DO NOT MERGE Bluetooth: Restrict gain for Absolute volume case am: 9ef7634fa9 (2fb16b06) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/audio/AudioService.java

+23 −2

Original line number	Diff line number	Diff line
		@@ -3737,8 +3737,29 @@ public class AudioService extends IAudioService.Stub {
		int index;
		if (mIsMuted) {
		index = 0;
		} else if (((device & AudioSystem.DEVICE_OUT_ALL_A2DP) != 0 && mAvrcpAbsVolSupported)
		\|\| ((device & mFullVolumeDevices) != 0)) {
		} else if ((device & AudioSystem.DEVICE_OUT_ALL_A2DP) != 0 && mAvrcpAbsVolSupported) {
		/* Special handling for Bluetooth Absolute Volume scenario
		* If we send full audio gain, some accessories are too loud even at its lowest
		* volume. We are not able to enumerate all such accessories, so here is the
		* workaround from phone side.
		* For the lowest volume steps 1 and 2, restrict audio gain to 50% and 75%.
		* For volume step 0, set audio gain to 0 as some accessories won't mute on their end.
		*/
		int i = (getIndex(device) + 5)/10;
		if (i == 0) {
		// 0% for volume 0
		index = 0;
		} else if (i == 1) {
		// 50% for volume 1
		index = (int)(mIndexMax * 0.5) /10;
		} else if (i == 2) {
		// 75% for volume 2
		index = (int)(mIndexMax * 0.75) /10;
		} else {
		// otherwise, full gain
		index = (mIndexMax + 5)/10;
		}
		} else if ((device & mFullVolumeDevices) != 0) {
		index = (mIndexMax + 5)/10;
		} else {
		index = (getIndex(device) + 5)/10;