[FFmpeg-devel] How to correctly use init and uninit

[Ulf Zibis]

Am 19.04.19 um 14:35 schrieb Paul B Mahol:
>>> You do not need to use loop filter on single png.
>> I need real pictures to prove the correctness of my hacking. The
>> smptebars is not appopriate to see errors in the output e.g. from mirroring.
>>
>>> Use something like this:
>>>
>>> ffmpeg -f lavfi -i smptebars=size=hd720 -vf fillborders=... -f null -
>> For performance testing I use the like:
>> -f rawvideo -pix_fmt gray16 -s 400x600 -i /dev/zero
>>
>> Are there doubts if that is good either?
> Use ffmpeg -f lavfi -i color=color=black:size=400x600 ...
>
> Thing about /dev/zero and -f rawvideo is that it will decode zeroes
> over and over again and thus use more CPU for that.

I can not confirm that. :-(

My benchmark needs 60 seconds with
ffmpeg -f lavfi -i
color=color=black:size=400x600,format=rgba64/gray/gray16 ...
but only 25 seconds with
ffmpeg -f rawvideo -pix_fmt rgba64/gray/gray16 -s 400x600 -i /dev/zero ...

-Ult