Ok here are some updates. We managed to fix most of the hw decoding issues and playback is now as smooth as we know it from 3.14 gxm,gxl and gxbb devices. Just some little things remaining but this is already alpha/beta quality and can be used to watch stuff. Audio is also mostly fixed. Some DD+ samples make some trouble.
I was able to do some power consumption tests today with my good power meter:
Netflix 1080p SW decoding through widevine 4.2W top, temperature stays low playback is smooth.
1080p HEVC video SW decoding 4.1W top, low stable temp and smooth playback.
Same video with HW decoding 2.7W, low stable temp and smooth playback.
4K 60Hz HDR HEVC video with HW decoding 3.5W, low temp and smooth playback. SW decoding for this video was too much to play smooth.
N2 off 0.7W