There is a new pull request by mamins1376 against master on the void-packages repository

https://github.com/mamins1376/void-packages ffmpeg-webp
https://github.com/void-linux/void-packages/pull/25009

ffmpeg: Add support for webp codec
Adds dependency on `libwebp` with `--enable-libwebp`, behind enabled-by-default feature `webp`.

A patch file from https://github.com/void-linux/void-packages/pull/25009.patch is attached