Some video frames are black / missing ancillary data?

Ask software engineering and SDK questions for developers working on Mac OS X, Windows or Linux.
  • Author
  • Message
Offline

MarkusPilen

  • Posts: 11
  • Joined: Mon Feb 08, 2016 4:15 pm

Some video frames are black / missing ancillary data?

PostTue Mar 01, 2016 3:08 pm

Hi,

We're having problems with some input frames being completely black, or corrupted, at a fixed time interval.

It seems like every 7 seconds (approx.), two frames close to, but not right after, each other are black, and reading ancillary data from them fails. We're using a DeckLink Quad card and running 1080i 59.94 fps. I've run the SDK samples (for instance LoopThroughWithOpenGLCompositing, which is very similar to what we're doing) but the problem doesn't appear there using the same video format.

The problem does not appear when using two other DeckLink cards (Duo for input, SDI 4K for output), or for 720p60. SOMETIMES (about 10% of the times the app is run) it works also for 1080i 59.94. Using the two cards solution isn't an option since our production servers all have a single Quad card.

the only proper idea I had to fix it was to make a call to AddRef on the input frame when it has arrived, and to Release it first when I'm completely sure that the data has been read (to stop data from being read/written to at the same time by my code and by DeckLink), but that didn't change anything.

Does anyone get a feel for what the problem might be?

Best,
Markus
Offline

Jason Priebe

  • Posts: 10
  • Joined: Fri Dec 14, 2012 4:29 pm

Re: Some video frames are black / missing ancillary data?

PostFri Jun 17, 2016 6:00 pm

Markus -- did you find out what was happening? We are seeing similar problems with our DeckLink mini.

We have been using DeckLinks of all types, including the mini, for a number of years without this problem.

We just upgraded from 10.2 to 10.6, and we're trying to use the cards in a newer OS (CentOS 7 versus CentOS 6). I'm not sure if it's the OS (maybe the kernel), the driver, or our software that is to blame...
Offline

MarkusPilen

  • Posts: 11
  • Joined: Mon Feb 08, 2016 4:15 pm

Re: Some video frames are black / missing ancillary data?

PostTue Jun 21, 2016 12:30 pm

Hi,

Yes, we actually did find a solution, a bit out there but here we go: we're using DeckLink cards with PCIe 2.0, but they were placed in a PCIe 3.0 slot. When we moved the Quad card to a PCIe 2.0 slot, we got rid of the problem. Apparently, PCIe 3.0 isn't fully backwards compatible with PCIe 2.0, at least not on HP servers.

Another recent issue we've had was with flashing output, for some reason also with approx. 7 seconds intervals. That was solved by using tri-level sync. However, that problem was only in our output, the previous one was in the input.

Hope it helps,
Markus

mtestcapture

missing ancillary data for Intencity 4K card in CapturePrevi

PostTue Jan 12, 2021 2:47 pm

I have connected Blackmagic 4K capture card connected on Ubuntu system and HDMI input from Roku 4K. When start playing Youtube video no data ancillary data showing.
Can someone please let me know what could be the cause.

Return to Software Developers

Who is online

Users browsing this forum: No registered users and 1 guest