Auto Demo Recording

JK2MV 1.2 and later provide commands and cvars to make recording demos easier (thanks to @entdark).

Go to Main Menu -> Setup -> JK2MV and set "Auto Demo" to "On". This will make JK2MV continuously record to demos/LastDemo/LastDemo_recording file.

Bind a key of your choice in "Save Demo Key" field. Pressing it will store currently recording demo with unique filename on map restart or when you exit the game. Currently there is no way to finish demo when you want to, you can use /stoprecord to discard current demo and start a new one. Pressing "Save Demo Key" will also add current in-game time to the demo time to the demo name so you can press it multiple times to mark interesting moments in your demo. For example:

In a CTF game on ctf_bespin I pressed "Save Demo Key" to at 00:55 and 02:59 to store my flag runs. At 13:37 I scored an epic air rocket so I hit the bind again. When the game ended at 15 minute mark I had following demo file containing whole 15 minute game: demos/LastDemo/ctf_bespin_0055_0259_1337.dm_16.

Bind a key of your choice in "Save Last Demo Key" field or use saveLastDemo command. It will save a single previous demo in case you forgot to mark it with "Save Demo Key"

You can customize demo name by changing cl_autoDemoFormat cvar. Read about it on the Cvars page.