I have been playing with Vivaldi browser recently. It is available from SBo, where the recommended dependencies are pepperflash-plugin, ffmpeg and vivaldi-codecs-ffmpeg-extra. However, I still seemed to experience problems with some websites content. Maybe I did something wrong…
So, what to do?
Apparently, all I had to do for Slackware64 was paste this in a terminal :
curl -L vvld.in/lm64|tail -c+1075|tar CxJ ~ --wildcards \*libffmpeg\.so --xform 's,.*/,.local/lib/vivaldi/,'