android: multidevice capabilites and accessiblity features (and "liquid glass")

AAP Definitions.md

@@ -279,50 +279,27 @@ duplicated thrice for some reason
 ## Customize Transparency mode
 
 ```
-52 18 00
-For left bud
-[Enabled]
+12 18 00 [enabled]
+<left bud>
 [EQ1][EQ2][EQ3][EQ4][EQ5][EQ6][EQ7][EQ8]
 [Amplification]
 [Tone]
 [Conversation Boost]
 [Ambient Noise Reduction]
-00 0080 3F
-<same for the right bud>
+<repeat for right bud>
 ```
 
-<!-- demo packet
-52 18 00 00 00 00 00 62 10 DA 41 62 10 DA 41 62 10 DA 41 62 10 DA 41 62 10 DA 41 62 10 DA 41 62 10 DA 41 62 10 DA 41 62 10 DA 41 00 00 80 3f 00 00 80 3f 00 00 80 3f 62 10 DA 41 62 10 DA 41 62 10 DA 41 62 10 DA 41 62 10 DA 41 62 10 DA 41 62 10 DA 41 62 10 DA 41 62 10 DA 41 00 00 80 3f 00 00 80 3f 00 00 80 3f
-
--->
-<!-- 
-5218 0000 0080 3F62 10DA 413D 0AF0 4160
-E50C 42AC 9C1E 421B 2F29 429E 6F33 4293
-1846 4293 1846 4206 9476 BF00 576E BB00
-0080 3F00 0080 3F62 10DA 413D 0AF0 4160
-E50C 42AC 9C1E 421B 2F29 429E 6F33 4293
-1846 4293 1846 4200 0080 BF00 576E BB00
-0080 3F00 0080 3F
--->
-
-<!-- 
-5218 0000 0000 0062 10DA 413D 0AF0 4160
-E50C 42AC 9C1E 421B 2F29 429E 6F33 4293
-1846 4293 1846 4206 9476 BF00 576E BB00
-0080 3F00 0080 3F62 10DA 413D 0AF0 4160
-E50C 42AC 9C1E 421B 2F29 429E 6F33 4293
-1846 4293 1846 4200 0080 BF00 576E BB00
-0080 3F00 0080 3F
- -->
-
-All values are formatted as Little Endian from float values.
-| Data                | Type          | Value range |
-|---------------------|---------------|-------------|
-| Enabled             | Little Endian | 0 or 1      |
-| EQ                  | Little Endian | 0 to 100    |
-| Amplification       | Little Endian | -1 to 1     |
-| Tone                | Little Endian | -1 to 1     |
-| Conversation Boost  | Little Endian | 0 or 1      |
+
+All values are formatted as IEEE 754 floats in little endian order.
+| Data                    | Type          | Range |
+|-------------------------|---------------|-------|
+| Enabled                 | IEEE754 Float | 0/1   |
+| EQ                      | IEEE754 Float | 0-100 |
+| Amplification           | IEEE754 Float | 0-2   |
+| Tone                    | IEEE754 Float | 0-2   |
+| Conversation Boost      | IEEE754 Float | 0/1   |
+| Ambient Noise Reduction | IEEE754 Float | 0-1   |
+| Ambient Noise Reduction | IEEE754 Float | 0-1   |
 
 > [!IMPORTANT]
 > Also send the [Headphone Accomodation](#headphone-accomodation) after this.

README.md

@@ -11,16 +11,17 @@
 
 ## What is LibrePods?
 
-LibrePods unlocks Apple's exclusive AirPods features on non-Apple devices. Get access to noise control modes, adaptive transparency, ear detection, battery status, and more - all the premium features you paid for but Apple locked to their ecosystem.
+LibrePods unlocks Apple's exclusive AirPods features on non-Apple devices. Get access to noise control modes, adaptive transparency, ear detection, hearing aid, customized transparency mode, battery status, and more - all the premium features you paid for but Apple locked to their ecosystem.
 
 ## Device Compatibility
 
 | Status | Device | Features |
 |--------|--------|----------|
 | ✅ | AirPods Pro (2nd Gen) | Fully supported and tested |
+| ✅ | AirPods Pro (3rd Gen) | Fully supported (except heartrate monitoring) |
 | ⚠️ | Other AirPods models | Basic features (battery status, ear detection) should work |
 
-Most features should work with any AirPods. Currently, testing is only performed with AirPods Pro 2.
+Most features should work with any AirPods. Currently, I've only got AirPods Pro 2 to test with.
 
 ## Key Features
 
@@ -29,6 +30,9 @@ Most features should work with any AirPods. Currently, testing is only performed
 - **Battery Status**: Accurate battery levels
 - **Head Gestures**: Answer calls just by nodding your head
 - **Conversational Awareness**: Volume automatically lowers when you speak
+- **Hearing Aid\***
+- **Customize Transparency Mode\***
+- **Multi-device connectivity\*** (upto 2 devices)
 - **Other customizations**:
   - Rename your AirPods
   - Customize long-press actions
@@ -63,7 +67,13 @@ For installation and detailed info, see the [Linux README](/linux/README.md).
 | ![Settings 1](/android/imgs/settings-1.png) | ![Settings 2](/android/imgs/settings-2.png) | ![Debug Screen](/android/imgs/debug.png) |
 | ![Battery Notification and QS Tile for NC Mode](/android/imgs/notification-and-qs.png) | ![Popup](/android/imgs/popup.png) | ![Head Tracking and Gestures](/android/imgs/head-tracking-and-gestures.png) |
 | ![Long Press Configuration](/android/imgs/long-press.png) | ![Widget](/android/imgs/widget.png) | ![Customizations 1](/android/imgs/customizations-1.png) |
-| ![Customizations 2](/android/imgs/customizations-2.png) | ![audio-popup](/android/imgs/audio-connected-island.png) | |
+| ![Customizations 2](/android/imgs/customizations-2.png) | ![accessibility](/android/imgs/accessibility.png) |![transparency](/android/imgs/transparency.png) |
+|![hearing-aid](/android/imgs/hearing-aid.png) |![hearing-aid-adjustments](/android/imgs/hearing-aid-adjustments.png) | |
+
+
+here's a very unprofessional demo video
+
+https://github.com/user-attachments/assets/43911243-0576-4093-8c55-89c1db5ea533
 
 #### Root Requirement
 
@@ -72,24 +82,41 @@ For installation and detailed info, see the [Linux README](/linux/README.md).
 > 
 > There are **no exceptions** to the root requirement until Google merges the fix.
 
+## Bluetooth DID (Device Identification) Hook
+
+Turns out, if you change the manufacturerid to that of Apple, you get access to several special features!
+
+### Multi-device Connectivity
+
+Upto two devices can be simultaneously connected to AirPods, for audio and control both. Seamless connection switching. The same notification shows up on Apple device when Android takes over the AirPods as if it were an Apple device ("Move to iPhone"). Android also shows a popup when the other device takes over.
+
+### Accessibility Settings and Hearing Aid
+
+Accessibility settings like customizing transparency mode (amplification, balance, tone, conversation boost, and ambient noise reduction), and loud sound reduction can be configured.
+
+The hearing aid feature can now also be used. Currently it can only be used to adjust the settings, not actually take a hearing test because it requires much more precision. It is much better to use an already available audiogram result.
+
+
 #### Installation Methods
 
 ##### Method 1: Xposed Module (Recommended)
 This method is less intrusive and should be tried first:
 
 1. Install LSPosed, or another Xposed provider on your rooted device
 2. Download the LibrePods app from the releases section, and install it.
-3. Enable the Xposed module for the bluetooth app in your Xposed manager
-4. Follow the instructions in the app to set up the module.
-5. Open the app and connect your AirPods
+3. Enable the Xposed module for the bluetooth app in your Xposed manager.
+4. Disable unmount modules for the Bluetooth app if enabled. 
+5. Follow the instructions in the app to set up the module.
+6. Open the app and connect your AirPods
 
 ##### Method 2: Root Module (Backup Option)
 If the Xposed method doesn't work for you:
 
 1. Download the `btl2capfix.zip` module from the releases section
 2. Install it using your preferred root manager (KernelSU, Apatch, or Magisk).
-3. Reboot your device
-4. Connect your AirPods
+3. Disable Unmount modules for the Bluetooth aop if enabled. 
+4. Reboot your device
+5. Connect your AirPods
 
 ##### Method 3: Patching it yourself
 If you prefer to patch the Bluetooth stack yourself, follow these steps:
@@ -111,25 +138,6 @@ If you're unfamiliar with these steps, search for tutorials online or ask in And
 
 - When renaming your AirPods through the app, you'll need to re-pair them with your phone for the name change to take effect. This is a limitation of how Bluetooth device naming works on Android.
 
-## Development Resources
-
-For developers interested in the protocol details, check out the [AAP Definitions](/AAP%20Definitions.md) documentation.
-
-## CrossDevice Stuff
-
-> [!IMPORTANT]
-> This feature is still in early development and might not work as expected. No support is provided for this feature yet.
-
-### Features in Development
-
-- **Battery Status Sync**: Get battery status on any device when you connect your AirPods to one of them
-- **Cross-device Controls**: Control your AirPods from either device when connected to one
-- **Automatic Device Switching**: Seamlessly switch between Linux and Android devices based on active audio sources
-
-Check out the demo below:
-
-https://github.com/user-attachments/assets/d08f8a51-cd52-458b-8e55-9b44f4d5f3ab
-
 ## Star History
 
 [![Star History Chart](https://api.star-history.com/svg?repos=kavishdevar/librepods&type=Date)](https://star-history.com/#kavishdevar/librepods&Date)

android/.gitignore

@@ -1,3 +1,4 @@
+crowdin.yml
 *.iml
 .gradle
 /local.properties

android/app/build.gradle.kts

@@ -13,8 +13,8 @@ android {
         applicationId = "me.kavishdevar.librepods"
         minSdk = 28
         targetSdk = 35
-        versionCode = 7
-        versionName = "0.1.0-rc.4"
+        versionCode = 8
+        versionName = "0.2.0-alpha"
     }
 
     buildTypes {
@@ -62,5 +62,12 @@ dependencies {
     implementation(libs.haze)
     implementation(libs.haze.materials)
     implementation(libs.androidx.dynamicanimation)
-    compileOnly(fileTree(mapOf("dir" to "libs", "include" to listOf("*.aar"))))
+    implementation(libs.androidx.compose.ui)
+    debugImplementation(libs.androidx.compose.ui.tooling)
+    implementation(libs.androidx.compose.foundation.layout)
+    // compileOnly(fileTree(mapOf("dir" to "libs", "include" to listOf("*.aar"))))
+    // implementation(fileTree(mapOf("dir" to "lib", "include" to listOf("*.aar"))))
+    compileOnly(files("libs/libxposed-api-100.aar"))
+    debugImplementation(files("libs/backdrop-debug.aar"))
+    releaseImplementation(files("libs/backdrop-release.aar"))
 }

android/app/src/main/AndroidManifest.xml

@@ -7,7 +7,8 @@
         android:required="false" />
 
     <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
-    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE"
+        tools:ignore="ForegroundServicesPolicy" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_CONNECTED_DEVICE" />
     <uses-permission android:name="android.permission.INTERACT_ACROSS_USERS"
         tools:ignore="ProtectedPermissions" />
@@ -30,11 +31,10 @@
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"
         tools:ignore="ScopedStorage" />
-
     <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"
         android:maxSdkVersion="30" />
-
-    <protected-broadcast android:name="batterywidget.impl.action.update_bluetooth_data" />
+    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"
+        android:maxSdkVersion="30" />
 
     <application
         android:allowBackup="true"
@@ -60,6 +60,7 @@
                 android:name="android.appwidget.provider"
                 android:resource="@xml/noise_control_widget_info" />
         </receiver>
+
         <receiver
             android:name=".widgets.BatteryWidget"
             android:exported="false">
@@ -72,15 +73,6 @@
                 android:resource="@xml/battery_widget_info" />
         </receiver>
 
-        <activity
-            android:name=".CustomDevice"
-            android:exported="true"
-            android:label="@string/title_activity_custom_device"
-            android:theme="@style/Theme.LibrePods">
-            <intent-filter>
-                <category android:name="android.intent.category.LAUNCHER" />
-            </intent-filter>
-        </activity>
         <activity
             android:name=".MainActivity"
             android:exported="true"
@@ -90,13 +82,13 @@
 
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
-            <intent-filter android:autoVerify="true">
+            <!-- <intent-filter android:autoVerify="true">
                 <action android:name="android.intent.action.VIEW" />
                 <category android:name="android.intent.category.DEFAULT" />
                 <category android:name="android.intent.category.BROWSABLE" />
-                <data android:scheme="librepods" 
+                <data android:scheme="librepods"
                     android:host="add-magic-keys" />
-            </intent-filter>
+            </intent-filter> -->
         </activity>
 
         <activity
@@ -124,7 +116,17 @@
                 <action android:name="android.service.quicksettings.action.QS_TILE" />
             </intent-filter>
         </service>
-
+        <service
+            android:name=".services.AppListenerService"
+            android:permission="android.permission.BIND_ACCESSIBILITY_SERVICE"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.accessibilityservice.AccessibilityService" />
+            </intent-filter>
+            <meta-data
+                android:name="android.accessibilityservice"
+                android:resource="@xml/app_listener_service_config" />
+        </service>
         <receiver
             android:name=".receivers.BootReceiver"
             android:enabled="true"

android/app/src/main/cpp/l2c_fcr_hook.cpp

@@ -24,6 +24,8 @@
 #include <string>
 #include <sys/system_properties.h>
 #include "l2c_fcr_hook.h"
+#include <cerrno>
+#include <cstdlib>
 
 #define LOG_TAG "AirPodsHook"
 #define LOGI(...) __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)
@@ -126,6 +128,9 @@ static void (*original_l2cu_process_our_cfg_req)(tL2C_CCB* p_ccb, tL2CAP_CFG_INF
 static void (*original_l2c_csm_config)(tL2C_CCB* p_ccb, uint8_t event, void* p_data) = nullptr;
 static void (*original_l2cu_send_peer_info_req)(tL2C_LCB* p_lcb, uint16_t info_type) = nullptr;
 
+// Add original pointer for BTA_DmSetLocalDiRecord
+static tBTA_STATUS (*original_BTA_DmSetLocalDiRecord)(tSDP_DI_RECORD* p_device_info, uint32_t* p_handle) = nullptr;
+
 uint8_t fake_l2c_fcr_chk_chan_modes(void* p_ccb) {
     LOGI("l2c_fcr_chk_chan_modes hooked, returning true.");
     return 1;
@@ -156,6 +161,53 @@ void fake_l2cu_send_peer_info_req(tL2C_LCB* p_lcb, uint16_t info_type) {
     return;
 }
 
+// New loader for SDP hook offset (persist.librepods.sdp_offset)
+uintptr_t loadSdpOffset() {
+    const char* property_name = "persist.librepods.sdp_offset";
+    char value[PROP_VALUE_MAX] = {0};
+
+    int len = __system_property_get(property_name, value);
+    if (len > 0) {
+        LOGI("Read sdp offset from property: %s", value);
+        uintptr_t offset;
+        char* endptr = nullptr;
+
+        const char* parse_start = value;
+        if (value[0] == '0' && (value[1] == 'x' || value[1] == 'X')) {
+            parse_start = value + 2;
+        }
+
+        errno = 0;
+        offset = strtoul(parse_start, &endptr, 16);
+
+        if (errno == 0 && endptr != parse_start && *endptr == '\0' && offset > 0) {
+            LOGI("Parsed sdp offset: 0x%x", offset);
+            return offset;
+        }
+
+        LOGE("Failed to parse sdp offset from property value: %s", value);
+    }
+
+    LOGI("No sdp offset property present - skipping SDP hook");
+    return 0;
+}
+
+// Fake BTA_DmSetLocalDiRecord: set vendor/vendor_id_source then call original
+tBTA_STATUS fake_BTA_DmSetLocalDiRecord(tSDP_DI_RECORD* p_device_info, uint32_t* p_handle) {
+    LOGI("BTA_DmSetLocalDiRecord hooked - forcing vendor fields");
+    if (p_device_info) {
+        p_device_info->vendor = 0x004C;
+        p_device_info->vendor_id_source = 0x0001;
+    }
+    LOGI("Set vendor=0x%04x, vendor_id_source=0x%04x", p_device_info->vendor, p_device_info->vendor_id_source);
+    if (original_BTA_DmSetLocalDiRecord) {
+        return original_BTA_DmSetLocalDiRecord(p_device_info, p_handle);
+    }
+
+    LOGE("Original BTA_DmSetLocalDiRecord not available");
+    return BTA_FAILURE;
+}
+
 uintptr_t loadHookOffset([[maybe_unused]] const char* package_name) {
     const char* property_name = "persist.librepods.hook_offset";
     char value[PROP_VALUE_MAX] = {0};
@@ -320,6 +372,7 @@ bool findAndHookFunction(const char *library_name) {
     uintptr_t l2cu_process_our_cfg_req_offset = loadL2cuProcessCfgReqOffset();
     uintptr_t l2c_csm_config_offset = loadL2cCsmConfigOffset();
     uintptr_t l2cu_send_peer_info_req_offset = loadL2cuSendPeerInfoReqOffset();
+    uintptr_t sdp_offset = loadSdpOffset();
 
     bool success = false;
 
@@ -392,6 +445,21 @@ bool findAndHookFunction(const char *library_name) {
         LOGI("Skipping l2cu_send_peer_info_req hook as offset is not available");
     }
 
+    if (sdp_offset > 0) {
+        void* target = reinterpret_cast<void*>(base_addr + sdp_offset);
+        LOGI("Hooking BTA_DmSetLocalDiRecord at offset: 0x%x, base: %p, target: %p",
+             sdp_offset, (void*)base_addr, target);
+
+        int result = hook_func(target, (void*)fake_BTA_DmSetLocalDiRecord, (void**)&original_BTA_DmSetLocalDiRecord);
+        if (result != 0) {
+            LOGE("Failed to hook BTA_DmSetLocalDiRecord, error: %d", result);
+        } else {
+            LOGI("Successfully hooked BTA_DmSetLocalDiRecord (SDP)");
+        }
+    } else {
+        LOGI("Skipping BTA_DmSetLocalDiRecord hook as sdp offset is not available");
+    }
+
     return success;
 }