as mentioned 3.1 may be a good option. I can't see surround backs in this room for 7.1 but it may be possible to wall mount surround speakers to get 5.1 but the problem is the positions to correctly place these speakers to get a proper placment are not ideal. They should be between your seated ear level and 2' above ear level and positioned a couple of fee behind the couch on the side walls. The left speaker would almost be where the head of that animal skin should be if it had one and the right speaker would be next to the fireplace on the opposite side. Hiding the wires well can be an issue sometimes. Also anyone sitting close to the surround speaker will not get a great experience.
Another interesting idea is that you can run 2-4 Atmos/DTS:X speakers in your room. You can get ceiling mounted speakers if you have easy access to the ceiling space. But you also have those beams you may be able to use. you either have two speakers in top middle position which is I think a couple of feet down one of those beams. Or you can do 4 channels and use Top Front and Top Rear speakers (AVR's that support 4 height channels cost a bit more though as 2 channel support height support is in many entry level units now.) you seem to have tow beams that almost perfectly line up with the ideal Front Left and Front Right speaker positions which is ideal as top speakers are meant to be in the same line. You can reuse the speaker mounts you already have for those existing speakers and just move them to the new positions and get a small satellite speaker that matches your LCR speakers well if possible. Would be interesting to try a 3.1.4 atmos/DTS:X setup as this will give you a sort of surround sound experience with sound coming from behind even though you lack the normally important surround speakers. You have to apply the dolby/DTS upmixers to get the height channels to do this though and so you would have the option to leave them off if you want simpler 3.1/2.1 sound for some sources.
View attachment 18329
FL= Front Left position
TF = Top Front left position (would be right positions two beams over)
TM = Top Middle for 2 height channels only
TR = Top Rear
SL = Surround Left
For the top speakers you need to measure the angles to get the best position but you are looking for around 45 degree angles front and back for TF/TR speakers from your head position when seated. This may put the speakers much further forward and back than my picture above as it is hard for me to know the correct positions based on a single photo.
Maybe the surround speakers in the rear corners as they are now if you get the L/C/R speakers well positioned may also sound ok. Also note that as mentioned above your room with lots of reflective surfaces is going to have a HUGE impact on your sound if you don't do something about it. Getting good AVR based room correction may help a little but correcting the problem directly will give better results.
