obsproject
DeckLink SDK needs updating
Operating System Info
Windows 11
Other OS
No response
OBS Studio Version
31.1.2
OBS Studio Version (Other)
No response
OBS Studio Log URL
No log (not my computers)
OBS Studio Crash Log URL
No response
Expected Behavior
Video and audio output of DeckLink be in sync
Current Behavior
It is in sync after a computer restart but then slowly gets worse over time no matter what we do with settings in both OBS and BM's Desktop Video Setup.
Steps to Reproduce
1.DeckLink SDK 14.5 or 15.0 installed 2.OBS video output set to 1080p29.97 3.DeckLink output set to 1080i59.94 ...
Anything else we should know?
I work on the corporate side for Nexstar Media Group. As a company, we are running roughly 100 setups which include OBS and a DeckLink Duo 2 card. I have been trying to solve the many issues popping up occurring specifically with the DeckLink output of OBS's output. I just noticed in the GitHub that OBS is still running off of Blackmagic SDK 12 while they are now on 15. I'm hoping this is an easy thing to update and may, perhaps, be the solution to the issues. Feel free to reach out if you need more info.
Chip Brewster Manager of Digital Innovation Nexstar Media Group [email protected]
As a follow-up, after some brief reading it appears SDK 14 had some MAJOR changes in it. So perhaps OBS still using 12 is even more detrimental than I realized. We would very much appreciate a dev taking a look at this particular issue.
IIRC, after version 12.0 (e.g. #10379) the licensing of the headers were changed from MIT to something custom linked to an EULA. So compatibility with GPL-2.0-or-later needs to be checked thoroughly.
Darn. So not as easy of a lift as I had hoped. We still appreciate consideration of this update!
Will your video and audio sync issue solved by updating the SDK version? If you have not tested, I would not expect much change, since the SDK provides mostly just entry points to the runtime.
I'm reminded the discussion on #1865. Could you clarify what is the actual issue? Is the audio lagged to the video or the other way around?
Video is ahead of audio in the drift. That discussion is a very interesting read! We weren't rocking all of these systems at that time otherwise I would have spoken up in that thread.
I fully admit, I am out of my depth even being in GitHub. So no, I don't know if updating the SDK will fix my problem. I found things like this from BM which state they made major changes with 14, so that's the only reason I suspect it as a potential solution: https://documents.blackmagicdesign.com/UserManuals/DeckLinkSDKMigrationGuide.pdf?_v=1732780810000
Commenting on this to see if anyone has taken a look at the Blackmagic documentation on this. It sure seems like the command language itself did actually change and could be having an impact. @norihiro perhaps?
According to the migration guide, I cannot see any modifications for the audio output.
[!TIP] The removal of
IDeckLinkVideoFrame::GetBytesis interesting to me. I was suffering a captured video frame is old one (2 second or so), which happened once an hour or less, if I remember correctly. Though, this is off-topic.
I appreciate someone with knowledge and experience taking a look. Many thanks! I was really hoping I had found our issue. Whomp.
Different audio issue but still DeckLink related
You can hear it here right at the start - then it magically clears at 12:39 right in line with a stinger transition: https://www.youtube.com/watch?v=Ls6E9hNOke0 - this is the 3rd or 4th OBS setup we have in the company where I've heard this crackle issue.
It was solved by replacing the DeckLink with an AJA product. One of our engineers proposed this as the cause: "AJA does a great job of initializing the audio buffers in the driver stack before the video stream starts". If that is indeed the issue, could it have anything to do with the SDK updates for DeckLink? Or perhaps something else related to how OBS works with DeckLink?
This thread is a little older, but what is the feasibility of updating OBS to desktop video 15.3 SDK? With the new atem mini extreme ISO g2, OBS decklink output has become obsolete unless the SDK gets updated to 15.3.
It's certainly feasible, just low priority for the core team. We'd welcome a PR for an update.
It's certainly feasible, just low priority for the core team. We'd welcome a PR for an update.
If I had even a modicum of skill in this area I would do this for y'all in a heartbeat. Love this software and the community behind it. Fingers-crossed someone out there can lend a hand!
I will do my best in the next couple weeks to work on an implementation!