Using Blackmagic DeckLink Output Devices

The new Videowall Configurator allows creation of a virtual output device that consists of multiple Blackmagic Decklink output devices driving displays arranged in a grid of (up-to) 4×4 slices. This feature makes videowall setup a hassle-free, instant process. Simply assign display slices (grid cells) to output devices, select the output profile (resolution and frame rate) for each device/slice and apply any bezel correction settings as necessary. Thanks to the test pattern output feature, identification of display connections and adjustment of bezel correction settings can be performed very easily.

A major advantage of using Decklink cards with CW’s Videowall Option is that the Videowall output runs completely independently of the Windows desktop, which prevents unwanted interference due to user input (e.g. pressing Ctrl+Alt+Del) or applications running in the background. SDI to HDMI converters can be employed for driving inexpensive displays from Decklink cards with multiple SDI outputs (such as Decklink Duo 2 and Quad 2 models). To avoid any tearing issues, sync reference inputs on the output cards can be used.

Using nVidia Graphics Cards with Mosaic Technology

Videowalls can also be driven using the HDMI/DisplayPort output capability of CharacterWorks. In this case, the division of the large virtual display into multiple HDMI/Displayport outputs can be handled by graphics cards equipped with nVidia Mosaic technology. Outputs are perfectly synchonized, which means there are no tearing issues, and bezel correction or projector overlap adjustments can be applied.

Mosaic technology is usually found on NVS or Quadro series video cards. When used with CharacterWorks, performance of an NVS card may not be enough to render the large resolutions required by videowalls. On the other hand, Quadro cards with sufficient computing power can be rather expensive compared to GTX or RTX cards with equivalent raw performance. CharacterWorks can overcome this issue by redirecting the output of a GTX or RTX card to an NVS or Quadro card. This means that the GTX/RTX card is used for rendering and the NVS/Quadro card is used for videowall output, resulting in a highly cost-effective solution.

As the Mosaic solution uses HDMI or Displayport outputs on the graphics cards, it does not require any signal converters like the Decklink solution. This is a major advantage. However, the process of setting up a Mosaic-based system can be a bit cumbersome, since it involves modification of graphics card driver settings. Furthermore, the Mosaic display operates as part of the Windows desktop. Therefore, user input (e.g. pressing Ctrl+Alt+Del) or background applications can cause unwanted interference. If this presents a problem, we recommend considering the Decklink device output as an alternative.