Desktop Video 14.3 drivers not backwards compatible

Desktop Video 14.3 drivers not backwards compatible.

That happens (at least) on windows platform.

Most stable windows drivers ? 12.9

Cheers!

[Cameron Nichols]

Hi Michele,

Can you provide details of which application and a description of the issue?

Yes, there are significant changes to interfaces in Desktop Video SDK 14.3. However we do maintain references to the. GUIDs for older interfaces, so applications built against earlier SDK versions will continue to run against later Desktop Video versions. This is achieved by the DeckLinkAPI with a compatibility layer to provide interface between the current and legacy API. This layer will provide linkage between the legacy and modern interfaces by passing the appropriate GUID to IUnknown::QueryInterface. You can confirm this behaviour by running the samples from Desktop Video SDK versions earlier than 14.3.

Please feel free to reach out to developer support directly if in depth assistance is required - https://www.blackmagicdesign.com/develo ... ms/contact

Regards
Cameron

Hi Cameron,

I tested with NewTek ConnectPro and many other applications (including ours). No output.
Win11 - 8Kpro

Cheers,

Mik
--

Hi Cameron,

FFmpeg fails to compile against 14.3 as well.

Best regards

There is in fact a breaking change. Implementators of IDeckLinkVideoFrame (now IDeckLinkVideoFrame_v14_2_1) were not required to return properly on QueryInterface(1). Under new SDK when also using IDeckLinkVideoOutputCallback_v14_2_1 the frame is displayed but the callback is never triggered, as it seems now driver is calling QueryInterface on the video frame, and this failure cannot be logged.

(1) http--github-com/FFmpeg/FFmpeg/blob/6b31e42c47c00817f6249f43391873a15b1c00a4/libavdevice/decklink_enc.cpp#L114

Thank you pabloko, you saved me quite a bit of time! Correctly implementing QueryInterface fixed the issue on my side.

Hi guys,
I've created an account to share the following, it might help someone in the future.

Although I wasn't able to compile ffmpeg 7.1 against sdk > 12.9, this post pointed me in the right direction.

Building ffmpeg 7.1 against bm sdk 12.9 AND installing desktopvideo 12.9, allows for smooth video output on a DeckLink Studio 4K.

Thank you for your time!