notes

If you are experiencing high CPU usage when watching videos on youtube, verify that the following packages are installed (requires RPMFusion repository):

# RPMFuison repositories
sudo dnf install https://mirrors.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm https://mirrors.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm

# Codecs
sudo dnf install gstreamer1-plugins-{bad-\*,good-\*,base} gstreamer1-plugin-openh264 gstreamer1-libav --exclude=gstreamer1-plugins-bad-free-devel
sudo dnf install lame\* --exclude=lame-devel
sudo dnf group upgrade --with-optional Multimedia

CPU usage for i3-8100T is down from 80% to 50% with this video sample

I’ve started to experience quite high CPU usage when watching youtube videos on 1440p screen (video sample). By default, youtube loads videos in VP9 codec. Using this codec results in 80% CPU usage (i3-8100T). By installing this extension enhanced-h264ify and by blocking VP8, VP9 and AV1, youtube will load videos in avc1(h.264) codec. The CPU usage is down to about 30%.

Unfortunately, this will disable all 4k videos - they are available only in VP9.