The file exists at /gnu/store/mwcgqw9ggi02p8mhzac8cg0x671j7wd1-mesa-20.2.4/lib/vdpau/libvdpau_radeonsi.so but it doesn't seem to be found (by libva?). Videos still play. Probably requires a Radeon card to reproduce. I got confused trying to figure out where exactly its loaded.
libva info: VA-API version 1.10.0 libva info: Trying to open /gnu/store/gvncg7gzdzjx0gvyi4sm02m7qgnsmx5q-mesa-20.2.4/lib/dri/radeonsi_drv_video.so libva info: Found init function __vaDriverInit_1_10 libva info: va_openDriver() returns 0 [00007f6928001f80] glconv_vaapi_x11 gl error: vaDeriveImage: operation failed [00007f69240ba3a0] main video output error: video output creation failed [00007f69e8c929f0] main decoder error: failed to create video output Failed to open VDPAU backend libvdpau_radeonsi.so: cannot open shared object file: No such file or directory Failed to open VDPAU backend libvdpau_radeonsi.so: cannot open shared object file: No such file or directory
