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Chumboy
19th December 2001, 15:51
if a movie has both AC3 2 channnel and AC3 6 channel, do i need to grab both or will just the 6 channel work?
Derrow
19th December 2001, 22:10
Just if you like director's comments.
Mostly the other 2 channel AC3 streams are director or whatever comments.
tenebrenz
20th December 2001, 21:15
I've got quite a lot of dvd's with both 5.1 and seperate 2.0 surround (not director's comments or anything) which is a real waste of space. Anyone know why they do this?
Deathman
20th December 2001, 22:33
DVD Specs require a 2ch audio track for compatibility reasons... although a lot of dvds these days dont follow the specs 100% anymore...
mpucoder
21st December 2001, 00:20
There is no requirement for a 2ch track. All that is mandated is that one track be AC3 or LPCM (and if it's PAL it may also be MPEG)
The usual difference is the 5.1 track is discrete surround, while the 2ch is Dolby Surround properly downmixed for Pro Logic decoders.

You were probably thinking of the requirement that all mPEG audio be backward compatible with 2ch decoders.