7.1 audio from HTPC questions

One of the main reasons I am thinking of going HTPC over separate components is that my surround sound receiver is only capable of HDMI pass-through of video and I will need to use the 7.1 analog audio inputs in order to listen to Dolby TrueHD or DTS-MA.

Is there a software BD/HD-DVD player that will decode the 7.1 surround track? I have heard that PowerDVD does not handle this process yet.

Will it be possible to make speaker setup adjustments with the HTPC? For example, setting up speaker placement distances to adjust for delay and setting crossover frequency. Would these adjustments be done in the DVD player software or some other software?

Is there a way to use a microphone with a sound card and software to make Audyssey room adjustments?

My receiver sounds great with DVDs using Dolby Digital EX and the Audyssey adjustments, but the only way to take full advantage of 7.1 surround with it is through the analog inputs. I would lose the Audyssey and speaker placement adjustments when using the 8-channel analog inputs. If these adjustments cannot be made with a HTPC, it may be better to continue using Dolby Digital EX.

I guess those will be the only two movies ever with a 7.1 discrete sound track.

I understand that the source material for 7.1 discrete is not at all prevalent today, but this is not a good reason to ignore the hardware and software requirements to play Dolby TrueHD or DTS-MA. Your argument is like Henry Ford saying "why bother making cars when there's no good roads?"

Thanks for the input. It sounds like the CE gear is ahead of HTPC in regard to fully implementing all the benefits of the Blu-Ray and HD-DVD specs at this time, mostly due to the challenges of DRM (from what I've gathered elsewhere - lack of a "protected audio path" in Vista).

Because I need to use the analog inputs to my receiver to get discrete 7.1, I would lose the speaker calibrations unless they were available in my HD-DVD or Blu-Ray player. It seems like speaker calibration would be a very worthwhile feature to implement with quality sound cards. I have to believe that there would be some demand for it as more people go the HTPC route.

Isn't the whole point of buying a good sound card in a HTPC to upgrade the DACs and ADCs compared to those on the mobo? A digital signal that has not undergone any DA or AD conversion in the computer should be the same whether from the on-board output or a sound card. If that's the case, the real benefit of having a good sound card would only be realized when sending an analog signal from the HTPC to an amp. The HTPC should handle all the DSP, including speaker/room adjustments in this case, otherwise a AD-DA conversion would need to be added by the receiver to handle those adjustments.

Anyway, looks like I will be very happy with my upscaling DVD, Dolby D-EX and Audyssey for now and wait on Blu-Ray and HD-DVD are cheaper and/or the HTPC implementation of Blu-Ray, HD-DVD, and D* or CableCard improve. Receivers capable of decoding Dolby TrueHD and DTS-MA are becoming very affordable now, so upgrading the receiver could be the most hassle-free option.