Headphone Amp Control

This app is now open sourced and is available at:
https://github.com/EternalMelody/HeadphoneAmpControl

Disclaimer: I am not responsible for any damage this app may cause.

This app allows the user to handily change Headphone Amplifier Levels. Root access is required for file permission changes to the following files:
-"/sys/class/misc/wolfson_control/headphone_left"
-"/sys/class/misc/wolfson_control/headphone_right"

Two launchers can be found in the app drawer. One launches the Control app, another launches an overlay dialog for quick amplification level changes.

App Guide:
-Balance L/R toggle: Toggles amplification level balance between the left and right channels. When checked, disables the right channel seekbar and copies the left channel amplification level value to the right channel.
-Main seekbars: Current amplification level values. The top one is left channel's, bottom one is right channel's. The minimum and maximum values are defined by "Min level" and "Max level".

Control App Guide:
-Min level seekbar: Minimum amplification level that is settable by the main seekbars. Cannot be higher than safety level or max level.
-Max level seekbar: Maximum amplification level that is settable by the main seekbars. Cannot be lower than safety level or min level.
-Toggle service (notification bar shortcut): Enables notification shortcut. Must be checked to enable safety level. Notification only appears when headset is currently plugged in.
-Toggle volume button hack: Automatically sets checked volume type to almost max. The volume buttons can then be used to directly adjust amp levels, depending on context. The seekbar determines amp level jump.
-Hack music volume: Enables volume button hack for music, media, video, and games volume
-Hack voice call volume: Enables volume button hack for voice call volume
-Hack ring volume: Enables volume button hack for call ringtone volume
-Safety level: When headset is plugged in the first time, the current amplification level is compared with the safety level. If current level is higher than the safety level, then the current level is lowered to the safety level.

Has only been tested on Samsung Galaxy Note II

Development made possible by help of:
-AndreiLux