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Dolby TrueHD from Media Centre PC to receiver

post #1 of 4
9/29/09 at 9:54am
Thread Starter 

I've recently upgraded my home theatre PC to HD by changing the DVD unit to an LG Blu-Ray player and installing an ATI 4670 graphics card. This passes the digital audio stream directly to the receiver (Onkyo TX-SR607) over the HDMI connection.

However, this doesn't work for HD. It seems to pass the audio for everything except Dolby TrueHD and DTS HD sound - something to do with copy protection?

If I connect the digital tos-link cable from the motherboard digital output to the receiver, will it carry the TrueHD signals? If not, do I have to get a separate sound card?

Thank you: Terry Farrell

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post #2 of 4
9/29/09 at 11:50am
hi Terry,

i wish i could link you to 'the other site' where there is a lot of resources that talk about this, but in brief:
-Radeon 4xxx series has the technical capabilities to pass TrueHD/DTS-HD MA bitstream BUT not the copyright mechanisms that hollywood wants (PAP, which stands for protected audio path). in the meantime, you can use LPCM 7.1 or 5.1 from card to AV Receiver, but because you don't have PAP, your software will down-sample everything to 16-bit/48kHz (even if your content is 24-bit/96kHz or 24/192, etc.).

if you purchase a PAP-card from Auzentech:
http://www.auzentech.com/site/products/x-fi_hometheater_hd.php
or Asus Xonar HDA:
http://benchmarkreviews.com/index.php?option=com_content&task=view&id=341&Itemid=59

THEN you can pass bitstream.

but if you are willing to sell your current 4670, you can buy a NEWER 5800 series card:
http://www.amd.com/us/products/desktop/graphics/ati-radeon-hd-5000/hd-5870/Pages/ati-radeon-hd-5870-specifications.aspx

taht DOES have PAP and CAN pass bitstream. i know, i know, it's never-ending, but 5800 should be it ;).
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post #3 of 4
10/2/09 at 9:31am
Thread Starter 
Thanks for those explanations. I have discovered that I wasn't getting the 7.1 (downsampled) because the graphics card setup had defaulted itself to 5.1. I shall look into those solutions you suggest.

PAP rhymes nicely with CR*P.

Why they bother is beyond me as PAP was cracked yonks ago. If they want to stop users file swapping, all they need to do is to let people download movies in HD and bring down the prices. But they will never stop piracy (villans duplicating DVD).

Terry
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post #4 of 4
10/13/09 at 11:43am
Thread Starter 

I found another - cheaper - way to achieve this. I updated PowerDVD 7.3 (came bundled with my LG Blu-Ray ROM drive) to PowerDVD 9 Ultra ($59). PowerDVD 9 Ultra is able to decode PAP and pass uncompressed Dobly TrueHD and DTS HD through the graphics card HDMI output. It is also Win 7 compatible.

I've tested it and it works a treat. I asked ATI (AMD) if there may be a firmware update to other graphics cards (like my HD4670) to pass Dolby TrueHD and they relied that they don't have any plans at the moment. I suppose that will help sell more replacement cards!

Terry

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