[FFmpeg-user] fftfilt

Michael Koch astroelectronic at t-online.de
Mon Oct 18 21:40:04 EEST 2021


Am 14.10.2021 um 23:34 schrieb Michael Koch:
> Am 14.10.2021 um 16:13 schrieb Michael Koch:
>>
>> This is the command line for the lowpass filter, where the filter 
>> freqency isn't a function of input size. The constant "8" is the 
>> filter wavelength in pixels per linepair.
>>
>> ffmpeg -i test.png -vf 
>> scale=2*iw:2*ih,fftfilt=dc_Y=0:dc_U=0:dc_V=0:weight_Y='lte(hypot(X/pow(2,ceil(log(ceil(W*10/9))/log(2))),Y/pow(2,ceil(log(ceil(H*10/9))/log(2)))),1.0/8)':weight_U=1:weight_V=1,scale=iw/2:ih/2 
>> -y lowpass.png
>>
>> With two new variables for the FFT array size
>>
>> ARRAY_H = pow(2,ceil(log(ceil(W*10/9))/log(2)))
>> ARRAY_V = pow(2,ceil(log(ceil(H*10/9))/log(2)))
>>
>
> Thanks for the patch. I will test it in a few days.

Tested and working fine.

Thanks,
Michael



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