Editing Media key (section)

===USB===
In the [[USB]] HID ("Human Interface Device") standard, while most key codes are in the "Keyboard/Keypad" usage page (0x07), most most media keys are in "Consumer" usage page (0x0C). System control keys (Power, Sleep, Wake) are in the "Generic Desktop" usage page (0x01).

The "Consumer Usage Page" has also codes for ''linear'' relative values for volume control, bass and treble. While it may appear to be analogue, the knob or roller is usually connected to a [[rotary encoder]].
The values are relative to the volume level set by the user in the operating system and application software. If the controls had absolute values, they would have needed to be motorized and under computer control, which is something that the USB HID specification does not support.

The controls in each Usage Page are transmitted in a separate packet. Therefore, media keys may have separate [[rollover]] characteristics from regular keys.