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Android 12 修改系统音量默认初始值_android 默认音量

作者：盐析白兔 | 2024-04-08 20:13:34

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android 默认音量

1.需求:Android 系统出厂默认的音量值过小,需要把音量默认初始值改成音量的最大值.

2.涉及核心代码:

  1. frameworks/base/media/java/android/media/AudioSystem.java
  2. frameworks/base/services/core/java/com/android/server/audio/AudioService.java

3.系统音量默认初始值在AudioSystem.java中定义,代码如下:

  1.    /** @hide */
  2.     public static int[] DEFAULT_STREAM_VOLUME = new int[] {
  3.         4,  // STREAM_VOICE_CALL
  4.         7,  // STREAM_SYSTEM
  5.         5,  // STREAM_RING
  6.         5, // STREAM_MUSIC
  7.         6,  // STREAM_ALARM
  8.         5,  // STREAM_NOTIFICATION
  9.         7,  // STREAM_BLUETOOTH_SCO
  10.         7,  // STREAM_SYSTEM_ENFORCED
  11.         5, // STREAM_DTMF
  12.         5, // STREAM_TTS
  13.         5, // STREAM_ACCESSIBILITY
  14.         5, // STREAM_ASSISTANT
  15.     };

3.系统音量最大值和最小值定义在AudioService.java 中,代码如下:

  1.   /** Maximum volume index values for audio streams */
  2.     protected static int[] MAX_STREAM_VOLUME = new int[] {
  3.         5,  // STREAM_VOICE_CALL
  4.         7,  // STREAM_SYSTEM
  5.         7,  // STREAM_RING
  6.         15, // STREAM_MUSIC
  7.         7,  // STREAM_ALARM
  8.         7,  // STREAM_NOTIFICATION
  9.         15, // STREAM_BLUETOOTH_SCO
  10.         7,  // STREAM_SYSTEM_ENFORCED
  11.         15, // STREAM_DTMF
  12.         15, // STREAM_TTS
  13.         15, // STREAM_ACCESSIBILITY
  14.         15  // STREAM_ASSISTANT
  15.     };
  16.  
  17.     /** Minimum volume index values for audio streams */
  18.     protected static int[] MIN_STREAM_VOLUME = new int[] {
  19.         1,  // STREAM_VOICE_CALL
  20.         0,  // STREAM_SYSTEM
  21.         0,  // STREAM_RING
  22.         0,  // STREAM_MUSIC
  23.         1,  // STREAM_ALARM
  24.         0,  // STREAM_NOTIFICATION
  25.         0,  // STREAM_BLUETOOTH_SCO
  26.         0,  // STREAM_SYSTEM_ENFORCED
  27.         0,  // STREAM_DTMF
  28.         0,  // STREAM_TTS
  29.         1,  // STREAM_ACCESSIBILITY
  30.         0   // STREAM_ASSISTANT
  31.     };

------------------------------------------------------------修改方案一---------------------------------------------

在AudioSystem.Java中,修改把默认的音量值改成需要的值,如:把设置里音量中的"媒体音量","通话音量","铃声和通知音量","闹钟音量" 改成最大值. 

(1)第一步:对照AudioService.java中的MAX_STREAM_VOLUME数组中的值做相应的修改.

  1.  
  2.     /** @hide */
  3.     public static int[] DEFAULT_STREAM_VOLUME = new int[] {
  4.         5,  // STREAM_VOICE_CALL
  5.         7,  // STREAM_SYSTEM
  6.         7,  // STREAM_RING
  7.         15, // STREAM_MUSIC
  8.         7,  // STREAM_ALARM
  9.         7,  // STREAM_NOTIFICATION
  10.         15,  // STREAM_BLUETOOTH_SCO
  11.         7,  // STREAM_SYSTEM_ENFORCED
  12.         15, // STREAM_DTMF
  13.         15, // STREAM_TTS
  14.         15, // STREAM_ACCESSIBILITY
  15.         15, // STREAM_ASSISTANT
  16.     };

(2)步骤二:由于AudioService.java在构造函数中,会覆盖最大值和默认初始值,所以需要把构造函数中从配置文件中取值的代码注释掉,才能让步骤一中修改的数组的值起作用,最后清楚系统数据后便会生效.

  1.  
  2.     /** @hide */
  3.     public AudioService(Context context) {
  4.         this(context, AudioSystemAdapter.getDefaultAdapter(),
  5.                 SystemServerAdapter.getDefaultAdapter(context));
  6.     }
  7.  
  8.     public AudioService(Context context, AudioSystemAdapter audioSystem,
  9.             SystemServerAdapter systemServer) {
  10.         sLifecycleLogger.log(new AudioEventLogger.StringEvent("AudioService()"));
  11.         mContext = context;
  12.         mContentResolver = context.getContentResolver();
  13.         mAppOps = (AppOpsManager)context.getSystemService(Context.APP_OPS_SERVICE);
  14.  
  15.         mAudioSystem = audioSystem;
  16.         mSystemServer = systemServer;
  17.  
  18.         mPlatformType = AudioSystem.getPlatformType(context);
  19.  
  20.         mIsSingleVolume = AudioSystem.isSingleVolume(context);
  21.  
  22.         mUserManagerInternal = LocalServices.getService(UserManagerInternal.class);
  23.         mActivityManagerInternal = LocalServices.getService(ActivityManagerInternal.class);
  24.         mSensorPrivacyManagerInternal =
  25.                 LocalServices.getService(SensorPrivacyManagerInternal.class);
  26.  
  27.         PowerManager pm = (PowerManager)context.getSystemService(Context.POWER_SERVICE);
  28.         mAudioEventWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "handleAudioEvent");
  29.  
  30.         mSfxHelper = new SoundEffectsHelper(mContext);
  31.  
  32.         mVibrator = (Vibrator) context.getSystemService(Context.VIBRATOR_SERVICE);
  33.         mHasVibrator = mVibrator == null ? false : mVibrator.hasVibrator();
  34.  
  35.         mSupportsMicPrivacyToggle = context.getSystemService(SensorPrivacyManager.class)
  36.                 .supportsSensorToggle(SensorPrivacyManager.Sensors.MICROPHONE);
  37.  
  38.         mUseVolumeGroupAliases = mContext.getResources().getBoolean(
  39.                 com.android.internal.R.bool.config_handleVolumeAliasesUsingVolumeGroups);
  40.  
  41.         // Initialize volume
  42.         // Priority 1 - Android Property
  43.         // Priority 2 - Audio Policy Service
  44.         // Priority 3 - Default Value
  45.         if (AudioProductStrategy.getAudioProductStrategies().size() > 0) {
  46.             int numStreamTypes = AudioSystem.getNumStreamTypes();
  47.  
  48.             for (int streamType = numStreamTypes - 1; streamType >= 0; streamType--) {
  49.                 AudioAttributes attr =
  50.                         AudioProductStrategy.getAudioAttributesForStrategyWithLegacyStreamType(
  51.                                 streamType);
  52.                 int maxVolume = AudioSystem.getMaxVolumeIndexForAttributes(attr);
  53.                 if (maxVolume != -1) {
  54.                     MAX_STREAM_VOLUME[streamType] = maxVolume;
  55.                 }
  56.                 int minVolume = AudioSystem.getMinVolumeIndexForAttributes(attr);
  57.                 if (minVolume != -1) {
  58.                     MIN_STREAM_VOLUME[streamType] = minVolume;
  59.                 }
  60.             }
  61.             if (mUseVolumeGroupAliases) {
  62.                 // Set all default to uninitialized.
  63.                 for (int stream = 0; stream < AudioSystem.DEFAULT_STREAM_VOLUME.length; stream++) {
  64.                     AudioSystem.DEFAULT_STREAM_VOLUME[stream] = UNSET_INDEX;
  65.                 }
  66.             }
  67.         }
  68.  
  69. /*注释开始
  70.         int maxCallVolume = SystemProperties.getInt("ro.config.vc_call_vol_steps", -1);
  71.         if (maxCallVolume != -1) {
  72.             MAX_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL] = maxCallVolume;
  73.         }
  75.         int defaultCallVolume = SystemProperties.getInt("ro.config.vc_call_vol_default", -1);
  76.         if (defaultCallVolume != -1 &&
  77.                 defaultCallVolume <= MAX_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL] &&
  78.                 defaultCallVolume >= MIN_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL]) {
  79.             AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL] = defaultCallVolume;
  80.         } else {
  81.             AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL] =
  82.                     (MAX_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL] * 3) / 4;
  83.         }
  85.         int maxMusicVolume = SystemProperties.getInt("ro.config.media_vol_steps", -1);
  86.         if (maxMusicVolume != -1) {
  87.             MAX_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] = maxMusicVolume;
  88.         }
  90.         int defaultMusicVolume = SystemProperties.getInt("ro.config.media_vol_default", -1);
  91.         if (defaultMusicVolume != -1 &&
  92.                 defaultMusicVolume <= MAX_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] &&
  93.                 defaultMusicVolume >= MIN_STREAM_VOLUME[AudioSystem.STREAM_MUSIC]) {
  94.             AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] = defaultMusicVolume;
  95.         } else {
  96.             if (isPlatformTelevision()) {
  97.                 AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] =
  98.                         MAX_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] / 4;
  99.             } else {
  100.                 AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] =
  101.                         MAX_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] / 3;
  102.             }
  103.         }
  105.         int maxAlarmVolume = SystemProperties.getInt("ro.config.alarm_vol_steps", -1);
  106.         if (maxAlarmVolume != -1) {
  107.             MAX_STREAM_VOLUME[AudioSystem.STREAM_ALARM] = maxAlarmVolume;
  108.         }
  110.         int defaultAlarmVolume = SystemProperties.getInt("ro.config.alarm_vol_default", -1);
  111.         if (defaultAlarmVolume != -1 &&
  112.                 defaultAlarmVolume <= MAX_STREAM_VOLUME[AudioSystem.STREAM_ALARM]) {
  113.             AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_ALARM] = defaultAlarmVolume;
  114.         } else {
  115.             // Default is 6 out of 7 (default maximum), so scale accordingly.
  116.             AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_ALARM] =
  117.                         6 * MAX_STREAM_VOLUME[AudioSystem.STREAM_ALARM] / 7;
  118.         }
  120.         int maxSystemVolume = SystemProperties.getInt("ro.config.system_vol_steps", -1);
  121.         if (maxSystemVolume != -1) {
  122.             MAX_STREAM_VOLUME[AudioSystem.STREAM_SYSTEM] = maxSystemVolume;
  123.         }
  125.         int defaultSystemVolume = SystemProperties.getInt("ro.config.system_vol_default", -1);
  126.         if (defaultSystemVolume != -1 &&
  127.                 defaultSystemVolume <= MAX_STREAM_VOLUME[AudioSystem.STREAM_SYSTEM]) {
  128.             AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_SYSTEM] = defaultSystemVolume;
  129.         } else {
  130.             // Default is to use maximum.
  131.             AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_SYSTEM] =
  132.                         MAX_STREAM_VOLUME[AudioSystem.STREAM_SYSTEM];
  133.         }
  134. 注释结束*/
  135.  
  136.         createAudioSystemThread();
  137.  
  138.         AudioSystem.setErrorCallback(mAudioSystemCallback);
  139.  
  140.         updateAudioHalPids();
  141.  
  142.         boolean cameraSoundForced = readCameraSoundForced();
  143.         mCameraSoundForced = new Boolean(cameraSoundForced);
  144.         sendMsg(mAudioHandler,
  145.                 MSG_SET_FORCE_USE,
  146.                 SENDMSG_QUEUE,
  147.                 AudioSystem.FOR_SYSTEM,
  148.                 cameraSoundForced ?
  149.                         AudioSystem.FORCE_SYSTEM_ENFORCED : AudioSystem.FORCE_NONE,
  150.                 new String("AudioService ctor"),
  151.                 0);
  152.  
  153.         mSafeMediaVolumeState = Settings.Global.getInt(mContentResolver,
  154.                                             Settings.Global.AUDIO_SAFE_VOLUME_STATE,
  155.                                             SAFE_MEDIA_VOLUME_NOT_CONFIGURED);
  156.         // The default safe volume index read here will be replaced by the actual value when
  157.         // the mcc is read by onConfigureSafeVolume()
  158.         mSafeMediaVolumeIndex = mContext.getResources().getInteger(
  159.                 com.android.internal.R.integer.config_safe_media_volume_index) * 10;
  160.  
  161.         mUseFixedVolume = mContext.getResources().getBoolean(
  162.                 com.android.internal.R.bool.config_useFixedVolume);
  163.  
  164.         mDeviceBroker = new AudioDeviceBroker(mContext, this);
  165.  
  166.         mRecordMonitor = new RecordingActivityMonitor(mContext);
  167.         mRecordMonitor.registerRecordingCallback(mVoiceRecordingActivityMonitor, true);
  168.  
  169.         // must be called before readPersistedSettings() which needs a valid mStreamVolumeAlias[]
  170.         // array initialized by updateStreamVolumeAlias()
  171.         updateStreamVolumeAlias(false /*updateVolumes*/, TAG);
  172.         readPersistedSettings();
  173.         readUserRestrictions();
  174.  
  175.         mPlaybackMonitor =
  176.                 new PlaybackActivityMonitor(context, MAX_STREAM_VOLUME[AudioSystem.STREAM_ALARM]);
  177.         mPlaybackMonitor.registerPlaybackCallback(mVoicePlaybackActivityMonitor, true);
  178.  
  179.         mMediaFocusControl = new MediaFocusControl(mContext, mPlaybackMonitor);
  180.  
  181.         readAndSetLowRamDevice();
  182.  
  183.         mIsCallScreeningModeSupported = AudioSystem.isCallScreeningModeSupported();
  184.  
  185.         if (mSystemServer.isPrivileged()) {
  186.             LocalServices.addService(AudioManagerInternal.class, new AudioServiceInternal());
  187.  
  188.             mUserManagerInternal.addUserRestrictionsListener(mUserRestrictionsListener);
  189.  
  190.             mRecordMonitor.initMonitor();
  191.         }
  192.  
  193.         mMonitorRotation = SystemProperties.getBoolean("ro.audio.monitorRotation", false);
  194.  
  195.         // done with service initialization, continue additional work in our Handler thread
  196.         queueMsgUnderWakeLock(mAudioHandler, MSG_INIT_STREAMS_VOLUMES,
  197.                 0 /* arg1 */,  0 /* arg2 */, null /* obj */,  0 /* delay */);
  198.     }

--------------------------------------修改方案二---------------------------------------------

由于AudioService.java构造函数中会从配置文件中对音量默认值和音量最大值再次赋值,

  1.     int maxCallVolume = SystemProperties.getInt("ro.config.vc_call_vol_steps", -1);
  2.         if (maxCallVolume != -1) {
  3.             MAX_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL] = maxCallVolume;
  4.         }
  5.  
  6. //从系统属性"ro.config.vc_call_vol_default"中获取默认电话音量
  7.         int defaultCallVolume = SystemProperties.getInt("ro.config.vc_call_vol_default", -1);
  8.         if (defaultCallVolume != -1 &&
  9.                 defaultCallVolume <= MAX_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL] &&
  10.                 defaultCallVolume >= MIN_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL]) {
  11.             AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL] = defaultCallVolume;
  12.         } else {
  13.             AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL] =
  14.                     (MAX_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL] * 3) / 4;
  15.         }
  16.  
  17.         int maxMusicVolume = SystemProperties.getInt("ro.config.media_vol_steps", -1);
  18.         if (maxMusicVolume != -1) {
  19.             MAX_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] = maxMusicVolume;
  20.         }
  21.  
  22. //从系统属性"ro.config.media_vol_default"中获取默认媒体音量
  23.         int defaultMusicVolume = SystemProperties.getInt("ro.config.media_vol_default", -1);
  24.         if (defaultMusicVolume != -1 &&
  25.                 defaultMusicVolume <= MAX_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] &&
  26.                 defaultMusicVolume >= MIN_STREAM_VOLUME[AudioSystem.STREAM_MUSIC]) {
  27.             AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] = defaultMusicVolume;
  28.         } else {
  29.             if (isPlatformTelevision()) {
  30.                 AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] =
  31.                         MAX_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] / 4;
  32.             } else {
  33.                 AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] =
  34.                         MAX_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] / 3;
  35.             }
  36.         }
  37.  
  38.         int maxAlarmVolume = SystemProperties.getInt("ro.config.alarm_vol_steps", -1);
  39.         if (maxAlarmVolume != -1) {
  40.             MAX_STREAM_VOLUME[AudioSystem.STREAM_ALARM] = maxAlarmVolume;
  41.         }
  42.  
  43. //从系统属性"ro.config.alarm_vol_default"中获取默认闹钟和通知音量
  44.         int defaultAlarmVolume = SystemProperties.getInt("ro.config.alarm_vol_default", -1);
  45.         if (defaultAlarmVolume != -1 &&
  46.                 defaultAlarmVolume <= MAX_STREAM_VOLUME[AudioSystem.STREAM_ALARM]) {
  47.             AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_ALARM] = defaultAlarmVolume;
  48.         } else {
  49.             // Default is 6 out of 7 (default maximum), so scale accordingly.
  50.             AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_ALARM] =
  51.                         6 * MAX_STREAM_VOLUME[AudioSystem.STREAM_ALARM] / 7;
  52.         }
  53.  
  54.         int maxSystemVolume = SystemProperties.getInt("ro.config.system_vol_steps", -1);
  55.         if (maxSystemVolume != -1) {
  56.             MAX_STREAM_VOLUME[AudioSystem.STREAM_SYSTEM] = maxSystemVolume;
  57.         }
  58.  
  59. //从系统属性"ro.config.system_vol_default"中获取默认系统音量
  60.         int defaultSystemVolume = SystemProperties.getInt("ro.config.system_vol_default", -1);
  61.         if (defaultSystemVolume != -1 &&
  62.                 defaultSystemVolume <= MAX_STREAM_VOLUME[AudioSystem.STREAM_SYSTEM]) {
  63.             AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_SYSTEM] = defaultSystemVolume;
  64.         } else {
  65.             // Default is to use maximum.
  66.             AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_SYSTEM] =
  67.                         MAX_STREAM_VOLUME[AudioSystem.STREAM_SYSTEM];
  68.         }

所以可以在配置文件中添加对应的属性,并赋值,这样就不需要修改代码.默认Android 源码中并没有给这些属性配值,所以直接添加上去就可以了.其中,配置文件在设备的 /system/build.prop .

  1. <property name="ro.config.vc_call_vol_default" value="5">
  2. <property name="ro.config.media_vol_default" value="15">
  3. <property name="ro.config.alarm_vol_default" value="7">
  4. <property name="ro.config.system_vol_default" value="7">

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