No. Grain can be part of the original photographed image or an intentional creative treatment. Compression noise and electronic sensor noise are different, although they can overlap visually. Judge whether texture behaves naturally and whether the encoded stream preserves it without obvious blocks or smearing.
Look at how texture moves
Natural grain tends to vary across frames rather than forming fixed large squares around objects. Compression can make grain clump, pulse or disappear during movement. A heavily processed picture may look superficially clean while losing real texture in skin and clothing, so complete smoothness is not automatically more faithful.
Compare a restrained picture mode
Reduce aggressive noise reduction and sharpness separately, replaying the same scene. If detail returns along with fine texture, the previous mode may have been smoothing the image excessively. Keep other controls stable and avoid judging from a paused frame alone, because temporal processing can behave differently during playback.
Respect the source style
An older film, a dark digital production and a clean studio broadcast need not look alike. Do not promise that every title should have the same polished surface. If one stream shows distracting blocks or unstable texture, report the title and time rather than asking support to remove all grain from the entire catalogue.
