Stefan, because you have Nvidia setup - can you test if using this wrapper actually works with cingg set to vaapi decode accel, and if yes test performance in this specific case with hw accel? May be modern gpu can brute-force their way around slow seeking (as far as I understand you can', in common case seek to arbitrary frame in long-gop video without decoding quite a lot of in-between frames. So having two "views" into same compressed file require constant re-decoding while playing/seeking)