dolby: Implement DSPVolumeSynchronizer

Some Xiaomi devices have a speaker that needs a framework to cooperate
with DSP to synchronize volume so that the DSP can limit bass when the
volume is high to prevent distortion.

Change-Id: I750803d94161e1e7482552d2a39566f42e82fc0a
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>

DSPVolumeSynchronizer/Android.bp

@@ -0,0 +1,39 @@
+//
+// Copyright (C) 2024-2025 The LineageOS Project
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+android_app {
+    name: "DSPVolumeSynchronizer",
+    certificate: "platform",
+    srcs: ["src/**/*.java"],
+    platform_apis: true,
+    privileged: true,
+    system_ext_specific: true,
+    static_libs: [
+        "androidx.core_core",
+        "SettingsLib",
+    ],
+
+    required: [
+        "privapp-permissions-dspvolume",
+        "config-dspvolume",
+    ],
+}
+
+prebuilt_etc {
+    name: "privapp-permissions-dspvolume",
+    relative_install_path: "permissions",
+    src: "privapp-permissions-dspvolume.xml",
+    system_ext_specific: true,
+    filename_from_src: true,
+}
+
+prebuilt_etc {
+    name: "config-dspvolume",
+    relative_install_path: "sysconfig",
+    src: "config-dspvolume.xml",
+    system_ext_specific: true,
+    filename_from_src: true,
+}

DSPVolumeSynchronizer/AndroidManifest.xml

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="org.lineageos.dspvolume.xiaomi"
+    android:versionCode="1"
+    android:versionName="1.0"
+    android:sharedUserId="android.uid.system">
+
+    <uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />
+
+    <application
+        android:label="@string/app_name"
+        android:persistent="true"
+        android:defaultToDeviceProtectedStorage="true"
+        android:directBootAware="true">
+
+        <receiver
+            android:name=".BootReceiver"
+            android:exported="true"
+            android:permission="android.permission.RECEIVE_BOOT_COMPLETED">
+            <intent-filter android:priority="999">
+                <action android:name="android.intent.action.BOOT_COMPLETED" />
+                <category android:name="android.intent.category.DEFAULT" />
+            </intent-filter>
+        </receiver>
+
+        <service
+            android:name=".VolumeListenerService" />
+    </application>
+</manifest>
+

DSPVolumeSynchronizer/config-dspvolume.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
+<config>
+    <allow-in-power-save package="org.lineageos.dspvolume.xiaomi" />
+    <hidden-api-whitelisted-app package="org.lineageos.dspvolume.xiaomi" />
+</config>

DSPVolumeSynchronizer/privapp-permissions-dspvolume.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<permissions>
+    <privapp-permissions package="org.lineageos.dspvolume.xiaomi">
+        <permission name="android.permission.INTERACT_ACROSS_USERS" />
+        <permission name="android.permission.INTERACT_ACROSS_USERS_FULL" />
+        <permission name="android.permission.MODIFY_AUDIO_SETTINGS" />
+        <permission name="android.permission.RECEIVE_BOOT_COMPLETED" />
+    </privapp-permissions>
+</permissions>

DSPVolumeSynchronizer/res/values/strings.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <!-- App Name -->
+    <string name="app_name">DSP Volume Synchronizer</string>
+</resources>

DSPVolumeSynchronizer/src/org/lineageos/dspvolume/xiaomi/BootReceiver.java

@@ -0,0 +1,16 @@
+package org.lineageos.dspvolume.xiaomi;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+
+
+public class BootReceiver extends BroadcastReceiver {
+    @Override
+    public void onReceive(final Context context, Intent intent) {
+        if (context == null) {
+            return;
+        }
+        context.startService(new Intent(context, VolumeListenerService.class));
+    }
+}

DSPVolumeSynchronizer/src/org/lineageos/dspvolume/xiaomi/VolumeListenerReceiver.java

@@ -0,0 +1,28 @@
+package org.lineageos.dspvolume.xiaomi;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.media.AudioManager;
+import android.util.Log;
+
+import android.os.Bundle;
+
+public class VolumeListenerReceiver extends BroadcastReceiver {
+
+    @Override
+    public void onReceive(Context context, Intent intent) {
+        if (context == null) {
+            return;
+        }
+
+        if(intent.getIntExtra("android.media.EXTRA_VOLUME_STREAM_TYPE", 0) == AudioManager.STREAM_MUSIC) {
+            AudioManager audioManager = context.getSystemService(AudioManager.class);
+            int current = intent.getIntExtra(
+                            "android.media.EXTRA_VOLUME_STREAM_VALUE",
+                            0
+                          );
+            audioManager.setParameters("volume_change=" + current + ";flags=8");
+        }
+    }
+}

DSPVolumeSynchronizer/src/org/lineageos/dspvolume/xiaomi/VolumeListenerService.java

@@ -0,0 +1,30 @@
+package org.lineageos.dspvolume.xiaomi;
+
+import android.app.Service;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.media.AudioManager;
+import android.os.IBinder;
+
+import androidx.annotation.Nullable;
+
+public class VolumeListenerService extends Service {
+    @Nullable
+    @Override
+    public IBinder onBind(Intent intent) {
+        return null;
+    }
+
+    @Override
+    public int onStartCommand(Intent intent, int flags, int startId) {
+        IntentFilter intentFilter = new IntentFilter();
+        intentFilter.addAction("android.media.VOLUME_CHANGED_ACTION");
+        registerReceiver(new VolumeListenerReceiver(), intentFilter);
+
+        AudioManager audioManager = getSystemService(AudioManager.class);
+        int current = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
+        audioManager.setParameters("volume_change=" + current + ";flags=8");
+
+        return super.onStartCommand(intent, flags, startId);
+    }
+}

dolby.mk

@@ -85,6 +85,10 @@ PRODUCT_VENDOR_PROPERTIES += \
 PRODUCT_PACKAGES += \
     RemovePackagesDolby
 
+# DSP Volume Synchronizer
+PRODUCT_PACKAGES += \
+    DSPVolumeSynchronizer
+
 # XiaomiDolby
 PRODUCT_PACKAGES += \
     XiaomiDolby \