Bug: Black / no video playback when running Blackmagic Desktop Video 14.3

[carmacoma]

Observed Behavior

After upgrading Blackmagic's Desktop Video software from 14.2.1 to the current 14.3, video playback fails to output. Server does not register errors - initial startup logs are good, and play command reports success. All logs look good, no errors.
However, both virtual outputs (screen consumers) and physical Blackmagic Decklink 8k Pro outputs remain in black.

This has been reproduced on three separate PCs, with different server versions (all 2.4 and up)

This has also been proven to be fixed by rolling back to Desktop Video 14.2.1

Expected behaviour

Expect video to play successfully

Steps to reproduce

1. Ensure working system - Windows PC, Decklink 8k pro, CasparCG server,
2. Install Blackmagic Desktop Video 14.3
3. After rebooting as part of install process, start Caspar server, and attempt to play video
4. CasparCG Server will report successful video playing, but no picture will appear on screen consumer or Blackmagic outputs

Environment

• Commits: 3ab57d, 5e29af9 Stable
• Server versions: 2.4.0-3ab57d, 2.4.1 stable
• Operating system: Windows 11
• Decklink 8k Pro
• Blackmagic Desktop Video 14.3 version

[Sidonai-1]

I can confirm this issue on Win10 as well.

The only giveaway for me was the diag graph not showing any 'lines' on the decklink.

[Julusian]

I can reproduce this on ubuntu. I have narrowed the problem down to being how we sub-class IDeckLinkVideoFrame, but as the SDK docs say that we are allowed to do this, I am contacting blackmagic about this.
By doing the same pattern inside their TestPattern sample, it also gets stalled in a similar way.

Interestingly, it is outputting video, but it never calls the ScheduledFrameCompleted so is only outputting the frames we provide as pre-roll (which are always black)

[shenyanjie0807]

Blackmagic Design released the latest DesktopVideo V14.4 just now. Is it any help to CasparCG?

[nerijus]

No, both 14.3 and 14.4 do not work.

[Julusian]

This is fixed in the latest release https://github.com/CasparCG/server/releases/tag/v2.4.2-stable

[dimitry-ishenko]

@Julusian 2.5.0 release please...