Nicely done but I can't believe that your Oppo has a lesser quality picture than Direct TV, as you are correct in that the Signal is highly compressed ans the Oppo shouldn't be. Could be your set prefers a 720P signal as its preset definition(lines of resolution).

Here is a very lengthy discussion on the subject.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70