[FFmpeg-user] Detecting upscaled video (resolution), detecting lower to higher encoding

[Moritz Barsnick]

On Fri, Jul 19, 2019 at 09:08:23 -0400, Jim Shupert wrote:
> On 7/19/2019 5:26 AM, Marc Roos wrote:
> > Is there a way to ffmpeg or maybe another tool that detects if video has
> > been re-coded to a higher resolution?
> I have wondered on this as well
> my notion is there is a ' traceable artifact' left in the up Scaled -
> somewhere , somehow.
> but how?

Actually, it's apparently easiert to programmatically detect in the
frequency domain.

There's a tool out there which implements this - resdet:
https://github.com/0x09/resdet

It does seem to work!

The algorithm could probably be ported to an ffmpeg filter (similar to
cropdetect). Though it's probably not useful analyzing a whole video
with it, just after every scene change or so.

Cheers,
Moritz