diff --git a/media/audioaidlconversion/AidlConversionCore.cpp b/media/audioaidlconversion/AidlConversionCore.cpp
new file mode 100644
index 0000000..948e35d
--- /dev/null
+++ b/media/audioaidlconversion/AidlConversionCore.cpp
@@ -0,0 +1,64 @@
+/*
+ * 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 "AidlConversionCore"
+//#define LOG_NDEBUG 0
+#include <utils/Log.h>
+
+#include <media/AidlConversionCore.h>
+#include <media/AidlConversionCppNdk.h>
+
+namespace aidl {
+namespace android {
+
+using MicrophoneDirection = hardware::audio::core::IStreamIn::MicrophoneDirection;
+using ::android::BAD_VALUE;
+using ::android::OK;
+using ::android::status_t;
+using ::android::base::unexpected;
+
+ConversionResult<audio_microphone_direction_t>
+aidl2legacy_MicrophoneDirection_audio_microphone_direction_t(MicrophoneDirection aidl) {
+    switch (aidl) {
+        case MicrophoneDirection::UNSPECIFIED:
+            return MIC_DIRECTION_UNSPECIFIED;
+        case MicrophoneDirection::FRONT:
+            return MIC_DIRECTION_FRONT;
+        case MicrophoneDirection::BACK:
+            return MIC_DIRECTION_BACK;
+        case MicrophoneDirection::EXTERNAL:
+            return MIC_DIRECTION_EXTERNAL;
+    }
+    return unexpected(BAD_VALUE);
+}
+
+ConversionResult<MicrophoneDirection>
+legacy2aidl_audio_microphone_direction_t_MicrophoneDirection(audio_microphone_direction_t legacy) {
+    switch (legacy) {
+        case MIC_DIRECTION_UNSPECIFIED:
+            return MicrophoneDirection::UNSPECIFIED;
+        case MIC_DIRECTION_FRONT:
+            return MicrophoneDirection::FRONT;
+        case MIC_DIRECTION_BACK:
+            return MicrophoneDirection::BACK;
+        case MIC_DIRECTION_EXTERNAL:
+            return MicrophoneDirection::EXTERNAL;
+    }
+    return unexpected(BAD_VALUE);
+}
+
+}  // namespace android
+}  // aidl
diff --git a/media/audioaidlconversion/Android.bp b/media/audioaidlconversion/Android.bp
index bdb3a2c..1ec4849 100644
--- a/media/audioaidlconversion/Android.bp
+++ b/media/audioaidlconversion/Android.bp
@@ -152,6 +152,37 @@
 }
 
 /**
+ * Only including AIDL core HAL conversion.
+ */
+cc_library {
+    name: "libaudio_aidl_conversion_core_ndk",
+    srcs: [
+        "AidlConversionCore.cpp",
+    ],
+    header_libs: [
+        "libaudio_aidl_conversion_common_util_ndk",
+    ],
+    export_header_lib_headers: [
+        "libaudio_aidl_conversion_common_util_ndk",
+    ],
+    defaults: [
+        "audio_aidl_conversion_common_default",
+        "latest_android_hardware_audio_common_ndk_shared",
+        "latest_android_hardware_audio_core_ndk_shared",
+        "latest_android_media_audio_common_types_ndk_shared",
+    ],
+    shared_libs: [
+        "libaudio_aidl_conversion_common_ndk",
+        "libbinder_ndk",
+        "libbase",
+    ],
+    cflags: [
+        "-DBACKEND_NDK",
+    ],
+    min_sdk_version: "31", //AParcelableHolder has been introduced in 31
+}
+
+/**
  * Only including AIDL effect HAL conversion.
  */
 cc_library {
diff --git a/media/audioaidlconversion/include/media/AidlConversionCore.h b/media/audioaidlconversion/include/media/AidlConversionCore.h
new file mode 100644
index 0000000..aaa2e53
--- /dev/null
+++ b/media/audioaidlconversion/include/media/AidlConversionCore.h
@@ -0,0 +1,36 @@
+/*
+ * 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
+
+/**
+ * Can only handle conversion between AIDL (NDK backend) and legacy type.
+ */
+#include <aidl/android/hardware/audio/core/IStreamIn.h>
+#include <media/AidlConversionUtil.h>
+#include <system/audio.h>
+
+namespace aidl {
+namespace android {
+
+ConversionResult<audio_microphone_direction_t>
+aidl2legacy_MicrophoneDirection_audio_microphone_direction_t(
+        hardware::audio::core::IStreamIn::MicrophoneDirection aidl);
+ConversionResult<hardware::audio::core::IStreamIn::MicrophoneDirection>
+legacy2aidl_audio_microphone_direction_t_MicrophoneDirection(audio_microphone_direction_t legacy);
+
+}  // namespace android
+}  // namespace aidl
diff --git a/media/libaudiohal/impl/Android.bp b/media/libaudiohal/impl/Android.bp
index 9901fc0..1e3d45f 100644
--- a/media/libaudiohal/impl/Android.bp
+++ b/media/libaudiohal/impl/Android.bp
@@ -284,6 +284,7 @@
         "libbinder_ndk",
         "libaudio_aidl_conversion_common_cpp",
         "libaudio_aidl_conversion_common_ndk",
+        "libaudio_aidl_conversion_core_ndk",
         "libaudio_aidl_conversion_effect_ndk",
         "libaudioaidlcommon",
     ],
diff --git a/media/libaudiohal/impl/StreamHalAidl.cpp b/media/libaudiohal/impl/StreamHalAidl.cpp
index d40deae..6c43591 100644
--- a/media/libaudiohal/impl/StreamHalAidl.cpp
+++ b/media/libaudiohal/impl/StreamHalAidl.cpp
@@ -22,6 +22,7 @@
 
 #include <audio_utils/clock.h>
 #include <media/AidlConversion.h>
+#include <media/AidlConversionCore.h>
 #include <media/AidlConversionCppNdk.h>
 #include <media/AidlConversionNdk.h>
 #include <media/AidlConversionUtil.h>
@@ -890,11 +891,10 @@
                 std::move(context), getStreamCommon(stream)),
           mStream(stream), mMicInfoProvider(micInfoProvider) {}
 
-status_t StreamInHalAidl::setGain(float gain __unused) {
+status_t StreamInHalAidl::setGain(float gain) {
     TIME_CHECK();
     if (!mStream) return NO_INIT;
-    ALOGE("%s not implemented yet", __func__);
-    return OK;
+    return statusTFromBinderStatus(mStream->setHwGain({gain}));
 }
 
 status_t StreamInHalAidl::read(void *buffer, size_t bytes, size_t *read) {
@@ -967,19 +967,20 @@
     return statusTFromBinderStatus(mStream->updateMetadata(aidlMetadata));
 }
 
-status_t StreamInHalAidl::setPreferredMicrophoneDirection(
-            audio_microphone_direction_t direction __unused) {
+status_t StreamInHalAidl::setPreferredMicrophoneDirection(audio_microphone_direction_t direction) {
     TIME_CHECK();
     if (!mStream) return NO_INIT;
-    ALOGE("%s not implemented yet", __func__);
-    return OK;
+    ::aidl::android::hardware::audio::core::IStreamIn::MicrophoneDirection aidlDirection =
+              VALUE_OR_RETURN_STATUS(
+                      ::aidl::android::legacy2aidl_audio_microphone_direction_t_MicrophoneDirection(
+                              direction));
+    return statusTFromBinderStatus(mStream->setMicrophoneDirection(aidlDirection));
 }
 
-status_t StreamInHalAidl::setPreferredMicrophoneFieldDimension(float zoom __unused) {
+status_t StreamInHalAidl::setPreferredMicrophoneFieldDimension(float zoom) {
     TIME_CHECK();
     if (!mStream) return NO_INIT;
-    ALOGE("%s not implemented yet", __func__);
-    return OK;
+    return statusTFromBinderStatus(mStream->setMicrophoneFieldDimension(zoom));
 }
 
 } // namespace android