there is a standard for calculating the checksum of a thumbnail using md5sum, but in some file managers (dolphin, deepin-FM) it is considered in some other way.
For example, for a file whose absolute path is file:///media/home/file.mkv nautilus and caja create a thumbnail file named 682433b1f02832783d4cb739d2e705ff.png, which conforms to the standard,
echo -n "file:///media/home/file.mkv" | md5sum 682433b1f02832783d4cb739d2e705ff -
but dolphin create thumbnails named 682433b1f02832783d4cb739d2e705ff.png, 33a417e81b4f8894d1a23406e827a23b.png and 44feee170f71b4894f399af9f5a8eb33.png, deepin-FM create thumbnails named 668464f69987d58a1062a34490fc4dec.png.
Attention to the question, how (preferably a command or a link to the standard) checksums are calculated in the dolphin and deepin-FM file managers?
I tryed any commands md5sum <<< "file:///media/home/file.mkv"``echo "file:///media/home/file.mkv" | md5sum echo -e "file:///media/home/file.mkv" | md5sum its not work