Status: This feature is implemented in Mixxx v1.11.
Allow both players to be controlled via a single turntable with vinyl control. At least one commercial DJ application offers this feature, and Mixxx would be more competitive with it.
Single deck mode works by setting both decks to use the same audio input. The DJ then alternates activating vinyl control on one deck, then the other. This feature is designed so that when deck control is disabled, playback continues without interruption.
It is theoretically possible to mess up and activate vinyl control for both players, and thus have vinyl input affect two decks at once, but in practice it's easy to turn off control on one deck, and on on the other.
It is also possible to forget that you've changed the pitch on the turntable, and reenable control on an old deck. The playback speed suddenly changes, with disastrous DJ-fail results. Just don't do that.
With the new vinyl code, there is a special vinyl status light that can indicate much important state information. A solid green indicates “active,” for instance. With single deck mode, the DJ looks for which deck has an active indicator lit. The indicators should be large and prominent, making it easy to see at a glance which deck is active.
Basically I rewrote a lot of stuff.
If you're interested in helping to code this feature, sign up your name below: