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Old 17th September 2022, 18:10   #46  |  Link
Beelzebubu
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Join Date: Feb 2003
Location: New York, NY (USA)
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Quote:
Originally Posted by benwaggoner View Post
Sounds like the FGS filter keeps running even when the video stops. Since it's an out-of-loop postprocessor, that sort of thing isn't unprecedented. In the implementations I'm aware of, the FGS filter isn't even part of the codec itself, and can be triggered by the same SEI metadata in other codecs as well.
True, except that the process is defined and the seed coded in the bitstream header. So if the seed is static (e.g. when paused, or because so coded), the grain looks the same every frame. So the above behaviour suggests the seed is changing even if the video is paused. Where does it get the new seeds from? And if from someplace else than the bitstream header, does that mean it looks anything like intended by the encoder?

(It's true that encoders like aomenc don't choose a specific seed based on reconstruction characteristics, they just randomly generate a number. But in theory, an encoder could select a seed expecting a particular reconstruction, and that's what I'd expect to see in the decoder as well then.)
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