diff --git a/audio/aidl/default/Android.bp b/audio/aidl/default/Android.bp
index 1e6785f..248ba84 100644
--- a/audio/aidl/default/Android.bp
+++ b/audio/aidl/default/Android.bp
@@ -69,6 +69,7 @@
         "Module.cpp",
         "SoundDose.cpp",
         "Stream.cpp",
+        "StreamStub.cpp",
         "Telephony.cpp",
     ],
     generated_sources: [
diff --git a/audio/aidl/default/Module.cpp b/audio/aidl/default/Module.cpp
index 13b04cd..acad70f 100644
--- a/audio/aidl/default/Module.cpp
+++ b/audio/aidl/default/Module.cpp
@@ -28,6 +28,7 @@
 #include "core-impl/Bluetooth.h"
 #include "core-impl/Module.h"
 #include "core-impl/SoundDose.h"
+#include "core-impl/StreamStub.h"
 #include "core-impl/Telephony.h"
 #include "core-impl/utils.h"
 
@@ -102,9 +103,10 @@
     erase_all_values(mPatches, std::set<int32_t>{patchId});
 }
 
-ndk::ScopedAStatus Module::createStreamContext(int32_t in_portConfigId, int64_t in_bufferSizeFrames,
-                                               std::shared_ptr<IStreamCallback> asyncCallback,
-                                               StreamContext* out_context) {
+ndk::ScopedAStatus Module::createStreamContext(
+        int32_t in_portConfigId, int64_t in_bufferSizeFrames,
+        std::shared_ptr<IStreamCallback> asyncCallback,
+        std::shared_ptr<IStreamOutEventCallback> outEventCallback, StreamContext* out_context) {
     if (in_bufferSizeFrames <= 0) {
         LOG(ERROR) << __func__ << ": non-positive buffer size " << in_bufferSizeFrames;
         return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
@@ -147,7 +149,7 @@
                 std::make_unique<StreamContext::ReplyMQ>(1, true /*configureEventFlagWord*/),
                 portConfigIt->format.value(), portConfigIt->channelMask.value(),
                 std::make_unique<StreamContext::DataMQ>(frameSize * in_bufferSizeFrames),
-                asyncCallback, params);
+                asyncCallback, outEventCallback, params);
         if (temp.isValid()) {
             *out_context = std::move(temp);
         } else {
@@ -545,14 +547,15 @@
     }
     StreamContext context;
     if (auto status = createStreamContext(in_args.portConfigId, in_args.bufferSizeFrames, nullptr,
-                                          &context);
+                                          nullptr, &context);
         !status.isOk()) {
         return status;
     }
     context.fillDescriptor(&_aidl_return->desc);
     std::shared_ptr<StreamIn> stream;
-    if (auto status = StreamIn::createInstance(in_args.sinkMetadata, std::move(context),
-                                               mConfig->microphones, &stream);
+    // TODO: Add a mapping from module instance names to a corresponding 'createInstance'.
+    if (auto status = StreamInStub::createInstance(in_args.sinkMetadata, std::move(context),
+                                                   mConfig->microphones, &stream);
         !status.isOk()) {
         return status;
     }
@@ -598,14 +601,16 @@
     }
     StreamContext context;
     if (auto status = createStreamContext(in_args.portConfigId, in_args.bufferSizeFrames,
-                                          isNonBlocking ? in_args.callback : nullptr, &context);
+                                          isNonBlocking ? in_args.callback : nullptr,
+                                          in_args.eventCallback, &context);
         !status.isOk()) {
         return status;
     }
     context.fillDescriptor(&_aidl_return->desc);
     std::shared_ptr<StreamOut> stream;
-    if (auto status = StreamOut::createInstance(in_args.sourceMetadata, std::move(context),
-                                                in_args.offloadInfo, &stream);
+    // TODO: Add a mapping from module instance names to a corresponding 'createInstance'.
+    if (auto status = StreamOutStub::createInstance(in_args.sourceMetadata, std::move(context),
+                                                    in_args.offloadInfo, &stream);
         !status.isOk()) {
         return status;
     }
diff --git a/audio/aidl/default/Stream.cpp b/audio/aidl/default/Stream.cpp
index 0520cba..25814e4 100644
--- a/audio/aidl/default/Stream.cpp
+++ b/audio/aidl/default/Stream.cpp
@@ -85,16 +85,19 @@
     if (mCommandMQ == nullptr) return "Command MQ is null";
     if (mReplyMQ == nullptr) return "Reply MQ is null";
     if (mDataMQ == nullptr) return "Data MQ is null";
-    if (sizeof(decltype(mDataBuffer)::element_type) != mDataMQ->getQuantumSize()) {
+    if (sizeof(DataBufferElement) != mDataMQ->getQuantumSize()) {
         return "Unexpected Data MQ quantum size: " + std::to_string(mDataMQ->getQuantumSize());
     }
     mDataBufferSize = mDataMQ->getQuantumCount() * mDataMQ->getQuantumSize();
-    mDataBuffer.reset(new (std::nothrow) int8_t[mDataBufferSize]);
+    mDataBuffer.reset(new (std::nothrow) DataBufferElement[mDataBufferSize]);
     if (mDataBuffer == nullptr) {
         return "Failed to allocate data buffer for element count " +
                std::to_string(mDataMQ->getQuantumCount()) +
                ", size in bytes: " + std::to_string(mDataBufferSize);
     }
+    if (::android::status_t status = mDriver->init(); status != STATUS_OK) {
+        return "Failed to initialize the driver: " + std::to_string(status);
+    }
     return "";
 }
 
@@ -191,46 +194,59 @@
             }
             break;
         case Tag::drain:
-            if (command.get<Tag::drain>() == StreamDescriptor::DrainMode::DRAIN_UNSPECIFIED) {
+            if (const auto mode = command.get<Tag::drain>();
+                mode == StreamDescriptor::DrainMode::DRAIN_UNSPECIFIED) {
                 if (mState == StreamDescriptor::State::ACTIVE) {
-                    usleep(1000);  // Simulate a blocking call into the driver.
-                    populateReply(&reply, mIsConnected);
-                    // Can switch the state to ERROR if a driver error occurs.
-                    mState = StreamDescriptor::State::DRAINING;
+                    if (::android::status_t status = mDriver->drain(mode);
+                        status == ::android::OK) {
+                        populateReply(&reply, mIsConnected);
+                        mState = StreamDescriptor::State::DRAINING;
+                    } else {
+                        LOG(ERROR) << __func__ << ": drain failed: " << status;
+                        mState = StreamDescriptor::State::ERROR;
+                    }
                 } else {
                     populateReplyWrongState(&reply, command);
                 }
             } else {
-                LOG(WARNING) << __func__
-                             << ": invalid drain mode: " << toString(command.get<Tag::drain>());
+                LOG(WARNING) << __func__ << ": invalid drain mode: " << toString(mode);
             }
             break;
         case Tag::standby:
             if (mState == StreamDescriptor::State::IDLE) {
-                usleep(1000);  // Simulate a blocking call into the driver.
-                populateReply(&reply, mIsConnected);
-                // Can switch the state to ERROR if a driver error occurs.
-                mState = StreamDescriptor::State::STANDBY;
+                if (::android::status_t status = mDriver->standby(); status == ::android::OK) {
+                    populateReply(&reply, mIsConnected);
+                    mState = StreamDescriptor::State::STANDBY;
+                } else {
+                    LOG(ERROR) << __func__ << ": standby failed: " << status;
+                    mState = StreamDescriptor::State::ERROR;
+                }
             } else {
                 populateReplyWrongState(&reply, command);
             }
             break;
         case Tag::pause:
             if (mState == StreamDescriptor::State::ACTIVE) {
-                usleep(1000);  // Simulate a blocking call into the driver.
-                populateReply(&reply, mIsConnected);
-                // Can switch the state to ERROR if a driver error occurs.
-                mState = StreamDescriptor::State::PAUSED;
+                if (::android::status_t status = mDriver->pause(); status == ::android::OK) {
+                    populateReply(&reply, mIsConnected);
+                    mState = StreamDescriptor::State::PAUSED;
+                } else {
+                    LOG(ERROR) << __func__ << ": pause failed: " << status;
+                    mState = StreamDescriptor::State::ERROR;
+                }
             } else {
                 populateReplyWrongState(&reply, command);
             }
             break;
         case Tag::flush:
             if (mState == StreamDescriptor::State::PAUSED) {
-                usleep(1000);  // Simulate a blocking call into the driver.
-                populateReply(&reply, mIsConnected);
-                // Can switch the state to ERROR if a driver error occurs.
-                mState = StreamDescriptor::State::STANDBY;
+                if (::android::status_t status = mDriver->flush(); status == ::android::OK) {
+                    populateReply(&reply, mIsConnected);
+                    mState = StreamDescriptor::State::STANDBY;
+                } else {
+                    LOG(ERROR) << __func__ << ": flush failed: " << status;
+                    mState = StreamDescriptor::State::ERROR;
+                }
             } else {
                 populateReplyWrongState(&reply, command);
             }
@@ -247,33 +263,39 @@
 }
 
 bool StreamInWorkerLogic::read(size_t clientSize, StreamDescriptor::Reply* reply) {
-    // Can switch the state to ERROR if a driver error occurs.
     const size_t byteCount = std::min({clientSize, mDataMQ->availableToWrite(), mDataBufferSize});
     const bool isConnected = mIsConnected;
+    size_t actualFrameCount = 0;
     bool fatal = false;
-    // Simulate reading of data, or provide zeroes if the stream is not connected.
-    for (size_t i = 0; i < byteCount; ++i) {
-        using buffer_type = decltype(mDataBuffer)::element_type;
-        constexpr int kBufferValueRange = std::numeric_limits<buffer_type>::max() -
-                                          std::numeric_limits<buffer_type>::min() + 1;
-        mDataBuffer[i] = isConnected ? (std::rand() % kBufferValueRange) +
-                                               std::numeric_limits<buffer_type>::min()
-                                     : 0;
+    int32_t latency = Module::kLatencyMs;
+    if (isConnected) {
+        if (::android::status_t status = mDriver->transfer(
+                    mDataBuffer.get(), byteCount / mFrameSize, &actualFrameCount, &latency);
+            status != ::android::OK) {
+            fatal = true;
+            LOG(ERROR) << __func__ << ": read failed: " << status;
+        }
+    } else {
+        usleep(3000);  // Simulate blocking transfer delay.
+        for (size_t i = 0; i < byteCount; ++i) mDataBuffer[i] = 0;
+        actualFrameCount = byteCount / mFrameSize;
     }
-    usleep(3000);  // Simulate a blocking call into the driver.
-    // Set 'fatal = true' if a driver error occurs.
-    if (bool success = byteCount > 0 ? mDataMQ->write(&mDataBuffer[0], byteCount) : true; success) {
-        LOG(DEBUG) << __func__ << ": writing of " << byteCount << " bytes into data MQ"
+    const size_t actualByteCount = actualFrameCount * mFrameSize;
+    if (bool success =
+                actualByteCount > 0 ? mDataMQ->write(&mDataBuffer[0], actualByteCount) : true;
+        success) {
+        LOG(DEBUG) << __func__ << ": writing of " << actualByteCount << " bytes into data MQ"
                    << " succeeded; connected? " << isConnected;
         // Frames are provided and counted regardless of connection status.
-        reply->fmqByteCount += byteCount;
-        mFrameCount += byteCount / mFrameSize;
+        reply->fmqByteCount += actualByteCount;
+        mFrameCount += actualFrameCount;
         populateReply(reply, isConnected);
     } else {
-        LOG(WARNING) << __func__ << ": writing of " << byteCount << " bytes of data to MQ failed";
+        LOG(WARNING) << __func__ << ": writing of " << actualByteCount
+                     << " bytes of data to MQ failed";
         reply->status = STATUS_NOT_ENOUGH_DATA;
     }
-    reply->latencyMs = Module::kLatencyMs;
+    reply->latencyMs = latency;
     return !fatal;
 }
 
@@ -395,17 +417,22 @@
             }
             break;
         case Tag::drain:
-            if (command.get<Tag::drain>() == StreamDescriptor::DrainMode::DRAIN_ALL ||
-                command.get<Tag::drain>() == StreamDescriptor::DrainMode::DRAIN_EARLY_NOTIFY) {
+            if (const auto mode = command.get<Tag::drain>();
+                mode == StreamDescriptor::DrainMode::DRAIN_ALL ||
+                mode == StreamDescriptor::DrainMode::DRAIN_EARLY_NOTIFY) {
                 if (mState == StreamDescriptor::State::ACTIVE ||
                     mState == StreamDescriptor::State::TRANSFERRING) {
-                    usleep(1000);  // Simulate a blocking call into the driver.
-                    populateReply(&reply, mIsConnected);
-                    // Can switch the state to ERROR if a driver error occurs.
-                    if (mState == StreamDescriptor::State::ACTIVE && mForceSynchronousDrain) {
-                        mState = StreamDescriptor::State::IDLE;
+                    if (::android::status_t status = mDriver->drain(mode);
+                        status == ::android::OK) {
+                        populateReply(&reply, mIsConnected);
+                        if (mState == StreamDescriptor::State::ACTIVE && mForceSynchronousDrain) {
+                            mState = StreamDescriptor::State::IDLE;
+                        } else {
+                            switchToTransientState(StreamDescriptor::State::DRAINING);
+                        }
                     } else {
-                        switchToTransientState(StreamDescriptor::State::DRAINING);
+                        LOG(ERROR) << __func__ << ": drain failed: " << status;
+                        mState = StreamDescriptor::State::ERROR;
                     }
                 } else if (mState == StreamDescriptor::State::TRANSFER_PAUSED) {
                     mState = StreamDescriptor::State::DRAIN_PAUSED;
@@ -414,46 +441,58 @@
                     populateReplyWrongState(&reply, command);
                 }
             } else {
-                LOG(WARNING) << __func__
-                             << ": invalid drain mode: " << toString(command.get<Tag::drain>());
+                LOG(WARNING) << __func__ << ": invalid drain mode: " << toString(mode);
             }
             break;
         case Tag::standby:
             if (mState == StreamDescriptor::State::IDLE) {
-                usleep(1000);  // Simulate a blocking call into the driver.
-                populateReply(&reply, mIsConnected);
-                // Can switch the state to ERROR if a driver error occurs.
-                mState = StreamDescriptor::State::STANDBY;
+                if (::android::status_t status = mDriver->standby(); status == ::android::OK) {
+                    populateReply(&reply, mIsConnected);
+                    mState = StreamDescriptor::State::STANDBY;
+                } else {
+                    LOG(ERROR) << __func__ << ": standby failed: " << status;
+                    mState = StreamDescriptor::State::ERROR;
+                }
             } else {
                 populateReplyWrongState(&reply, command);
             }
             break;
         case Tag::pause: {
-            bool commandAccepted = true;
+            std::optional<StreamDescriptor::State> nextState;
             switch (mState) {
                 case StreamDescriptor::State::ACTIVE:
-                    mState = StreamDescriptor::State::PAUSED;
+                    nextState = StreamDescriptor::State::PAUSED;
                     break;
                 case StreamDescriptor::State::DRAINING:
-                    mState = StreamDescriptor::State::DRAIN_PAUSED;
+                    nextState = StreamDescriptor::State::DRAIN_PAUSED;
                     break;
                 case StreamDescriptor::State::TRANSFERRING:
-                    mState = StreamDescriptor::State::TRANSFER_PAUSED;
+                    nextState = StreamDescriptor::State::TRANSFER_PAUSED;
                     break;
                 default:
                     populateReplyWrongState(&reply, command);
-                    commandAccepted = false;
             }
-            if (commandAccepted) {
-                populateReply(&reply, mIsConnected);
+            if (nextState.has_value()) {
+                if (::android::status_t status = mDriver->pause(); status == ::android::OK) {
+                    populateReply(&reply, mIsConnected);
+                    mState = nextState.value();
+                } else {
+                    LOG(ERROR) << __func__ << ": pause failed: " << status;
+                    mState = StreamDescriptor::State::ERROR;
+                }
             }
         } break;
         case Tag::flush:
             if (mState == StreamDescriptor::State::PAUSED ||
                 mState == StreamDescriptor::State::DRAIN_PAUSED ||
                 mState == StreamDescriptor::State::TRANSFER_PAUSED) {
-                populateReply(&reply, mIsConnected);
-                mState = StreamDescriptor::State::IDLE;
+                if (::android::status_t status = mDriver->flush(); status == ::android::OK) {
+                    populateReply(&reply, mIsConnected);
+                    mState = StreamDescriptor::State::IDLE;
+                } else {
+                    LOG(ERROR) << __func__ << ": flush failed: " << status;
+                    mState = StreamDescriptor::State::ERROR;
+                }
             } else {
                 populateReplyWrongState(&reply, command);
             }
@@ -472,6 +511,7 @@
 bool StreamOutWorkerLogic::write(size_t clientSize, StreamDescriptor::Reply* reply) {
     const size_t readByteCount = mDataMQ->availableToRead();
     bool fatal = false;
+    int32_t latency = Module::kLatencyMs;
     if (bool success = readByteCount > 0 ? mDataMQ->read(&mDataBuffer[0], readByteCount) : true) {
         const bool isConnected = mIsConnected;
         LOG(DEBUG) << __func__ << ": reading of " << readByteCount << " bytes from data MQ"
@@ -483,23 +523,36 @@
             // simulate partial write.
             byteCount -= mFrameSize;
         }
+        size_t actualFrameCount = 0;
+        if (isConnected) {
+            if (::android::status_t status = mDriver->transfer(
+                        mDataBuffer.get(), byteCount / mFrameSize, &actualFrameCount, &latency);
+                status != ::android::OK) {
+                fatal = true;
+                LOG(ERROR) << __func__ << ": write failed: " << status;
+            }
+        } else {
+            if (mAsyncCallback == nullptr) {
+                usleep(3000);  // Simulate blocking transfer delay.
+            }
+            actualFrameCount = byteCount / mFrameSize;
+        }
+        const size_t actualByteCount = actualFrameCount * mFrameSize;
         // Frames are consumed and counted regardless of the connection status.
-        reply->fmqByteCount += byteCount;
-        mFrameCount += byteCount / mFrameSize;
+        reply->fmqByteCount += actualByteCount;
+        mFrameCount += actualFrameCount;
         populateReply(reply, isConnected);
-        usleep(3000);  // Simulate a blocking call into the driver.
-        // Set 'fatal = true' if a driver error occurs.
     } else {
         LOG(WARNING) << __func__ << ": reading of " << readByteCount
                      << " bytes of data from MQ failed";
         reply->status = STATUS_NOT_ENOUGH_DATA;
     }
-    reply->latencyMs = Module::kLatencyMs;
+    reply->latencyMs = latency;
     return !fatal;
 }
 
-template <class Metadata, class StreamWorker>
-StreamCommonImpl<Metadata, StreamWorker>::~StreamCommonImpl() {
+template <class Metadata>
+StreamCommonImpl<Metadata>::~StreamCommonImpl() {
     if (!isClosed()) {
         LOG(ERROR) << __func__ << ": stream was not closed prior to destruction, resource leak";
         stopWorker();
@@ -507,8 +560,8 @@
     }
 }
 
-template <class Metadata, class StreamWorker>
-void StreamCommonImpl<Metadata, StreamWorker>::createStreamCommon(
+template <class Metadata>
+void StreamCommonImpl<Metadata>::createStreamCommon(
         const std::shared_ptr<StreamCommonInterface>& delegate) {
     if (mCommon != nullptr) {
         LOG(FATAL) << __func__ << ": attempting to create the common interface twice";
@@ -518,8 +571,8 @@
     AIBinder_setMinSchedulerPolicy(mCommonBinder.get(), SCHED_NORMAL, ANDROID_PRIORITY_AUDIO);
 }
 
-template <class Metadata, class StreamWorker>
-ndk::ScopedAStatus StreamCommonImpl<Metadata, StreamWorker>::getStreamCommon(
+template <class Metadata>
+ndk::ScopedAStatus StreamCommonImpl<Metadata>::getStreamCommon(
         std::shared_ptr<IStreamCommon>* _aidl_return) {
     if (mCommon == nullptr) {
         LOG(FATAL) << __func__ << ": the common interface was not created";
@@ -529,31 +582,30 @@
     return ndk::ScopedAStatus::ok();
 }
 
-template <class Metadata, class StreamWorker>
-ndk::ScopedAStatus StreamCommonImpl<Metadata, StreamWorker>::updateHwAvSyncId(
-        int32_t in_hwAvSyncId) {
+template <class Metadata>
+ndk::ScopedAStatus StreamCommonImpl<Metadata>::updateHwAvSyncId(int32_t in_hwAvSyncId) {
     LOG(DEBUG) << __func__ << ": id " << in_hwAvSyncId;
     return ndk::ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
 }
 
-template <class Metadata, class StreamWorker>
-ndk::ScopedAStatus StreamCommonImpl<Metadata, StreamWorker>::getVendorParameters(
+template <class Metadata>
+ndk::ScopedAStatus StreamCommonImpl<Metadata>::getVendorParameters(
         const std::vector<std::string>& in_ids, std::vector<VendorParameter>* _aidl_return) {
     LOG(DEBUG) << __func__ << ": id count: " << in_ids.size();
     (void)_aidl_return;
     return ndk::ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
 }
 
-template <class Metadata, class StreamWorker>
-ndk::ScopedAStatus StreamCommonImpl<Metadata, StreamWorker>::setVendorParameters(
+template <class Metadata>
+ndk::ScopedAStatus StreamCommonImpl<Metadata>::setVendorParameters(
         const std::vector<VendorParameter>& in_parameters, bool in_async) {
     LOG(DEBUG) << __func__ << ": parameters count " << in_parameters.size()
                << ", async: " << in_async;
     return ndk::ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
 }
 
-template <class Metadata, class StreamWorker>
-ndk::ScopedAStatus StreamCommonImpl<Metadata, StreamWorker>::addEffect(
+template <class Metadata>
+ndk::ScopedAStatus StreamCommonImpl<Metadata>::addEffect(
         const std::shared_ptr<::aidl::android::hardware::audio::effect::IEffect>& in_effect) {
     if (in_effect == nullptr) {
         LOG(DEBUG) << __func__ << ": null effect";
@@ -563,8 +615,8 @@
     return ndk::ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
 }
 
-template <class Metadata, class StreamWorker>
-ndk::ScopedAStatus StreamCommonImpl<Metadata, StreamWorker>::removeEffect(
+template <class Metadata>
+ndk::ScopedAStatus StreamCommonImpl<Metadata>::removeEffect(
         const std::shared_ptr<::aidl::android::hardware::audio::effect::IEffect>& in_effect) {
     if (in_effect == nullptr) {
         LOG(DEBUG) << __func__ << ": null effect";
@@ -574,16 +626,16 @@
     return ndk::ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
 }
 
-template <class Metadata, class StreamWorker>
-ndk::ScopedAStatus StreamCommonImpl<Metadata, StreamWorker>::close() {
+template <class Metadata>
+ndk::ScopedAStatus StreamCommonImpl<Metadata>::close() {
     LOG(DEBUG) << __func__;
     if (!isClosed()) {
         stopWorker();
         LOG(DEBUG) << __func__ << ": joining the worker thread...";
-        mWorker.stop();
+        mWorker->stop();
         LOG(DEBUG) << __func__ << ": worker thread joined";
         mContext.reset();
-        mWorker.setClosed();
+        mWorker->setClosed();
         return ndk::ScopedAStatus::ok();
     } else {
         LOG(ERROR) << __func__ << ": stream was already closed";
@@ -591,8 +643,8 @@
     }
 }
 
-template <class Metadata, class StreamWorker>
-void StreamCommonImpl<Metadata, StreamWorker>::stopWorker() {
+template <class Metadata>
+void StreamCommonImpl<Metadata>::stopWorker() {
     if (auto commandMQ = mContext.getCommandMQ(); commandMQ != nullptr) {
         LOG(DEBUG) << __func__ << ": asking the worker to exit...";
         auto cmd = StreamDescriptor::Command::make<StreamDescriptor::Command::Tag::halReservedExit>(
@@ -608,9 +660,8 @@
     }
 }
 
-template <class Metadata, class StreamWorker>
-ndk::ScopedAStatus StreamCommonImpl<Metadata, StreamWorker>::updateMetadata(
-        const Metadata& metadata) {
+template <class Metadata>
+ndk::ScopedAStatus StreamCommonImpl<Metadata>::updateMetadata(const Metadata& metadata) {
     LOG(DEBUG) << __func__;
     if (!isClosed()) {
         mMetadata = metadata;
@@ -621,16 +672,11 @@
 }
 
 // static
-ndk::ScopedAStatus StreamIn::createInstance(const common::SinkMetadata& sinkMetadata,
-                                            StreamContext context,
-                                            const std::vector<MicrophoneInfo>& microphones,
-                                            std::shared_ptr<StreamIn>* result) {
-    auto stream = ndk::SharedRefBase::make<StreamIn>(sinkMetadata, std::move(context), microphones);
+ndk::ScopedAStatus StreamIn::initInstance(const std::shared_ptr<StreamIn>& stream) {
     if (auto status = stream->init(); !status.isOk()) {
         return status;
     }
     stream->createStreamCommon(stream);
-    *result = std::move(stream);
     return ndk::ScopedAStatus::ok();
 }
 
@@ -645,8 +691,10 @@
 }  // namespace
 
 StreamIn::StreamIn(const SinkMetadata& sinkMetadata, StreamContext&& context,
+                   const DriverInterface::CreateInstance& createDriver,
+                   const StreamWorkerInterface::CreateInstance& createWorker,
                    const std::vector<MicrophoneInfo>& microphones)
-    : StreamCommonImpl<SinkMetadata, StreamInWorker>(sinkMetadata, std::move(context)),
+    : StreamCommonImpl<SinkMetadata>(sinkMetadata, std::move(context), createDriver, createWorker),
       mMicrophones(transformMicrophones(microphones)) {
     LOG(DEBUG) << __func__;
 }
@@ -704,23 +752,20 @@
 }
 
 // static
-ndk::ScopedAStatus StreamOut::createInstance(const SourceMetadata& sourceMetadata,
-                                             StreamContext context,
-                                             const std::optional<AudioOffloadInfo>& offloadInfo,
-                                             std::shared_ptr<StreamOut>* result) {
-    auto stream =
-            ndk::SharedRefBase::make<StreamOut>(sourceMetadata, std::move(context), offloadInfo);
+ndk::ScopedAStatus StreamOut::initInstance(const std::shared_ptr<StreamOut>& stream) {
     if (auto status = stream->init(); !status.isOk()) {
         return status;
     }
     stream->createStreamCommon(stream);
-    *result = std::move(stream);
     return ndk::ScopedAStatus::ok();
 }
 
 StreamOut::StreamOut(const SourceMetadata& sourceMetadata, StreamContext&& context,
+                     const DriverInterface::CreateInstance& createDriver,
+                     const StreamWorkerInterface::CreateInstance& createWorker,
                      const std::optional<AudioOffloadInfo>& offloadInfo)
-    : StreamCommonImpl<SourceMetadata, StreamOutWorker>(sourceMetadata, std::move(context)),
+    : StreamCommonImpl<SourceMetadata>(sourceMetadata, std::move(context), createDriver,
+                                       createWorker),
       mOffloadInfo(offloadInfo) {
     LOG(DEBUG) << __func__;
 }
diff --git a/audio/aidl/default/StreamStub.cpp b/audio/aidl/default/StreamStub.cpp
new file mode 100644
index 0000000..5442179
--- /dev/null
+++ b/audio/aidl/default/StreamStub.cpp
@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2023 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 "AHAL_Stream"
+#include <android-base/logging.h>
+
+#include "core-impl/Module.h"
+#include "core-impl/StreamStub.h"
+
+using aidl::android::hardware::audio::common::SinkMetadata;
+using aidl::android::hardware::audio::common::SourceMetadata;
+using aidl::android::media::audio::common::AudioOffloadInfo;
+
+namespace aidl::android::hardware::audio::core {
+
+DriverStub::DriverStub(const StreamContext& context, bool isInput)
+    : mFrameSizeBytes(context.getFrameSize()), mIsInput(isInput) {}
+
+::android::status_t DriverStub::init() {
+    usleep(1000);
+    return ::android::OK;
+}
+
+::android::status_t DriverStub::drain(StreamDescriptor::DrainMode) {
+    usleep(1000);
+    return ::android::OK;
+}
+
+::android::status_t DriverStub::flush() {
+    usleep(1000);
+    return ::android::OK;
+}
+
+::android::status_t DriverStub::pause() {
+    usleep(1000);
+    return ::android::OK;
+}
+
+::android::status_t DriverStub::transfer(void* buffer, size_t frameCount, size_t* actualFrameCount,
+                                         int32_t* latencyMs) {
+    usleep(3000);
+    if (mIsInput) {
+        uint8_t* byteBuffer = static_cast<uint8_t*>(buffer);
+        for (size_t i = 0; i < frameCount * mFrameSizeBytes; ++i) {
+            byteBuffer[i] = std::rand() % 255;
+        }
+    }
+    *actualFrameCount = frameCount;
+    *latencyMs = Module::kLatencyMs;
+    return ::android::OK;
+}
+
+::android::status_t DriverStub::standby() {
+    usleep(1000);
+    return ::android::OK;
+}
+
+// static
+ndk::ScopedAStatus StreamInStub::createInstance(const SinkMetadata& sinkMetadata,
+                                                StreamContext&& context,
+                                                const std::vector<MicrophoneInfo>& microphones,
+                                                std::shared_ptr<StreamIn>* result) {
+    std::shared_ptr<StreamIn> stream =
+            ndk::SharedRefBase::make<StreamInStub>(sinkMetadata, std::move(context), microphones);
+    if (auto status = initInstance(stream); !status.isOk()) {
+        return status;
+    }
+    *result = std::move(stream);
+    return ndk::ScopedAStatus::ok();
+}
+
+StreamInStub::StreamInStub(const SinkMetadata& sinkMetadata, StreamContext&& context,
+                           const std::vector<MicrophoneInfo>& microphones)
+    : StreamIn(
+              sinkMetadata, std::move(context),
+              [](const StreamContext& ctx) -> DriverInterface* {
+                  return new DriverStub(ctx, true /*isInput*/);
+              },
+              [](const StreamContext& ctx, DriverInterface* driver) -> StreamWorkerInterface* {
+                  // The default worker implementation is used.
+                  return new StreamInWorker(ctx, driver);
+              },
+              microphones) {}
+
+// static
+ndk::ScopedAStatus StreamOutStub::createInstance(const SourceMetadata& sourceMetadata,
+                                                 StreamContext&& context,
+                                                 const std::optional<AudioOffloadInfo>& offloadInfo,
+                                                 std::shared_ptr<StreamOut>* result) {
+    std::shared_ptr<StreamOut> stream = ndk::SharedRefBase::make<StreamOutStub>(
+            sourceMetadata, std::move(context), offloadInfo);
+    if (auto status = initInstance(stream); !status.isOk()) {
+        return status;
+    }
+    *result = std::move(stream);
+    return ndk::ScopedAStatus::ok();
+}
+
+StreamOutStub::StreamOutStub(const SourceMetadata& sourceMetadata, StreamContext&& context,
+                             const std::optional<AudioOffloadInfo>& offloadInfo)
+    : StreamOut(
+              sourceMetadata, std::move(context),
+              [](const StreamContext& ctx) -> DriverInterface* {
+                  return new DriverStub(ctx, false /*isInput*/);
+              },
+              [](const StreamContext& ctx, DriverInterface* driver) -> StreamWorkerInterface* {
+                  // The default worker implementation is used.
+                  return new StreamOutWorker(ctx, driver);
+              },
+              offloadInfo) {}
+
+}  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/include/core-impl/Module.h b/audio/aidl/default/include/core-impl/Module.h
index 000a704..9e4499b 100644
--- a/audio/aidl/default/include/core-impl/Module.h
+++ b/audio/aidl/default/include/core-impl/Module.h
@@ -115,6 +115,7 @@
     ndk::ScopedAStatus createStreamContext(
             int32_t in_portConfigId, int64_t in_bufferSizeFrames,
             std::shared_ptr<IStreamCallback> asyncCallback,
+            std::shared_ptr<IStreamOutEventCallback> outEventCallback,
             ::aidl::android::hardware::audio::core::StreamContext* out_context);
     std::vector<::aidl::android::media::audio::common::AudioDevice> findConnectedDevices(
             int32_t portConfigId);
diff --git a/audio/aidl/default/include/core-impl/Stream.h b/audio/aidl/default/include/core-impl/Stream.h
index 2cf5951..7cd4259 100644
--- a/audio/aidl/default/include/core-impl/Stream.h
+++ b/audio/aidl/default/include/core-impl/Stream.h
@@ -31,12 +31,14 @@
 #include <aidl/android/hardware/audio/core/BnStreamIn.h>
 #include <aidl/android/hardware/audio/core/BnStreamOut.h>
 #include <aidl/android/hardware/audio/core/IStreamCallback.h>
+#include <aidl/android/hardware/audio/core/IStreamOutEventCallback.h>
 #include <aidl/android/hardware/audio/core/MicrophoneInfo.h>
 #include <aidl/android/hardware/audio/core/StreamDescriptor.h>
 #include <aidl/android/media/audio/common/AudioDevice.h>
 #include <aidl/android/media/audio/common/AudioOffloadInfo.h>
 #include <fmq/AidlMessageQueue.h>
 #include <system/thread_defs.h>
+#include <utils/Errors.h>
 
 #include "core-impl/utils.h"
 
@@ -76,6 +78,7 @@
                   const ::aidl::android::media::audio::common::AudioFormatDescription& format,
                   const ::aidl::android::media::audio::common::AudioChannelLayout& channelLayout,
                   std::unique_ptr<DataMQ> dataMQ, std::shared_ptr<IStreamCallback> asyncCallback,
+                  std::shared_ptr<IStreamOutEventCallback> outEventCallback,
                   DebugParameters debugParameters)
         : mCommandMQ(std::move(commandMQ)),
           mInternalCommandCookie(std::rand()),
@@ -84,6 +87,7 @@
           mChannelLayout(channelLayout),
           mDataMQ(std::move(dataMQ)),
           mAsyncCallback(asyncCallback),
+          mOutEventCallback(outEventCallback),
           mDebugParameters(debugParameters) {}
     StreamContext(StreamContext&& other)
         : mCommandMQ(std::move(other.mCommandMQ)),
@@ -93,6 +97,7 @@
           mChannelLayout(other.mChannelLayout),
           mDataMQ(std::move(other.mDataMQ)),
           mAsyncCallback(std::move(other.mAsyncCallback)),
+          mOutEventCallback(std::move(other.mOutEventCallback)),
           mDebugParameters(std::move(other.mDebugParameters)) {}
     StreamContext& operator=(StreamContext&& other) {
         mCommandMQ = std::move(other.mCommandMQ);
@@ -102,6 +107,7 @@
         mChannelLayout = std::move(other.mChannelLayout);
         mDataMQ = std::move(other.mDataMQ);
         mAsyncCallback = std::move(other.mAsyncCallback);
+        mOutEventCallback = std::move(other.mOutEventCallback);
         mDebugParameters = std::move(other.mDebugParameters);
         return *this;
     }
@@ -120,6 +126,9 @@
     bool getForceSynchronousDrain() const { return mDebugParameters.forceSynchronousDrain; }
     size_t getFrameSize() const;
     int getInternalCommandCookie() const { return mInternalCommandCookie; }
+    std::shared_ptr<IStreamOutEventCallback> getOutEventCallback() const {
+        return mOutEventCallback;
+    }
     ReplyMQ* getReplyMQ() const { return mReplyMQ.get(); }
     int getTransientStateDelayMs() const { return mDebugParameters.transientStateDelayMs; }
     bool isValid() const;
@@ -133,9 +142,24 @@
     ::aidl::android::media::audio::common::AudioChannelLayout mChannelLayout;
     std::unique_ptr<DataMQ> mDataMQ;
     std::shared_ptr<IStreamCallback> mAsyncCallback;
+    std::shared_ptr<IStreamOutEventCallback> mOutEventCallback;  // Only used by output streams
     DebugParameters mDebugParameters;
 };
 
+struct DriverInterface {
+    using CreateInstance = std::function<DriverInterface*(const StreamContext&)>;
+    virtual ~DriverInterface() = default;
+    // This function is called once, on the main thread, before starting the worker thread.
+    virtual ::android::status_t init() = 0;
+    // All the functions below are called on the worker thread.
+    virtual ::android::status_t drain(StreamDescriptor::DrainMode mode) = 0;
+    virtual ::android::status_t flush() = 0;
+    virtual ::android::status_t pause() = 0;
+    virtual ::android::status_t transfer(void* buffer, size_t frameCount, size_t* actualFrameCount,
+                                         int32_t* latencyMs) = 0;
+    virtual ::android::status_t standby() = 0;
+};
+
 class StreamWorkerCommonLogic : public ::android::hardware::audio::common::StreamLogic {
   public:
     bool isClosed() const {
@@ -145,8 +169,11 @@
     void setIsConnected(bool connected) { mIsConnected = connected; }
 
   protected:
-    explicit StreamWorkerCommonLogic(const StreamContext& context)
-        : mInternalCommandCookie(context.getInternalCommandCookie()),
+    using DataBufferElement = int8_t;
+
+    StreamWorkerCommonLogic(const StreamContext& context, DriverInterface* driver)
+        : mDriver(driver),
+          mInternalCommandCookie(context.getInternalCommandCookie()),
           mFrameSize(context.getFrameSize()),
           mCommandMQ(context.getCommandMQ()),
           mReplyMQ(context.getReplyMQ()),
@@ -164,6 +191,7 @@
         mTransientStateStart = std::chrono::steady_clock::now();
     }
 
+    DriverInterface* const mDriver;
     // Atomic fields are used both by the main and worker threads.
     std::atomic<bool> mIsConnected = false;
     static_assert(std::atomic<StreamDescriptor::State>::is_always_lock_free);
@@ -171,9 +199,9 @@
     // All fields are used on the worker thread only.
     const int mInternalCommandCookie;
     const size_t mFrameSize;
-    StreamContext::CommandMQ* mCommandMQ;
-    StreamContext::ReplyMQ* mReplyMQ;
-    StreamContext::DataMQ* mDataMQ;
+    StreamContext::CommandMQ* const mCommandMQ;
+    StreamContext::ReplyMQ* const mReplyMQ;
+    StreamContext::DataMQ* const mDataMQ;
     std::shared_ptr<IStreamCallback> mAsyncCallback;
     const std::chrono::duration<int, std::milli> mTransientStateDelayMs;
     std::chrono::time_point<std::chrono::steady_clock> mTransientStateStart;
@@ -181,15 +209,46 @@
     const bool mForceSynchronousDrain;
     // We use an array and the "size" field instead of a vector to be able to detect
     // memory allocation issues.
-    std::unique_ptr<int8_t[]> mDataBuffer;
+    std::unique_ptr<DataBufferElement[]> mDataBuffer;
     size_t mDataBufferSize;
     long mFrameCount = 0;
 };
 
+// This interface is used to decouple stream implementations from a concrete StreamWorker
+// implementation.
+struct StreamWorkerInterface {
+    using CreateInstance = std::function<StreamWorkerInterface*(const StreamContext& context,
+                                                                DriverInterface* driver)>;
+    virtual ~StreamWorkerInterface() = default;
+    virtual bool isClosed() const = 0;
+    virtual void setIsConnected(bool isConnected) = 0;
+    virtual void setClosed() = 0;
+    virtual bool start() = 0;
+    virtual void stop() = 0;
+};
+
+template <class WorkerLogic>
+class StreamWorkerImpl : public StreamWorkerInterface,
+                         public ::android::hardware::audio::common::StreamWorker<WorkerLogic> {
+    using WorkerImpl = ::android::hardware::audio::common::StreamWorker<WorkerLogic>;
+
+  public:
+    StreamWorkerImpl(const StreamContext& context, DriverInterface* driver)
+        : WorkerImpl(context, driver) {}
+    bool isClosed() const override { return WorkerImpl::isClosed(); }
+    void setIsConnected(bool isConnected) override { WorkerImpl::setIsConnected(isConnected); }
+    void setClosed() override { WorkerImpl::setClosed(); }
+    bool start() override {
+        return WorkerImpl::start(WorkerImpl::kThreadName, ANDROID_PRIORITY_AUDIO);
+    }
+    void stop() override { return WorkerImpl::stop(); }
+};
+
 class StreamInWorkerLogic : public StreamWorkerCommonLogic {
   public:
     static const std::string kThreadName;
-    explicit StreamInWorkerLogic(const StreamContext& context) : StreamWorkerCommonLogic(context) {}
+    StreamInWorkerLogic(const StreamContext& context, DriverInterface* driver)
+        : StreamWorkerCommonLogic(context, driver) {}
 
   protected:
     Status cycle() override;
@@ -197,21 +256,23 @@
   private:
     bool read(size_t clientSize, StreamDescriptor::Reply* reply);
 };
-using StreamInWorker = ::android::hardware::audio::common::StreamWorker<StreamInWorkerLogic>;
+using StreamInWorker = StreamWorkerImpl<StreamInWorkerLogic>;
 
 class StreamOutWorkerLogic : public StreamWorkerCommonLogic {
   public:
     static const std::string kThreadName;
-    explicit StreamOutWorkerLogic(const StreamContext& context)
-        : StreamWorkerCommonLogic(context) {}
+    StreamOutWorkerLogic(const StreamContext& context, DriverInterface* driver)
+        : StreamWorkerCommonLogic(context, driver), mEventCallback(context.getOutEventCallback()) {}
 
   protected:
     Status cycle() override;
 
   private:
     bool write(size_t clientSize, StreamDescriptor::Reply* reply);
+
+    std::shared_ptr<IStreamOutEventCallback> mEventCallback;
 };
-using StreamOutWorker = ::android::hardware::audio::common::StreamWorker<StreamOutWorkerLogic>;
+using StreamOutWorker = StreamWorkerImpl<StreamOutWorkerLogic>;
 
 // This provides a C++ interface with methods of the IStreamCommon Binder interface,
 // but intentionally does not inherit from it. This is needed to avoid inheriting
@@ -283,7 +344,7 @@
     std::weak_ptr<StreamCommonInterface> mDelegate;
 };
 
-template <class Metadata, class StreamWorker>
+template <class Metadata>
 class StreamCommonImpl : public StreamCommonInterface {
   public:
     ndk::ScopedAStatus close() override;
@@ -301,21 +362,25 @@
 
     ndk::ScopedAStatus getStreamCommon(std::shared_ptr<IStreamCommon>* _aidl_return);
     ndk::ScopedAStatus init() {
-        return mWorker.start(StreamWorker::kThreadName, ANDROID_PRIORITY_AUDIO)
-                       ? ndk::ScopedAStatus::ok()
-                       : ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_STATE);
+        return mWorker->start() ? ndk::ScopedAStatus::ok()
+                                : ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_STATE);
     }
-    bool isClosed() const { return mWorker.isClosed(); }
+    bool isClosed() const { return mWorker->isClosed(); }
     void setIsConnected(
             const std::vector<::aidl::android::media::audio::common::AudioDevice>& devices) {
-        mWorker.setIsConnected(!devices.empty());
+        mWorker->setIsConnected(!devices.empty());
         mConnectedDevices = devices;
     }
     ndk::ScopedAStatus updateMetadata(const Metadata& metadata);
 
   protected:
-    StreamCommonImpl(const Metadata& metadata, StreamContext&& context)
-        : mMetadata(metadata), mContext(std::move(context)), mWorker(mContext) {}
+    StreamCommonImpl(const Metadata& metadata, StreamContext&& context,
+                     const DriverInterface::CreateInstance& createDriver,
+                     const StreamWorkerInterface::CreateInstance& createWorker)
+        : mMetadata(metadata),
+          mContext(std::move(context)),
+          mDriver(createDriver(mContext)),
+          mWorker(createWorker(mContext, mDriver.get())) {}
     ~StreamCommonImpl();
     void stopWorker();
     void createStreamCommon(const std::shared_ptr<StreamCommonInterface>& delegate);
@@ -324,16 +389,16 @@
     ndk::SpAIBinder mCommonBinder;
     Metadata mMetadata;
     StreamContext mContext;
-    StreamWorker mWorker;
+    std::unique_ptr<DriverInterface> mDriver;
+    std::unique_ptr<StreamWorkerInterface> mWorker;
     std::vector<::aidl::android::media::audio::common::AudioDevice> mConnectedDevices;
 };
 
-class StreamIn : public StreamCommonImpl<::aidl::android::hardware::audio::common::SinkMetadata,
-                                         StreamInWorker>,
+class StreamIn : public StreamCommonImpl<::aidl::android::hardware::audio::common::SinkMetadata>,
                  public BnStreamIn {
     ndk::ScopedAStatus getStreamCommon(std::shared_ptr<IStreamCommon>* _aidl_return) override {
-        return StreamCommonImpl<::aidl::android::hardware::audio::common::SinkMetadata,
-                                StreamInWorker>::getStreamCommon(_aidl_return);
+        return StreamCommonImpl<::aidl::android::hardware::audio::common::SinkMetadata>::
+                getStreamCommon(_aidl_return);
     }
     ndk::ScopedAStatus getActiveMicrophones(
             std::vector<MicrophoneDynamicInfo>* _aidl_return) override;
@@ -343,42 +408,46 @@
     ndk::ScopedAStatus setMicrophoneFieldDimension(float in_zoom) override;
     ndk::ScopedAStatus updateMetadata(const ::aidl::android::hardware::audio::common::SinkMetadata&
                                               in_sinkMetadata) override {
-        return StreamCommonImpl<::aidl::android::hardware::audio::common::SinkMetadata,
-                                StreamInWorker>::updateMetadata(in_sinkMetadata);
+        return StreamCommonImpl<::aidl::android::hardware::audio::common::SinkMetadata>::
+                updateMetadata(in_sinkMetadata);
     }
     ndk::ScopedAStatus getHwGain(std::vector<float>* _aidl_return) override;
     ndk::ScopedAStatus setHwGain(const std::vector<float>& in_channelGains) override;
 
-  public:
-    static ndk::ScopedAStatus createInstance(
-            const ::aidl::android::hardware::audio::common::SinkMetadata& sinkMetadata,
-            StreamContext context, const std::vector<MicrophoneInfo>& microphones,
-            std::shared_ptr<StreamIn>* result);
-
-  private:
+  protected:
     friend class ndk::SharedRefBase;
+
+    static ndk::ScopedAStatus initInstance(const std::shared_ptr<StreamIn>& stream);
+
     StreamIn(const ::aidl::android::hardware::audio::common::SinkMetadata& sinkMetadata,
-             StreamContext&& context, const std::vector<MicrophoneInfo>& microphones);
+             StreamContext&& context, const DriverInterface::CreateInstance& createDriver,
+             const StreamWorkerInterface::CreateInstance& createWorker,
+             const std::vector<MicrophoneInfo>& microphones);
     void createStreamCommon(const std::shared_ptr<StreamIn>& myPtr) {
-        StreamCommonImpl<::aidl::android::hardware::audio::common::SinkMetadata,
-                         StreamInWorker>::createStreamCommon(myPtr);
+        StreamCommonImpl<
+                ::aidl::android::hardware::audio::common::SinkMetadata>::createStreamCommon(myPtr);
     }
 
     const std::map<::aidl::android::media::audio::common::AudioDevice, std::string> mMicrophones;
+
+  public:
+    using CreateInstance = std::function<ndk::ScopedAStatus(
+            const ::aidl::android::hardware::audio::common::SinkMetadata& sinkMetadata,
+            StreamContext&& context, const std::vector<MicrophoneInfo>& microphones,
+            std::shared_ptr<StreamIn>* result)>;
 };
 
-class StreamOut : public StreamCommonImpl<::aidl::android::hardware::audio::common::SourceMetadata,
-                                          StreamOutWorker>,
+class StreamOut : public StreamCommonImpl<::aidl::android::hardware::audio::common::SourceMetadata>,
                   public BnStreamOut {
     ndk::ScopedAStatus getStreamCommon(std::shared_ptr<IStreamCommon>* _aidl_return) override {
-        return StreamCommonImpl<::aidl::android::hardware::audio::common::SourceMetadata,
-                                StreamOutWorker>::getStreamCommon(_aidl_return);
+        return StreamCommonImpl<::aidl::android::hardware::audio::common::SourceMetadata>::
+                getStreamCommon(_aidl_return);
     }
     ndk::ScopedAStatus updateMetadata(
             const ::aidl::android::hardware::audio::common::SourceMetadata& in_sourceMetadata)
             override {
-        return StreamCommonImpl<::aidl::android::hardware::audio::common::SourceMetadata,
-                                StreamOutWorker>::updateMetadata(in_sourceMetadata);
+        return StreamCommonImpl<::aidl::android::hardware::audio::common::SourceMetadata>::
+                updateMetadata(in_sourceMetadata);
     }
     ndk::ScopedAStatus getHwVolume(std::vector<float>* _aidl_return) override;
     ndk::ScopedAStatus setHwVolume(const std::vector<float>& in_channelVolumes) override;
@@ -400,26 +469,31 @@
             override;
     ndk::ScopedAStatus selectPresentation(int32_t in_presentationId, int32_t in_programId) override;
 
-  public:
-    static ndk::ScopedAStatus createInstance(
-            const ::aidl::android::hardware::audio::common::SourceMetadata& sourceMetadata,
-            StreamContext context,
-            const std::optional<::aidl::android::media::audio::common::AudioOffloadInfo>&
-                    offloadInfo,
-            std::shared_ptr<StreamOut>* result);
-
-  private:
-    friend class ndk::SharedRefBase;
-    StreamOut(const ::aidl::android::hardware::audio::common::SourceMetadata& sourceMetadata,
-              StreamContext&& context,
-              const std::optional<::aidl::android::media::audio::common::AudioOffloadInfo>&
-                      offloadInfo);
     void createStreamCommon(const std::shared_ptr<StreamOut>& myPtr) {
-        StreamCommonImpl<::aidl::android::hardware::audio::common::SourceMetadata,
-                         StreamOutWorker>::createStreamCommon(myPtr);
+        StreamCommonImpl<::aidl::android::hardware::audio::common::SourceMetadata>::
+                createStreamCommon(myPtr);
     }
 
+  protected:
+    friend class ndk::SharedRefBase;
+
+    static ndk::ScopedAStatus initInstance(const std::shared_ptr<StreamOut>& stream);
+
+    StreamOut(const ::aidl::android::hardware::audio::common::SourceMetadata& sourceMetadata,
+              StreamContext&& context, const DriverInterface::CreateInstance& createDriver,
+              const StreamWorkerInterface::CreateInstance& createWorker,
+              const std::optional<::aidl::android::media::audio::common::AudioOffloadInfo>&
+                      offloadInfo);
+
     std::optional<::aidl::android::media::audio::common::AudioOffloadInfo> mOffloadInfo;
+
+  public:
+    using CreateInstance = std::function<ndk::ScopedAStatus(
+            const ::aidl::android::hardware::audio::common::SourceMetadata& sourceMetadata,
+            StreamContext&& context,
+            const std::optional<::aidl::android::media::audio::common::AudioOffloadInfo>&
+                    offloadInfo,
+            std::shared_ptr<StreamOut>* result)>;
 };
 
 class StreamWrapper {
diff --git a/audio/aidl/default/include/core-impl/StreamStub.h b/audio/aidl/default/include/core-impl/StreamStub.h
new file mode 100644
index 0000000..98a062a
--- /dev/null
+++ b/audio/aidl/default/include/core-impl/StreamStub.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#pragma once
+
+#include "core-impl/Stream.h"
+
+namespace aidl::android::hardware::audio::core {
+
+class DriverStub : public DriverInterface {
+  public:
+    DriverStub(const StreamContext& context, bool isInput);
+    ::android::status_t init() override;
+    ::android::status_t drain(StreamDescriptor::DrainMode) override;
+    ::android::status_t flush() override;
+    ::android::status_t pause() override;
+    ::android::status_t transfer(void* buffer, size_t frameCount, size_t* actualFrameCount,
+                                 int32_t* latencyMs) override;
+    ::android::status_t standby() override;
+
+  private:
+    const size_t mFrameSizeBytes;
+    const bool mIsInput;
+};
+
+class StreamInStub final : public StreamIn {
+  public:
+    static ndk::ScopedAStatus createInstance(
+            const ::aidl::android::hardware::audio::common::SinkMetadata& sinkMetadata,
+            StreamContext&& context, const std::vector<MicrophoneInfo>& microphones,
+            std::shared_ptr<StreamIn>* result);
+
+  private:
+    friend class ndk::SharedRefBase;
+    StreamInStub(const ::aidl::android::hardware::audio::common::SinkMetadata& sinkMetadata,
+                 StreamContext&& context, const std::vector<MicrophoneInfo>& microphones);
+};
+
+class StreamOutStub final : public StreamOut {
+  public:
+    static ndk::ScopedAStatus createInstance(
+            const ::aidl::android::hardware::audio::common::SourceMetadata& sourceMetadata,
+            StreamContext&& context,
+            const std::optional<::aidl::android::media::audio::common::AudioOffloadInfo>&
+                    offloadInfo,
+            std::shared_ptr<StreamOut>* result);
+
+  private:
+    friend class ndk::SharedRefBase;
+    StreamOutStub(const ::aidl::android::hardware::audio::common::SourceMetadata& sourceMetadata,
+                  StreamContext&& context,
+                  const std::optional<::aidl::android::media::audio::common::AudioOffloadInfo>&
+                          offloadInfo);
+};
+
+}  // namespace aidl::android::hardware::audio::core