Never mind. I got it working. As I mentioned previously, the symlink of render0 to card0 does not get created by the post init script. I moved these commands into jail's exec_poststart as Duffyx did. It did the trick. Now, the transcoding page of emby is showing the hardware options for both encoders and decoders. However, I don't know why H.265 option is not shown. Also, I encoded a sample video file with and without hardware option but find out there is no difference on performance. I wonder w