高通 msm8909
diff --git a/frameworks/base/media/java/android/media/AudioSystem.java b/frameworks/base/media/java/android/media/AudioSystem.java
index af27d36..eeefcc0 100644
--- a/frameworks/base/media/java/android/media/AudioSystem.java
+++ b/frameworks/base/media/java/android/media/AudioSystem.java
@@ -695,12 +695,12 @@ public class AudioSystem
???? }
?//设置默认的音量值，方便调节的时候变动的格数相同；
???? public static int[] DEFAULT_STREAM_VOLUME = new int[] {
-??????? 2,? // STREAM_VOICE_CALL
+??????? 7,? // STREAM_VOICE_CALL
???????? 7,? // STREAM_SYSTEM
???????? 3,? // STREAM_RING
???????? 7, // STREAM_MUSIC
-??????? 3,? // STREAM_ALARM
-??????? 5,? // STREAM_NOTIFICATION
+??????? 7,? // STREAM_ALARM
+??????? 7,? // STREAM_NOTIFICATION
???????? 7,? // STREAM_BLUETOOTH_SCO
???????? 7,? // STREAM_SYSTEM_ENFORCED
???????? 7, // STREAM_DTMF
diff --git a/frameworks/base/services/core/java/com/android/server/audio/AudioService.java b/frameworks/base/services/core/java/com/android/server/audio/Au
index 9ec414b..5b654e2 100644
--- a/frameworks/base/services/core/java/com/android/server/audio/AudioService.java
+++ b/frameworks/base/services/core/java/com/android/server/audio/AudioService.java
@@ -281,27 +281,27 @@ public class AudioService extends IAudioService.Stub {
?
?//设置默认的最大音量值，格数相同；
??? /** Maximum volume index values for audio streams */
???? private static int[] MAX_STREAM_VOLUME = new int[] {
-??????? 5,? // STREAM_VOICE_CALL
-??????? 7,? // STREAM_SYSTEM
+??????? 15,? // STREAM_VOICE_CALL
+??????? 15,? // STREAM_SYSTEM
???????? 7,? // STREAM_RING
???????? 15, // STREAM_MUSIC
-??????? 7,? // STREAM_ALARM
-??????? 7,? // STREAM_NOTIFICATION
+??????? 15,? // STREAM_ALARM
+??????? 15,? // STREAM_NOTIFICATION
???????? 15, // STREAM_BLUETOOTH_SCO
-??????? 7,? // STREAM_SYSTEM_ENFORCED
+??????? 15,? // STREAM_SYSTEM_ENFORCED
???????? 15, // STREAM_DTMF
???????? 15? // STREAM_TTS
???? };
?//设置默认的最小音量值，格数相同；
???? /** Minimum volume index values for audio streams */
???? private static int[] MIN_STREAM_VOLUME = new int[] {
-??????? 1,? // STREAM_VOICE_CALL
+??????? 0,? // STREAM_VOICE_CALL
???????? 0,? // STREAM_SYSTEM
???????? 0,? // STREAM_RING
???????? 0,? // STREAM_MUSIC
???????? 0,? // STREAM_ALARM
???????? 0,? // STREAM_NOTIFICATION
-??????? 1,? // STREAM_BLUETOOTH_SCO
+??????? 0,? // STREAM_BLUETOOTH_SCO
???????? 0,? // STREAM_SYSTEM_ENFORCED
???????? 0,? // STREAM_DTMF
???????? 0?? // STREAM_TTS
//我没有控制铃声，所以铃声没改；这里需要控制哪个音量就改哪个
@@ -320,13 +320,13 @@ public class AudioService extends IAudioService.Stub {
private final int[] STREAM_VOLUME_ALIAS_VOICE = new int[] {
???????? AudioSystem.STREAM_VOICE_CALL,????? // STREAM_VOICE_CALL
???????? AudioSystem.STREAM_RING,??????????? // STREAM_SYSTEM
???????? AudioSystem.STREAM_RING,??????????? // STREAM_RING
-??????? AudioSystem.STREAM_MUSIC,?????????? // STREAM_MUSIC
-??????? AudioSystem.STREAM_ALARM,?????????? // STREAM_ALARM
+??????? AudioSystem.STREAM_VOICE_CALL,?????????? // STREAM_MUSIC
+??????? AudioSystem.STREAM_VOICE_CALL,?????????? // STREAM_ALARM
???????? AudioSystem.STREAM_RING,??????????? // STREAM_NOTIFICATION
-??????? AudioSystem.STREAM_BLUETOOTH_SCO,?? // STREAM_BLUETOOTH_SCO
+??????? AudioSystem.STREAM_VOICE_CALL,?? // STREAM_BLUETOOTH_SCO
???????? AudioSystem.STREAM_RING,??????????? // STREAM_SYSTEM_ENFORCED
???????? AudioSystem.STREAM_RING,??????????? // STREAM_DTMF
-??????? AudioSystem.STREAM_MUSIC??????????? // STREAM_TTS
+??????? AudioSystem.STREAM_VOICE_CALL??????????? // STREAM_TTS
???? };
???? private final int[] STREAM_VOLUME_ALIAS_TELEVISION = new int[] {
???????? AudioSystem.STREAM_MUSIC,?????? // STREAM_VOICE_CALL
下面是文章链接内容
?参考：https://www.freesion.com/article/8053740494/
需求
音量条控制时需要将媒体音量，电话铃声等统一控制，即移动一个音量条其他音量条也跟着变化。
修改
frameworks/base/services/core/java/com/android/server/audio/AudioService.java
修改STREAM_VOLUME_ALIAS_DEFAULT数组改成跟STREAM_VOLUME_ALIAS_TELEVISION数组内容一样所以音量条都属于music分组
代码分析
Android系统创建AudioTrack时可以指定10种stream
目录：frameworks/base/media/java/android/media/AudioSystem.java
各种stream的音量也可以单独设置、互不影响。
比如"音乐音量"不应该影响到"来电振铃"、“闹钟”、"通话"的音量。
手机音量控制界面有5种滑动条, 用于设置某种类型的声音音量.
这5种滑动条如何控制10种stream?
必须分组!在Android源码中称之为"别名", 即alias
frameworks/base/services/core/java/com/android/server/audio/AudioService.java
在key-down事件时调整音量，在key-up时播放调节音量的声音
目录：frameworks/base/media/java/android/media/AudioManager.java
这里的flags是FLAG_SHOW_UI | FLAG_VIBRATE，会显示进度条，有震动。
这里的flags是FLAG_PLAY_SOUND,表示播放音乐
最终会调用到：frameworks/base/services/core/java/com/android/server/audio/AudioService.java
先通过getActiveStreamType获取当前活跃的流类型
接着看audioservice，如何处理音量调节的。
//step1，为streamType查找alias归类，使用流类型别名是为了让有相同别名的流，有相同的行为。
int streamTypeAlias = mStreamVolumeAlias[streamType];
//step2，为streamtypealias寻找匹配的device。
final int device = getDeviceForStream(streamTypeAlias);
//step3，获取对应的aliasindex
int aliasIndex = streamState.getIndex(device);
// step4，调节index，把UI上的加1、减1的步骤，转成流别名上内部单元中的数字
// convert one UI step (+/-1) into a number of internal units on the stream alias
step = rescaleIndex(10, streamType, streamTypeAlias);
//step5，对音量模式的影响
// If either the client forces allowing ringer modes for this adjustment,
// or the stream type is one that is affected by ringer modes
if (((flags & AudioManager.FLAG_ALLOW_RINGER_MODES) != 0) ||
(streamTypeAlias == getUiSoundsStreamType())) {
//step6，将调节音量的事件发给下一个处理者。
sendMsg(mAudioHandler,
MSG_SET_DEVICE_VOLUME,
SENDMSG_QUEUE,
device,
0,
streamState,
0);
接下来看看MSG_SET_DEVICE_VOLUME消息处理做了什么
版权声明：本文为qq_33487044原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接和本声明。
本文链接：https://blog.csdn.net/qq_33487044/article/details/87449522
https://blog.csdn.net/bberdong/article/details/51792319
Android 4.4 音量的统一调节
https://blog.csdn.net/h1217256980/article/details/101211287
https://blog.csdn.net/bberdong/article/details/83068688
另外，通话音量无法设置为无声；
没法将通话音量调到最低的原因是，通话音量的最小就是1，这是在audioservice中设定的；
// VOICE_CALL stream has minVolumeIndex > 0 but can be muted directly by an // app that has MODIFY_PHONE_STATE permission. if (((index < mVolumeCurves>getVolumeIndexMin(stream)) && !(stream == AUDIO_STREAM_VOICE_CALL && index == 0)) || (index > mVolumeCurves->getVolumeIndexMax(stream))) { return BAD_VALUE; }
以下代码是android8.0原生代码，与项目中代码略有差异，但是基本一致；return BAD_VALUE; 之前增加了log，编译发现log的确打印出来了， mVolumeCurves->getVolumeIndexMin(stream) 音量曲线的最低点是大于0的；稍后继续验证分析下，您也可以尝试下； status_t AudioPolicyManager::setStreamVolumeIndex(audio_stream_type_t stream, int index, audio_devices_t device) { if ((index < mVolumeCurves>getVolumeIndexMin(stream)) || (index > mVolumeCurves->getVolumeIndexMax(stream))) { return BAD_VALUE; }
已经确认清楚了，audio驱动音频参数模块里面的设置的最低音量就是有声音的，项目这边最低是-15db;所以肯定是有声音的， 这个是可以通过修改ACDB文件来配置相关音频参数，将最低音量修改下就可以了；