DeckLink Duo2 Card capture time stamp?

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Bing Fan

  • Posts: 3
  • Joined: Wed Jan 17, 2018 10:08 am

DeckLink Duo2 Card capture time stamp?

PostTue Jan 23, 2018 11:52 am

Hi,
Everyone,I use DeckLink Duo2 for capture.When a Frame is arrived ,the card will call :IDeckLinkInputCallback->VideoInputFrameArrived(IDeckLinkVideoInputFrame* pIVideoFrame, IDeckLinkAudioInputPacket* pAudioPacket),give me a Video sample and a audio sample.
I use :BMDTimeScale timeScale = 1000;
//
HRESULT hr = S_OK;
BMDTimeValue llFrameTime = 0;
BMDTimeValue llFrameDur = 0;
//
hr = pIVideoFrame->GetHardwareReferenceTimestamp(timeScale, &llFrameTime, &llFrameDur);
The llFrameTime is frame time stamp,Is it right?
Then I have a question:I know that the time stamp can be extracted from the SDI signal,What is the relationship between SDI signal and llFrameTime.
Who knows,Please help me ,This is very important and useful for me.Thank you very much.
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Cameron Nichols

Blackmagic Design

  • Posts: 57
  • Joined: Mon Sep 04, 2017 4:05 am

Re: DeckLink Duo2 Card capture time stamp?

PostMon Jan 29, 2018 3:10 am

Hi Bing,

There is no relationship between the SDI timecode and timestamp returned by GetHardwareReferenceTimestamp.

The timestamp output by IDeckLinkVideoInputFrame::GetHardwareReferenceTimestamp() method[1] is the system time when the video input frame is captured by the DeckLink Duo 2. There is also IDeckLinkVideoInputFrame::GetStreamTime method[2] that will return the input stream time in multiples of BMDTimeScale.

To capture the VITC/RP188 timecode, you need to call IDeckLinkVideoInputFrame::GetTimecode() method on the input frame[3]. The CapturePreview sample will also be a good reference for timecode capture.

Kind Regards
Cameron

Refs (DeckLink SDK Manual):
[1] 2.5.11.2 IDeckLinkVideoInputFrame:: GetHardwareReferenceTimestamp method
[2] 2.5.11.1 IDeckLinkVideoInputFrame::GetStreamTime method
[3] 2.4.9.1 Timecode Capture
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Bing Fan

  • Posts: 3
  • Joined: Wed Jan 17, 2018 10:08 am

Re: DeckLink Duo2 Card capture time stamp?

PostThu Feb 01, 2018 4:13 am

Hi,
Thank you very much ,Good day.

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