Video hub: input to multiple outputs

Do al of the BlackMagic videohuds support the routing of the same input to multiple outputs? We are specially interested in the Micro, Smart or Compact video hub.

They are matrix routers so yes.

Thx!

I do have 2 more questions... They may seem obvious, but I just wanna be sure before buying...

- can you route 2 or more inputs to the same output (not for using simultaneously of course. But for example we have 4 players we want to connect to the same monitor. We don't use the players at the same time.

- in for example the compact hub... can you use the 40 inputs at the same time? Or is there a maximum of routes that can be handled by the router.

1. An output can only have one input routed to it at the same time, but you are of course free to route another signal to the output when you need.

2. Yes, you can use the full router capacity simultaneously. 40 inputs to 40 different outputs, or one input to 40 outputs, or anything in between.

- can you route 2 or more inputs to the same output (not for using simultaneously of course. But for example we have 4 players we want to connect to the same monitor. We don't use the players at the same time.

Any given output may be switched to any input without restriction.

...for example the compact hub... can you use the 40 inputs at the same time? Or is there a maximum of routes that can be handled by the router.

There is no restriction; if you want, you can certainly send input N to every output.

Perhaps a brief explanation of what is inside the routers would help.

Every incoming signal hits an input stage that includes equalization, level correction and reclocking in order to stabilize the signal, and effectively restore it to its original condition. They then typically hit buffer amplifiers that allows the signals to feed the crosspoint switches. The crosspoint matrix is a whole lot of video switches -- in a 40x40 router there would be 1,600 of them -- and each switch can tie a given input signal to a given output. For a particular output, only one switch is active at a time: the one for the source you want to see on that output. Finally, each crosspoint output hits a driver amplifier that sends the signal down your coaxial cable to whatever its destination might be -- a monitor, a recorder, or whatever. Without going into a huge amount of technical detail, the job of the buffer amplifiers ahead of the crosspoints is to make sure there's enough drive for a given input signal to feed any number of outputs simultaneously; part of the job of the output drivers that follow the crosspoints is to present almost no load to the crosspoint. To put it another way, while the outside world of coax interconnection is at a rather low impedance (75 ohms), the crosspoint switching is done at rather high impedance.

The bottom line is, on smaller routers like these you don't need to worry about blocking -- that is, hitting a limit to how many unique destinations may be fed one or more signals. As a practical matter, blocking is only an issue on really enormous routing systems that are in reality a number of smaller routers cascaded together with tie lines linking the routers, and special routing software to steer the signals where they need to go... we're talking about the sort of thing you might find at a network facility like ABC New York or NBC Burbank.

Regards,

-- Jeff

Thx Jef! Now I understand