...playback? I need to know what the TRIANGLE, CIRCLE, X, SQUARE, L1, L2, L3, R1, R2, R3, START and SELECT buttons do during DVD/BluRay playback.

just hit the triangle and the controls will pop out on the screen. then to navigate this controls, you would just need to use the directional buttons (up, down' left anf right) to choose a command then X to activate it. press triangle again to close the command window.