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Decklink output “shifts” in dissolves
Just got a new turnkey system with the Decklink Studio and we’ve encountered a problem when adding transitions.
On the SDI and Component outputs ONLY, the video “shifts” a few pixels to the left (or right) when a dissolve is used. This is most noticeable when we add a titler graphic key over video. At the dissolve point, the video moves a few pixels horizontally, then returns when the graphic is dissolved off.
Oddly, this doesn’t happen on the on-screen preview within Premiere. It only shows on our SDI monitor, and on our Betacam deck via the component cables.
The system is an HP Z600 workstation with 12 GB RAM, Windows 7 64-bit, nVidia Quadro FX 3800, and the CS5 suite of apps.
If I turn off the Mercury Playback Engine and go software only, the problem seems to go away (or at least be less prevalent). The only issue there is now the transitions need rendered.
Thoughts?
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13 Replies
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I’ve always had this problem with my Decklink card (year and half or so). For me, using CS4, the shift happens on clips or transisitions with a redline (even though the areas play realtime). The shift remians if I render the area. To solve the problem I add an effect that causes the entire timeline to redline (like CineForm’s force render), then I get a shift on everything equally.
It’s only a problem on the Decklink outputs, all of them for me, I use the SDI HD and SD, HDMI and component outputs. When rendering the timeline to digital files the problem does not occur.
Contact Blackmagic and tell them, I have submitted a support ticket several times about this, but to no avail.Jeff Kosmicki
http://www.toyraygun.net -
That’s a HORRIBLE flaw in their system(s). 95% of my stuff gets outputted to Betacam, and if I have to render everything to avoid this ‘shift’, it’ll be very time consuming.
They need to address this.
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James Orlowski
RYNO Production, Inc.
http://www.rynoproduction.com
800-860-7966 -
I don’t know if this is useful information or not, but with Final Cut and my DecklinkSP card some still images and titles have a slight shift when I initially render my timeline (Command+R), but there is yet a second render for certain stills and/or text. It is Ctrl+R. You’ll have realtime playback and video will look fine without this additional render, but that pixel shift on my SDI monitor will take place unless I do the second render.
This, as I understand it, is not a Blackmagic issue, but rather goes back to what tasks are given to what (Final Cut or Blackmagic) as indicated in your System Settings Menu. You can change these.
If I have misunderstood your issues, or if my system is nothing like yours, I apologize. It took me a while to figure out how to correct this.
Best regards,
Greg GoldenGreg Golden
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Yeah it sucks, that’s why we need to make sure Blackmagic is aware of it.
Jeff Kosmicki
http://www.toyraygun.net -
I contacted BlackMagic, and they actually got back to me the next day.
Someone named Albert Chu from their support engineering department said they weren’t aware of this “shifting” issue, but they’d look into it.
I mentioned that others have this same problem. It might help if you also contact Albert. I’ll give you his email in private, so contact me.
Send him your system specs. I did. Maybe if more people inform them of this, they’d develop a solution.
We have three Decklink Studio workstations here. All have this seemingly random “shifting” issue.
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James Orlowski
RYNO Production, Inc.
http://www.rynoproduction.com
800-860-7966 -
I’ve talked to Albert before with other issues. I will contact him with this problem (although I’m sure I did originally when I first got the DeckLink card).
Jeff Kosmicki
http://www.toyraygun.net -
Hello James,
Sorry you didn’t hear back from me sooner, but we had nothing new to report. Rest assured that we are looking into the original issue you mentioned as most pressing, the picture shift.
We are continually unable to reproduce this same issue (across a few systems) which is why I asked for step by step directions in your workflow. I have a copy of your email and will contact you after more testing has been completed.
We do appreciate your patience in this matter.
Regards,
Albert Chu
Support Engineer
Blackmagic Design Inc.
https://www.blackmagic-design.com -
Albert,
I can reproduce the problem by:
1) create a Blackmagic NTSC SD timeline
2) add 2 Blackmagic AVI’s that are SD with interlaced fields
3) add a dissovle between the two clips, make sure the clips have NO yellow or red lines above them. Make sure the dissovle DOES have a yellow or red line above it.
4) start the timeline and the picture will shift a pixel when the dissovle plays.For me the problem happens with interlaced footage (Blackmagic codec)in both CS4 and CS5. The shift occurs when the CTI goes from an area of the timeline with no colored render bar to an area with yellow or red colored render bar (or green for that matter).
Jeff Kosmicki
http://www.toyraygun.net -
Here’s a little video I just recorded that demonstrates the shifting problem:
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James Orlowski
RYNO Production, Inc.
http://www.rynoproduction.com
800-860-7966 -
And here’s a full-resolution sample of the output I see when this “shifting” occurs.
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James Orlowski
RYNO Production, Inc.
http://www.rynoproduction.com
800-860-7966
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