I apologise for my unnecessary jibe, monacoger You are a much-valued friend and forum member and it was not my intention to cause offence, and I hope that you will forgive my crassness Erik
If those timbers are weight bearing then I'd suggest getting straps from Amazon that you can hang hammocks or punch bags from, it would save you the bother of trying to fix brackets to the walls. Make sure your carabiner is up to the job as they are often the weak point. Handy to have if anyone needs to do a Speedy too. please log in to view this image
No brackets were ever going to be going into the wall, the "brackets" I posted were I assume for safety so the rope didn't slip. The strap things you mean are good right enough, have them on my back terrace for one of those big circular swings for the kids.
