[FFmpeg-user] denoise after scaling or before?

[Michael Koch]

Am 24.04.2019 um 10:43 schrieb Ulf Zibis:
> Am 23.04.19 um 11:43 schrieb Jon bae:
>> Makes it a different when I denoise after scaling a video, or is the
>> quality better when I denoise before scaling.
>>
>> In terms of speed it would be better for me, denoising after scaling, but
>> when the quality is better, then I would go that way.
> If I see this correctly, most denoisers define a spacial area to work on.
> So denoising before downscaling in the end will affect a smaller spacial
> area then in opposite order.

What are the pros and cons of the 8 available denoisers?
Which of them is the best choice for which purpose?
Are there any recommendations?
I did try a few of them (but not all) and found that atadenoise is good 
for high-ISO videos of the night sky. This testing is very time 
consuming because most denoisers have several parameters that must also 
be optimized.

Michael