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Topic: AC3 5.0 Problem (yes 5.0) (Read 2692 times) previous topic - next topic
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AC3 5.0 Problem (yes 5.0)

[Please note I have posted to Doom9.org as well as I thought this might be a more DVD related problem as just apposed to audio]

Ever encoded AC3 5.1 (including LFE) and come out with a DVD that has only Dolby Digital (that's what DVD players call it) and as DVD Decrypter calls it, Dolby Digital 5.0?

My problem is that some decoders do not decode it as 5.1 and some do. Demuxing the AC3 from the VOB and decoding it (BeSweet) gives 6 discreet channels, including LFE. So really it should be 5.1.

Anyone have any idea of what could be the problem?
 

AC3 5.0 Problem (yes 5.0)

Reply #1 –
ay takkun.

had a bit of a google, and i'm convinced it's a metadata problem.

unfortunately i've yet to find an app that can modify ac3 metadata, and if i did, it would be difficult to change the stream flags without possibly breaking compatibility with other decoders (i'd assume that in theory if an ac3 stream has had it's metadata modified but not it's actual data that it would probably not be standard compliant anymore).

here's a thread that proved *semi* useful, and a couple links off that thread to some possibly interesting specs that i haven't looked at yet.

http://www.audiocourses.com/postt442.html

http://www.dolby.com/tech/desgnac3.pdf

and in particular this one:
http://www.dolby.com/products/DP571/571_2_3.pdf


[edit]

oh... i'm not sure that link was all that useful after all.  but take a look.

see you tomorrow...