vainfo の問題。vaInitialize がエラー コード -1 で失敗しました (不明な libva エラー)

Question

なぜこのようなことが起こるのでしょうか:

$ vainfo

libva info: VA-API version 1.7.0
libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/nvidia_drv_video.so
libva info: Found init function __vaDriverInit_1_0
GPU at BusId 0xa doesn't have a supported video decoder
libva error: /usr/lib/x86_64-linux-gnu/dri/nvidia_drv_video.so init failed
libva info: va_openDriver() returns -1
vaInitialize failed with error code -1 (unknown libva error),exit