Whenever i use a Video player that uses the AV1PRO encoder, on playback it severely lowers my GPU usage and everything else, making my fps drop to 17 fps and my windows to become laggy too
My PC:
CPU - Intel i7 8700 (with integrated graphics)
GPU - RX 5700 XT (Latest AMD drivers 25.6.3)
RAM - DDR4 16gb
Windows 11 24H2
I tried verifying the file integrity through steam, nothing really changed after doing so. And I cannot find any discussion about this problem.
In VRChat AMD GPUs have hardware accelerated video decoding disabled by default, meaning the CPU must handle this work, this is fine at 720P and lower with 1080P being fine for good CPUs, but above that especially at 4k it gets messy for the vast majority of CPUs.
The reason itās disabled on AMD GPUs is AMD for quite a while didnāt really have good video encoders / decoders, so if VRChat didnāt do this the video would become abnormally dark to the point you canāt see anything on the screen.
Itās actually why some video players have a brightness slider.
You can re-enable it by adding a launch option in Steam, specifically you will want to try the one listed below. This should fix performance with video players but may introduce issues with the video itself.
--enable-hw-video-decoding
Thank you so much! This fixed it, and so far i havenāt seen any problems with the videos themselves, i can finally go on my homeworld without having to turn off the tv haha.
One thing though, there needs to be two dashes at the start of the command ā- -ā for it to work, the forum may have turned them into a long dash haha. Again tysm 
