The DeckLink Input Module
The DeckLink Input module is used to ingest a video stream from a Blackmagic DeckLink video capture device directly, bypassing its DirectShow driver to obtain better performance. Due to their software processing* DeckLink cards are more prone to frame dropping, so an additional Phase Locked Loop with buffering is added to keep the stream and buffer size (and so latency) constant.
*Blackmagic DeckLink cards are designed quite differently from other brands in that most processing is done in software. The advantage is lower production cost. The disadvantages are higher CPU and memory usage and higher bandwidth requirements for the motherboard.
Right click the module to open its popup menu. The following additional menu entries are available.
A list of all DeckLink devices available and their inputs. Note inputs can be relabelled for easier reference, and in fact this is a necessity when multiple cards with the same name are installed. In the Desktop Video Setup utility select the input you want to relabel, open its properties, select About and enter the new name in Label. If an input has several ports (e.g. Intensity Pro) you can select the desired port in this utility as well. If you are using bidirectional cards (e.g. DeckLink Duo 2) then keep in mind port direction is properly set, typically you'll want to disable passthrough and map each port to a single connector. Port mapping can be set under Connectors > Connector, choose a single and unique connector here.
DeckLink devices are extremely picky and will only work if you select the exact same signal format as applied to the device. Colour bars will be displayed if you select a format that is supported but that does not correspond to the applied video signal (or if there's no video signal at all).