s: failed to process capture result!", __FUNCTION__);
+    }
+    signalRequestDone();
+    return true;
+}
+
+Status ExternalCameraOfflineSession::importBuffer(int32_t streamId,
+        uint64_t bufId, buffer_handle_t buf,
+        /*out*/buffer_handle_t** outBufPtr,
+        bool allowEmptyBuf) {
+    Mutex::Autolock _l(mCbsLock);
+    return V3_4::implementation::importBufferImpl(
+            mCirculatingBuffers, sHandleImporter, streamId,
+            bufId, buf, outBufPtr, allowEmptyBuf);
+    return Status::OK;
+};
+
+#define UPDATE(md, tag, data, size)               \
+do {                                              \
+    if ((md).update((tag), (data), (size))) {     \
+        ALOGE("Update " #tag " failed!");         \
+        return BAD_VALUE;                         \
+    }                                             \
+} while (0)
+
+status_t ExternalCameraOfflineSession::fillCaptureResult(
+        common::V1_0::helper::CameraMetadata &md, nsecs_t timestamp) {
+    bool afTrigger = false;
+    {
+        std::lock_guard<std::mutex> lk(mAfTriggerLock);
+        afTrigger = mAfTrigger;
+        if (md.exists(ANDROID_CONTROL_AF_TRIGGER)) {
+            camera_metadata_entry entry = md.find(ANDROID_CONTROL_AF_TRIGGER);
+            if (entry.data.u8[0] == ANDROID_CONTROL_AF_TRIGGER_START) {
+                mAfTrigger = afTrigger = true;
+            } else if (entry.data.u8[0] == ANDROID_CONTROL_AF_TRIGGER_CANCEL) {
+                mAfTrigger = afTrigger = false;
+            }
+        }
+    }
+
+    // For USB camera, the USB camera handles everything and we don't have control
+    // over AF. We only simply fake the AF metadata based on the request
+    // received here.
+    uint8_t afState;
+    if (afTrigger) {
+        afState = ANDROID_CONTROL_AF_STATE_FOCUSED_LOCKED;
+    } else {
+        afState = ANDROID_CONTROL_AF_STATE_INACTIVE;
+    }
+    UPDATE(md, ANDROID_CONTROL_AF_STATE, &afState, 1);
+
+    camera_metadata_ro_entry activeArraySize =
+            mChars.find(ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE);
+
+    return V3_4::implementation::fillCaptureResultCommon(md, timestamp, activeArraySize);
+}
+
+#undef UPDATE
+
+Status ExternalCameraOfflineSession::processCaptureResult(std::shared_ptr<HalRequest>& req) {
+    ATRACE_CALL();
+    // Fill output buffers
+    hidl_vec<CaptureResult> results;
+    results.resize(1);
+    CaptureResult& result = results[0];
+    result.frameNumber = req->frameNumber;
+    result.partialResult = 1;
+    result.inputBuffer.streamId = -1;
+    result.outputBuffers.resize(req->buffers.size());
+    for (size_t i = 0; i < req->buffers.size(); i++) {
+        result.outputBuffers[i].streamId = req->buffers[i].streamId;
+        result.outputBuffers[i].bufferId = req->buffers[i].bufferId;
+        if (req->buffers[i].fenceTimeout) {
+            result.outputBuffers[i].status = BufferStatus::ERROR;
+            if (req->buffers[i].acquireFence >= 0) {
+                native_handle_t* handle = native_handle_create(/*numFds*/1, /*numInts*/0);
+                handle->data[0] = req->buffers[i].acquireFence;
+                result.outputBuffers[i].releaseFence.setTo(handle, /*shouldOwn*/false);
+            }
+            notifyError(req->frameNumber, req->buffers[i].streamId, ErrorCode::ERROR_BUFFER);
+        } else {
+            result.outputBuffers[i].status = BufferStatus::OK;
+            // TODO: refactor
+            if (req->buffers[i].acquireFence >= 0) {
+                native_handle_t* handle = native_handle_create(/*numFds*/1, /*numInts*/0);
+                handle->data[0] = req->buffers[i].acquireFence;
+                result.outputBuffers[i].releaseFence.setTo(handle, /*shouldOwn*/false);
+            }
+        }
+    }
+
+    // Fill capture result metadata
+    fillCaptureResult(req->setting, req->shutterTs);
+    const camera_metadata_t *rawResult = req->setting.getAndLock();
+    V3_2::implementation::convertToHidl(rawResult, &result.result);
+    req->setting.unlock(rawResult);
+
+    // Callback into framework
+    invokeProcessCaptureResultCallback(results, /* tryWriteFmq */true);
+    V3_4::implementation::freeReleaseFences(results);
+    return Status::OK;
+};
+
+void ExternalCameraOfflineSession::invokeProcessCaptureResultCallback(
+        hidl_vec<CaptureResult> &results, bool tryWriteFmq) {
+    if (mProcessCaptureResultLock.tryLock() != OK) {
+        const nsecs_t NS_TO_SECOND = 1000000000;
+        ALOGV("%s: previous call is not finished! waiting 1s...", __FUNCTION__);
+        if (mProcessCaptureResultLock.timedLock(/* 1s */NS_TO_SECOND) != OK) {
+            ALOGE("%s: cannot acquire lock in 1s, cannot proceed",
+                    __FUNCTION__);
+            return;
+        }
+    }
+    if (tryWriteFmq && mResultMetadataQueue->availableToWrite() > 0) {
+        for (CaptureResult &result : results) {
+            if (result.result.size() > 0) {
+                if (mResultMetadataQueue->write(result.result.data(), result.result.size())) {
+                    result.fmqResultSize = result.result.size();
+                    result.result.resize(0);
+                } else {
+                    ALOGW("%s: couldn't utilize fmq, fall back to hwbinder", __FUNCTION__);
+                    result.fmqResultSize = 0;
+                }
+            } else {
+                result.fmqResultSize = 0;
+            }
+        }
+    }
+    auto status = mCallback->processCaptureResult(results);
+    if (!status.isOk()) {
+        ALOGE("%s: processCaptureResult ERROR : %s", __FUNCTION__,
+              status.description().c_str());
+    }
+
+    mProcessCaptureResultLock.unlock();
+}
+
+Status ExternalCameraOfflineSession::processCaptureRequestError(
+        const std::shared_ptr<HalRequest>& req,
+        /*out*/std::vector<NotifyMsg>* outMsgs,
+        /*out*/std::vector<CaptureResult>* outResults) {
+    ATRACE_CALL();
+
+    if (outMsgs == nullptr) {
+        notifyError(/*frameNum*/req->frameNumber, /*stream*/-1, ErrorCode::ERROR_REQUEST);
+    } else {
+        NotifyMsg shutter;
+        shutter.type = MsgType::SHUTTER;
+        shutter.msg.shutter.frameNumber = req->frameNumber;
+        shutter.msg.shutter.timestamp = req->shutterTs;
+
+        NotifyMsg error;
+        error.type = MsgType::ERROR;
+        error.msg.error.frameNumber = req->frameNumber;
+        error.msg.error.errorStreamId = -1;
+        error.msg.error.errorCode = ErrorCode::ERROR_REQUEST;
+        outMsgs->push_back(shutter);
+        outMsgs->push_back(error);
+    }
+
+    // Fill output buffers
+    hidl_vec<CaptureResult> results;
+    results.resize(1);
+    CaptureResult& result = results[0];
+    result.frameNumber = req->frameNumber;
+    result.partialResult = 1;
+    result.inputBuffer.streamId = -1;
+    result.outputBuffers.resize(req->buffers.size());
+    for (size_t i = 0; i < req->buffers.size(); i++) {
+        result.outputBuffers[i].streamId = req->buffers[i].streamId;
+        result.outputBuffers[i].bufferId = req->buffers[i].bufferId;
+        result.outputBuffers[i].status = BufferStatus::ERROR;
+        if (req->buffers[i].acquireFence >= 0) {
+            native_handle_t* handle = native_handle_create(/*numFds*/1, /*numInts*/0);
+            handle->data[0] = req->buffers[i].acquireFence;
+            result.outputBuffers[i].releaseFence.setTo(handle, /*shouldOwn*/false);
+        }
+    }
+
+    if (outResults == nullptr) {
+        // Callback into framework
+        invokeProcessCaptureResultCallback(results, /* tryWriteFmq */true);
+        V3_4::implementation::freeReleaseFences(results);
+    } else {
+        outResults->push_back(result);
+    }
+    return Status::OK;
+};
+
+ssize_t ExternalCameraOfflineSession::getJpegBufferSize(
+        uint32_t /*width*/, uint32_t /*height*/) const {
+    // Empty implementation here as the jpeg buffer size is passed in by ctor
+    return 0;
+};
+
+void ExternalCameraOfflineSession::notifyError(uint32_t frameNumber, int32_t streamId, ErrorCode ec) {
+    NotifyMsg msg;
+    msg.type = MsgType::ERROR;
+    msg.msg.error.frameNumber = frameNumber;
+    msg.msg.error.errorStreamId = streamId;
+    msg.msg.error.errorCode = ec;
+    mCallback->notify({msg});
+};
+
+Return<void> ExternalCameraOfflineSession::setCallback(const sp<ICameraDeviceCallback>& cb) {
+    Mutex::Autolock _il(mInterfaceLock);
+    if (mCallback != nullptr && cb != nullptr) {
+        ALOGE("%s: callback must not be set twice!", __FUNCTION__);
+        return Void();
+    }
+    mCallback = cb;
+
+    initOutputThread();
+
+    if (mOutputThread == nullptr) {
+        ALOGE("%s: init OutputThread failed!", __FUNCTION__);
+    }
+    return Void();
+}
+
+Return<void> ExternalCameraOfflineSession::getCaptureResultMetadataQueue(
+        V3_3::ICameraDeviceSession::getCaptureResultMetadataQueue_cb _hidl_cb) {
+    Mutex::Autolock _il(mInterfaceLock);
+    _hidl_cb(*mResultMetadataQueue->getDesc());
+    return Void();
+}
+
+void ExternalCameraOfflineSession::cleanupBuffersLocked(int id) {
+    for (auto& pair : mCirculatingBuffers.at(id)) {
+        sHandleImporter.freeBuffer(pair.second);
+    }
+    mCirculatingBuffers[id].clear();
+    mCirculatingBuffers.erase(id);
+}
+
+Return<void> ExternalCameraOfflineSession::close() {
+    Mutex::Autolock _il(mInterfaceLock);
+    {
+        Mutex::Autolock _l(mLock);
+        if (mClosed) {
+            ALOGW("%s: offline session already closed!", __FUNCTION__);
+            return Void();
+        }
+    }
+    if (mBufferRequestThread) {
+        mBufferRequestThread->requestExit();
+        mBufferRequestThread->join();
+        mBufferRequestThread.clear();
+    }
+    if (mOutputThread) {
+        mOutputThread->flush();
+        mOutputThread->requestExit();
+        mOutputThread->join();
+        mOutputThread.clear();
+    }
+
+    Mutex::Autolock _l(mLock);
+    // free all buffers
+    {
+        Mutex::Autolock _cbl(mCbsLock);
+        for(auto stream : mOfflineStreams) {
+            cleanupBuffersLocked(stream.id);
+        }
+    }
+    mCallback.clear();
+    mClosed = true;
+    return Void();
+}
+
+} // namespace implementation
+}  // namespace V3_6
+}  // namespace device
+}  // namespace camera
+}  // namespace hardware
+}  // namespace android
diff --git a/camera/device/3.6/default/include/ext_device_v3_6_impl/ExternalCameraDeviceSession.h b/camera/device/3.6/default/include/ext_device_v3_6_impl/ExternalCameraDeviceSession.h
index 0e57c4c..db0d9a5 100644
--- a/camera/device/3.6/default/include/ext_device_v3_6_impl/ExternalCameraDeviceSession.h
+++ b/camera/device/3.6/default/include/ext_device_v3_6_impl/ExternalCameraDeviceSession.h
@@ -14,12 +14,13 @@
  * limitations under the License.
  */
 
-#ifndef ANDROID_HARDWARE_CAMERA_DEVICE_V3_6_EXTCAMERADEVICE3SESSION_H
-#define ANDROID_HARDWARE_CAMERA_DEVICE_V3_6_EXTCAMERADEVICE3SESSION_H
+#ifndef ANDROID_HARDWARE_CAMERA_DEVICE_V3_6_EXTCAMERADEVICESESSION_H
+#define ANDROID_HARDWARE_CAMERA_DEVICE_V3_6_EXTCAMERADEVICESESSION_H
 
 #include <android/hardware/camera/device/3.5/ICameraDeviceCallback.h>
 #include <android/hardware/camera/device/3.6/ICameraDeviceSession.h>
 #include <../../3.5/default/include/ext_device_v3_5_impl/ExternalCameraDeviceSession.h>
+#include "ExternalCameraOfflineSession.h"
 
 namespace android {
 namespace hardware {
@@ -37,6 +38,7 @@
 using ::android::hardware::camera::device::V3_2::Stream;
 using ::android::hardware::camera::device::V3_5::StreamConfiguration;
 using ::android::hardware::camera::device::V3_6::ICameraDeviceSession;
+using ::android::hardware::camera::device::V3_6::ICameraOfflineSession;
 using ::android::hardware::camera::common::V1_0::Status;
 using ::android::hardware::camera::external::common::ExternalCameraConfig;
 using ::android::hardware::graphics::common::V1_0::PixelFormat;
@@ -69,13 +71,6 @@
         return new TrampolineSessionInterface_3_6(this);
     }
 
-    static Status isStreamCombinationSupported(const V3_2::StreamConfiguration& config,
-            const std::vector<SupportedV4L2Format>& supportedFormats,
-            const ExternalCameraConfig& devCfg) {
-        return V3_4::implementation::ExternalCameraDeviceSession::isStreamCombinationSupported(
-                config, supportedFormats, devCfg);
-    }
-
 protected:
     // Methods from v3.5 and earlier will trampoline to inherited implementation
     Return<void> configureStreams_3_6(
@@ -86,6 +81,28 @@
             const hidl_vec<int32_t>& streamsToKeep,
             ICameraDeviceSession::switchToOffline_cb _hidl_cb);
 
+    void fillOutputStream3_6(const V3_3::HalStreamConfiguration& outStreams_v33,
+            /*out*/V3_6::HalStreamConfiguration* outStreams_v36);
+    bool supportOfflineLocked(int32_t streamId);
+
+    // Main body of switchToOffline. This method does not invoke any callbacks
+    // but instead returns the necessary callbacks in output arguments so callers
+    // can callback later without holding any locks
+    Status switchToOffline(const hidl_vec<int32_t>& offlineStreams,
+            /*out*/std::vector<NotifyMsg>* msgs,
+            /*out*/std::vector<CaptureResult>* results,
+            /*out*/CameraOfflineSessionInfo* info,
+            /*out*/sp<ICameraOfflineSession>* session);
+
+    // Whether a request can be completely dropped when switching to offline
+    bool canDropRequest(const hidl_vec<int32_t>& offlineStreams,
+            std::shared_ptr<V3_4::implementation::HalRequest> halReq);
+
+    void fillOfflineSessionInfo(const hidl_vec<int32_t>& offlineStreams,
+            std::deque<std::shared_ptr<HalRequest>>& offlineReqs,
+            const std::map<int, CirculatingBuffers>& circulatingBuffers,
+            /*out*/CameraOfflineSessionInfo* info);
+
 private:
 
     struct TrampolineSessionInterface_3_6 : public ICameraDeviceSession {
@@ -188,4 +205,4 @@
 }  // namespace hardware
 }  // namespace android
 
-#endif  // ANDROID_HARDWARE_CAMERA_DEVICE_V3_6_EXTCAMERADEVICE3SESSION_H
+#endif  // ANDROID_HARDWARE_CAMERA_DEVICE_V3_6_EXTCAMERADEVICESESSION_H
diff --git a/camera/device/3.6/default/include/ext_device_v3_6_impl/ExternalCameraOfflineSession.h b/camera/device/3.6/default/include/ext_device_v3_6_impl/ExternalCameraOfflineSession.h
new file mode 100644
index 0000000..230b67c
--- /dev/null
+++ b/camera/device/3.6/default/include/ext_device_v3_6_impl/ExternalCameraOfflineSession.h
@@ -0,0 +1,232 @@
+/*
+ * Copyright (C) 2020 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_HARDWARE_CAMERA_DEVICE_V3_6_EXTCAMERAOFFLINESESSION_H
+#define ANDROID_HARDWARE_CAMERA_DEVICE_V3_6_EXTCAMERAOFFLINESESSION_H
+
+#include <android/hardware/camera/device/3.5/ICameraDeviceCallback.h>
+#include <android/hardware/camera/device/3.6/ICameraDeviceSession.h>
+#include <android/hardware/camera/device/3.6/ICameraOfflineSession.h>
+#include <android/hardware/camera/common/1.0/types.h>
+#include <fmq/MessageQueue.h>
+#include <hidl/MQDescriptor.h>
+#include <deque>
+#include <../../3.4/default/include/ext_device_v3_4_impl/ExternalCameraUtils.h>
+#include <../../3.5/default/include/ext_device_v3_5_impl/ExternalCameraDeviceSession.h>
+#include <HandleImporter.h>
+#include <Exif.h>
+#include <android-base/unique_fd.h>
+
+namespace android {
+namespace hardware {
+namespace camera {
+namespace device {
+namespace V3_6 {
+namespace implementation {
+
+using ::android::hardware::camera::device::V3_2::BufferCache;
+using ::android::hardware::camera::device::V3_5::BufferRequest;
+using ::android::hardware::camera::device::V3_5::BufferRequestStatus;
+using ::android::hardware::camera::device::V3_2::BufferStatus;
+using ::android::hardware::camera::device::V3_2::CameraMetadata;
+using ::android::hardware::camera::device::V3_2::CaptureRequest;
+using ::android::hardware::camera::device::V3_2::CaptureResult;
+using ::android::hardware::camera::device::V3_2::ErrorCode;
+using ::android::hardware::camera::device::V3_5::ICameraDeviceCallback;
+using ::android::hardware::camera::device::V3_2::MsgType;
+using ::android::hardware::camera::device::V3_2::NotifyMsg;
+using ::android::hardware::camera::device::V3_2::RequestTemplate;
+using ::android::hardware::camera::device::V3_2::Stream;
+using ::android::hardware::camera::device::V3_5::StreamConfiguration;
+using ::android::hardware::camera::device::V3_2::StreamConfigurationMode;
+using ::android::hardware::camera::device::V3_2::StreamRotation;
+using ::android::hardware::camera::device::V3_2::StreamType;
+using ::android::hardware::camera::device::V3_2::DataspaceFlags;
+using ::android::hardware::camera::device::V3_2::CameraBlob;
+using ::android::hardware::camera::device::V3_2::CameraBlobId;
+using ::android::hardware::camera::device::V3_4::HalStreamConfiguration;
+using ::android::hardware::camera::device::V3_6::ICameraOfflineSession;
+using ::android::hardware::camera::common::V1_0::Status;
+using ::android::hardware::camera::common::V1_0::helper::HandleImporter;
+using ::android::hardware::camera::common::V1_0::helper::ExifUtils;
+using ::android::hardware::camera::external::common::ExternalCameraConfig;
+using ::android::hardware::camera::external::common::Size;
+using ::android::hardware::camera::external::common::SizeHasher;
+using ::android::hardware::graphics::common::V1_0::BufferUsage;
+using ::android::hardware::graphics::common::V1_0::Dataspace;
+using ::android::hardware::graphics::common::V1_0::PixelFormat;
+using ::android::hardware::kSynchronizedReadWrite;
+using ::android::hardware::MessageQueue;
+using ::android::hardware::MQDescriptorSync;
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+using ::android::hardware::hidl_vec;
+using ::android::hardware::hidl_string;
+using ::android::sp;
+using ::android::Mutex;
+using ::android::base::unique_fd;
+
+using ::android::hardware::camera::device::V3_4::implementation::SupportedV4L2Format;
+using ::android::hardware::camera::device::V3_4::implementation::CroppingType;
+using ::android::hardware::camera::device::V3_4::implementation::CirculatingBuffers;
+using ::android::hardware::camera::device::V3_4::implementation::HalRequest;
+using ::android::hardware::camera::device::V3_4::implementation::OutputThreadInterface;
+
+struct ExternalCameraOfflineSession : public virtual RefBase,
+        public virtual OutputThreadInterface {
+
+    ExternalCameraOfflineSession(
+            const CroppingType& croppingType,
+            const common::V1_0::helper::CameraMetadata& chars,
+            const std::string& cameraId,
+            const std::string& exifMake,
+            const std::string& exifModel,
+            uint32_t blobBufferSize,
+            bool afTrigger,
+            const hidl_vec<Stream>& offlineStreams,
+            std::deque<std::shared_ptr<HalRequest>>& offlineReqs,
+            const std::map<int, CirculatingBuffers>& circulatingBuffers);
+
+    bool initialize();
+
+    virtual ~ExternalCameraOfflineSession();
+
+    // Retrieve the HIDL interface, split into its own class to avoid inheritance issues when
+    // dealing with minor version revs and simultaneous implementation and interface inheritance
+    virtual sp<V3_6::ICameraOfflineSession> getInterface() {
+        return new TrampolineSessionInterface_3_6(this);
+    }
+
+protected:
+
+    // Methods from OutputThreadInterface
+    virtual Status importBuffer(int32_t streamId,
+            uint64_t bufId, buffer_handle_t buf,
+            /*out*/buffer_handle_t** outBufPtr,
+            bool allowEmptyBuf) override;
+
+    virtual Status processCaptureResult(std::shared_ptr<HalRequest>&) override;
+
+    virtual Status processCaptureRequestError(const std::shared_ptr<HalRequest>&,
+            /*out*/std::vector<NotifyMsg>* msgs = nullptr,
+            /*out*/std::vector<CaptureResult>* results = nullptr) override;
+
+    virtual ssize_t getJpegBufferSize(uint32_t width, uint32_t height) const override;
+
+    virtual void notifyError(uint32_t frameNumber, int32_t streamId, ErrorCode ec) override;
+    // End of OutputThreadInterface methods
+
+    class OutputThread : public V3_5::implementation::ExternalCameraDeviceSession::OutputThread {
+    public:
+        OutputThread(
+                wp<OutputThreadInterface> parent, CroppingType ct,
+                const common::V1_0::helper::CameraMetadata& chars,
+                sp<V3_5::implementation::ExternalCameraDeviceSession::BufferRequestThread> bufReqThread,
+                std::deque<std::shared_ptr<HalRequest>>& offlineReqs) :
+                V3_5::implementation::ExternalCameraDeviceSession::OutputThread(
+                        parent, ct, chars, bufReqThread),
+                mOfflineReqs(offlineReqs) {}
+
+        virtual bool threadLoop() override;
+
+    protected:
+        std::deque<std::shared_ptr<HalRequest>> mOfflineReqs;
+    }; // OutputThread
+
+
+    Return<void> setCallback(const sp<ICameraDeviceCallback>& cb);
+
+    Return<void> getCaptureResultMetadataQueue(
+            V3_3::ICameraDeviceSession::getCaptureResultMetadataQueue_cb _hidl_cb);
+
+    Return<void> close();
+
+    void initOutputThread();
+
+    void invokeProcessCaptureResultCallback(
+            hidl_vec<CaptureResult> &results, bool tryWriteFmq);
+
+    status_t fillCaptureResult(common::V1_0::helper::CameraMetadata& md, nsecs_t timestamp);
+
+    void cleanupBuffersLocked(int id);
+
+    // Protect (most of) HIDL interface methods from synchronized-entering
+    mutable Mutex mInterfaceLock;
+
+    mutable Mutex mLock; // Protect all data members except otherwise noted
+
+    bool mClosed = false;
+    const CroppingType mCroppingType;
+    const common::V1_0::helper::CameraMetadata mChars;
+    const std::string mCameraId;
+    const std::string mExifMake;
+    const std::string mExifModel;
+    const uint32_t mBlobBufferSize;
+
+    std::mutex mAfTriggerLock; // protect mAfTrigger
+    bool mAfTrigger;
+
+    const hidl_vec<Stream> mOfflineStreams;
+    std::deque<std::shared_ptr<HalRequest>> mOfflineReqs;
+
+    // Protect mCirculatingBuffers, must not lock mLock after acquiring this lock
+    mutable Mutex mCbsLock;
+    std::map<int, CirculatingBuffers> mCirculatingBuffers;
+
+    static HandleImporter sHandleImporter;
+
+    using ResultMetadataQueue = MessageQueue<uint8_t, kSynchronizedReadWrite>;
+    std::shared_ptr<ResultMetadataQueue> mResultMetadataQueue;
+
+    // Protect against invokeProcessCaptureResultCallback()
+    Mutex mProcessCaptureResultLock;
+
+    sp<ICameraDeviceCallback> mCallback;
+
+    sp<V3_5::implementation::ExternalCameraDeviceSession::BufferRequestThread> mBufferRequestThread;
+    sp<OutputThread> mOutputThread;
+private:
+
+    struct TrampolineSessionInterface_3_6 : public ICameraOfflineSession {
+        TrampolineSessionInterface_3_6(sp<ExternalCameraOfflineSession> parent) :
+                mParent(parent) {}
+
+        virtual Return<void> setCallback(const sp<ICameraDeviceCallback>& cb) override {
+            return mParent->setCallback(cb);
+        }
+
+        virtual Return<void> getCaptureResultMetadataQueue(
+                V3_3::ICameraDeviceSession::getCaptureResultMetadataQueue_cb _hidl_cb) override {
+            return mParent->getCaptureResultMetadataQueue(_hidl_cb);
+        }
+
+        virtual Return<void> close() override {
+            return mParent->close();
+        }
+
+    private:
+        sp<ExternalCameraOfflineSession> mParent;
+    };
+};
+
+}  // namespace implementation
+}  // namespace V3_6
+}  // namespace device
+}  // namespace camera
+}  // namespace hardware
+}  // namespace android
+
+#endif  // ANDROID_HARDWARE_CAMERA_DEVICE_V3_6_EXTCAMERAOFFLINESESSION_H