Interlaced mode often reversed on DeckLink

Hello,

When I use interlaced mode at Blackmagic DeckLink, the fields often reversed.

I checked this problem using DeckLink Quad Pro2 and 10.11.4 blackmagic desktop video driver(latest driver) at Video Device Input/Output TOP.

Cam → DeckLink Quad Pro2(IN1) → Video Device Input TOP → Video Device Output TOP → DeckLink Quad Pro2(OUT2)

This problem have occurred Build 2018.27300 and 41570 as same, and transfer mode did not affect this problem.

Please check the attached sample movie. (<- I could not upload this. server problem?)
thank you,

hey aokey,

I don’t think you are seeing a bug. Internally TouchDesigner uses only progressive video, and as your network could be anything, it does not know to what input you want to sync to unless you specify. That means if you want to sync the interlaced output from a specific Video Device Out TOP in your network to a specific Video Device In TOP capturing interlaced video, you need to enable this yourself.

See the documentation on docs.derivative.ca/Video_Device_Out_TOP, specifically the parameter manual field control:

So to summarize: just export the “odd field” channel from the Info CHOP to your Video Device Out TOP’s “first frame” parameter, and enable the toggle “manual field control”

Hello nettoyeur,

Thank you for your good advice.
When the manual field control enabled and changed fps from 60 to 59.94, the problem was disappeared in stable version. But it have still occurd in the experimental version.

In the experimental version, there is no problem only when the Video Device In TOP connect to the Video Device Out TOP directly. In other case, it occurs.

aokey, could you contact us at support and provide the movie example file. We can look into it for you if we have the example and we’ll discuss over email.

Hello Ben-san,

I will send you the movie.
thanks. :slight_smile:

Hey,

Were you deinterlacing in the Video Device In using “Bob (Split)”. If you are just feeding the interlaced frame through the network, then it’s possible that frame will be switching not in sync with when the Video Device Out TOP is sending out it’s frames, so its mixing fields from one frame with another.
If you use the deinterlacing, and the technique that Idzard mentioned, things should work.
If they don’t can you post an example .toe file?
Thanks

Hi malcolm,

Thank you for your reply,
I have never used Bob(split).
I’ll test it the time when I come back to my office. Now, I’m in Derivative LA.

thank you,