The Inconvenient Truth about SPDIF Input! - Page 3

Why I would like to get AC3 from a PS3 via a computer:
Story goes.. my son got a PS3 2 years ago. He also bought a Altec Lansing 5.1 loudspeaker set (no SPDIF) and a 22" LG HD ready computer monitor.
He's a PC gamer and a PS3 gamer. So it would be pretty cool for him to be able to get surround in his speakers from the computer as well as the PS3.

So we bought a X-FI PCI-Express sound card with SPDIF. I didn't even check wheter it would be possible to use it as surround option for his PS3 - I just thought "of course it will work". But reading a lot of sites, I have now come to the conclusion "not possible", actually with no sound card I know of. This is pretty shocking!!!
I guess the error is at the PS3. We really don't care if it's AC3, Digital or whatever, just we can get simple surround from the PS3 to the computer. We are living in 2010, aren't we?!??! I had my first PC gaming surround exprience almost 10 years ago, and I build my own surround receiver 15 years ago.

I was then hoping at least to use the CMSS-3D option on the X-Fi to generate some kond of fake surround via the PCM analog signal or via the SPDIF, but even that doesn't seem to be possible.

I could get my xbox 360 to output 2channel PCM on SPDIF and was able to use my x-FI titanium to hear the sound. There was no noticable lag.
That being said, whenever i switch the sound mode from dolby stereo to dolby 5.1 it just goes silent.
This is all under Window 7 x64
So I think if you disabled 5.1 out over SPDIF on the PS3 you should be able to hear sounds out of your PC speakers

akyhne, ferhanmm:
So long as you can get 2-channel pcm working, it's always possible to get some sort of fake 3d matrix manipulation working too. One way is to change the ac3filter settings (you can play around with it by opening graphstudio or graphedit, etc., and building a "graph" by adding the input device ("insert filter"), then adding ac3filter, then adding an output device. Then you can just tweak the ac3filter settings to distribute the 2channels to the 5 speakers.

I agree that it's shocking that we can't do something simple like this. Reading through these threads and everything, I think it's because of paranoia over copy protection, etc. It's a shame that this technology is arbitrarily limited like this.



I'd like to hear more details from the people that got this working. If the sound card we are using is NOT giving us bit-perfect reproduction of our input, and is resampling it or in some way corrupting it, what would it look like? Can anyone who has 5.1 spdif input working try to hook up an xbox 360 and give us info about the sample rate, etc. of the xbox 360's version of dolby digital? For instance, mine is not working, and my sample rate is detected as 44.1khz. I notice some people with working devices are detecting a 48khz rate with their device, but maybe that is a result of a different source device...? I'm still in way over my head; I've pretty much given up getting it to work... but not completely, I still want to play around with it. I think I've got xp installed, so I'll probably try to use different drivers with my device later...

Thanks again for the great thread, this is the best source of information about this topic on the web as far as I know

AC3 streams (Dolby Digital) whether mono, stereo, or 5.1 MUST be at 48khz.

I can only get the SPDIF to work with music, and only by recording the signal. Can't find the right option to enable live playback on the PC.
I also know it should be possible to make some kind of fake surround, but then you might as well use the analog signal anyway. I also heard that the sound would be delayed this way... no good solution for gaming.

Another possability was to skip the PC, then buy a set of Logitech Z-5500 Digital 5.1 Speaker System. They should be able to use the Dolby signal. But it's a pretty expensive solution.

Oh, I see, thanks for telling me. Clearly I really don't know what I'm doing, lol. I wonder why my computer is reporting the input to be 44.1..? I guess the sound card is resamping it and so it is impossible to use the input with my current setup...

I'm just curious as to what people believe to be the best card nowadays for digital-in of the various surround formats created by DD & DTS.
[they're responsible for 99% of SS encoded content right?]

Initially it'd only be for taking encoded content from my Xbox360 & Wi...
But soon it'd also be for a PS3 which for BD content I believe uses newer DD & DTS formats, namely: TrueHD, & HD MA.

Ideally it'd be happy to take any DTS/DD content thrown at it, & pass it to the appropriate (licensed) software for decoding.
[or hardware if there's a card that can do this]

Mostly I'd like to decode and run it through a stereo surround simulation scheme like; DH, CMSS, or DTS-SS.
But occasionally I'll decode/convert & do multi-channel analogue-out via my Essence ST + H6 (7.1 daughter-board).

I was investigating X-Fi cards but they seem to have regressed in this area recently, I hope it's not a conscious trend influenced by big content!
I'm yet to check out Auzentech and Xonar cards for this use....

Then I got to thinking, maybe HDMI-audio capable devices are better suited for this sort of thing than S/PDIF?
Perhaps there's sound-cards that can take HDMI-in, or if not graphics cards?

I know that currently "bit-stream in" for graphics cards acts only as a pass-through to AVR's etc.
The big question mark is if there's dvrs/software that can recognise this incoming bit-stream, & instead decompress it.
Then we have raw digital PCM ready for decoding...

I'm guessing this step is something deliberately kept in the realm of AVR's, but if there's a way, perhaps it's a better path than via S/PDIF?

Assuming a way is found...
Then it's a matter of redirecting the PCM stream to software or hardware (assuming there's cards) decoder/s.
And then (in my situation) have this decoded signal pass through the analogue output circuitry of an Essence ST + H6.

Utopia/profit!

have you read this thread?

Yes, perhaps I missed something...
I don't suppose you could explain why anything I've hypothesised is out of the realm of possibility?
I'd be most appreciative, thank-you.

There is no viable current solution for AC3-input decoding on the market.

Hmm, that doesn't attempt to clearly/logically refute each of the points raised.
So not sure how anyone could take it as gospel, but thanks for your input.

take it for what it's worth... I spent a LOT of time going down that path...

Well I have read of a few that have successfully done non-HD DD/DTS via S/PDIF using AC3Filter, or FFDShow, or Graphedit, and the right card/s.
But that's only part of what I'm hypothesising/asking.....

Happy Hypothesising

You know, one doesn't sound knowledgeable just by saying:
"LOLz, x can't be done, just trust me I know all".

People demonstrate knowledge by explaining the basis to their claims.
A nice by-product of that is that they get to help others.

No offense but I'm already weary of trusting you as an authority on this issue because of an earlier somewhat absolute statement:
"There is no viable current solution for AC3-input decoding on the market."

Which I know from my own readings is not entirely correct.

No offense intended, just highlighting the futility of your responses thus far.
Perhaps it's very late where you are, or you're just tired of explaining this issue.

Care to elucidate?

http://www.avsforum.com/avs-vb/showt...9#post18128579
http://ac3filter.net/forum/index.php?topic=130.15

There's a few other's I can't recall right now, will dig em up

From your second link:


hmmm...

I'm skeptical of those claims but I'll see if I can find one of those cards to test it. In the second link, he claims that it works for BD movies but not for games. I suspect that they are actually capturing 2 channel PCM audio and AC3 is encoding it to DD.

Come on, start adding something constructive instead of smug remarks.
It's easy to do that, anyone can do it, the idea is to try to forward progression in this area.

Anyone can read that others had success in that thread; albeit only for DTS/DD, not HD content.
Perhaps that is the limit, I'm not saying it isn't....

And with that I gotta go to bed, man it sucks being in different time-zone to mos of you guys!
Night.

HD audio cannot and never will be bitstreamed via S/PDIF. S/PDIF does not have the bandwidth to bitstream multichannel HD audio.

I'm not suggesting that, see earlier posts.
Thanks/night.

I'm guessing this is the problem I'm having at the moment. I'm trying to stream the spdif from my verizon fios stb to an EnMab-8cm on Windows 7, then out to my klipsch promedia ultra's... haven't tried the AC3-Filter/GraphEdit "fix" yet but will tonight. Currently I get just a clicking sound when I hook it all up, guessing that's the "not-yet-decoded" audio dumping out. God I hope this works with no delay, otherwise I guess I'd have to take a gamble with a Creative Card right?

jalyst, instead of asking how to decode on the input, you should be trying to make the HTPC your source for more media types, like Blu-ray. Yesterday I enjoyed watching/listening to Chris Botti Live In Boston on Blu-ray with my Essence ST and H6.

You asked these same questions last week on head-fi.org and got the same answer you are getting here.

DLNA might be the solution in the future, but so far I think that the PS3, X-Box, etc., are just DLNA receivers and can't stream data to the PC.

With all the brilliant minds registered to this forum and this quest having existed for 5+ years, don't you think this would have been solved back when SPDIF was king if it was feasible? It's not like nobody ever tried! But no, no sound answer exists that is easily implemented, user friendly and complete.

So the GraphEdit > AC3 Filter method worked on my WinXP machine, but not on my Win7 machine. However upon changing channels that tiny time between signals... it would make an uncomfortably loud squeelch. Sadly then I noticed it was going slightly out of sync with the tv speaker, it only recovered when i restarted the graph.

I suppose the next LOGICAL step would be, sell my Kenwood vr-616 and 5.1's. As well as my Klipsch ProMedia Ultra 5.1's, pool that cash with some birthday cash and buy a new receiver and 5.1 or 7.1 system, and get a better sound card for my HTPC.

Prolly the best solutions I've come across so far are: HDAV1.3 or Hometheatre HD

Quote: A main feature of the HTHD 7.1 is offering HDMI 1.3a I/O to the end user which allows full resolution, high definition audio with no down sampling. A very interesting feature of the HTHD 7.1 is the use of an external receiver is NOT required to have support for these high definition standards.
While the use of an external receiver is an option, the card allows any speaker system connected to the card to output Dolby Digital Plus, Dolby True HD and DTS-HDMA in full resolution.

What's not certain to me yet is whether these cards can decode & do dac to DTS/DD content (HD or non-HD) coming via HDMI, instead of locally.

Even more ideal would be to use my existing Core i3-530 + motherboard w/HDMI-in...
But I'm not sure if Intel HD Graphics is able to receive A/V via HDMI, let alone decode w/approp. s'ware & redirect to 3rd party DAC.
I doubt it's able to, nor do I expect it'd be possible with sw updates & right mobo/adapters, but TBH I'm not 100% certain!

The main reasons I want something like this is to;
1) Send digi-Audio (HD or non-HD) to my PC to create virtual surround in stereo (CMSS, DH etc)...
2) Have a PAP* compliant solution so I can receive & play or locally play HD A/V, for the times I'm too lazy to rip/transcode.

It's a shame that I prolly won't be able to redirect decoded DD & DTS formats to my Essence ST + H6 for superior analogue output.
I suspect that'd break the PAP/xxx....
So for analogue-out of received or locally played HD DD & DTS, I'll be forced to use the same card.
Unless I've gone to the effort of ripping & transcoding beforehand...

*forgotten what the video equivalent is called

Haven't read the whole thread...

How can the PC replace a receiver? The PC has no audio amplifiers.

There are amps in PCI/e form-factor, but the only ones implemented thus far are anaemic "wattage wise".
There are better ones, but they've been implemented as part of an entire mobo (MSI divia), which has many shortcomings itself.

It's still unclear if one of the other big OEMS like GB or Asus will take-up the tech too, there has been murmurings...
Doesn't bother me either way personally, as I'll prolly always use "discretes", whether I use a HTPC as part of the equation or not.

Anyway that's getting-off the focus of this thread, did anyone see my last post? Thank-you.

And the setup I was trying to use had powered speakers through a 500w BASH amp in the sub enclosure, Klipsch ProMedia Ultra 5.1.