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

[Paul B Mahol]

On 7/19/20, Paul B Mahol <onemda at gmail.com> wrote:
> On 7/19/20, Paul B Mahol <onemda at gmail.com> wrote:
>> On 7/19/20, Steinar H. Gunderson <steinar+ffmpeg at gunderson.no> wrote:
>>> On Sun, Jul 19, 2020 at 09:02:30PM +0200, Paul B Mahol wrote:
>>>>> Yes, this is the non-recursive version, which is O(n) in the number of
>>>>> samples. This is why I recommended the recursive version, which is
>>>>> O(log
>>>>> n)
>>>>> in the number of samples and thus avoids the problem with big lengths.
>>>>> It is fairly straightforward to convert one to the other.
>>>> Really? How so?
>>>
>>> As previously mentioned, you do two samples, then save to a temporary
>>> buffer,
>>> two samples from that buffer with half the distance and so on until your
>>> samples are only one pixel apart.
>>>
>>> You can also try doing three or four samples at a time instead of two;
>>> experiment a bit and see what gives the best performance.
>>
>> This is very slow.
>>
>
> Also I fixed silly center artifacts in rblur implementation.
>
> Speed here on historic CPU for hd720 is 12-13 frames per second for 23
> fps video with slice threading enabled on 4 core CPU.
>
> This could be made even faster at expense of more memory usage.
> I really doubt there is faster algorithm that needs less memory but
> with no quality drop.
>

Gonna apply this soon, as I'm happy with overall performance and output quality.