[nmzhizcn] Slideshow programs on Linux

Cursory research into programs in Linux which (might) show a slideshow of a bunch of images:

eog (especially consider the "Slideshow Shuffle" plugin in eog-plugins) qiv pqiv feh gnome-photos gthumb gwenview mirage phototonic viewnior xscreensaver

Selected pqiv which is small and did what I want.  Fading between images works, though is very CPU intensive and a little bit jerky for a slow 6 second fade.  Ought to use vector instructions, wherever they may be.