Assuming RPMFusion is enabled (Configuration - RPM Fusion).
Have you tried enabling HW media decoding as per Howto/Multimedia - RPM Fusion instructions ? Are ffmpeg-free and ffmpeg packages installed ? Is the driver for HW accelerated decoding - intel-media-driver or libva-intel-driver for older Intel GPUs - installed ?
Which web browser do you use ? Is HW decoding enabled in the browser ?
That’s not all info
The best start is to post (in text, not a picture/screenshot) your system information from, e.g., GNOME Settings/About and then copy all details from there. In pre-F39 you will get it all on the same page, for F39 and later you will have to go to System Details, there you will have the Copy button
Next, provide the output of uname -a comand and be specific about what apps/commands you are using to achieve your goals. E.g., now we still have to guess which web browser you are using.
Later, more information from log files might be needed to debug your issue further, but the good habit is to start problem description with system information, OS (kernel) details and specific description on what (apps, CLI commands, etc) was used until problem happen.
And please regard everything above as good intentions to make your (and maybe others) problem reporting better - it saves your time at the end, it saves community members’ time and potentially your issues get fixed faster.