#webkit (for #epiphany) needed a small patch (https://trac.webkit.org/changeset/273960/webkit) to leverage the #gstreamer work that accelerates #h264 on the #librem5 (https://social.librem.one/@agx/105799071793016596). Resource usage did drop but not as much as i'd expected so there's more debugging needed.
Situation improves further when bringing the #arm64 #pixman optimizations forward to #PureOS #Byzantium (https://gitlab.freedesktop.org/pixman/pixman/-/merge_requests/20) which were only in amber-phone and which everyone needs to pull since it's not merged in #pixman upstream.
