[FFmpeg-devel] [PATCHv2] lavfi: add gblur_opencl filter

[Dylan Fernando]

On Sun, May 12, 2019 at 10:47 PM Paul B Mahol <onemda at gmail.com> wrote:

> On 5/8/19, Song, Ruiling <ruiling.song at intel.com> wrote:
> >
> >
> >> -----Original Message-----
> >> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On Behalf
> >> Of Dylan Fernando
> >> Sent: Tuesday, May 7, 2019 8:27 AM
> >> To: ffmpeg-devel at ffmpeg.org
> >> Subject: Re: [FFmpeg-devel] [PATCHv2] lavfi: add gblur_opencl filter
> >>
> >> Anyone have any comments/feedback?
> > I think unsharp_opencl with a negative amount should do similar thing as
> > this one.
>
> Not really.
>
> > What's the difference? Better quality? or better speed?
>
> This one can blur image with larger radius.
>
> But why step parameter was removed?
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This one doesn't use a Gaussian approximation, it uses a Gaussian kernel
calculated with:
matrix_horiz[i] = (1 / sqrt(2 * 3.14159*pow(s->sigma, 2)))*exp(-(pow(x, 2)
/ (2 * pow(s->sigma, 2))))
with kernel size 6 * sigma.
Should there be a parameter for adjusting the kernel size?