Hi everyone,
I am running fedora kde and have an interesting behaviour:
I have some videos shot with a gopro, dragonplayer crashing when trying to watch them.
After installing vlc media player I noticed, that dragonplayer now works too.

How can I determine what VLC media player is installing additionaly? I think there is something missing with dragonplayer… (I want to uninstall VLC, I like dragonplayer better)

Best regards,
Manuel

Try to launch Dragonplayer from the command line. It should display errors there. I am reading GoPro encodes in H264 or H265 HEVC formats. There could be some issue with codecs and/or GPU drivers.

In my case, using Totem (Video) on Gnome, I could not play H264 videos until I installed gstreamer1.vaapi package.

When trying to run from command line at first I see a lot of lines with

QPainter::fillRect: Painter not active
and after that there is
[00007f43e8086710] gstdecode decoder: got new caps video/x-raw, format=(string)I420, width=(int)1920, height=(int)1080, interlace-mode=(string)progressive, pixel-aspect-ratio=(fraction)1/1, chroma-site=(string)mpeg2, colorimetry=(string)1:3:5:1, framerate=(fraction)60000/1001
[00007f43dc138100] chain filter error: Too high level of recursion (3)
[00007f43dd1d8ee0] main filter error: Failed to create video converter
KCrash: Application 'dragon' crashing... crashRecursionCounter = 2
Speicherzugriffsfehler (Speicherabzug geschrieben)
I tried installing gpm-libs and aalib-libs (because I found this one get installed by VLC), but these alone does not seem to help dragonplayer at all.
              
This thread was marked as solved. Is the solution to not use Dragon player?

I guess I will do that for now.

I am having the exact same problems as the OP, did all rpmfusion instructions and still cannot play video in Dragon player.
              
There are many different players out there.
Haruna is the KDE MPV GUI, Celluloid for GTK.
Dragonplayer is the gstreamer GUI for KDE, Glide for GTK.
In my experience MPV works better.
              
Well, I have tried mpv. It works, the interface is nice and simple. Can’t ask for more for now.

thanks to all of you.
And to make it clear. I installed everything I could, following the full instructions at rpmfusion: Howto/Multimedia - RPM Fusion

and Dragon player refuses to play videos.  VLC does work on the other hand (it does not scale in KDE, separate issue). I did not install the Sound and Video group, that would have brought in a bunch of packages that I did not want to install (VLC included)