AC3 decoding

spellinn · Oct 14, 2003, 04:55 PM

From the latest release notes, kX now supports AC/3 decoding on 10k2-based cards. I have some questions :

Is this a purely CPU-based decoder, or does it use any of the DSP/hardware features present on the 10k2? Is this the same method as Creative use in their implementation of AC/3 decoding?

Can it decode AC3 passed to it over the PCI bus (ie from a software DVD player) or AC3 fed into the S/PDIF input? (or both methods?)

Cheers,

Neil

FieroGT · Nov 1, 2003, 09:46 PM

ya, i would also like to know? i got a sblive 5.1, will it work??????? need it bad!

thanx

Rob

Max M. · Nov 1, 2003, 10:19 PM

Lives (10k1 based cards) has following features under kX (today):

Decoding of ac3 from software player - yes
Decoding of ac3 from spdif input - no
Passing ac3 from software player to spdif-out - no
Passing ac3 from spdif-in to spdif-out - yes

Audigy X (10k2 based cards):

Decoding of ac3 from software player - yes
Decoding of ac3 from spdif input - yes
Passing ac3 from software player to spdif-out - yes
Passing ac3 from spdif-in to spdif-out - yes

----
(although some users reported they can't get "Passing ac3 from software player to spdif-out" to work properly)

luterry24 · Nov 22, 2003, 12:06 AM

can tell me how to connect them in dsp??

Max M. · Nov 22, 2003, 10:01 AM

you cannot "connect them in dsp" since none of these functions are performed by dsp... you configure them at main kxmixer page instead.

HunterZ · Nov 23, 2003, 02:32 AM

How do I configure my DVD software's sound settings and the kX Mixer to decode AC3 in software to send to my 4.1 analog speaker setup? The settings are not self-explanatory enough for me, and I'm sure others would like to know too. Thanks.

Lucean · Dec 4, 2003, 05:19 AM

I don't have DVD, but I have an avi with AC3 audio. I guess I need a player with 3 outputs, that would send the front stereo output to Wave 4/5, rear stereo output to Wave 6/7 and center+subwoofer to Wave8/9 ...
I don't know if exists such a player.
But you can test AC3 with http://www.tfm.ro/ac3/download/test_ac3.rar

PITmaster · Dec 4, 2003, 03:22 PM

I do not have any problem with AC3 software decoding with my SBLive but I'm using Vigovsky Alexander's AC3Filter in fact. Every time when I'm playing *.AC3 file or DivX movie with AC3 sound track, the AC3Filter is used by Media Player. Without AC3Filter there's just no AC3 decoding.

How to decode DD sound track with kX software with SBLive and without AC3Filter?

PITmaster

**Eugene Gavrilov** · Dec 4, 2003, 03:41 PM

>> I do not have any problem with AC3 software decoding

in this case I doubt you really need to test the (more or less) unstable kX code, since the decoding is performed in software, too

/E

HunterZ · Dec 5, 2003, 06:34 PM

Since we're on the topic of AC3Filter, is there a reason why the sound is all scratchy if I set it to 24-bit or 32-bit PCM instead of 16-bit? Does kX not support the higher sample sizes or is it a bug in AC3Filter?

**Eugene Gavrilov** · Dec 6, 2003, 05:00 PM

kX doesn't support 24-bit audio for regular output devices (such as 'Wave 0/1') -- but it does support 24/96 for 'Wave HQ' (for audigy2 boards)

(well... the only exception is 24/48 format for audigy1/2 + fxbusx -- search the forum for details)

if you select 24-bit output, windows (in most cases) will automatically convert the audio data into 16/48 or similar 'compatible' format (software resampling)

so, in most cases don't select 24-bit (and 32-bit, of course) -- unless you know what you are doing

(since FXBusX requires some additional wires and the audio format should be 'true 24/48'...)

/Eugene

Orestis · Dec 28, 2003, 11:00 AM

Guys, could you please prioritize a bit the "Passing ac3 from software player to spdif-out" function on live! cards?

...and , when you're done with it, tell the Creative folks how to do it, because they screwed it up (at least under XP)

)

**dj_stick** · Jan 4, 2004, 12:09 AM

no offence to those wanting AC-3 and 3d sound, but the drivers were primarily designed for low latency audio production, only adding on the extra features the card had to offer, so when it comes to priorities, those issues relation to audio production come first

daPyr0x · Jan 27, 2004, 04:52 PM

Okay.....so am I understanding this right?

If I have my Audigy setup with 5.1 Dolby Digital coming in through the S/PDIF inputs on my card, the kX drivers are now able to decode that?

I know the Audigy drivers are, but if the kX drivers are, too....all the better....

Can they? or am I just daydreaming again?

**Eugene Gavrilov** · Jan 27, 2004, 06:07 PM

yes, kx drivers DO decode incoming spdif signal
note that the built-in decoder is not perfect -- you may experience BSODs and reboots

/E

andyvisser · Jan 28, 2004, 07:54 PM

By the sounds of things, ac3 decoding from an external spdif source in an audigy card appears to be pretty sketchy. I was considering upgrading my Live! card to an Audigy 1 (using my current digital i/o addon card) JUST so I could decode my external source. Is the decoding that bad that I should save my money and buy an external hardware decoder (or a higher end soundcard)?

trituref · Apr 21, 2004, 03:38 PM

is there a chance that sblive! support spdif ac3 decode one day or not ? if it's not i think i have to buy an audigy :-(

**dj_stick** · Apr 24, 2004, 08:53 AM

with the AC-3 filter the Live! will decode ac-3

daPyr0x · Jul 9, 2004, 12:28 AM

Sweetness. AC-3 decoding works and it's far better than Creative's AC-3.

That said, I do have a problem. I'm taking in dolby digital from an external source (it's a custom input from my XBox to what the card thinks is a LiveDrive optical in) and I have a problem with the drivers not getting correct sync with the signal. It was really bad with the creative drivers, because if it couldn't keep up because something ate up cpu cycles of whathaveyou it would stop playback alltogether, whereas the kX driver will continue (choppily) until the cpu is free and then it will catch back on.

Unfortunately, every once in a while (I do'nt know exactly what is causing it yet) I'll turn on the xbox and as soon as the AC-3 kicks in it will go all choppy like that and be unable to recover. The only way I could make it recover is by shorting the signal and ground pins (Bad tape job meant I could short out the wires at will, which is what I had to do often with the Creative drivers). Is there any way for even a button to just say "re-gain sync" or something with the AC-3 input?

Also, why is the volume so damn low on it? I see that in the 'issues' thing it says there's no volume control, but it's like really low....any way to help that?

stevenz · Sep 1, 2004, 03:55 AM

I've got a Soundblaster Live 5.1 (SB0100 - Kx ID's it as SB0102) - as of the current official version (3537?) am I able to input an encoded AC3 stream via an optical daughterboard and have it decode the AC3 to the analog channels with this EMU10K1 chipset? If it's still a bit flaky with the 10k1, could anyone point me towards where I might find the creative drivers that provide this functionality - I've had a hunt but have only managed to find fairly old base drivers. If it works with the AC3Filter utility, any suggestions for configurations in the Kx drivers and/or AC3Filter?

Thanks for the great work in the Kx drivers guys - much nicer to use than the Creative ones!

**dj_stick** · Sep 1, 2004, 05:32 AM

AC-3 Decode and passthrough is unavailable through kX for 10k1 cards (and decode is buggy on 10k2 chips)
try using AC-3 Filter

legion7 · Sep 14, 2004, 06:45 PM

Quote:

Originally Posted by Max M.

Lives (10k1 based cards) has following features under kX (today):

Decoding of ac3 from software player - yes
Decoding of ac3 from spdif input - no
Passing ac3 from software player to spdif-out - no
Passing ac3 from spdif-in to spdif-out - yes

Audigy X (10k2 based cards):

Decoding of ac3 from software player - yes
Decoding of ac3 from spdif input - yes
Passing ac3 from software player to spdif-out - yes
Passing ac3 from spdif-in to spdif-out - yes

----
(although some users reported they can't get "Passing ac3 from software player to spdif-out" to work properly)

Hi, I had to passthrough ac3 to spdif-out but it was impossible by my SBlive, OK !
Yesterday I went to a computer shop for a SBAudigy and I got it for 45 euro, and so ? Always PCM to my Sony STRDE485E coaxial input ! 45 EURO !

my SB0162 10K2, your driver, my pain

----
ac3filter.ax -> unregistered | iviaudio.ax -> unregistered | claud.ax -> unregistered

legion7 · Sep 14, 2004, 08:21 PM

Don't care anymore since I GOT IT ! kX Mixer control panel italian translation made me a little confused but switching it at english brought me to light ! W kX Audio Driver !

Max M. · Sep 14, 2004, 11:23 PM

>Don't care anymore since

Good...
[color=grey]
(i would also ask you to choose the right words next time you face the problem... All that "45 EURO! your driver, my pain" sound strange a bit)[/color]

legion7 · Sep 15, 2004, 08:15 AM

Quote:

Originally Posted by Max M.

[color=#00e0](i would also ask you to choose the right words next time you face the problem... [/color]

OK

classic_leon · Sep 18, 2004, 02:57 PM

SBlive! has already supported AC3 decode by hardware, if you install YouP-PAX 2.66 modded driver for SBlive! with EMU10K1.
I have been expecting the latest KX driver which supports AC3 decode for SBLive! and DTS decoded for Audigy2 series.

triqe · Dec 21, 2005, 05:52 PM

first of all, compliments on a better driver than a huge corporation is capable of creating...

im trying to use an audigy2 platinum ex to decode an external optical spdif AC3 (dolby digital 5.1) signal (in this case from an xbox360).

man am i having fun doing this...

the creative drivers have so much crackling and distortion in them when certain sounds are produced in game.

your driver(3537) is much better, but certain sounds in say fifa RTWC2006, any speech comes out sounding like one of those voice simulators on a C64. most of the rest of the sound is a-ok.

wierd. ive looked at all the settings so many times i feel like im going insane.

AND - if I install AC3filter, it causes any attempt to make any sound cause a BSOD. even if i uninstall it. nasty and dangerous. (but all hail the joy that is norton ghost).

is anyone getting this behaviour too ? did you solve it ? can anyone suggest a solution ?

or am i just a muppet ? h