There's radeontop, but it doesn't seem to say anything about video acceleration. mpv does say what it uses and complains when you ask it to do something unsuppo

There's radeontop, but it doesn't seem to say anything about video acceleration. mpv does say what it uses and complains when you ask it to do something unsupported, and since there's a clear difference in CPU usage between hardware and software decoding, I figure CPU use is a good enough indicator.