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Eric Hansen
problem getting stable video out of VideoHub
on Dec 19, 2009 at 9:55:07 pm

hey all

i also sent this to BMD Support. i'm currently using version 4.2 on a Studio VideoHub:

a few things:

1. i've hooked up a AJA Gen10 sync to inputs 13 and 14. Input 13 is a 23.98psf HD signal and Input 14 is a 29.97 SD signal. when i try to select this input on my edit systems as their sync (using the Monitoring output set), they don't recognize any signal at all.

2. when running an SRW5500 deck for tape capture in Final Cut, the edit systems can't seem to lock on to its video. the deck plays back fine (on its built in preview monitor) and locks to the Gen10 on its Sync In (not going through VideoHub). but the edit systems, whether they are trying to lock sync to the video from the SRW5500, or lock sync to the sync signal cannot.

if i unplug the SDI cables from the VideoHub, and run the deck straight to the edit system using a female BNC to female BNC, the edit system can lock to the video just fine, with or without the separate sync input.

i have tried running both HD and SD sync to the Ref In on the VideoHub, and gone without. but i can't seem to get stable video out of the VideoHub.

thanks

e

Eric Hansen - The Audio Visual Plumber - http://www.avplumber.com


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maurice jansen
Re: problem getting stable video out of VideoHub
on Dec 19, 2009 at 10:16:02 pm

hi eric

you are trying to get analog syncpulses through a SDI router. i'm sorry but your system setup will never work.
do what bob already suggested quite alot buy a patchbay buy 2 cheap ass VDA's one for trilevel one for BB. normalize the patchbay to give al your decks BB and make trilevel patchable.
and bring all the SDI or HD-SDI output's to the videohub.

greet
Maurice





People saying they don't make mistake's often make nothing at all!


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Eric Hansen
Re: problem getting stable video out of VideoHub
on Dec 19, 2009 at 10:30:19 pm

thanks Maurice

that's too bad that the VideoHub can't route Sync signals. i read Bob suggesting that in another post, but the post must be old and no longer relevant.

either way, i still can't get stable video out of the VideoHub. as i stated in number 2, Final Cut cannot lock onto the incoming HD-SDI feed from the VideoHub when trying to capture footage from our SRW5500. i've tried this on 2 different edit systems. the 5500 gets its sync directly from the Gen10, and i ran another cable from the Gen10 to the edit system. whether i give the edit system reference or not, it cannot lock onto the video signal coming from the VideoHub. in the AJA ControlPanel it goes between blue and red constantly and the image in the log and capture window flickers. if i pull the SDI cables out of the router and connect them together with a coupler (5500 going directly to edit system over the house HD-SDI cabling), the video is fine. that's why i think theres an issue with the router.

e

Eric Hansen - The Audio Visual Plumber - http://www.avplumber.com


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Bob Zelin
Re: problem getting stable video out of VideoHub
on Dec 19, 2009 at 10:58:01 pm

Eric -
what you are observing, is that you can't live life in a complex facility without a scope. And don't you DARE tell me that you can't afford one, with a client that owns a SRW5500.

As Maurice just told you, ANY SD-SDI or HD-SDI router handles these signals, and not tri level sync, or analog video (NTSC composite black is an NTSC analog video signal). So it's not just Blackmagic - you could own a Pesa, or Leitch, or Miranda, or Evertz, or GVG - NO ONE has a HD-SDI router that can pass an analog video signal. So that's the end of that story.

As for "the picture is still unstable" - what the hell does that mean ? I install Blackmagic routers all the time now, and there is NEVER a problem. I am not questioning that you are having a problem, but be it ANALOG or SD-SDI or HD-SDI - without a HD scope, you cannot analyze or determine ANY problems (gee, it's not working - how come). Blackmagic, by a miracle of God, had released the Blackmagic Ultrascope - a product that is $10,000 cheaper than anything else on the market, to allow you to observe the HD-SDI signals coming out of your router (or anything else). If you intend to work in hi end, complex HD-SDI facilities, you MUST have an HD scope - how the @#$% can your client deliver a Sony HDCam SR tape without a scope to check everything anyway ? No one owns a SRW VTR to make corporate videos - it's got to be for network delivery (I assume). Stick a HD scope on the output of your VTR, and then on the output of your router, and you will quickly determine your problem.

To build a cheap Ultrascope system, I recommend the Ultrascope
$660 street price), a bare bones HP Z400 (about $900 with no graphics card) and an ATI 4670 (about 80 bucks). Now, you can properly diagnose your problem. If I was standing there, I could not determine what the problem was without a scope. I could not diagnose an analog Beta system without my Tektronix WFM90 waveform monitor, and I certainly could not do an HD system troubleshooting (with issues like you are having) without a scope.

Bob Zelin




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Eric Hansen
Re: problem getting stable video out of VideoHub
on Dec 20, 2009 at 12:39:55 am

Bob said: "NO ONE has a HD-SDI router that can pass an analog video signal. So that's the end of that story."

i didn't know that the tri-level sync put out an analog signal. i guess that shows how much i know about sync. this facility didnt even own one and were a bit surprised when i said they needed one. yes the SRW5500 is for broadcast delivery. its also to playback SR tapes that are shot on their Sony 1500 (i'm not sure of the exact model, but it's a derivative of the F23) that's housed in a Cineflex mount. so yes, some heavy iron around here. but these guys are fairly new to broadcast delivery. they have previously only made movies for independent release, or done contract shoots, working out of the owners house. a very small operation. this is a brand new post facility with a staff that's relatively new to broadcast post. Blackmagic's scope would be a great addition. right now we have the 24" FSI monitor. do you know if Blackmagic added error logging to their Ultrascope yet?

"the picture is still unstable" - sorry for the lack of description. sometimes its hard to put visuals into words. the best i can describe it is what an image would look like if there was no reference for the deck or for the Kona. the lower half of the image will go from image to green and back to image. the whole image tears. it looks like its skipping frames. this is all in Final Cut and not at the deck. the deck's built-in monitor is clean and the deck is locked to sync. i'm not at the facility now, otherwise i would capture a short clip and post a link. along with this, the SDI input on the AJA ControlPanel goes from blue to red to blue, even if the Ref In is locked to the Gen10. this only happens when the video is running through the VIdeoHub. i thought there might be an issue with the installed cables. so i pulled the SDI cables for the SRW and the Edit system and connected them with a coupler, and the Kona/FCP was able to lock onto the signal.

is there a way to tell that the VideoHub is getting a signal through its Ref In? it looks like there's a light behind the BNC, but it doesn't change as i attach the sync. i think it might just be the power light shining through the gap in the housing around the BNC. the manual says it can handle SD or HD sync from either a blackburst or a tri-level sync. so i've tried 29.97 SD, 29.97 HD and 23.98 HD. the footage here is primarily 23.98psf. i also tried to reflash the firmware on the VideoHub.

i know how you feel Bob. when the AE called me describing the problem i told him it was impossible. but when i drove over there, sure enough. the Hub is still new. this is the first time they have attempted captures though it. up until now, all captures were to a direct attached system to the SRW. i'm thinking if its not user error, then it's possible its a bad unit.

i will post a video clip on Monday

btw, for reference distribution, are you talking about something like this?: http://www.comprehensiveinc.com/distribution-amplifiers/7707-comprehensive-...

e

Eric Hansen - The Audio Visual Plumber - http://www.avplumber.com


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maurice jansen
Re: problem getting stable video out of VideoHub
on Dec 20, 2009 at 10:38:03 am

well

on the first place what do you expect to happen when you want to lock a video router? the only thing that can happen is that you can cleanly switch source's that are locked, properly timed and from the same signal type. (it does not lock input signals to ref)
which is not a real must in a post-only facility. so IMO don't worry about the REFinput of the hub.
how big is the facility what kind of cable run's in meters do you have??
and more important what kind of cable is used?
have you tried a SD-SDI signal yet?

i have the strong feel that you have a DOA (death on arrival)

without measurement it's hard to find problems. the ultrascope is a nice scope for measuring the incapsulated signal like video/audio levels and is a real breakthrough and i guess it's nice to give these to the editors. but it still (maybe there is more to come) cannot measure problems on the physical layer.(which you are experiencing) so for a engineer it is actually not enough. if i must invest with a small budget in measurement i would use the
http://www.phabrix.com/phabrix-sxe-eye-and-jitter-767-0.html

greet
Maurice


People saying they don't make mistake's often make nothing at all!


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Bob Zelin
Re: problem getting stable video out of VideoHub
on Dec 20, 2009 at 4:52:08 pm

this facility didnt even own one and were a bit surprised when i said they needed one. yes the SRW5500 is for broadcast delivery.

REPLY - amazing to me that someone uses and needs an SRW, and has no concept of reference video. Newbies never even see an SRW



right now we have the 24" FSI monitor. do you know if Blackmagic added error logging to their Ultrascope yet?

REPLY - the 24" FSI has a very nice scope function that you can use to observe what you need for this problem. The Ultrascope doesn't offer error logging, and I can only hope that it's on Blackmagic's list to offer this in the future (and they should charge for it).



"the picture is still unstable" - sorry for the lack of description. sometimes its hard to put visuals into words.

REPLY - play the SRW into the FSI with the scope on. Bypass the router. Is it stable. Is the signal stable on the waveform function ? Now simply plug the same HD-SDI signal into the router (crosspoint 1 for example) and look at the output of the router (output 1) on the FSI, using the scope function. Disconnect the reference to the router (you don't need it). Is the signal unstable now ? I assume that these are SHORT runs, and you are using the proper double shielded coax for HD-SDI, and not old video cable, that could cause jitter. Long runs of 100' with regular RG59 cable will cause jitter, and you will never pass a HD signal with this. (short runs - 10 - 20' you can get away with).




the best i can describe it is what an image would look like if there was no reference for the deck or for the Kona. the lower half of the image will go from image to green and back to image.

REPLY - so how does it look whne you go straight into the FSI, and bypass the router ?


it looks like its skipping frames. this is all in Final Cut and not at the deck.

REPLY - how is the tape shot - 23.98, or 59.94. Is the SRW5500 reference setup correctly, and for the right frame rate. This VTR is insanely complicated to setup. And of course, FCP settings must match the tape soure (using your EASY SETUP functions in FCP).




this only happens when the video is running through the VIdeoHub. i thought there might be an issue with the installed cables. so i pulled the SDI cables for the SRW and the Edit system and connected them with a coupler, and the Kona/FCP was able to lock onto the signal.

REPLY - hey, you could have a bad router - its certainly possible, but it is so unlikely. But if everything is clean until you introduce the router in the path - it may be the router. Get rid of the ref signal going into the router please.


is there a way to tell that the VideoHub is getting a signal through its Ref In?

REPLY - disconnect it. You do not need it. You are not trying to do clean switching between crosspoints on the router.




i know how you feel Bob. when the AE called me describing the problem i told him it was impossible. but when i drove over there, sure enough. the Hub is still new. this is the first time they have attempted captures though it. up until now, all captures were to a direct attached system to the SRW. i'm thinking if its not user error, then it's possible its a bad unit.

REPLY - I hope that they have any other HD source so you can try to confirm if it's the router - WAIT they do - pass the AJA Kona HD-SDI output (bring up bars in the control panel), and pass that thru the router, into the FSI. This will tell you if your router is ok.




btw, for reference distribution, are you talking about something like this?:

In the AVID days for cheapie black DA's, I used the Sigma VDA26, but now that Sigma has fallen apart as a company, I use the cheapo Kramer VM80V, which is a 1x8 analog DA that costs under $300. Kramer also sells larger rack mount DA's, like a 1x20 that I use all the time for larger facilities. But the Kramers work fine for both tri level and NTSC black. Kramer is also sold under the name Comprehensive Video, and Ocean Matrix (via Markertek). I am waiting for AJA (and Blackmagic) to offer little analog DA's, as it's an obvious product that every facility needs.

Bob Zelin




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maurice jansen
Re: problem getting stable video out of VideoHub
on Dec 20, 2009 at 7:40:06 pm

hmmmm

i don't want to be offensive but what more do you want to see on the scope's of the FSI. maybe i look over something if so learn me.
they are IMO only representing picture data. and telling you nothing about the physical layer of the signal. there are no CRC's or EDH checked in the FSI nor jitter or level problems.

if there are no other source's indeed use your NLE as a source. if there are more source's maybe disconnect them all. maybe there is some crosstalk going on. a other thing not likely but possible is a groundloop.

greet
Maurice

People saying they don't make mistake's often make nothing at all!


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Eric Hansen
Re: problem getting stable video out of VideoHub
on Jan 4, 2010 at 9:03:12 pm

so i was thinking about what else could be causing the problems with my hub. i thought there might be electrical interference or a grounding issue. so i pulled it out of the rack to isolate it, but no difference. then i got an extension cord and ran the power to another circuit separate from the server rack, and it was fine. the snow and tearing went away on my monitor. so i guess its an electrical issue. i'm now going to get a UPS for just the video hub and run an electrical line to another circuit.

hopefully that's it.

thanks for all the help and suggestions

e

Eric Hansen - The Audio Visual Plumber - http://www.avplumber.com


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Eric Hansen
Re: problem getting stable video out of VideoHub
on Jan 4, 2010 at 9:20:27 pm

ooops. posted too soon. the problem has lessened. but it's still there.

time to pull out the scopes.

e

Eric Hansen - The Audio Visual Plumber - http://www.avplumber.com


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Eric Hansen
Re: problem getting stable video out of VideoHub
on Jan 5, 2010 at 3:48:51 am

i contacted BMD support and they suggested that i set one Final Cut system to output Bars and have another Final Cut system capture it so they could see what's going on. when i did that, it looked clean. so it seems like theres only video glitches when the SRW5500 deck is outputting to the VideoHub.

i hooked up an HDCAM SR field deck to the VideoHub and it looked clean when running through the VideoHub, so i guess in the end, its an issue with the SRW5500. what i'm hung up on though, is that when the 5500 is connected directly to an edit system for capture (using BNC couplers to bypass the VideoHub) it looks fine with no glitches. but when i run the deck's output through the hub, it gets glitchy. i tried this with reference running to the hub and no reference. all edit systems get genlock from the same AJA Gen10 that's connected to the 5500.

any thoughts? could the SR deck have a slight sync issue (judder?) that Final Cut/Kona doesnt notice, but the VideoHub does? i have the deck set for HD external sync, and the Servo Ref is set to external. thanks for any insight.

e

Eric Hansen - The Audio Visual Plumber - http://www.avplumber.com


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Steven Schoonover
Re: problem getting stable video out of VideoHub
on Jan 11, 2010 at 5:11:38 pm

Eric I am having the same problem. I was sending a DVW A500 signal through a new videohub and received a similar signal to the one that you describe. I took the videohub out of the path and everything works. So I patched the signal to different inputs of the videohub and seems to work. The problem is not consistent and BMD insist that it is my deck. So I connected my ultrascope to the deck and I get the problem which I never had a problem with the deck's signal through the ultrascope before.
If I run a cable from the deck to any of the three FCP suites everything looks great. My sony deck seems to hate Blackmagic and I am stuck


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Marc Wauters
Re: problem getting stable video out of VideoHub
on Mar 27, 2010 at 4:39:19 pm

We have the same stability problem with three Sony DigiBeta DVW decks (2 players and 1 recorder). When we route their SDI output through the VideoHub, the resulting signal is totally unstable and unusable, even when simply routing them to a monitor. When we by-pass the VideoHub, the deck output is fine. Previously, the decks were connected to a Leitch SDI router for 5 years, without any problems.

We also have Sony HD decks connected to the VideoHub, and they seem "compatible", the resulting signal is stable.

Since we are apparently not alone, I would think the VideoHub has a problem with Digital Betacam decks.
BM support says that it can't be the VideoHub, because it is in use across the globe, and my machines must be off-spec. All three of them???


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Eric Hansen
Re: problem getting stable video out of VideoHub
on Mar 27, 2010 at 5:22:19 pm

it seemed like input 16 was giving me the problems. when i switched the decks to 14 and 15, things got better. i also moved the router power from the UPS with our RAIDs attached, to the UPS with the server attached. so this combo seems to have ended the issue.

i say "seems" because we've actually captured very few tapes since the problem started. we mainly shoot cameras with flash drives, and we haven't had to deliver a single tape yet. all of our deliverables have been ProResHQ on hard drives or SD MPEG-2 via FTP to DG Fastchannel.

in a few weeks we're going to capture about 20 hours of SR, so i'll know pretty quickly if this issue has returned. we also should have an Ultrascope setup arriving around then

e

Eric Hansen - http://www.erichansen.tv


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Ron Shaw
Re: problem getting stable video out of VideoHub
on Mar 12, 2011 at 10:40:45 am

Hi I'm new here but have been in the video production business since 1984, having started with production formats like Beta I (That's Betamax kids, not Betacam), then 3/4 U-Matic, 3/4 SP, Betacam, Betacam SP, Digital Betacam (still in use), Betacam SX, IMX, and now XDCam and XDCam HD 4:2:2

OK I won't bore you any more. I just thought I would comment on a new BM Videohub that we got recently. We are trying it in live production, where seamless "glitchfree" switching is desirable. We have noticed the same issues mentioned in this thread and have sent it back to our dealer for evaluation. It has just been returned after being tested without issue, so we are going to try it again.

We had two situations where noise was visible in the video picture when the Videohub was in the signal path and immediately went away when the unit was bypassed. These were both temporary set-ups for field multi-camera productions.

One was with SD-SDI signals from/to gear like a Sony DVS-2000 switcher, CCU-550D camera control, DVW Digital Betacam decks, BVM/PVM SDI monitors etc. Noise was visible on a Tektronics SDI scope (although I confess that I'm not an expert when it comes to signal evaluation) In this set-up we were also using a legacy Miranda (Nvision) 16x16 SDI router for many of the same sources/destinations, all without issue.

The other was with HD-SDI signals from/to the new Sony BRS-200 switcher, PDW-HD1500 XDcam decks, LMD monitors.

In both cases, we were feeding the Videohub analog blackburst reference and in both cases we ended up pulling the Videohub and manually patching to complete the jobs.

I'll post if we ever figure this out... take care all.


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Steven Schoonover
Re: problem getting stable video out of VideoHub
on Mar 14, 2011 at 9:22:18 pm

Is you reference signal only NTSC? Black magic mentioned that for HD, your reference had to match resolution and frame rate. Since my last post, I did more testing of the video hub with my DVM A500. Of course BM tested the video hub with their DVM and sent the unit back with "no problems." I sent signals from a friend's DVM A500 and the same issues occurred. Looking at the signal through a HDSDI scope (not ultrascope), I did notice some noise in the signal path but not the same as through the video hub. Sony did make at least two different SDI output cards for the DVM, so the conclusion that I made is that the problem is in the SDI output of my deck. Since this issue is only on the output of the DVM, I manually patch that cable.

As for the problem of one input or output not working on the video hub. This issue seems to be random and temporary at least in my case. Just try a new port on the video hub.

The Black Magic Video Hub is a convenient headache.


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