Can anyone recommend a good, professional quality test disc that will thoroughly demonstrate and test the various Dolby Digital encodings and allow one to verify that their system, player or pre/pro is decoding them properly?

For example, I would like to find something that tests "this signal when played through a DD PLIIx decoder should only be audible in the left-side channel" (rotating though the channels).

Also samples of the various DD encoding formats like TrueHD vs DD+ set up for quick A/B comparisons would be great. (Comparisons against dts and other encoding formats would be even better).

It might also be nice if the test disc included samples of improper encodings to see how your equipment handles them.

I have a copy of Avia which I find to be more filler than useful tests. Also I just acquired the THX Optimizer disc which as a useful phase test, but little else.

If such a thing doesn't exist, can anyone recommend software that could be used to create such a test? Thanks,