DeckLink Quad HDMI Recorder - Captures Black Screen

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engnfrc

  • Posts: 3
  • Joined: Tue Nov 08, 2022 6:56 pm
  • Real Name: Joshua Quesenberry

DeckLink Quad HDMI Recorder - Captures Black Screen

PostWed Feb 01, 2023 11:35 pm

Good Evening,

I have a DeckLink Quad HDMI Recorder and am having trouble recording HDMI feeds from another computer. The host is a Dell Precision 5820 with Ubuntu 22.04, Linux 5.15.0-58-generic, BlackMagic Driver 12.4.1, and GStreamer 1.20.3. I'm able to capture HDMI from both an RPi and Dell Latitude (Intel graphics) and preview using GStreamer / decklinkvideosrc without issue, however I am now trying to capture from another PC using NVIDIA cards and I only get a black image, regardless of if the HDMI cable is direct to the capture card or if it comes from an HDMI splitter teeing off the feed between that PC and a TV (which shows the HDMI feed without issue). Using BlackmagicDesktopVideoSetup the HDMI signal is recognized and a mode of 2160p30 is listed, however using this exact same mode in GStreamer is resulting in no collected video. I've also tried using mode=auto and there's still no image shown.

What could be the problem?
What can I do to troubleshoot this issue?
Is the NVIDIA card doing something different that's interfering with how the HDMI capture card has worked with the RPi or Dell Latitude with Intel Graphics?
Why would BlackmagicDesktopVideoSetup be able to see the HDMI feed and even list a mode, but that mode not work correctly from within GStreamer?

Sample GStreamer pipeline for previewing the HDMI feed:
gst-launch-1.0 decklinkvideosrc persistent-id=3347096529 mode=2160p30 ! videorate ! video/x-raw,framerate=1/1 ! videoconvert ! videoscale ! video/x-raw,width=640,height=360 ! ximagesink

Thanks for the help!

Josh Q

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