Huami/Zepp OS: Improve music info stability

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/huami/Huami2021Service.java

@@ -27,7 +27,6 @@ public class Huami2021Service {
     public static final short CHUNKED2021_ENDPOINT_VIBRATION_PATTERNS = 0x0018;
     public static final short CHUNKED2021_ENDPOINT_WORKOUT = 0x0019;
     public static final short CHUNKED2021_ENDPOINT_FIND_DEVICE = 0x001a;
-    public static final short CHUNKED2021_ENDPOINT_MUSIC = 0x001b;
     public static final short CHUNKED2021_ENDPOINT_HEARTRATE = 0x001d;
     public static final short CHUNKED2021_ENDPOINT_BATTERY = 0x0029;
     public static final short CHUNKED2021_ENDPOINT_SILENT_MODE = 0x003b;
@@ -115,21 +114,6 @@ public class Huami2021Service {
     public static final byte WORKOUT_STATUS_START = 0x01;
     public static final byte WORKOUT_STATUS_END = 0x04;
 
-    /**
-     * Music, for {@link Huami2021Service#CHUNKED2021_ENDPOINT_MUSIC}.
-     */
-    public static final byte MUSIC_CMD_MEDIA_INFO = 0x03;
-    public static final byte MUSIC_CMD_APP_STATE = 0x04;
-    public static final byte MUSIC_CMD_BUTTON_PRESS = 0x05;
-    public static final byte MUSIC_APP_OPEN = 0x01;
-    public static final byte MUSIC_APP_CLOSE = 0x02;
-    public static final byte MUSIC_BUTTON_PLAY = 0x00;
-    public static final byte MUSIC_BUTTON_PAUSE = 0x01;
-    public static final byte MUSIC_BUTTON_NEXT = 0x03;
-    public static final byte MUSIC_BUTTON_PREVIOUS = 0x04;
-    public static final byte MUSIC_BUTTON_VOLUME_UP = 0x05;
-    public static final byte MUSIC_BUTTON_VOLUME_DOWN = 0x06;
-
     /**
      * Weather, for {@link Huami2021Service#CHUNKED2021_ENDPOINT_WEATHER}.
      */

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/Huami2021Support.java

@@ -43,7 +43,6 @@ import android.net.Uri;
 import android.os.Handler;
 import android.widget.Toast;
 
-import org.apache.commons.lang3.ArrayUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -51,36 +50,27 @@ import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
-import java.net.MalformedURLException;
-import java.net.URL;
-import java.net.URLDecoder;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Calendar;
-import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.UUID;
 import java.util.concurrent.TimeUnit;
-import java.util.regex.Pattern;
 
 import nodomain.freeyourgadget.gadgetbridge.GBApplication;
 import nodomain.freeyourgadget.gadgetbridge.activities.devicesettings.DeviceSettingsPreferenceConst;
 import nodomain.freeyourgadget.gadgetbridge.deviceevents.GBDeviceEventAppInfo;
 import nodomain.freeyourgadget.gadgetbridge.capabilities.loyaltycards.LoyaltyCard;
 import nodomain.freeyourgadget.gadgetbridge.deviceevents.GBDeviceEventFindPhone;
-import nodomain.freeyourgadget.gadgetbridge.deviceevents.GBDeviceEventMusicControl;
 import nodomain.freeyourgadget.gadgetbridge.deviceevents.GBDeviceEventScreenshot;
 import nodomain.freeyourgadget.gadgetbridge.deviceevents.GBDeviceEventUpdatePreferences;
-import nodomain.freeyourgadget.gadgetbridge.devices.DeviceCoordinator;
 import nodomain.freeyourgadget.gadgetbridge.devices.huami.Huami2021Coordinator;
 import nodomain.freeyourgadget.gadgetbridge.devices.huami.Huami2021Service;
 import nodomain.freeyourgadget.gadgetbridge.devices.huami.HuamiConst;
@@ -99,7 +89,6 @@ import nodomain.freeyourgadget.gadgetbridge.model.CalendarEventSpec;
 import nodomain.freeyourgadget.gadgetbridge.model.CallSpec;
 import nodomain.freeyourgadget.gadgetbridge.model.CannedMessagesSpec;
 import nodomain.freeyourgadget.gadgetbridge.model.Contact;
-import nodomain.freeyourgadget.gadgetbridge.model.DeviceType;
 import nodomain.freeyourgadget.gadgetbridge.model.MusicSpec;
 import nodomain.freeyourgadget.gadgetbridge.model.MusicStateSpec;
 import nodomain.freeyourgadget.gadgetbridge.model.NotificationSpec;
@@ -123,6 +112,7 @@ import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.zeppos.service
 import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.zeppos.services.ZeppOsHttpService;
 import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.zeppos.services.ZeppOsLogsService;
 import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.zeppos.services.ZeppOsLoyaltyCardService;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.zeppos.services.ZeppOsMusicService;
 import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.zeppos.services.ZeppOsNotificationService;
 import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.zeppos.services.ZeppOsRemindersService;
 import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.zeppos.services.ZeppOsServicesService;
@@ -139,9 +129,7 @@ import nodomain.freeyourgadget.gadgetbridge.util.DeviceHelper;
 import nodomain.freeyourgadget.gadgetbridge.util.FileUtils;
 import nodomain.freeyourgadget.gadgetbridge.util.GB;
 import nodomain.freeyourgadget.gadgetbridge.util.GBPrefs;
-import nodomain.freeyourgadget.gadgetbridge.util.MapUtils;
 import nodomain.freeyourgadget.gadgetbridge.util.Prefs;
-import nodomain.freeyourgadget.gadgetbridge.util.StringUtils;
 
 public abstract class Huami2021Support extends HuamiSupport implements ZeppOsFileTransferService.Callback {
     private static final Logger LOG = LoggerFactory.getLogger(Huami2021Support.class);
@@ -176,6 +164,7 @@ public abstract class Huami2021Support extends HuamiSupport implements ZeppOsFil
     private final ZeppOsHttpService httpService = new ZeppOsHttpService(this);
     private final ZeppOsRemindersService remindersService = new ZeppOsRemindersService(this);
     private final ZeppOsLoyaltyCardService loyaltyCardService = new ZeppOsLoyaltyCardService(this);
+    private final ZeppOsMusicService musicService = new ZeppOsMusicService(this);
 
     private final Map<Short, AbstractZeppOsService> mServiceMap = new LinkedHashMap<Short, AbstractZeppOsService>() {{
         put(servicesService.getEndpoint(), servicesService);
@@ -200,6 +189,7 @@ public abstract class Huami2021Support extends HuamiSupport implements ZeppOsFil
         put(httpService.getEndpoint(), httpService);
         put(remindersService.getEndpoint(), remindersService);
         put(loyaltyCardService.getEndpoint(), loyaltyCardService);
+        put(musicService.getEndpoint(), musicService);
     }};
 
     public Huami2021Support() {
@@ -555,17 +545,12 @@ public abstract class Huami2021Support extends HuamiSupport implements ZeppOsFil
 
     @Override
     public void onSetPhoneVolume(final float volume) {
-        // FIXME: we need to send the music info and state as well, or it breaks the info
+        musicService.sendVolume(volume);
-        sendMusicStateToDevice(bufferMusicSpec, bufferMusicStateSpec);
     }
 
-    protected void sendMusicStateToDevice(final MusicSpec musicSpec,
+    @Override
-                                          final MusicStateSpec musicStateSpec) {
+    protected void sendMusicStateToDevice(final MusicSpec musicSpec, final MusicStateSpec musicStateSpec) {
-        byte[] cmd = ArrayUtils.addAll(new byte[]{MUSIC_CMD_MEDIA_INFO}, encodeMusicState(musicSpec, musicStateSpec, true));
+        musicService.sendMusicState(musicSpec, musicStateSpec);
-
-        LOG.info("sendMusicStateToDevice: {}, {}", musicSpec, musicStateSpec);
-
-        writeToChunked2021("send playback info", CHUNKED2021_ENDPOINT_MUSIC, cmd, false);
     }
 
     @Override
@@ -1091,9 +1076,6 @@ public abstract class Huami2021Support extends HuamiSupport implements ZeppOsFil
             case CHUNKED2021_ENDPOINT_SILENT_MODE:
                 handle2021SilentMode(payload);
                 return;
-            case CHUNKED2021_ENDPOINT_MUSIC:
-                handle2021Music(payload);
-                return;
             default:
                 LOG.warn("Unhandled 2021 payload {}", String.format("0x%04x", type));
         }
@@ -1320,55 +1302,6 @@ public abstract class Huami2021Support extends HuamiSupport implements ZeppOsFil
         }
     }
 
-    protected void handle2021Music(final byte[] payload) {
-        switch (payload[0]) {
-            case MUSIC_CMD_APP_STATE:
-                switch (payload[1]) {
-                    case MUSIC_APP_OPEN:
-                        onMusicAppOpen();
-                        break;
-                    case MUSIC_APP_CLOSE:
-                        onMusicAppClosed();
-                        break;
-                    default:
-                        LOG.warn("Unexpected music app state {}", String.format("0x%02x", payload[1]));
-                        break;
-                }
-                return;
-
-            case MUSIC_CMD_BUTTON_PRESS:
-                LOG.info("Got music button press");
-                final GBDeviceEventMusicControl deviceEventMusicControl = new GBDeviceEventMusicControl();
-                switch (payload[1]) {
-                    case MUSIC_BUTTON_PLAY:
-                        deviceEventMusicControl.event = GBDeviceEventMusicControl.Event.PLAY;
-                        break;
-                    case MUSIC_BUTTON_PAUSE:
-                        deviceEventMusicControl.event = GBDeviceEventMusicControl.Event.PAUSE;
-                        break;
-                    case MUSIC_BUTTON_NEXT:
-                        deviceEventMusicControl.event = GBDeviceEventMusicControl.Event.NEXT;
-                        break;
-                    case MUSIC_BUTTON_PREVIOUS:
-                        deviceEventMusicControl.event = GBDeviceEventMusicControl.Event.PREVIOUS;
-                        break;
-                    case MUSIC_BUTTON_VOLUME_UP:
-                        deviceEventMusicControl.event = GBDeviceEventMusicControl.Event.VOLUMEUP;
-                        break;
-                    case MUSIC_BUTTON_VOLUME_DOWN:
-                        deviceEventMusicControl.event = GBDeviceEventMusicControl.Event.VOLUMEDOWN;
-                        break;
-                    default:
-                        LOG.warn("Unexpected music button {}", String.format("0x%02x", payload[1]));
-                        return;
-                }
-                evaluateGBDeviceEvent(deviceEventMusicControl);
-                return;
-            default:
-                LOG.warn("Unexpected music byte {}", String.format("0x%02x", payload[0]));
-        }
-    }
-
     @Override
     public void onFileUploadFinish(final boolean success) {
         LOG.warn("Unexpected file upload finish: {}", success);

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/HuamiSupport.java

@@ -19,6 +19,7 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>. */
 package nodomain.freeyourgadget.gadgetbridge.service.devices.huami;
 
+import android.bluetooth.BluetoothAdapter;
 import android.bluetooth.BluetoothGatt;
 import android.bluetooth.BluetoothGattCharacteristic;
 import android.content.Context;
@@ -27,8 +28,9 @@ import android.content.SharedPreferences;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
 import android.location.Location;
-import android.media.AudioManager;
 import android.net.Uri;
+import android.os.Handler;
+import android.os.Looper;
 import android.widget.Toast;
 
 import androidx.localbroadcastmanager.content.LocalBroadcastManager;
@@ -112,6 +114,7 @@ import nodomain.freeyourgadget.gadgetbridge.entities.MiBandActivitySample;
 import nodomain.freeyourgadget.gadgetbridge.entities.User;
 import nodomain.freeyourgadget.gadgetbridge.externalevents.gps.GBLocationManager;
 import nodomain.freeyourgadget.gadgetbridge.externalevents.opentracks.OpenTracksController;
+import nodomain.freeyourgadget.gadgetbridge.impl.GBDevice;
 import nodomain.freeyourgadget.gadgetbridge.impl.GBDevice.State;
 import nodomain.freeyourgadget.gadgetbridge.model.ActivityKind;
 import nodomain.freeyourgadget.gadgetbridge.model.ActivitySample;
@@ -130,6 +133,7 @@ import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.operations.Fet
 import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.operations.FetchStressManualOperation;
 import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.operations.HuamiFetchDebugLogsOperation;
 import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.zeppos.services.ZeppOsCannedMessagesService;
+import nodomain.freeyourgadget.gadgetbridge.util.MediaManager;
 import nodomain.freeyourgadget.gadgetbridge.util.calendar.CalendarEvent;
 import nodomain.freeyourgadget.gadgetbridge.util.calendar.CalendarManager;
 import nodomain.freeyourgadget.gadgetbridge.model.CallSpec;
@@ -327,8 +331,7 @@ public abstract class HuamiSupport extends AbstractBTLEDeviceSupport implements
     private RealtimeSamplesSupport realtimeSamplesSupport;
 
     protected boolean isMusicAppStarted = false;
-    protected MusicSpec bufferMusicSpec = null;
+    protected MediaManager mediaManager;
-    protected MusicStateSpec bufferMusicStateSpec = null;
     private boolean heartRateNotifyEnabled;
     private int mMTU = 23;
     protected int mActivitySampleSize = 4;
@@ -360,6 +363,12 @@ public abstract class HuamiSupport extends AbstractBTLEDeviceSupport implements
         addSupportedProfile(deviceInfoProfile);
     }
 
+    @Override
+    public void setContext(final GBDevice gbDevice, final BluetoothAdapter btAdapter, final Context context) {
+        super.setContext(gbDevice, btAdapter, context);
+        this.mediaManager = new MediaManager(context);
+    }
+
     @Override
     protected TransactionBuilder initializeDevice(TransactionBuilder builder) {
         try {
@@ -1337,53 +1346,49 @@ public abstract class HuamiSupport extends AbstractBTLEDeviceSupport implements
     }
 
     @Override
-    public void onSetMusicState(MusicStateSpec stateSpec) {
+    public void onSetMusicState(final MusicStateSpec stateSpec) {
-        DeviceCoordinator coordinator = DeviceHelper.getInstance().getCoordinator(gbDevice);
+        if (!getCoordinator().supportsMusicInfo()) {
-        if (!coordinator.supportsMusicInfo()) {
             return;
         }
 
-        if (stateSpec != null && !stateSpec.equals(bufferMusicStateSpec)) {
+        if (mediaManager.onSetMusicState(stateSpec) && isMusicAppStarted) {
-            bufferMusicStateSpec = stateSpec;
+            sendMusicStateToDevice(null, mediaManager.getBufferMusicStateSpec());
-            if (isMusicAppStarted) {
-                sendMusicStateToDevice(null, bufferMusicStateSpec);
-            }
         }
     }
 
     @Override
-    public void onSetMusicInfo(MusicSpec musicSpec) {
+    public void onSetMusicInfo(final MusicSpec musicSpec) {
-        DeviceCoordinator coordinator = DeviceHelper.getInstance().getCoordinator(gbDevice);
+        if (!getCoordinator().supportsMusicInfo()) {
-        if (!coordinator.supportsMusicInfo()) {
             return;
         }
 
-        if (musicSpec != null && !musicSpec.equals(bufferMusicSpec)) {
+        if (mediaManager.onSetMusicInfo(musicSpec) && isMusicAppStarted) {
-            bufferMusicSpec = musicSpec;
+            sendMusicStateToDevice(mediaManager.getBufferMusicSpec(), mediaManager.getBufferMusicStateSpec());
-            if (bufferMusicStateSpec != null) {
-                bufferMusicStateSpec.state = 0;
-                bufferMusicStateSpec.position = 0;
-            }
-            if (isMusicAppStarted) {
-                sendMusicStateToDevice(bufferMusicSpec, bufferMusicStateSpec);
-            }
         }
     }
 
-    protected void onMusicAppOpen() {
+    public void onMusicAppOpen() {
         LOG.info("Music app started");
         isMusicAppStarted = true;
-        sendMusicStateToDevice();
+        sendMusicStateDelayed();
-        sendVolumeStateToDevice();
     }
 
-    protected void onMusicAppClosed() {
+    public void onMusicAppClosed() {
         LOG.info("Music app terminated");
         isMusicAppStarted = false;
     }
 
-    private void sendMusicStateToDevice() {
+    /**
-        sendMusicStateToDevice(bufferMusicSpec, bufferMusicStateSpec);
+     * Send the music state after a small delay. If we send it right as the app notifies us that it opened,
+     * it won't be recognized.
+     */
+    private void sendMusicStateDelayed() {
+        final Looper mainLooper = Looper.getMainLooper();
+        new Handler(mainLooper).postDelayed(() -> {
+            mediaManager.refresh();
+            sendMusicStateToDevice(mediaManager.getBufferMusicSpec(), mediaManager.getBufferMusicStateSpec());
+            onSetPhoneVolume(mediaManager.getPhoneVolume());
+        }, 100);
     }
 
     @Override
@@ -1406,20 +1411,6 @@ public abstract class HuamiSupport extends AbstractBTLEDeviceSupport implements
         LOG.info("sendVolumeStateToDevice: {}", volume);
     }
 
-    private void sendVolumeStateToDevice() {
-        onSetPhoneVolume(getPhoneVolume());
-    }
-
-    protected int getPhoneVolume() {
-        final AudioManager audioManager = (AudioManager) getContext().getSystemService(Context.AUDIO_SERVICE);
-
-        final int volumeLevel = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
-        final int volumeMax = audioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
-        final int volumePercentage = (byte) Math.round(100 * (volumeLevel / (float) volumeMax));
-
-        return volumePercentage;
-    }
-
     protected void sendMusicStateToDevice(final MusicSpec musicSpec, final MusicStateSpec musicStateSpec) {
         if (characteristicChunked == null) {
             return;
@@ -1431,7 +1422,7 @@ public abstract class HuamiSupport extends AbstractBTLEDeviceSupport implements
 
         try {
             TransactionBuilder builder = performInitialized("send playback info");
-            writeToChunked(builder, 3, encodeMusicState(musicSpec, musicStateSpec, false));
+            writeToChunked(builder, 3, encodeMusicState(getContext(), musicSpec, musicStateSpec, false));
             builder.queue(getQueue());
         } catch (IOException e) {
             LOG.error("Unable to send playback state");
@@ -1439,7 +1430,10 @@ public abstract class HuamiSupport extends AbstractBTLEDeviceSupport implements
         LOG.info("sendMusicStateToDevice: {}, {}", musicSpec, musicStateSpec);
     }
 
-    protected byte[] encodeMusicState(final MusicSpec musicSpec, final MusicStateSpec musicStateSpec, final boolean includeVolume) {
+    public static byte[] encodeMusicState(final Context context,
+                                          final MusicSpec musicSpec,
+                                          final MusicStateSpec musicStateSpec,
+                                          final boolean includeVolume) {
         String artist = "";
         String album = "";
         String track = "";
@@ -1518,7 +1512,7 @@ public abstract class HuamiSupport extends AbstractBTLEDeviceSupport implements
         }
 
         if (includeVolume) {
-            buf.put((byte) getPhoneVolume());
+            buf.put((byte) MediaManager.getPhoneVolume(context));
         }
 
         return buf.array();

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/amazfitcor/AmazfitCorSupport.java

@@ -51,9 +51,8 @@ public class AmazfitCorSupport extends AmazfitBipSupport {
 
     @Override
     public void onSetMusicState(MusicStateSpec stateSpec) {
-        if (stateSpec != null && !stateSpec.equals(bufferMusicStateSpec)) {
+        if (mediaManager.onSetMusicState(stateSpec)) {
-            sendMusicStateToDevice(null, stateSpec);
+            sendMusicStateToDevice(null, mediaManager.getBufferMusicStateSpec());
-            bufferMusicStateSpec = stateSpec;
         }
     }
 

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/zeppos/services/ZeppOsMusicService.java

@@ -0,0 +1,142 @@
+/*  Copyright (C) 2023 José Rebelo
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.huami.zeppos.services;
+
+import org.apache.commons.lang3.ArrayUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import nodomain.freeyourgadget.gadgetbridge.deviceevents.GBDeviceEventMusicControl;
+import nodomain.freeyourgadget.gadgetbridge.model.MusicSpec;
+import nodomain.freeyourgadget.gadgetbridge.model.MusicStateSpec;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.Huami2021Support;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.HuamiSupport;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.zeppos.AbstractZeppOsService;
+
+public class ZeppOsMusicService extends AbstractZeppOsService {
+    private static final Logger LOG = LoggerFactory.getLogger(ZeppOsMusicService.class);
+
+    private static final short ENDPOINT = 0x001b;
+
+    private static final byte CMD_MEDIA_INFO = 0x03;
+    private static final byte CMD_APP_STATE = 0x04;
+    private static final byte CMD_BUTTON_PRESS = 0x05;
+    private static final byte MUSIC_APP_OPEN = 0x01;
+    private static final byte MUSIC_APP_CLOSE = 0x02;
+    private static final byte BUTTON_PLAY = 0x00;
+    private static final byte BUTTON_PAUSE = 0x01;
+    private static final byte BUTTON_NEXT = 0x03;
+    private static final byte BUTTON_PREVIOUS = 0x04;
+    private static final byte BUTTON_VOLUME_UP = 0x05;
+    private static final byte BUTTON_VOLUME_DOWN = 0x06;
+
+    public ZeppOsMusicService(final Huami2021Support support) {
+        super(support);
+    }
+
+    @Override
+    public short getEndpoint() {
+        return ENDPOINT;
+    }
+
+    @Override
+    public boolean isEncrypted() {
+        return false;
+    }
+
+    @Override
+    public void handlePayload(final byte[] payload) {
+        switch (payload[0]) {
+            case CMD_APP_STATE:
+                switch (payload[1]) {
+                    case MUSIC_APP_OPEN:
+                        onMusicAppOpen();
+                        break;
+                    case MUSIC_APP_CLOSE:
+                        onMusicAppClosed();
+                        break;
+                    default:
+                        LOG.warn("Unexpected music app state {}", String.format("0x%02x", payload[1]));
+                        break;
+                }
+                return;
+
+            case CMD_BUTTON_PRESS:
+                LOG.info("Got music button press");
+                final GBDeviceEventMusicControl deviceEventMusicControl = new GBDeviceEventMusicControl();
+                switch (payload[1]) {
+                    case BUTTON_PLAY:
+                        deviceEventMusicControl.event = GBDeviceEventMusicControl.Event.PLAY;
+                        break;
+                    case BUTTON_PAUSE:
+                        deviceEventMusicControl.event = GBDeviceEventMusicControl.Event.PAUSE;
+                        break;
+                    case BUTTON_NEXT:
+                        deviceEventMusicControl.event = GBDeviceEventMusicControl.Event.NEXT;
+                        break;
+                    case BUTTON_PREVIOUS:
+                        deviceEventMusicControl.event = GBDeviceEventMusicControl.Event.PREVIOUS;
+                        break;
+                    case BUTTON_VOLUME_UP:
+                        deviceEventMusicControl.event = GBDeviceEventMusicControl.Event.VOLUMEUP;
+                        break;
+                    case BUTTON_VOLUME_DOWN:
+                        deviceEventMusicControl.event = GBDeviceEventMusicControl.Event.VOLUMEDOWN;
+                        break;
+                    default:
+                        LOG.warn("Unexpected music button {}", String.format("0x%02x", payload[1]));
+                        return;
+                }
+                evaluateGBDeviceEvent(deviceEventMusicControl);
+                return;
+            default:
+                LOG.warn("Unexpected music byte {}", String.format("0x%02x", payload[0]));
+        }
+    }
+
+    private void onMusicAppOpen() {
+        getSupport().onMusicAppOpen();
+    }
+
+    private void onMusicAppClosed() {
+        getSupport().onMusicAppClosed();
+    }
+
+    public void sendMusicState(final MusicSpec musicSpec,
+                               final MusicStateSpec musicStateSpec) {
+        LOG.info("Sending music: {}, {}", musicSpec, musicStateSpec);
+
+        // TODO: Encode not playing state (flag 0x20, single 0x01 byte before volume)
+        final byte[] cmd = ArrayUtils.addAll(
+                new byte[]{CMD_MEDIA_INFO},
+                HuamiSupport.encodeMusicState(getContext(), musicSpec, musicStateSpec, false)
+        );
+
+        write("send music state", cmd);
+    }
+
+    public void sendVolume(final float volume) {
+        LOG.info("Sending volume: {}", volume);
+
+        final byte[] cmd = ArrayUtils.addAll(
+                new byte[]{CMD_MEDIA_INFO},
+                HuamiSupport.encodeMusicState(getContext(), null, null, true)
+        );
+
+        write("send volume", cmd);
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/util/MediaManager.java

@@ -0,0 +1,156 @@
+/*  Copyright (C) 2023 José Rebelo
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.util;
+
+import android.content.ComponentName;
+import android.content.Context;
+import android.media.AudioManager;
+import android.media.MediaMetadata;
+import android.media.session.MediaController;
+import android.media.session.MediaSessionManager;
+import android.media.session.PlaybackState;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.List;
+
+import nodomain.freeyourgadget.gadgetbridge.externalevents.NotificationListener;
+import nodomain.freeyourgadget.gadgetbridge.model.MusicSpec;
+import nodomain.freeyourgadget.gadgetbridge.model.MusicStateSpec;
+
+public class MediaManager {
+    private static final Logger LOG = LoggerFactory.getLogger(MediaManager.class);
+
+    private final Context context;
+
+    private MusicSpec bufferMusicSpec = null;
+    private MusicStateSpec bufferMusicStateSpec = null;
+
+    public MediaManager(final Context context) {
+        this.context = context;
+    }
+
+    public MusicSpec getBufferMusicSpec() {
+        return bufferMusicSpec;
+    }
+
+    public MusicStateSpec getBufferMusicStateSpec() {
+        return bufferMusicStateSpec;
+    }
+
+    /**
+     * Returns true if the spec changed, so the device should be updated.
+     */
+    public boolean onSetMusicState(final MusicStateSpec stateSpec) {
+        if (stateSpec != null && !stateSpec.equals(bufferMusicStateSpec)) {
+            bufferMusicStateSpec = stateSpec;
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Returns true if the spec changed, so the device should be updated.
+     */
+    public boolean onSetMusicInfo(MusicSpec musicSpec) {
+        if (musicSpec != null && !musicSpec.equals(bufferMusicSpec)) {
+            bufferMusicSpec = musicSpec;
+            if (bufferMusicStateSpec != null) {
+                bufferMusicStateSpec.state = 0;
+                bufferMusicStateSpec.position = 0;
+            }
+            return true;
+        }
+        return false;
+    }
+
+    public void refresh() {
+        LOG.info("Refreshing media state");
+
+        final MediaSessionManager mediaSessionManager =
+                (MediaSessionManager) context.getSystemService(Context.MEDIA_SESSION_SERVICE);
+
+        try {
+            final List<MediaController> controllers = mediaSessionManager.getActiveSessions(
+                    new ComponentName(context, NotificationListener.class)
+            );
+            if (controllers.isEmpty()) {
+                LOG.debug("No media controller available");
+                return;
+            }
+            final MediaController controller = controllers.get(0);
+
+            final MediaMetadata metadata = controller.getMetadata();
+            final PlaybackState playbackState = controller.getPlaybackState();
+
+            final MusicSpec musicSpec = new MusicSpec();
+            musicSpec.artist = StringUtils.ensureNotNull(metadata.getString(MediaMetadata.METADATA_KEY_ARTIST));
+            musicSpec.album = StringUtils.ensureNotNull(metadata.getString(MediaMetadata.METADATA_KEY_ALBUM));
+            musicSpec.track = StringUtils.ensureNotNull(metadata.getString(MediaMetadata.METADATA_KEY_TITLE));
+            musicSpec.trackNr = (int) metadata.getLong(MediaMetadata.METADATA_KEY_TRACK_NUMBER);
+            musicSpec.trackCount = (int) metadata.getLong(MediaMetadata.METADATA_KEY_NUM_TRACKS);
+            musicSpec.duration = (int) metadata.getLong(MediaMetadata.METADATA_KEY_DURATION) / 1000;
+
+            final MusicStateSpec stateSpec = new MusicStateSpec();
+            switch (playbackState.getState()) {
+                case PlaybackState.STATE_PLAYING:
+                case PlaybackState.STATE_FAST_FORWARDING:
+                case PlaybackState.STATE_REWINDING:
+                case PlaybackState.STATE_BUFFERING:
+                case PlaybackState.STATE_CONNECTING:
+                case PlaybackState.STATE_SKIPPING_TO_PREVIOUS:
+                case PlaybackState.STATE_SKIPPING_TO_NEXT:
+                case PlaybackState.STATE_SKIPPING_TO_QUEUE_ITEM:
+                    stateSpec.state = MusicStateSpec.STATE_PLAYING;
+                    break;
+                case PlaybackState.STATE_PAUSED:
+                    stateSpec.state = MusicStateSpec.STATE_PAUSED;
+                    break;
+                case PlaybackState.STATE_STOPPED:
+                case PlaybackState.STATE_ERROR:
+                    stateSpec.state = MusicStateSpec.STATE_STOPPED;
+                    break;
+                case PlaybackState.STATE_NONE:
+                default:
+                    stateSpec.state = MusicStateSpec.STATE_UNKNOWN;
+            }
+            stateSpec.position = (int) playbackState.getPosition() / 1000;
+            stateSpec.playRate = (int) (playbackState.getPlaybackSpeed() * 100);
+            stateSpec.repeat = MusicStateSpec.STATE_UNKNOWN;
+            stateSpec.shuffle = MusicStateSpec.STATE_UNKNOWN;
+
+            bufferMusicStateSpec = stateSpec;
+            bufferMusicSpec = musicSpec;
+        } catch (final SecurityException e) {
+            LOG.warn("No permission to get media sessions - did not grant notification access?", e);
+        }
+    }
+
+    public int getPhoneVolume() {
+        return getPhoneVolume(context);
+    }
+
+    public static int getPhoneVolume(final Context context) {
+        final AudioManager audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
+
+        final int volumeLevel = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
+        final int volumeMax = audioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
+        return Math.round(100 * (volumeLevel / (float) volumeMax));
+    }
+}