RK3566 安卓11 更改默认媒体音量为最大
需求是需要更改默认的媒体音没因为喇叭功率较小，所以需要直接开机就默认拉满的音量
涉及代码路径
frameworks/base/media/java/android/media/AudioSystem.java
frameworks/base/services/core/java/com/android/server/audio/AudioService.java
1.话不多说系统音量默认初始值在AudioSystem.java中定义,代码如下:
/** @hide */
public static int[] DEFAULT_STREAM_VOLUME = new int[] {
4, // STREAM_VOICE_CALL
7, // STREAM_SYSTEM
5, // STREAM_RING
5, // STREAM_MUSIC
6, // STREAM_ALARM
5, // STREAM_NOTIFICATION
7, // STREAM_BLUETOOTH_SCO
7, // STREAM_SYSTEM_ENFORCED
5, // STREAM_DTMF
5, // STREAM_TTS
5, // STREAM_ACCESSIBILITY
5, // STREAM_ASSISTANT
};
2.系统音量最大值和最小值定义在AudioService.java 中,代码如下:
/** Maximum volume index values for audio streams */
protected static int[] MAX_STREAM_VOLUME = new int[] {
5, // STREAM_VOICE_CALL
7, // STREAM_SYSTEM
7, // STREAM_RING
15, // STREAM_MUSIC
7, // STREAM_ALARM
7, // STREAM_NOTIFICATION
15, // STREAM_BLUETOOTH_SCO
7, // STREAM_SYSTEM_ENFORCED
15, // STREAM_DTMF
15, // STREAM_TTS
15, // STREAM_ACCESSIBILITY
15 // STREAM_ASSISTANT
};
/** Minimum volume index values for audio streams */
protected static int[] MIN_STREAM_VOLUME = new int[] {
1, // STREAM_VOICE_CALL
0, // STREAM_SYSTEM
0, // STREAM_RING
0, // STREAM_MUSIC
1, // STREAM_ALARM
0, // STREAM_NOTIFICATION
0, // STREAM_BLUETOOTH_SCO
0, // STREAM_SYSTEM_ENFORCED
0, // STREAM_DTMF
0, // STREAM_TTS
1, // STREAM_ACCESSIBILITY
0 // STREAM_ASSISTANT
};
最简单粗暴的办法
1.直接按照AudioService.java中的MAX_STREAM_VOLUME数组中的值做相应的修改.
/** @hide */
public static int[] DEFAULT_STREAM_VOLUME = new int[] {
5, // STREAM_VOICE_CALL
7, // STREAM_SYSTEM
7, // STREAM_RING
15, // STREAM_MUSIC
7, // STREAM_ALARM
7, // STREAM_NOTIFICATION
15, // STREAM_BLUETOOTH_SCO
7, // STREAM_SYSTEM_ENFORCED
15, // STREAM_DTMF
15, // STREAM_TTS
15, // STREAM_ACCESSIBILITY
15, // STREAM_ASSISTANT
};
如上，直接把所有的值都改为了AudioService.java的上限
2.还有一步很关键不然无效，需要注释以下代码
// Initialize volume
// Priority 1 - Android Property
// Priority 2 - Audio Policy Service
// Priority 3 - Default Value
if (AudioProductStrategy.getAudioProductStrategies().size() > 0) {
int numStreamTypes = AudioSystem.getNumStreamTypes();
for (int streamType = numStreamTypes - 1; streamType >= 0; streamType--) {
AudioAttributes attr =
AudioProductStrategy.getAudioAttributesForStrategyWithLegacyStreamType(
streamType);
int maxVolume = AudioSystem.getMaxVolumeIndexForAttributes(attr);
if (maxVolume != -1) {
MAX_STREAM_VOLUME[streamType] = maxVolume;
}
int minVolume = AudioSystem.getMinVolumeIndexForAttributes(attr);
if (minVolume != -1) {
MIN_STREAM_VOLUME[streamType] = minVolume;
}
}
if (mUseVolumeGroupAliases) {
// Set all default to uninitialized.
for (int stream = 0; stream < AudioSystem.DEFAULT_STREAM_VOLUME.length; stream++) {
AudioSystem.DEFAULT_STREAM_VOLUME[stream] = UNSET_INDEX;
}
}
}
/*注释开始
int maxCallVolume = SystemProperties.getInt("ro.config.vc_call_vol_steps", -1);
if (maxCallVolume != -1) {
MAX_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL] = maxCallVolume;
}
int defaultCallVolume = SystemProperties.getInt("ro.config.vc_call_vol_default", -1);
if (defaultCallVolume != -1 &&
defaultCallVolume <= MAX_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL] &&
defaultCallVolume >= MIN_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL]) {
AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL] = defaultCallVolume;
} else {
AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL] =
(MAX_STREAM_VOLUME[AudioSystem.STREAM_VOICE_CALL] * 3) / 4;
}
int maxMusicVolume = SystemProperties.getInt("ro.config.media_vol_steps", -1);
if (maxMusicVolume != -1) {
MAX_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] = maxMusicVolume;
}
int defaultMusicVolume = SystemProperties.getInt("ro.config.media_vol_default", -1);
if (defaultMusicVolume != -1 &&
defaultMusicVolume <= MAX_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] &&
defaultMusicVolume >= MIN_STREAM_VOLUME[AudioSystem.STREAM_MUSIC]) {
AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] = defaultMusicVolume;
} else {
if (isPlatformTelevision()) {
AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] =
MAX_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] / 4;
} else {
AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] =
MAX_STREAM_VOLUME[AudioSystem.STREAM_MUSIC] / 3;
}
}
int maxAlarmVolume = SystemProperties.getInt("ro.config.alarm_vol_steps", -1);
if (maxAlarmVolume != -1) {
MAX_STREAM_VOLUME[AudioSystem.STREAM_ALARM] = maxAlarmVolume;
}
int defaultAlarmVolume = SystemProperties.getInt("ro.config.alarm_vol_default", -1);
if (defaultAlarmVolume != -1 &&
defaultAlarmVolume <= MAX_STREAM_VOLUME[AudioSystem.STREAM_ALARM]) {
AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_ALARM] = defaultAlarmVolume;
} else {
// Default is 6 out of 7 (default maximum), so scale accordingly.
AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_ALARM] =
6 * MAX_STREAM_VOLUME[AudioSystem.STREAM_ALARM] / 7;
}
int maxSystemVolume = SystemProperties.getInt("ro.config.system_vol_steps", -1);
if (maxSystemVolume != -1) {
MAX_STREAM_VOLUME[AudioSystem.STREAM_SYSTEM] = maxSystemVolume;
}
int defaultSystemVolume = SystemProperties.getInt("ro.config.system_vol_default", -1);
if (defaultSystemVolume != -1 &&
defaultSystemVolume <= MAX_STREAM_VOLUME[AudioSystem.STREAM_SYSTEM]) {
AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_SYSTEM] = defaultSystemVolume;
} else {
// Default is to use maximum.
AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_SYSTEM] =
MAX_STREAM_VOLUME[AudioSystem.STREAM_SYSTEM];
}
注释结束*/
createAudioSystemThread();
因为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。