True, basically.
unfortunately your hardware is not really suitable for h265 hevc
I wouldn't recommend this resolution with a 650, but I have tried 4k with a 640gt ... 4k@h264 was perfectly, hevc with low bitrate too but software decoding with high bitrate hevc stuff makes no real sense and is very weak...
so back to ya problem, as i guessed your movie really is a hevc 10bit+ hdr and all very high quality. the tv episode is a tiny low bitrate file so that software decode will be enough...
btw. your mphc version is very old, it didn't even had fully integrate lav back then.
unfortunately your hardware is not really suitable for h265 hevc
I wouldn't recommend this resolution with a 650, but I have tried 4k with a 640gt ... 4k@h264 was perfectly, hevc with low bitrate too but software decoding with high bitrate hevc stuff makes no real sense and is very weak...
so back to ya problem, as i guessed your movie really is a hevc 10bit+ hdr and all very high quality. the tv episode is a tiny low bitrate file so that software decode will be enough...
but not with the higher quality stuff like the alita file...Overall bit rate : 416 kb/s
Overall bit rate : 15.5 Mb/s
btw. your mphc version is very old, it didn't even had fully integrate lav back then.