Problem with using DeckLink Quad 2

Yu Kumazaki's icon

Hi.

I'm using jit.grab to capture video inputs from Blackmagic's DeckLink Quad 2.
But when jit.grab object is created, Max crashes.

If I disable some inputs from Windows Device Manager, it looks working.

Here's crash dump file. Can anyone help for this?
https://www.dropbox.com/s/go9e6wpzyogpt7p/Max_crashdump.dmp?dl=0

Rob Ramirez's icon

If I disable some inputs from Windows Device Manager, it looks working.

Can you offer some more details and specific steps you are taking to make it work? That might help me understand why it is crashing.

Yu Kumazaki's icon

When all inputs are enabled, Max had crashed when I type "jit.grab" and hit return key.

But after disabling some inputs like this,

jit.grab object doesn't crash, and I could capture the video came from input 1.
I found 3 vdevices for each inputs (Blackmagic WDM Capture, Decklink Video Capture and DeckLink Quad 2 [Native]).
I think... jit.grab can cause crashing when it has too many vdevices?

Rob Ramirez's icon

ok thanks for the info. I will follow up with you through our support channel next week.

Jesse's icon

I use a Decklink Duo 2 card extensively on a Windows machine, with all four inputs active at 1080p59.94. I don't use jit.grab for this, but rather an external application called Black Spout, which offers native support for the Blackmagic driver and sends a live feed of each input to Max via Spout.

https://magicmusicvisuals.com/forums/viewtopic.php?f=6&t=201

Perhaps could be helpful to you. I've found the app to be quite stable and it offloads the frame capture to another process, so it's quite efficient. You'll need to open a new copy of the app for each stream you want to capture.

The preview window for Black Spout lags behind the input noticeably, but the textures that are shared via Spout into Max appear to be sent with no delay at all.

Yu Kumazaki's icon

Thank you, Jesse.
It looks working good. But it's better to hide Black Spout's preview window.

And I gonna wait Rob will fix this issue.

Thanks!

Rob Ramirez's icon

If anyone needs a fix for this issue, please contact me directly (email link in my profile)