vaapi
- The GPU wasn't to blame
I wrote that this Radeon 780M can't decode HEVC Main 10 on the GPU. It can. Fedora's Mesa build leaves HEVC out; ffmpeg exits 0 anyway.
- Enable VA-API HEVC decode on Fedora with an AMD GPU
Make an AMD GPU decode HEVC through VA-API on Fedora: check the hardware and the driver, install RPM Fusion's freeworld driver, prove it with a test clip.