TeMPOraL on Nov 14, 2022 [–]
You've stumbled on an actual, practical use case: encoding watermarks in the grain. I can imagine a watermark hidden in the grain, spread over long enough time (say couple seconds to a minute), so it can survive reencoding with heavy compression and containing enough bits to identify the source of the video on a per-copy/per-user basis.
Makes me want to experiment with streaming services and see how unique the streams they serve are and what might be hidden within.