HDMI is your best option. You need 4 in total.
One from the computer to the Yamaha.
One from your DirectTv to your Yamaha.
One from your Sony Blu-Ray player to your Yamaha.
One from your Yamaha to your TV.
Depending on the Yamaha, you might have to run a TOSLINK fiber cable from either AV1 or AV4 to your computer's Optical Out connector. You'll then have to (if possible) go into the menu and assign the HDMI to whichever input you plugged the TOSLINK into.
I haven't read through the manual of your receiver, you'll have to check into that.