Production Switchers

Hey all!

So we've run into an interesting situation here at a show. In a nutshell, when we dissolve up from black, the LED we are outputting to exhibits sync loss symptoms (looks like every tile is rebooting all at once). We've narrowed down the issue to something between the switcher and the way either the LED processor or the image pro II in front of it handles the signal from the switcher when it goes from source to black. We know this because we've fed the same signal from the switcher through a Vista Spyder and no issue.

This is where it gets fun. When the ext source is frame synced no issue. Also, there is no issue when the source is internally generated such as a media store, BG, or DVE.

Now I don't necessarily think this is a problem with the switcher because this is the first venue we've even been to who's equipment has reacted in this way.

Any thoughts?

Iain

Setup

INT Sync from Switcher

4 Cameras receiving sync from switcher

Feeding to Spyder going to LED NO issues

Aux 1 through a router to venue LED WITH issues

Hi Iain, Definitely sounds like a sync issue. You said "When the ext source is frame synced no issue" and internal sources are ok. Which sounds like a sync timing issue with the reference to the cameras maybe. Do you see any errors at all on those camera sources in the MultiViewers? If there were an issue with the reference that we are sending to the camera (i.e. wrong standard or H & V timing settings) I would expect that to manifest itself as an error at the input to the switcher.

What happens if you feed a camera directly to the wall that is locked to the switcher? If it shows sync loss, try removing genlock from it. Let us know what you find.

Nigel

#Carbonite

I have this exact issue will all of our Visions/Image Pros/LED walls. I was able to "solve" it by turning off Auto Acquire in the Image Pro. There is some "difference" between internal sources (black, backgrounds, stills) and external sources (cameras, VTRs) and the Image Pro is hiccuping. My Tektronix scope tells me color black from the Vision is 8 bit and everything else is 10bit but Im not convinced that is the cause.

I have tried to measure the timing of my external sources relative to the switcher but I just can't come up with a way to do it. Other switcher brands Ive worked on have a timing display in the menus that graphically shows these timing relationships. Without that display I have been stumped as to how to do it.

Or it could be something else different in the HDSDI bit stream. I don't know. So turning off Auto Acquire on the Image Pro is what I do.

#Carbonite

All good ideas. Unfortunately, we didn't have enough time at the venue to troubleshoot the problem. We just kinda stepped around it so the show would work. On second thought I noticed that when one dissolves to black from a Media Store, i'm able to monitor 16 channels of embedded audio (even though there is no sound, the stream is still there) and then once you dissolve to black, no more audio streams. Then when I dissolve up to a camera, the audio stream pops up really quick then disappears, but only after I have dissolved to black from a Media store. I am able to reproduce that over and over. I'm thinking that mixed with the auto-acquire that I'm assuming the Image Pro was set to is what may have been causing the problem.

It's a weird issue and I wish I had more time at that venue to poke around, alas, maybe we'll see it again someday and be better prepared to deal with it.

Oh and to answer your questions Nigel, I first thought it could be a sync issue, however, we had no issues system wide with sync except for their separate LED displays/processor. No drifting sources, no untimed dissolves, or anything else indicative of a vanilla sync issue.

Thanks for the input.

Cheers

Iain

#Carbonite

Here's my two cents. I have a reproducable and similar issue with my Carbonite outputting to a couple Christie Digital HD20k-J projectors.

Switching from computer source to an internal source, whether by fade or cut would cause a momentary sync loss.

The following workaround solved my problem: Strip out the ancillary content from the console. N strip was sufficient. This is only a minor issue for my setup since we reembed the "show audio" downstream of the switcher anyways.

From the setup manual:

To Strip or Pass Ancillary Data

1. Press MENU > SYSTEM > NEXT.

2. Use the Anclry knob to select whether ancillary data is stripped or passed.

"¢ N Strp "” ancillary data is stripped

"¢ N Pass "” ancillary data is passed unmodified

"¢ L Strp "” ancillary data and some lines of active video are replaced with black

"¢ L Pass "” ancillary data and some lines of active video are passed unmodified

#Carbonite