HACKER Q&A
📣 justo-rivera

can this be done?


If film grains are randomly or chaotically distributed, and fractal over enough orders of magnitude, grain might not be error but a medium which interprets and conveys information differently, with unique advantages. But now I'm afraid I sound like an audiophile who buys wooden amp knobs for performance.

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.


  👤 h2odragon Accepted Answer ✓
for video, a film grain effect could easily be a Steganography channel, not just watermark. the interactions with various re-encoding techniques (especially chaining different ones and pass around videos do) will cut into capacity but i expect some coding could be constructed to give you enough bits for a useful signature.

Makes me want to experiment with streaming services and see how unique the streams they serve are and what might be hidden within.