记录Android 8声音调整过程。
frameworksaseservicescorejavacomandroidserverpolicyPhoneWindowManager.java
private void dispatchDirectAudioEvent(KeyEvent event) {
if (event.getAction() != KeyEvent.ACTION_DOWN) {
return;
}
int keyCode = event.getKeyCode();
int flags = AudioManager.FLAG_SHOW_UI | AudioManager.FLAG_PLAY_SOUND
| AudioManager.FLAG_FROM_KEY;
String pkgName = mContext.getOpPackageName();
switch (keyCode) {
case KeyEvent.KEYCODE_VOLUME_UP:
try {
getAudioService().adjustSuggestedStreamVolume(AudioManager.ADJUST_RAISE,
AudioManager.USE_DEFAULT_STREAM_TYPE, flags, pkgName, TAG);
} catch (Exception e) {
Log.e(TAG, "Error dispatching volume up in dispatchTvAudioEvent.", e);
}
break;
case KeyEvent.KEYCODE_VOLUME_DOWN:
try {
getAudioService().adjustSuggestedStreamVolume(AudioManager.ADJUST_LOWER,
AudioManager.USE_DEFAULT_STREAM_TYPE, flags, pkgName, TAG);
} catch (Exception e) {
Log.e(TAG, "Error dispatching volume down in dispatchTvAudioEvent.", e);
}
break;
case KeyEvent.KEYCODE_VOLUME_MUTE:
try {
if (event.getRepeatCount() == 0) {
getAudioService().adjustSuggestedStreamVolume(
AudioManager.ADJUST_TOGGLE_MUTE,
AudioManager.USE_DEFAULT_STREAM_TYPE, flags, pkgName, TAG);
}
} catch (Exception e) {
Log.e(TAG, "Error dispatching mute in dispatchTvAudioEvent.", e);
}
break;
}
}
frameworksaseservicescorejavacomandroidserveraudioAudioService.java
/** @see AudioManager#adjustVolume(int, int) */
public void adjustSuggestedStreamVolume(int direction, int suggestedStreamType, int flags,
String callingPackage, String caller) {
adjustSuggestedStreamVolume(direction, suggestedStreamType, flags, callingPackage,
caller, Binder.getCallingUid());
}
private void adjustSuggestedStreamVolume(int direction, int suggestedStreamType, int flags,
String callingPackage, String caller, int uid) {
mVolumeLogger.log(new VolumeEvent(VolumeEvent.VOL_ADJUST_SUGG_VOL, suggestedStreamType,
direction/*val1*/, flags/*val2*/, new StringBuilder(callingPackage)
.append("/").append(caller).append(" uid:").append(uid).toString()));
final int streamType;
synchronized (mForceControlStreamLock) {
if (DEBUG_VOL) Log.d(TAG, "adjustSuggestedStreamVolume() stream=" + suggestedStreamType
+ ", flags=" + flags + ", caller=" + caller
+ ", volControlStream=" + mVolumeControlStream
+ ", userSelect=" + mUserSelectedVolumeControlStream);
if (mUserSelectedVolumeControlStream) { // implies mVolumeControlStream != -1
streamType = mVolumeControlStream;
} else {
// 获取当前StreamType类型，传入的是AudioManager.USE_DEFAULT_STREAM_TYPE
// AudioSystem.STREAM_MUSIC
final int maybeActiveStreamType = getActiveStreamType(suggestedStreamType);
final boolean activeForReal;
if (maybeActiveStreamType == AudioSystem.STREAM_MUSIC) {
// 判断AudioFlinger当前是否是用AudioSystem.STREAM_MUSIC
activeForReal = isAfMusicActiveRecently(0);
} else {
activeForReal = AudioSystem.isStreamActive(maybeActiveStreamType, 0);
}
// 获取声音类型, 就是前面getActiveStreamType得到的AudioSystem.STREAM_MUSIC
if (activeForReal || mVolumeControlStream == -1) {
streamType = maybeActiveStreamType;
} else {
streamType = mVolumeControlStream;
}
}
}
// 判断是否是MUTE操作
final boolean isMute = isMuteAdjust(direction);
// 判断类型是否合法
ensureValidStreamType(streamType);
final int resolvedStream = mStreamVolumeAlias[streamType];
// RING类型声音处理
// Play sounds on STREAM_RING only.
if ((flags & AudioManager.FLAG_PLAY_SOUND) != 0 &&
resolvedStream != AudioSystem.STREAM_RING) {
flags &= ~AudioManager.FLAG_PLAY_SOUND;
}
// 通知或者电话，显示UI,但是不进行MUTE操作
// For notifications/ring, show the ui before making any adjustments
// Don't suppress mute/unmute requests
if (mVolumeController.suppressAdjustment(resolvedStream, flags, isMute)) {
direction = 0;
// 将相应的位清零
flags &= ~AudioManager.FLAG_PLAY_SOUND;
flags &= ~AudioManager.FLAG_VIBRATE;
if (DEBUG_VOL) Log.d(TAG, "Volume controller suppressed adjustment");
}
adjustStreamVolume(streamType, direction, flags, callingPackage, caller, uid);
}
/** @see AudioManager#adjustStreamVolume(int, int, int) */
public void adjustStreamVolume(int streamType, int direction, int flags,
String callingPackage) {
if ((streamType == AudioManager.STREAM_ACCESSIBILITY) && !canChangeAccessibilityVolume()) {
Log.w(TAG, "Trying to call adjustStreamVolume() for a11y without"
+ "CHANGE_ACCESSIBILITY_VOLUME / callingPackage=" + callingPackage);
return;
}
mVolumeLogger.log(new VolumeEvent(VolumeEvent.VOL_ADJUST_STREAM_VOL, streamType,
direction/*val1*/, flags/*val2*/, callingPackage));
adjustStreamVolume(streamType, direction, flags, callingPackage, callingPackage,
Binder.getCallingUid());
}
private void adjustStreamVolume(int streamType, int direction, int flags,
String callingPackage, String caller, int uid) {
if (mUseFixedVolume) {
return;
}
if (DEBUG_VOL) Log.d(TAG, "adjustStreamVolume() stream=" + streamType + ", dir=" + direction
+ ", flags=" + flags + ", caller=" + caller);
// 判断参数是否合法
ensureValidDirection(direction);
ensureValidStreamType(streamType);
boolean isMuteAdjust = isMuteAdjust(direction);
// 判断声音是否受MUTE影响
if (isMuteAdjust && !isStreamAffectedByMute(streamType)) {
return;
}
// use stream type alias here so that streams with same alias have the same behavior,
// including with regard to silent mode control (e.g the use of STREAM_RING below and in
// checkForRingerModeChange() in place of STREAM_RING or STREAM_NOTIFICATION)
// 获取声音类型的别名
int streamTypeAlias = mStreamVolumeAlias[streamType];
VolumeStreamState streamState = mStreamStates[streamTypeAlias];
// 获取声音对应的device
final int device = getDeviceForStream(streamTypeAlias);
int aliasIndex = streamState.getIndex(device);
boolean adjustVolume = true;
int step;
// 跳过蓝牙请求，如果对应的设备不是蓝牙
// skip a2dp absolute volume control request when the device
// is not an a2dp device
if ((device & AudioSystem.DEVICE_OUT_ALL_A2DP) == 0 &&
(flags & AudioManager.FLAG_BLUETOOTH_ABS_VOLUME) != 0) {
return;
}
// 获取UID
// If we are being called by the system (e.g. hardware keys) check for current user
// so we handle user restrictions correctly.
if (uid == android.os.Process.SYSTEM_UID) {
uid = UserHandle.getUid(getCurrentUserId(), UserHandle.getAppId(uid));
}
if (mAppOps.noteOp(STREAM_VOLUME_OPS[streamTypeAlias], uid, callingPackage)
!= AppOpsManager.MODE_ALLOWED) {
return;
}
// reset any pending volume command
synchronized (mSafeMediaVolumeState) {
mPendingVolumeCommand = null;
}
flags &= ~AudioManager.FLAG_FIXED_VOLUME;
if ((streamTypeAlias == AudioSystem.STREAM_MUSIC) &&
((device & mFixedVolumeDevices) != 0)) {
flags |= AudioManager.FLAG_FIXED_VOLUME;
// Always toggle between max safe volume and 0 for fixed volume devices where safe
// volume is enforced, and max and 0 for the others.
// This is simulated by stepping by the full allowed volume range
if (mSafeMediaVolumeState == SAFE_MEDIA_VOLUME_ACTIVE &&
(device & mSafeMediaVolumeDevices) != 0) {
step = safeMediaVolumeIndex(device);
} else {
step = streamState.getMaxIndex();
}
if (aliasIndex != 0) {
aliasIndex = step;
}
} else {
// 更改UI上的显示，增加/减少一格
// convert one UI step (+/-1) into a number of internal units on the stream alias
step = rescaleIndex(10, streamType, streamTypeAlias);
}
// 对与RINGER_MODES有关的声音组处理
// 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())) {
int ringerMode = getRingerModeInternal();
// do not vibrate if already in vibrate mode
if (ringerMode == AudioManager.RINGER_MODE_VIBRATE) {
flags &= ~AudioManager.FLAG_VIBRATE;
}
// Check if the ringer mode handles this adjustment. If it does we don't
// need to adjust the volume further.
final int result = checkForRingerModeChange(aliasIndex, direction, step,
streamState.mIsMuted, callingPackage, flags);
adjustVolume = (result & FLAG_ADJUST_VOLUME) != 0;
// If suppressing a volume adjustment in silent mode, display the UI hint
if ((result & AudioManager.FLAG_SHOW_SILENT_HINT) != 0) {
flags |= AudioManager.FLAG_SHOW_SILENT_HINT;
}
// If suppressing a volume down adjustment in vibrate mode, display the UI hint
if ((result & AudioManager.FLAG_SHOW_VIBRATE_HINT) != 0) {
flags |= AudioManager.FLAG_SHOW_VIBRATE_HINT;
}
}
// If the ringermode is suppressing media, prevent changes
if (!volumeAdjustmentAllowedByDnd(streamTypeAlias, flags)) {
adjustVolume = false;
}
int oldIndex = mStreamStates[streamType].getIndex(device);
if (adjustVolume && (direction != AudioManager.ADJUST_SAME)) {
mAudioHandler.removeMessages(MSG_UNMUTE_STREAM);
// 判断是否要更新蓝牙的音量
// Check if volume update should be send to AVRCP
if (streamTypeAlias == AudioSystem.STREAM_MUSIC &&
(device & AudioSystem.DEVICE_OUT_ALL_A2DP) != 0 &&
(flags & AudioManager.FLAG_BLUETOOTH_ABS_VOLUME) == 0) {
synchronized (mA2dpAvrcpLock) {
if (mA2dp != null && mAvrcpAbsVolSupported) {
mA2dp.adjustAvrcpAbsoluteVolume(direction);
}
}
}
if (isMuteAdjust) {
boolean state;
if (direction == AudioManager.ADJUST_TOGGLE_MUTE) {
state = !streamState.mIsMuted;
} else {
state = direction == AudioManager.ADJUST_MUTE;
}
if (streamTypeAlias == AudioSystem.STREAM_MUSIC) {
setSystemAudioMute(state);
}
for (int stream = 0; stream < mStreamStates.length; stream++) {
if (streamTypeAlias == mStreamVolumeAlias[stream]) {
if (!(readCameraSoundForced()
&& (mStreamStates[stream].getStreamType()
== AudioSystem.STREAM_SYSTEM_ENFORCED))) {
mStreamStates[stream].mute(state);
}
}
}
} else if ((direction == AudioManager.ADJUST_RAISE) &&
!checkSafeMediaVolume(streamTypeAlias, aliasIndex + step, device)) {
Log.e(TAG, "adjustStreamVolume() safe volume index = " + oldIndex);
mVolumeController.postDisplaySafeVolumeWarning(flags);
} else if (streamState.adjustIndex(direction * step, device, caller)
|| streamState.mIsMuted) {
// Post message to set system volume (it in turn will post a
// message to persist).
if (streamState.mIsMuted) {
// 静音的情况下先unmute设备
// Unmute the stream if it was previously muted
if (direction == AudioManager.ADJUST_RAISE) {
// unmute immediately for volume up
streamState.mute(false);
} else if (direction == AudioManager.ADJUST_LOWER) {
if (mIsSingleVolume) {
sendMsg(mAudioHandler, MSG_UNMUTE_STREAM, SENDMSG_QUEUE,
streamTypeAlias, flags, null, UNMUTE_STREAM_DELAY);
}
}
}
// 调整声音大小，并保存声音的数据
sendMsg(mAudioHandler,
MSG_SET_DEVICE_VOLUME,
SENDMSG_QUEUE,
device,
0,
streamState,
0);
}
// Check if volume update should be sent to Hdmi system audio.
int newIndex = mStreamStates[streamType].getIndex(device);
if (streamTypeAlias == AudioSystem.STREAM_MUSIC) {
setSystemAudioVolume(oldIndex, newIndex, getStreamMaxVolume(streamType), flags);
}
if (mHdmiManager != null) {
synchronized (mHdmiManager) {
// mHdmiCecSink true => mHdmiPlaybackClient != null
if (mHdmiCecSink &&
streamTypeAlias == AudioSystem.STREAM_MUSIC &&
oldIndex != newIndex) {
synchronized (mHdmiPlaybackClient) {
int keyCode = (direction == -1) ? KeyEvent.KEYCODE_VOLUME_DOWN :
KeyEvent.KEYCODE_VOLUME_UP;
final long ident = Binder.clearCallingIdentity();
try {
mHdmiPlaybackClient.sendKeyEvent(keyCode, true);
mHdmiPlaybackClient.sendKeyEvent(keyCode, false);
} finally {
Binder.restoreCallingIdentity(ident);
}
}
}
}
}
}
int index = mStreamStates[streamType].getIndex(device);
sendVolumeUpdate(streamType, oldIndex, index, flags); //更新UI显示
}
frameworksaseservicescorejavacomandroidserveraudioAudioService.java
private class AudioHandler extends Handler {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_SET_DEVICE_VOLUME:
setDeviceVolume((VolumeStreamState) msg.obj, msg.arg1);
break;
case MSG_SET_ALL_VOLUMES:
setAllVolumes((VolumeStreamState) msg.obj);
break;
case MSG_PERSIST_VOLUME:
persistVolume((VolumeStreamState) msg.obj, msg.arg1);
break;
case MSG_PERSIST_RINGER_MODE:
// note that the value persisted is the current ringer mode, not the
// value of ringer mode as of the time the request was made to persist
persistRingerMode(getRingerModeInternal());
break;
private void setDeviceVolume(VolumeStreamState streamState, int device) {
synchronized (VolumeStreamState.class) {
// Apply volume
streamState.applyDeviceVolume_syncVSS(device); // 将声音的数据写到底层
// Apply change to all streams using this one as alias
int numStreamTypes = AudioSystem.getNumStreamTypes();
for (int streamType = numStreamTypes - 1; streamType >= 0; streamType--) {
if (streamType != streamState.mStreamType &&
mStreamVolumeAlias[streamType] == streamState.mStreamType) {
// Make sure volume is also maxed out on A2DP device for aliased stream
// that may have a different device selected
int streamDevice = getDeviceForStream(streamType);
if ((device != streamDevice) && mAvrcpAbsVolSupported &&
((device & AudioSystem.DEVICE_OUT_ALL_A2DP) != 0)) {
mStreamStates[streamType].applyDeviceVolume_syncVSS(device);
}
mStreamStates[streamType].applyDeviceVolume_syncVSS(streamDevice);
}
}
}
// Post a persist volume msg
sendMsg(mAudioHandler,
MSG_PERSIST_VOLUME,
SENDMSG_QUEUE,
device,
0,
streamState,
PERSIST_DELAY);
}
private void persistVolume(VolumeStreamState streamState, int device) {
if (mUseFixedVolume) {
return;
}
if (mIsSingleVolume && (streamState.mStreamType != AudioSystem.STREAM_MUSIC)) {
return;
}
if (streamState.hasValidSettingsName()) {
// 将参数保存
System.putIntForUser(mContentResolver,
streamState.getSettingNameForDevice(device),
(streamState.getIndex(device) + 5)/ 10,
UserHandle.USER_CURRENT);
}
}