separate instances for control and display (connected via network)

[mathisdt]

In some installations it is difficult to run the display cables from the computer at the control desk (in the back of the room) to the displays and projectors (at the ceiling in the front of the room). It would be easier if the connection could work via WiFi network. Also, at least on Windows, some graphics cards (or their respective drivers) have problems displaying everything correctly, so a separate SDB instance running under Linux would make sense.

To make this possible, it would be necessary to add special operation modes and some configuration for it ( ⚠️ 🛑 maybe this doesn't solve the problem - presentations apart from SDB are not possible using this setup):

• split mode, control part: the SDB doesn't use the configured display settings at all (especially it doesn't open any windows to display the lyrics) but it communicates over network what should be displayed, and how (including scrolling etc.)
• split mode, display part: the SDB doesn't show the control window but only one or two lyrics windows - the content is received via network
• configuration (via command line parameter or config file entry) for split mode, control part: under which hosts / ports / prefixes are the displays reachable? and with which authentication?
• configuration (via command line parameter or config file entry) for split mode, display part: on which port (and with which prefix) should the SDB listen for commands? and which authentication is used?

The listening part should provide an authenticated REST-like API so things can be scripted (even without having a SDB controlling what's displayed). The authentication can be a pre-shared token, there seems to be no need for something elaborate like OAuth2.