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Blackmagic Decklink cards

Using BlackMagic Decklink cards Declink specific settings

To activate the video capture of the Decklink card, the video VideoSize and VideoSubtype indexes must be set to 0, and the format must be specified by the VideoFormat index, e.g.:

VideoGrabber.VideoSubtype = 0 (default) VideoGrabber.VideoSize = 0 (default) VideoGrabber.VideoFormat = VideoGrabber.VideoFormatIndex ("HDYC 1920x1080 25 fps") VideoGrabber.VideoInput = VideoGrabber.VideoInputIndex ("HDMI") VideoGrabber.StartPreview()

Remark: If there is no image (black video window), it is possible that the VideoFormat selected is not suitable. To determine the proper video format, proceed as follows: - run the pre-compiled MainDemo.exe - select the Declink card in the VideoDevices list - set VideoSubtype and VideoSize to default - select the video input in the "Video Inputs" list - select the video format in the "Video formats" list - start the preview then try each one of the video formats available in the "Video Formats" list, until seeing the video capture.

Playout to the decklink renderer The VideoRendererExternal property makes it possible to activate the external renderer on the Blackmagic Declink card.

By default TVideoGrabber resizes to 720x480. To select the HD format, invoke UseNearestVideoSize (1920, 1080, true) before invoking OpenPlayer (to go back to the default setting invoke UseNearestVideoSize (0, 0, false))

Note that the Decklink renderer requires also a standard frame rate (e.g. 25 fps or 29.97 fps). If the clip has a non-standard frame rate it may fail to play on the Declink output.

Specifying the Decklink renderer to use when more than one Decklink card is installed in the same PC If more than one Decklink card is used in the same PC, specify the card number to use to the VideoRendererExternalIndex property (in the 0..n-1 range).