I got some friend at work who seems to bable alot about stuff he doesn't know about.
I just wanted to tjek that this is indeed BS.

A:
mpeg2 cannot contain real surround audio, only mpeg4 can. And that is the difference between mpeg2 and mpeg4

B:
You cannot have dolby digital playback on a PC from a dvd.


According to things i've read on doom9 and HA this has to be WAY off... or i'm i wrong ?

1) MPEG2 certainly can deal with 5.1 audio, how else would DVD's work?

MPEG2 also includes AAC as an audio codec, which has always supported multiple channels.

2) "Why not". Of course DD (AC3) is decodable by software...


Important improvements in MPEG4 are MP4 file format, MPEG4 ASP video codec, MPEG4 AVC video codec, some extensions to AAC profiles...

These aac extesions would be SBR & PS & some tools for the AAC main profile ?

mpeg2 AAC Low complexity and mpeg4 AAC low complexity should be indentical regarding the compressed audio data itself ?

-- edit --

Does mpeg2 alone have the ability of 5.1 audio.
With one of the three layers encoder and not by using AC3 ?

Does AC3 belong at all as a substandard into the mpeg2 and mpeg4 standards?

AC3 isn't part of mpeg but mpeg-2 includes both aac and layer 2 which can handle surround audio.

No. They are PNS and AAC LTP profile.



Yes, but MPEG4 AAC LC can additionally contains PNS.

MPEG-2 AAC can handle from 1 to 48 audio channels, along with zero to 16 subwoofer channels, 0 to 16 overdub channels, and some other stuff that I have completely forgotten about. Strictly speaking, I presume that MPEG-2 AAC can handle 0 audio channels, but what's the point of that?

MPEG-2 Layer 2 and 3 can handle 2 and 5.1 channels, at least. MPEG-2 BC, while it can "handle" 5.1, does not do so in any fashion that you would generally wish to use.