[FFmpeg-devel] [PATCH] avfilter: add ssim filter

[Paul B Mahol]

On 6/23/15, Nicolas George <george at nsup.org> wrote:
> Le quintidi 5 messidor, an CCXXIII, Paul B Mahol a ecrit :
>> Looks like there are no new comments so I can safely assume current
>> state as is is good enough.
>
> If you want to be really safe, you can observe that there is an unanswered
> question and assume that <20 hours is not enough to be sure there will be
> no
> answer. So here it is right now, since you use ultimatums:
>
>>> Just to put it into same file?
>>> Moving it into same filter would be also possible but how would then
>>> new filter be named then?
>
> That depends on the code, you know it better than me.
>
> If it often makes sense to compute both the PSNR and the SSIM, then a
> single
> filter would be preferred, especially if some of the computations can be
> used for both.

Well tiny_ssim computes PSNR from SSIM but numbers do not match other
implementations.
I'm sure that our MSE(and PSNR) calculations in vf_psnr.c matches
numbers from some page
linked from wikipedia.

Computations of PSNR and SSIM have not much in common. So the only
code that is actually
shared is set_meta() which could be moved to some other place in lavfi.

> If this is done in a single filter, various names come to mind: -vf quality
> is the most obvious.

I just do not like big filters, I made mistake putting multiple
different filters in single
histogram filter.