Audio without picture on Barco

[Richie May]

Hey guys,

This has been happening for a very long time. A random trailer or policy will play without picture for a show, but audio is fine. It's always been VERY intermittent and not often. The next show, it will be fine. Today, the same thing happened, except that it was the feature that had audio but no picture. After starting and stopping it didn't work, I rebooted the server (IMB). Still no good. I had to reboot the whole projector, then it was fine. Originally, when this issue started, 2 years ago, I thought it may be a corrupted file so I would delete it and ingest a new one. The funny thing is it only happens on the Barco projectors. It has never happened once on the Christies. We have 2 Barco DP4K-19B projectors with GDC SX3000 IMB's. We also have 2 Christie CP4220 projectors with GDC SX3000 IMB's. It happens on both Barco's. I've taken the cards out of both projectors already and cleaned the contacts. Any other thoughts?

[James Gardiner]

The fact it happens in two different machines would indicate a bug in either barco or GDC.

Are both on latest release software?

Any logs generated when this occurs on either proj or SMS?

What is barco and GDC saying about the problem?

[Richie May]

Oooops. How did I forget this part........This past December, I replaced one of the SX3000's that died in one of the Barco's with an SR1000. It didn't make the issue better or worse. I always keep the software up to date on everything here. Logs haven't shown anything and GDC and Barco have been no help. The ONLY common thing seems to be the Barco, as I changed one of the IMB's.

[Marco Giustini]

Interesting fault. Considering it’s a specific clip I’d blame the IMB as I don’t think the projector cares of a specific CPL.

still, you can try selecting a different macro to see if that by any chance fixes the video pipeline - but you’ll have to wait for the fault to show up.
I know the change in IMB points the finger at the projector but somehow I’d be tempted to blame the IMB here. Call it guts feeling ?

[Richie May]

That's a good troubleshooting idea. I will try it next time it happens. I'll also keep track of whether the issue happens with both IOP and SMPTE clips.

[Ioannis Syrogiannis]

I would as well check the framerate changes and -less likely- the audio.
I am not familiar with GDC, I never worked with one, only saw them at CinemaCon, but do they use internal black patterns?
Do you use them regularly between different framerates or/and aspect ratios?
My first suspect would be framerate, and subsequently, that may translate to SMPTE/Interop (since Interop should probably only be 24fps).

[Richie May]

We do use a mix of framerates (24, 25 &30). We don't put black in between. As far as changing ratios in a playlist, we use 1 ratio for the entire playlist. If the playlist is flat and a trailer is scope, we use the letterboxed trailers. Other way around for scope playlists. Maybe the Barco can't handle the framerate mix. As I said before, this has NEVER happened on the Christie's. As far as CPL standards goes, we also have a mix of IOP and SMPTE CPL's in every playlist. Again, maybe a Barco thing.

[Carsten Kurz]

I would try and analyse the frame rate changes. Are you familiar with the Barco macros? It could be worthwhile to reproduce the problem (black screen), then log into the projector with Communicator and view the current projector configuration and issue macro changes, then see if the image comes back. On our Barco S2 projector, we sometimes have a black screen issue, and only issuing full macro changes back and forth brings it back. Never happened mid-show, but, our usage profile for this projector is too specific to compare it to general cinema operations. I had it happen on me a few times when preparing the machine for operation, it worried the hell out of me initially, but now I know I can always revive it when it happens. I still don't know exactly why or when it happens.

[Richie May]

That would be good to do. I will have to wait till it happens next. It could be a day or a month. It's too inconsistent.

[Steve Guttag]

First, we are talking about normal S2 Barcos with the standard ICP module and not the ICP-D...correct?

Consider the video signal path in most any DCI projector, regardless of brand. The ICP is a 2x1 video switcher with one input being the IMB or SDI input and the other input being the DVI or other "alternative content" sources. Barco represents this in Communicator on their Diagnostics>Tests>Video Path page. So, what can interrupt the image?

1. The IMB isn't sending an image out. Why just Barco? It could be how the GDC software interacts when it is talking with a Barco projector and somehow they are not in the same state and one is waiting on the other for something to turn the image back on.
2. The IMB has the power to "blank" the ICP via command. This would show up in the logs, by the way, so it is worth looking at those. I discovered this when working with a Dolby DSS200/CAT745 system and the projector was running some DVI source content (like a preshow or DVD or something)...when rebooting the server, the CAT745 issued a "blank" command to the ICP and despite the CAT745 not being power cycled or even part of what was on screen, it issued a blank and then deblank command, internally. I would be worth adding an extra deblank with a 500msec or more delay to your Macros/Presets to see if this stops this. You could be in a situation where the commands in the Macros are in a timing such that the GDC IMB's deblank may be missed. So, issuing a delayed deblank fixes the issue. Try setting up a dedicated preset that just has the deblank in it so you can, if the problem arises again, you can press the preset to see if it is a blanking issue.
3. Never rule out the signal backplane on a Barco S2 projector. They are the cause of much grief. They can cause image issues, lens issues, sensor issues, they can certainly cause communication issues. Everything the IMB says to the ICP or the CCB goes through that thing and those connectors. If you ever find yourself "reseating" (mostly the ICP) to cure issues...that signal backplane is on the road to needing a replacement. Certainly, DeOxit, is worth a try on the ICP, IMB and CCB (All three play into a no-image).
4. The very first troubleshooting aid on any DLP projector for image is to put up a test pattern. That is generated on the ICP and it cuts the signal in half (before the ICP...the server, after the ICP). If the test pattern comes up fine, the ICP can output. If clearing the test pattern brings up the IMB's image, you have a lot of your answer (the IMB was outputting an image and likely the ICP was blanked), if the image is not restored, you have more digging but you know it is either the IMB not outputting an image, the ICP is looking at the wrong input, the ICP isn't locking onto the IMB's signal/clock. The Video Path page can aid in this as you can see what the ICP thinks the resolution and frame rate is and if there is no sync...that points to the IMB or signal backplane. It could also show if the ICP is on the wrong input but I haven't seen that.
5. Make a preset/macro that just toggles the input between DVI and IMB...that will force the ICP to resync with the IMB.
6. What sort of PCF file are you using? I try to avoid any of the "autos" and use specific ones. Since you have 4K projectors, I'd use the 4K PCFs (DC4K_DCDM_XYZ_<185 or 239 as appropriate for the container>. Using "auto" forces the ICP to decide what the image is coming in...since you have a dedicated flat or scope preset, why present that as a choice? It is just one more chance for the ICP to choose poorly. You should be able to configure your server to always output 4K so it is doing any 2K->4K scaling and it should put the subtitles/captions in the right place.

[Richie May]

Yeah, it's just a standard S2 projector with ICP. Only one Barco macro is sent when a playlist starts and the issue ONLY occurs many clips into the playlist. There are no macros sent between clips. I just made a "deblank only" macro for the next time it happens. I will see if that fixes it and figure it out from there.

I agree with the backplane thought also. I did Deoxit the card contacts as well as the backplane connector contacts about a month ago. Deoxit is awesome!!

Also, I don't use any of the auto PCF files. I do use the specific ones.

[Steve Guttag]

On a Barco, PCFs are the way to go (in truth, I like them for Christie and NEC too). All PCFs are doing is combining most of the individual ones together. What is the advantage of having a separate input, colorspace...etc. files? If done in a PCF...the timing is always right for loading those files.

I didn't pick up that you said this was happening mid show...if that is the case...this is becoming more of an IMB/ICP sync issue and/or communication when a frame rate changes. I would definitely set up a macro for toggling the ICP between inputs too.

[Jim Cassedy]

I once had an odd problem on a SONY serverthingy, where if I played an INTEROP clip with subtitles, directly after a SMPTE
clip, the subtitles wouldn't appear on screen. But as long as I put a short INTEROP black slug (even just 2sec) between the
clips, the subtitles ran fine. This only seemed to happen in one large screen auditorium, which used dual SRX-515b projs
for both 2D & 3D. On the single-projector sonysystemserverthingys, it wasn't an issue. (And this situation popped up so
rarely, that it wasn't worth spending alotta time looking into, especially since I had an easy work-around)

[Richie May]

So, it FINALLY happened when I was on today. I had already made the following Barco macros to try when the issue occurs.....a Deblank macro, a "push" IMB macro, and a toggle to DVI then back to IMB macro. None of them cleared the problem, which is no image. Audio is always okay. I just went right to a hard reset, and all was fine. I checked the Barco projector log and ICP log. Nothing showed up at all except a "Self Test Error" 30 seconds or so after power up. The first show started okay. The policy, ads and trailers ran fine until the feature, which started black with audio. One thing to note is that this is theater 4 with the Barco that had the problem today. The other day was theater 1 with the Barco. One common thing is it was the same movie, which is SMPTE. This specific movie, "Hilma" has been playing with no issues in the other 2 houses, which have Christie projectors. The other weird thing is last week it went black during the Feature Pres snipe and stayed black when the feature started. Not sure if the same occurred today.

[Carsten Kurz]

Did the screen go black EXACTLY when the main feature started, do you know this?