> ## Documentation Index
> Fetch the complete documentation index at: https://docs.comfy.org/llms.txt
> Use this file to discover all available pages before exploring further.

# BriaVideoReplaceBackground - ComfyUI Built-in Node Documentation

> This node replaces the background of a video with a supplied image or video using Bria's API.

This node replaces the background of a video with a supplied image or video using Bria's API. The output keeps the foreground video's resolution and frame rate; a background with a different aspect ratio is stretched to fit, so matching aspect ratios produces undistorted results.

## Inputs

| Parameter | Description | Data Type | Required | Range |
| - | - | - | - | - |
| `video` | Foreground video whose background is replaced. | VIDEO | Yes | - |
| `background_image` | Background image to composite behind the foreground. Provide either a background image or a background video, not both. | IMAGE | No | - |
| `background_video` | Background video to composite behind the foreground. Provide either a background image or a background video, not both. | VIDEO | No | - |
| `seed` | Seed controls whether the node should re-run; results are non-deterministic regardless of seed. (default: 0) | INT | Yes | 0 to 2147483647 |

**Note:** You must provide exactly one of `background_image` or `background_video` — not both and not neither. The foreground video and the background video (if used) must each be 60 seconds or shorter. When `background_image` is used, its alpha channel is removed before processing.

## Outputs

| Output Name | Description | Data Type |
| - | - | - |
| `video` | The resulting video with the background replaced, encoded as MP4 (H.264). | VIDEO |

> This documentation was AI-generated. If you find any errors or have suggestions for improvement, please feel free to contribute! [Edit on GitHub](https://github.com/Comfy-Org/embedded-docs/blob/main/comfyui_embedded_docs/docs/BriaVideoReplaceBackground/en.md)

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