[FFmpeg-devel] [PATCH] avfilter: add radial and circular blur video filter

[Steinar H. Gunderson]

On Sat, Jul 18, 2020 at 11:06:17AM +0200, Paul B Mahol wrote:
>>>> The above picture pretty clearly shows otherwise...? Could you tell me
>>>> where my confusion would lie?
>>> The filter option amount/angle set is very small.
>> It's the default value. Could you recommend a command line?
> Unless you want to propose patch, no.

OK, so the defaults create a broken image, and you're not willing to tell me
what parameters to use without me proposing a patch? (What would that patch
do?)

I tried setting angle=50, and got

  http://storage.sesse.net/ffmpeg-radialblur2.png

which looks more like a radial blur, but still is broken. Note the strong
aliasing (starburst) in the center, the jagged thick white lines (more
aliasing) on the left and right sides, and the fact that the vertical white
lines are all but gone.

If a blur creates strong high-frequency components (ie., the very opposite of
what a blur is supposed to do), it is a strong signal that the algorithm
chosen is just fundamentally wrong.

/* Steinar */
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