Filters with ffmpeg 6.1: hqdn3d (spatio-temporal, default), atadenoise (adaptive...
https://ton.halowerk.com/v1/video-denoiseOverview
Filters with ffmpeg 6.1: hqdn3d (spatio-temporal, default), atadenoise (adaptive temporal averaging, keeps edges, needs a mostly static camera) or nlmeans (non-local means, best detail but slow, therefore limited to short low-resolution clips). Strength presets light/medium/strong map to fixed filter parameters stated in the response.