涉及代码文件:
android/frameworks/base/services/core/java/com/android/server/policy/PhoneWindowManager.java
android/base/services/core/java/com/android/server/audio/AudioService.java
android/base/media/java/android/media/AudioSystem.java
android/base/core/jni/android_media_AudioSystem.cpp
android/av/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
android/av/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
下图时序图只跟踪了主流程,在设置声音的过程中还做了其他事项,这里未做体现。代码跟踪到逻辑音量映射到实际mic音量的db值,后续未再跟踪