Safari Video Freezing Unless Cursor Moved - SOLVED (for me)

This problem has been discussed on many threads on the Apple forums. The symptoms that I'm referring to are:

- YouTube videos freeze while audio plays on, but moving the mouse cursor unfreezes it temporarily.

- This is mainly reported as a Safari problem, and some people suggest other browsers might not have the problem.

- All video actually freezes, although most people notice it on YouTube.

- Something not noticed is that this actually affects some screen savers, like scrolling photos.

The usual solutions offered include removing extensions and add-ons, resetting Safari, clearing the Safari caches, rebooting, and various others. For me, none of these worked. I also monitored CPU and memory, plus GPU and memory, and it wasn't this.

The answer for me was to reset the PRAM. There are many articles on how to do this, and I suggest you search for them, but in a nutshell:

- Shut down the Mac completely.

- Hold down Alt(option), Command, 'P' and 'R'.

- Turn on the Mac. For this you will require at least 3 hands. Keep holding down those four keys. You should hear the bong twice. At this point you can let go.

- A menu might pop up offering to restore the Mac from Time Machine, or restore OSX completely, plus some other utilities. You can dismiss this, and the Mac will reboot again.

- For the above steps, I had to plug my wireless trackpad and keyboard in to the Mac directly using Lightning cables, but that might just have been me. Perhaps Bluetooth was disabled.

Once the Mac is finally back up, you might want to check some System Preferences for display and keyboard.

If you have the symptoms I described above, then I think resetting the PRAM will help.

Adam