How to determine the channel mapping (channel-to-track allocation) of a surround sound audio signal?

I'm working on a system that where I'm processing surround sound signals (Dolby Digital 5.1) real-time.

Because it's a real-time application I don't know in prior what kind of channelmap the audio signal has. There are a variety of different configurations (FL,C,FR,LF,BL,BR)(FL,FR,C,BL,BR,LF) and so on..

So far I think there might be some pattern in which audio codec the audio signals are encoded in (.ac3, .dts, .aac), but no certainty.

DD 5.1 only puts out recommendations and guidelines, but again no pre-specified configurations.

How do I determine the channelmapping based only on my 6-channel input stream? Does it contain some kind of header information maybe?

FYI I'm working in Matlab using their Audio System Toolbox.

Answer 1

[Jimmy Lapierre]

The proper order according to SMPTE is:

Front Left, Front Right, Center, LFE, Surround Left, Surround Right.

This is also the order they should be found in a WAV file (spec).