Affordable way to keep a projector synced

In the way that a cheap EDID box can keep a computer output happy even when unplugging cables (ie makes the computer think an output is still present), is there an affordable way to do the same on the output side - keeping a projector synced even when switching sources?

A Barco Image Pro is not considered affordable :)

it’s called DVI detective or DVI doctor…

That only helps on the source side

If you change source the projector will re sync

If you switch between two sources that are not synced there is no way around a resync on projector side. You can try to disable popups, set projector to show black instead of blue and - on some projectors - you can lock to a certain input, resolution and refresh rate. This usually speeds up resync alot since it does not start hunting on each signal loss. But still there will be a second or two black on screen if you change source.

The only way to avoid resync is to a device that has an internal framebuffer, aka TBC in analog SD world:

The most affordable device I know doing this for resolutions higher than SD and not limited to 1080i/p is spark´s d‑fuser. All TBC come with at least one frame delay penalty and this specific comes with nice pricetag of £825…

Maybe there is other, cheaper devices I do not know of… blackmagic maybe?

edit: this is the device spark controlls with his embedded box. It should be alot cheaper than the whole pack:

spark is actually quite doggy
mine burned down a capture card twice more expensive then it is…

If you could work with Broadcast resolutions, you could go for a HDMI mixer and go that route.

I guess you could go more into Pro AV stuff like this: perhaps @msberger have some insights into what works and what doesn’t

has been discussed years ago
it there some update?

I’ve ended up using one of the tv one units. I was going in that direction already, but given all I really need is the ability to blank / unblank my video output I was hoping to find something simpler

I get what you’re saying about the framebuffer.

The other downside of the tvone is the latency. not massive but enough to bother me…

If you just want to blank out, then use a second machine to feed the projector, I would try to turn signal down to black/very dark grey in V4 and then switch with a simple & cheap non-buffered HDMI or VGA switch to second machine. If both machines output the exact same resolution and refresh rate you might come away with a small glitch instead of a few seconds black. Depends alot on how your projector likes that. I remember having problems on some to detect pure black in such a case, at least when using oldskool VGA. Thus the dark grey.

About delay: delay sucks, but taking into account that sound travels only around 330 meter per second, a viewer that is 20 meters away from speaker already hears the sound ~60 ms delayed. One frame delay on 60 FPS is 16 ms, so if its about lipsync/audioreactive stuff in larger places this is a non issue.

If none of the above works for you and you don´t mind lugging around desktops you can use a Nvidia Quadro with genlock input to sync second source to first.
Would also work with older Quadro versions I guess.

@antokhio: Do you know what was to cause of burning down capture card? Internal failure sending out high voltage on signal lines? Or simply voltage difference in ground (aka happy little “sparks” when shielding touches plug…)

hey Meir, i have no clue, was trying to record some live video, then when i turned everything on the videocapture signal became green and jumpy, then it’s just went off… So now i can’t connect HDMI or Digital DVI to the capture card and spark, only VGA thru DVI on VGA…

i think it’s possible to use one of this