Infuse 5.7.6 uses a new, proprietary algorithm which includes some Lanzcos-inspired elements. This is implemented in our super-efficient Metal video rendering layer to provide a noticeable improvement when playing under-sampled videos (EG 480p on a 1080p TV, or 1080p on a 4K TV).
The new upscaling is available on all A9 and later devices (both tvOS and iOS).