Assigning Listening Modes for Onkyo TX-SR 705

fsabelis

Is it necessary or better for me to assign default listening modes to each input source? or does the receiver automatically detect the format of the signal coming in and choose the appropriate listening mode?
I just set up my Onkyo 705 and have a PS3 running through it via HDMI, and a 5.1 speaker setup. From what I've read on some of the threads, the PS3 processes the audio and sends it to the receiver via multichannel PCM (I think!!) So this is where I got confused......
The receiver allows me to assign default listening modes to each input source for all the different signal formats that it might receive from that source. So it asks me which listening mode for each type of signal.......Analog/PCM, Dolby digital, DTS, etc.....
First of all, I don't know which modes I should choose for each signal and second, if everything coming from the PS3 is multichannel PCM should I even bother with this. Thirdly, if i shouldn't even bother with it, what listening mode should I set the receiver to when watching a BluRay or DVD......Pure Audio, Direct, Multichannel? or does the receiver auto choose it.
This may seem simple to some, but i'm REALLY confused! Help