In 2024, I was frequently using TouchDesigner 2023.12000.
At that time, when capturing an SDI signal using a Blackmagic DeckLink 8K Pro with VideoDeviceInTOP, I occasionally experienced an issue where the video became noticeably jittery for a few seconds, occurring once every several hours.
When the image was unstable, I connected an Info CHOP to the VideoDeviceIn TOP and observed the “frame queue length” value. It was alternating every frame like: 1, 2, 1, 2, 1, 2, 1, 2…
(Because this issue was very difficult to reproduce reliably, I did not post it as a bug report on this forum at the time.)
To avoid this problem, throughout 2025 I used a custom CPlusPlus TOP that captures video directly via the Blackmagic SDK instead of using VideoDeviceIn TOP.
Now in 2026, I recently started using TouchDesigner 2025.31550 and decided to test this issue again by reconnecting VideoDeviceInTOP after a long time. So far, after running for three days, the issue has not occurred. This made me wonder if the problem has been resolved.
However, after reviewing the release notes from 2024 up to now, I could not clearly determine whether this specific issue was addressed.
So my questions are:
Was Derivative aware of this issue?
And if it has been resolved, was it fixed by a TouchDesigner update, or was it due to an update in the Blackmagic SDK?
I understand this may be a difficult question to answer, but I would really appreciate any insight.
Thank you very much.