StatusMonitor and input format detection

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dibbitson

  • Posts: 12
  • Joined: Mon Jul 16, 2018 7:29 pm
  • Real Name: David Ibbitson

StatusMonitor and input format detection

PostWed Aug 07, 2019 8:18 pm

DeckLink 8K Pro, SDK 11.2

I've been experimenting with DeckLinkStatus and DeckLinkNotification in an effort to detect the current input format and noticed that in the StatusMonitor application that bmdDeckLinkStatusDetectedVideoInputMode never gets output.

Why is that?

In my own application I can get it to function ONLY after an EnableVideoInput call on the same sub device.

However this hasn't been reliable either -- on the 8K Pro I can only reliably get this to work on Sub Devices 1&2. 3&4 are always flaky.

Any insight into what might be wrong here?

Accurate input format detection across all 4 sub devices is an important part of a workflow I'm developing.

Thanks,
David
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Cameron Nichols

Blackmagic Design

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  • Joined: Mon Sep 04, 2017 4:05 am

Re: StatusMonitor and input format detection

PostThu Aug 08, 2019 5:21 am

Hi David,

By design, a half-duplex sub-device on the DeckLink 8K Pro will be configured as an output until EnableVideoInput is called. Until configured as an input, mode detection will not work.

Regards
Cameron
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dibbitson

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  • Real Name: David Ibbitson

Re: StatusMonitor and input format detection

PostThu Aug 08, 2019 4:27 pm

Thanks Cameron,

Good to know. So it seems that there are a couple bugs here:

1. In the StatusMonitor demo app querying bmdDeckLinkStatusDetectedVideoInputMode will never work because EnableVideoInput doesn't get called anytime prior,

and

2. In my own application at least, where EnableVideoInput() IS called for all subdevices, querying bmdDeckLinkStatusDetectedVideoInputMode after is mostly unreliable for inputs 3 & 4. (sometimes it works, sometimes it doesn't)

I will say that VideoInputFormatChanged of IDeckLinkInputCallback does seem to work reliably, as an alternative method.

Thanks,
David
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Cameron Nichols

Blackmagic Design

  • Posts: 443
  • Joined: Mon Sep 04, 2017 4:05 am

Re: StatusMonitor and input format detection

PostFri Aug 09, 2019 1:18 am

Hi David,

The goal of the StatusMonitor example is to allow it to run in tandem with an external application such as CapturePreview/QuadPreview. If we call EnableVideoInput from within StatusMonitor, the input cannot be then used by the external application.

I sent you a message on the issue with mode detection on inputs 3&4, requesting further details of your setup.

Regards
Cameron

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