Dolby true HD and DTS-HD Master audio on the PC

dan dare · 21 Jul 2008 at 15:55

I must confess that I am more than a little confused with the whole subject of HD audio and how to get at it on the pc.

After digesting the following info:

http://www.hometheatermag.com/advicefromtheexperts/508audio/

http://www.highdefdigest.com/news/s...igh-Def_FAQ:_Is_HDMI_1.3_Really_Necessary/853

I conclude the following;

1. The only interconnect that will support the transmission of the raw/native HD audio bitstream is HDMI 1.3.
2. Number (1) applies only to the movie soundtrack itself. From the second link I get the impression this is for HD discs only authored in “Basic mode”?
3. Because most HD discs are not authored in “Basic mode” but rather in “Advanced mode” then (1) will rarely be achieved since the sound card or disc player will have to decode the HD audio to multi-channel PCM and do whatever mixing is required before outputting the audio (over HDMI).
4. The obvious difference between (1) and (3) is that in (1) the AV receiver does the decoding and in (3) the sound card or player does the decoding. This won't be too much of a problem if your sound card or player does the decoding well?
5. Anyone with a player or soundcard (pre-HDMI 1.3) that will decode the latest HD audio, and with an AV receiver (pre-HDMI 1.3), will be able to enjoy full-fat HD audio using method (3). Of course I don’t believe that any pre 1.3 HDMI sound cards exist?
6. I keep reading that the latest HD audio can be decoded and converted to analogue and sent over normal 6 or 8 channel analogue connectors. For example I think the Realtek integrated audio chip (ALC889) can decode the new HD audio bitstreams. Can anybody confirm this or must we all have HDMI equipped sound cards and AV receivers?

I have probably misinterpreted some/all of this stuff so apologies in advance.

craptakular · 21 Jul 2008 at 21:41

im really not sure, best asking over at avforums.com

dan dare · 23 Jul 2008 at 08:13

HD sound on the PC : Realtek 889a chip and Powerdvd

Oxy said:
im really not sure, best asking over at avforums.com

Thanks for the reply. Upon searching AVforums I came across this;

http://www.avforums.com/forums/showthread.php?t=748769

It seems Powerdvd, even version 8, currently downsamples the new HD audio bitstreams when getting sound back from the Realtek ALC889a audio chip. The reason of course is HDCP encryption. The way I interpret this is that Realtek implement a bespoke method of encryption and that powerdvd needs to ensure this method complies with various standards enforced by film studios etc. The following press release on Cyberlink's web site suggests a patch will be available later this year to allow the Realtek ALC889 chip to work with powerdvd.

http://www.cyberlink.com/eng/press_room/view_1725.html

Still not sure whether sound will be allowed to transmit over 6 or 8 channel analogue cables.

james.miller · 23 Jul 2008 at 13:08

its a pain in the arse, basically, and (one of) the reason(s) i cant be bothered with HD playback on my pc any more. we've had the software and drivers long enough, these issues should have been sorted out by now.

still, at least the hdmi soundcards arent too far off i guess.

Energize · 23 Jul 2008 at 20:59

dan dare said:
6. I keep reading that the latest HD audio can be decoded and converted to analogue and sent over normal 6 or 8 channel analogue connectors.

That's correct, when the pc has decoded an audio signal you can send it over the analogue connectors.

dan dare · 25 Jul 2008 at 07:51

Energize said:
That's correct, when the pc has decoded an audio signal you can send it over the analogue connectors.

This is good! It seems then that anyone with the Realtek ALC889 audio chip will be able to enjoy the new HD audio sound tracks (at least with Powerdvd when Cyberlink have released their patch). Furthermore anyone with a sound card or integrated sound that does the HD decoding should be able to listen to the new HD audio sound tracks subject to HDCP issues with that card/chip and Powerdvd.

Although an AV receiver and a good 5.1 surround sound setup will make the most of these new soundtracks (with HDMI connectivity or not), at least people can go down the computer speaker route. For example I have the Logitech z5400 system in a 5.1 surround sound setup with my media centre pc and it sounds quite good in a small viewing area.

Thanks for the replies.