[libav-tools] Changing filter size for lanczos rescaling

Luca Barbato lu_zero at gentoo.org
Tue Aug 25 22:11:49 CEST 2015

On 25/08/15 19:36, Zehan Wang wrote:
> Hi
> I was just wondering how I could change the filter size when I rescale
> videos with the lanczos filter?
> I've tried specifying -sws_flags lanczos -param0 <filterSize> but
> specifying -param0 doesn't really seem to change anything...
> Any help here would be greatly appreciated.

in utils.c I see

        else if (flags & SWS_LANCZOS)
            sizeFactor = param[0] != SWS_PARAM_DEFAULT ? ceil(2 *
param[0]) : 6;

So it should work in theory.


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