AC3 = Dolby Digital it can be 5.1 or 2 Channels. MP4 does supports only AAC
Ok, the codec used to encode(compress) this video from a HD is x264. There are pre-defined/default settings (Format Profile) on how to do it, now thats application-varied.
Mostly HD/BD-Rips uses "Format Profile" > High Profile. This ranges from High Profile 1 to High Profile 5.1 as of now. PS3/XBOX can take upto High Profile 4.1.
Then again, these default settings can be changed as the "encoder" wish. This may cause compatible issue with these consoles as they are set-up for default specs.
You can get "MediaInfo" (Link -PM'ed) to know all Video/Audio Specs. Also, I was told rather than converting to "mp4" it can be "M2TS" (Video extension for BD) (Guides - PM'ed). And also PM'ed links to encoders > console-compatible BD/HD/DVD Rips