The Blackmagic Design 3G-SDI Mezzanine Card is an expansion module designed to upgrade the I/O capabilities of compatible DeckLink capture cards, such as the DeckLink 4K Extreme 12G. This specific card adds four additional 3G-SDI inputs and outputs, allowing the host card to handle more simultaneous video channels for capture, playback, or monitoring. It is installed directly into a mezzanine slot on the compatible DeckLink card, effectively expanding its connectivity to support larger and more complex multi-camera or multi-channel workflows in post-production, broadcast, and live systems.

This card supports full 3G-SDI standards, carrying high definition video with embedded audio, and is compatible with a wide range of SD, HD, and 2K video formats. By adding this module, users can significantly increase the number of feeds they can record simultaneously in software like DaVinci Resolve or use for multi-display output in applications requiring numerous independent monitor feeds. Its design ensures reliable, broadcast-quality signal integrity and is built to match the professional standards of the DeckLink series.

This expansion card is a strategic solution for professionals who need to scale their video I/O without replacing their entire capture card. It provides a cost-effective upgrade path for facilities using DeckLink cards, enabling them to adapt to growing production demands, such as adding more camera ISO records, increasing monitoring outputs, or integrating with larger routing systems.