EnableVideoInput fails when there is no input signal

This is new behavior with the 14.4 drivers. I updated to 14.4.1.

If I call EnableVideoInput on the input device with display mode of bmdModeHD1080p2997 then the call fails with hr=0X80000002 which is E_OUTOFMEMORY ?

The InputLoopThrough sample has the same error in this mode.

I changed our code to use bmdModeNTSC like in the sample and the call succeeds. But I also can't get any frames to display when enabling the output device with either mode.

We were running the 12.7 drivers and never had this problem. EnableVideoInput succeeds and we can display a message on screen that indicates there is no input signal.

I found that I can still display an output if I set the IDeckLinkOutput device to a mode I can support, like bmdModeHD1080p2997. But setting anything other than bmdModeNTSC in IDeckLinkInput::EnableVideoInput returns E_OUTOFMEMORY.

Is this a bug in 14.4 or expected behavior?

It seems that this issue arises due to changes made to the buffer allocator starting with version 14.3. The NTSC mode works because it requires a smaller buffer size, which is why you can enable video input successfully with it.

I recommend checking the Desktop Video 14.3 SDK Migration Guide, as it may provide useful insights on how to handle this situation. However, please be aware that many users are still experiencing similar problems with the 14.3 and newer drivers. It would also be beneficial to review the posts and responses below from Cameron regarding these issues:

Memory Usage by EnableVideoInput

Frames no longer arrive with allocator

Desktop Video 14.3 drivers not backwards compatible


If you continue to have issues, consider reaching out to Blackmagic support for further clarification and potential fixes.