there is interesting commit about memcpy vs memmove.

i extracted two specific cases and they compile, but not sure how well they work

Also, from late commit messages we see post 7.4 Cin  HV  might work with hw accelerated rendering (not just preview) via opengl ...also hw decoding via ffmpeg 5.1! and fps counter in compositor (but in place of safe regions ....so I not very motivated to copy/paste this change as is, even if it fix one of our BT wishes....)