I've been experimenting with x265 via ffmpeg, encoding some TV episodes in HEVC. My experience is that it takes 3.5-7 seconds of CPU time to encode 1 second of video. (These are things like 576x432 resolution at roughly 700 kbps, or 704x528 resolution at 530 kbps.)<p>As for decoding performance, VLC appears to use 30-50% CPU when playing these videos back. (Haven't tried one at uber-high resolution yet.) As far as I'm concerned, if it's fast enough to never stutter, then that's the biggest goal it needs to hit, and beyond that, reducing power consumption is desirable but not too important.