Out of necessity I designed active video splitter based on THS7314 video amplifier and  TS5A3159A analog switch. Input and outputs are properly terminated by 75ohm resistors and inputs and outputs are AC coupled. For better high frequency response, outputs are coupled with 330uF and 100nF ceramics. Internally it is powered from 3.3V, allowing to run from 5V input. Input channel switch is inverted by transistor to suit my use case.  All components are SMD. Prototype is assembled on CNC milled PCB. Power trough is jump-wired on the bottom side. For future I plan to split design to video switch and video amplifier. Switch will be placed in airplane and controlled via OpenLRS. OpenLRS allows to set pin as switch, instead of servo output, allowing to skip unnecessary MCU to decode servo signal. This prototype will be put in Groundstation where both funcions will be used (switch between live and playback). All components are available trough Farnell.

• 2 inputs switchable by TTL signal
• 4 independent outputs
• Properly terminated inputs and outputs
• AC coupled inputs and outputs
• High end video amplifier
• Solid state analog switch
• 4V to 15V input power

EDIT:

You can download design files here. But beware there is an error. Emitter of PNP transistor shall be connected to 3V3, not VCC.

videoampswitch