LG8n: Introduce Mediatek In-Call Service

* My attempt at fixing in call gain control on MediaTek devices.

* It attempts to replicate what the stock MediaTek framework does
  when controlling the volume of the earpiece speaker, since MTK's
  audio HAL is not able to set the gain of the speaker from the
  values sent by AOSP framework.

[LinkBoi00] Rebrand to Mediatek In-Call Service

Change-Id: I43f727f6fb73a0d38457a41a8361653d1d00e220
Signed-off-by: LinkBoi00 <linkdevel@protonmail.com>
Signed-off-by: fjrXTR <fajarslebew31@gmail.com>
Signed-off-by: xyzuniverse <dev.xyzuniverse@gmail.com>
Signed-off-by: Shirayuki39 <lorddemecrius83@proton.me>

app/InCallService/Android.bp

@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2022 bengris32
+ * Copyright (C) 2022 LineageOS
+ *
+ * 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.
+ */
+
+android_app {
+    name: "MtkInCallService",
+
+    srcs: ["src/**/*.java"],
+    resource_dirs: ["res"],
+
+    certificate: "platform",
+    platform_apis: true,
+    privileged: true,
+
+    optimize: {
+        enabled: false,
+    }
+}

app/InCallService/AndroidManifest.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="org.lineageos.mediatek.incallservice"
+    android:versionCode="1"
+    android:versionName="1.0"
+    android:sharedUserId="android.uid.system">
+
+    <application
+        android:label="@string/app_name"
+        android:persistent="true">
+        <receiver
+            android:directBootAware="true"
+            android:exported="true"    
+            android:name="org.lineageos.mediatek.incallservice.OnLockedBootCompleteReceiver">
+            <intent-filter>
+                <action android:name="android.intent.action.LOCKED_BOOT_COMPLETED" />
+                <category android:name="android.intent.category.DEFAULT" />
+            </intent-filter>
+        </receiver>
+        <service
+            android:directBootAware="true"
+            android:name="org.lineageos.mediatek.incallservice.VolumeChangeService">
+        </service>
+    </application>
+</manifest>

app/InCallService/res/values/strings.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="app_name">Mediatek In-Call Service</string>
+</resources>

app/InCallService/src/org/lineageos/mediatek/incallservice/OnLockedBootCompleteReceiver.java

@@ -0,0 +1,19 @@
+package org.lineageos.mediatek.incallservice;
+
+import android.content.BroadcastReceiver;
+import android.content.Intent;
+import android.content.Context;
+
+import android.util.Log;
+
+public class OnLockedBootCompleteReceiver extends BroadcastReceiver {
+    private static final String LOG_TAG = "MediatekInCallService";
+
+    @Override
+    public void onReceive(final Context context, Intent intent) {
+        Log.i(LOG_TAG, "onBoot");
+
+        Intent sIntent = new Intent(context, VolumeChangeService.class);
+        context.startService(sIntent);
+    }
+}

app/InCallService/src/org/lineageos/mediatek/incallservice/VolumeChangeReceiver.java

@@ -0,0 +1,50 @@
+package org.lineageos.mediatek.incallservice;
+
+import android.content.Intent;
+import android.content.Context;
+import android.content.BroadcastReceiver;
+
+import android.media.AudioManager;
+import android.media.AudioSystem;
+import android.media.AudioDeviceInfo;
+
+import android.util.Log;
+
+public class VolumeChangeReceiver extends BroadcastReceiver {
+    public static final String LOG_TAG = "MediatekInCallService";
+
+    private AudioManager mAudioManager;
+
+    public VolumeChangeReceiver(Context context) {
+        mAudioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
+    }
+
+    @Override
+    public void onReceive(Context context, Intent intent) {
+        int streamType = intent.getIntExtra(AudioManager.EXTRA_VOLUME_STREAM_TYPE, -1);
+        if (streamType == AudioSystem.STREAM_VOICE_CALL) {
+            AudioDeviceInfo callDevice = mAudioManager.getCommunicationDevice();
+            if (callDevice.getInternalType() != AudioDeviceInfo.TYPE_BUILTIN_EARPIECE) {
+                // Device is not the built in earpiece, we don't need to do anything.
+                return;
+            }
+
+            // Start building parameters
+            String parameters = "volumeDevice=" + (callDevice.getId() - 1) + ";";
+            int volumeIndex = intent.getIntExtra(AudioManager.EXTRA_VOLUME_STREAM_VALUE, -1);
+            if (volumeIndex < 0) {
+                Log.w(LOG_TAG, "Could not get volumeIndex!");
+                return;
+            }
+
+            // Limit volumeIndex to a max of 7 since that's the size of
+            // MediaTek's gain table.
+            parameters += "volumeIndex=" + Math.min(7, volumeIndex) + ";";
+            parameters += "volumeStreamType=" + streamType;
+
+            // Set gain parameters
+            Log.d(LOG_TAG, "Setting audio parameters: " + parameters);
+            AudioSystem.setParameters(parameters);
+        }
+    }
+}

app/InCallService/src/org/lineageos/mediatek/incallservice/VolumeChangeService.java

@@ -0,0 +1,39 @@
+package org.lineageos.mediatek.incallservice;
+
+import android.media.AudioManager;
+
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.content.Context;
+import android.app.Service;
+import android.os.IBinder;
+
+import android.util.Log;
+
+public class VolumeChangeService extends Service {
+    public static final String LOG_TAG = "MediatekInCallService";
+
+    private Context mContext;
+    private VolumeChangeReceiver mVolumeChangeReceiver;
+
+    @Override
+    public IBinder onBind(Intent intent) {
+        return null;
+    }
+
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+    }
+
+    @Override
+    public int onStartCommand(Intent intent, int flags, int startid) {
+        mContext = this;
+        mVolumeChangeReceiver = new VolumeChangeReceiver(mContext);
+
+        Log.i(LOG_TAG, "Service is starting...");
+        this.registerReceiver(mVolumeChangeReceiver,
+                               new IntentFilter(AudioManager.VOLUME_CHANGED_ACTION));
+        return START_STICKY;
+    }
+}

device.mk

@@ -240,6 +240,10 @@ PRODUCT_PACKAGES += \
     libchrome.vendor \
     libtextclassifier_hash.vendor
 
+# MTK In-call service
+PRODUCT_PACKAGES += \
+    MtkInCallService
+
 # NFC
 PRODUCT_PACKAGES += \
     android.hardware.nfc@1.2.vendor \