Media key

A Media key is a key with a special purpose for a specific type of applications or operating system functions. Normally, these functions are concerned with media playback, but the term has been used for other functions as well.

A media key can be a dedicated key, or another key can act like a media key in conjunction with the Fn key. Some USB keyboards contain also a knob or roller, usually for volume control.

Gallery

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  Logitech Y-RJ20 cordless multimedia keyboard

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  Audio control panel on the Y-RJ20

Function-key mappings

On many keyboards, media keys are dedicated keys with no other function.

On some keyboard, media key functions are on Function keys when holding a Fn key.

On the Apple aluminium keyboards with MacOS, the default behaviour is the reverse: numbered function keys are available on the media keys when holding down Fn. This behaviour can be switched in MacOS.

On some PC keyboards from Microsoft, the Fn "key" is not a modifier key but a toggle switch.

Keyboard	Fn-F1	Fn-F2	Fn-F3	Fn-F4	Fn-F5	Fn-F6	Fn-F7	Fn-F8	Fn-F9	Fn-F10	Fn-F11	Fn-F12	Other
Apple Aluminium Keyboard A1243	Brightness Down	Brightness Up	Exposé / Mission Control	Dashboard / Launchpad			Rewind (Previous track)	Play/Pause	Fast Forward (Next track)	Mute	Volume Down	Volume Up	Eject, F13..F19
Arachnid Recore					Play/Pause	Stop	Previous track	Next track	Media player	Mute	Volume Down	Volume Up
CMStorm QuickFire Rapid					Play/Pause	Stop	Previous track	Next track		Mute	Volume Down	Volume Up
Ducky G2Pro/Shine	Mute	Volume Down	Volume Up	Play/Pause	Stop	Previous track	Next track						Calculator Computer Email Home/Browser
iOne (Func KB-460, QPad MK-50 etc.)	Mute	Volume Down	Volume Up	Play/Pause	Previous track	Next track
KeyCool 84, KeyCool 87	Computer	Home/Browser	Calculator	Media Player	Previous Track	Next Track	Play/Pause	Stop	Mute	Volume Down	Volume Up	(Windows lock)
KeyCool 108	Computer	Home/Browser	Mail	Media Player	Previous Track	Next Track	Play/Pause	Stop	Mute	Volume Down	Volume Up	(Windows lock)	Lock Sleep, Calculator, ... ?
Matias Quiet Pro Mini (PC)	Rewind (Previous track)	Forward (Next track)											Play/Pause on Esc, Mute Volume Up/Down on Fn-Arrow key
Max Keyboard Blackbird	Mute	Volume Down	Volume Up	Play/Pause	Previous Track	Next Track
Mionix Zibal 60	Mute	Volume Down	Volume Up		Play/Pause	Stop	Previous Track	Next Track
Noppoo Lolita	My Computer	Web Browser	Calculator	Media Player	Previous Track	Next Track	Play/Pause	(NKRO)	Mute	Volume Down	Volume Up
Noppoo Lolita Spyder	Previous Track	Play/Pause	Next Track	Stop	Mute	Volume Down	Volume Up
Plum 96	Mute	Volume Down	Volume Up	Play/Pause	Previous Track	Next Track	Home/Browser	My computer		(Debounce dec)	(Debounce inc)
SteelSeries 6GV2	Mute	Volume Down	Volume Up	Play/Pause	Previous Track	Next Track

Protocol

Media keys usually emit distinct codes to the host.

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.

PS/2

For PS/2, Microsoft has standardized media key scancodes for Windows.

Some vendors have used their own codes that have been activated first after having received a "magic" code from the host's keyboard driver.