This may not be exactly what you're asking for but every re-encode introduces additional noise (generational error). Over many re-encodings (even at same high b

This may not be exactly what you're asking for but every re-encode introduces additional noise (generational error). Over many re-encodings (even at same high bitrate/quality) the noise will accumulate in a predictable manner. See [0] for an interesting deep-dive blog post on the subject. Now, as for whether or not you can distinguish the re-encoding from it's original source.... difficult but plausible in certain scenarios? Perhaps if the content was heavily re-encoded to the point where you can statistically determine the presence of the generational noise. With only a single re-encode it may be impossible to determine. [0] https://goughlui.com/2016/11/22/video-compression-x264-crf-generational-loss-testing/ https://goughlui.com/2016/11/22/video-compression-x264-crf-g...