Reading VITC Timecode from Frame 2

jakegwater
Sat, 27 Feb 2021 16:45:04 +0000
Cinematics & Media

I am trying to feed timecode from my Blackmagic Pocket Cinema 4k into Unreal Engine using a Decklink 8k Pro, and the HDMI to SDI 3G Micro Converter. Everything is done in 1080p at 24fps. Here’s a diagram:

[BMPCC4k] —HDMI—> [Micro Converter] — SDI —> [Decklink 8k]

Unreal was accepting the external timecode source, but never changing from displaying 0:00:00:00. However Blackmagic Media Express does see the timecode, so I can verify that timecode is making it to the decklink.

I have narrowed down the bug, but I’m not sure who is doing it wrong, for lack of a better phrase. Here’s a screenshot from the Blackmagic CapturePreview app provided with their SDK. It shows the incoming video feed, along with metadata about the timecode format.

As you can see in the above image, the timecode from the Micro Converter is encoded using VITC and stored in frame 2. Unreal, however, only seems to read from VITC field 1. I asked on the Blackmagic forums, because I’m not sure which component would need to change.