Drag & drop a video file on the main window central icon, or use the 'Select source...' menu item.
Click the 'Image Settings' button to configure various video processing options.
Enable the 'Passtrough/OCR subtitles' checkbox to retain all text subtitles, and convert
PGS subs and VOB subs into text subtitles.
Mode: select between no rescaling, and rescaling to either 720p, 1080p, 2160p, or double-resolution.
Upscale: choose the upscaling algorithm, applicable if the resolution is increased.
'Super resolution (normal)' is a good, fast choice on modern Macs. 'Super res. RRDN' is more taxing but gives impressive results. 'Normal upscale' is similar to what your media player would do during playback.
Decomb: deinterlace your source material. 'Auto' is usually fine, but you can manually select if it is applied.
Denoise: remove camera noise, if needed, using a simple algorithm. You can choose the degree of denoising.
Deblock: blocking artefact from too much compressing can be attenuated using this parameter.
Sharpen: boost high-frequency components of your image. This can help retaining edges when denoising, or simply for sharpening slightly blurry video files.
Brightness, contrast, saturation: color manipulation, as you can find in most photo editing apps.
Disable auto-crop: by default, black borders are removed. You can disable it for the rare times it causes an issue, or temporarely when comparing different upscaling resolutions to avoid any small shift in position.