I’ve a Blackmagic Intensity Pro capture card in my machine at work, initially we were going to capture video for webcasts from a professional camera but that never came to pass.  It’s been sat in my machine gathering  dust soI thought it would make quite a nice virtual monitor for embedded devices.  As I’m playing with Raspberry Pis more at work it’s an idea way of not having to faff around switching inputs on my monitor.

Required software:  VLC and the Blackmagic drivers for the card.

Plug your HDMI device into the capture card, looking at the back of your machine it’ll be the one closest to your motherboard.  This may work for DVI capture too, I’ve not tried it.

Open VLC then File -> Open Capture Device.  Select Declink Video Capture, enter 1920×1080 for the video size, click on Advanced options and change the aspect ratio to 16:9.  Click on then click play and you should have a picture, albeit slightly laggy.  I’m using it as a virtual monitor so not an issue, if you are capturing a stream from a console it may be irritating.  I used to have a way of minimalising this when capturing from a webcam but can’t remember it, if you find out please leave a comment and I’ll update the post.  To reduce lag, click on “More options” and set caching to 0 ms, seems to have done the trick for me.

This one was more a note for me for the next time I try to use the card for this use and have forgotten, thought it may be useful for others.

Update:  To shortcut the whole process, this works nicely as a command line and if you create a shortcut to VLC and pass the arguments in accordingly you can open straight into the stream:
vlc dshow:// :dshow-vdev=”Decklink Video Capture” :dshow-size=1920×1080 :dshow-aspect-ratio=16\:9 :live-caching=0

Pretty sure if you change the device to the name of any capture card or webcam this should work, not tested so your mileage may vary.