Since I started experimenting with hardware video acceleration (hwdec=auto-safe) in mpv, ffmpeg has been outputting errors for various codecs (separate video files):
[ffmpeg/video] vc1: No support for codec vc1 profile 3.
[ffmpeg/video] h264: No support for codec h264 profile 100.
[ffmpeg/video] hevc: No support for codec hevc profile 1.
mpv itself occasionally reports:
Falling back to software decoding.
‘Direct rendering’ (HW acceleration) is enabled according to glxinfo.
It would be nice to know if you are running the limited codecs that are provided with fedora or if you have upgraded to the non-encumbered codecs that are provided from rpmfusion.
The limitations are partly from ffmpeg-free, libavcodec-free, and gstreamer1-plugins-ugly-free all of which come directly from fedora and do not support any codecs that are patent, license, or copyright encumbered. These can be replaced with the same packages but with slightly different names from rpmfusion. (libavcodec-freeworld, ffmpeg, and gstreamer1-plugins-ugly).
The related commands would be
sudo dnf swap ffmpeg-free ffmpeg
sudo dnf swap libavcodec-free libavcodec-freeworld
and
sudo dnf install gstreamer1-plugins-ugly
If not already done it might be necessary to enable the rpmfusion repos as shown here before running those commands. https://rpmfusion.org/Configuration