# Key & Fill Source

Source: https://mimolive.com/user-manual/sources-input/local-sources/key-fill-source/  
Last updated: 2025-05-09  
Section: Sources (Input) › Local Sources  

> **Important:** This feature requires a mimoLive Studio or Broadcast license.

For some use cases, it may be interesting to ingest a video with an alpha channel into mimoLive. For example, you can use the brilliant Blackmagic Design Ultimatte to get a near-perfect chroma key for your DSLR or pro studio camera against a green screen background. Since SDI doesn't support alpha channel video, the Ultimatte sends key and fill on two separate SDI channels. The Key & Fill source in mimoLive can take these signals using a Blackmagic Decklink card or other Blackmagic devices and convert them to alpha channel video. You can then use the video in mimoLive to place a news anchor in a virtual studio or send it to your NDI workflow via the NDI output.

![Ultimatte to NDI via mimoLive and the Key & Fill Source.](https://mimolive.com/wp-content/uploads/2023/05/Ultimatte-to-NDI-2.002-1024x576.png)

### Configuration

(This section is currently under construction.)