ALC889 SPDIF Audio from Internal Header?

[Captain Crunch]

I have a GTX 260 Core 216 plugged into a DVI - HDMI adapter. It is able to pass audio using a SPDIF header from my motherboard's ALC889. I've tested it in Windows and it works just fine, so don't tell me DVI can't transmit audio.

I'd like to do the same in OS X, while also keeping my normal ALC8xx functionality. Is this as simple as a DSDT edit or does the kext also need editing? The card does not have an audio codec on board.

 

[Red Chief]

It works OOTB for my hardware. I just plugged it in and voilà!
Maybe I got lucky this time.

 

[postal1]

Red Chief, what kexts are you using? I have a GTX285 that also passes audio through HDMI fine in Win 7, but no joy in SL.

 

[discreetlogic]

I've been trying to get the same thing working on my new system.

Worked on my previous build, and it took a good dsdt and a patched applehda.

Mald0n over at insanelymac gave me dsdt that has this in the profiler :

Intel High Definition Audio:

Audio ID: 889

S/PDIF Optical Digital Audio Output:

Connection: Internal

Line Output:

Connection: 1/8-Inch Jack

Line Output:

Connection: 1/8-Inch Jack

Line Output:

Connection: 1/8-Inch Jack

Line Output:

Connection: 1/8-Inch Jack

Internal Microphone:

Connection: Internal

S/PDIF Optical Digital Audio Input:

Connection: Optical

You see, there are two optical connections however, in the system preferences (AppleHDA) I only have one, presumably the back optical since the header doesnt work.
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There is a file in applehda called layout889.xml that defines what inputs/outputs you can select, but editing this is beyond my current comprehension.

Maybe someone has done this before, let's see!

@Captain Crunch : THis make any sense?

 

[toleda]

I've been trying to get the same thing working on my new system.

Worked on my previous build, and it took a good dsdt and a patched applehda.

Mald0n over at insanelymac gave me dsdt that has this in the profiler :

Intel High Definition Audio:

Audio ID: 889

S/PDIF Optical Digital Audio Output:

Connection: Internal

You see, there are two optical connections however, in the system preferences (AppleHDA) I only have one, presumably the back optical since the header doesnt work.

There is a file in applehda called layout889.xml that defines what inputs/outputs you can select, but editing this is beyond my current comprehension.

Maybe someone has done this before, let's see!

@Captain Crunch : THis make any sense?

A couple points of clarification:

The DSDT edits Mald0n provided are Device (HDEF); already included in every DSDT in the DSDT database.

System Profiler reports the first audio connection improperly. It is actually the analog internal speaker in a real Mac or the analog green audio line out rear in a hac.

Usually, the SPDIF connector (2 wire, not optical/coax) on the motherboard is enabled in the BIOS. Once enabled, connecting the motherboard SPDIF to the graphics card SPDIF connector and selecting Digital Optical in System Preferences/Sound/Output produces HDMI audio on those specific graphics cards.

AppleHDA provides a programmable interface to the audio codec in OS X. Numerous guides describe how to build pin configs, pathmaps and layouts for various codecs. However, current implementations of AppleHDA do not have two digital audio outputs.

The architecture of AppleHDA (v2.+) changed in 10.6.8. It will take some time for the experts to build new solutions for the common audio codecs.

Bottom line, if you have on board digital audio working, a motherboard and graphics card with SPDIF connectors, you can have HDMI audio without kext editing. This technique is not capable of HDMI bit streaming.

 

[discreetlogic]

Thanks for the writeup

Definitely helps us all understand what? going on.

Usually, the SPDIF connector (2 wire, not optical/coax) on the motherboard is enabled in the BIOS.

Ok, but I can seem to see where? There? just a switch to enable the audio codec.

 

[toleda]

Ok, but I can seem to see where? There? just a switch to enable the audio codec.

Check your manual for the SPDIF header location on the motherboard. Turn the audio codec switch on. Do you have the SPDIF audio cable installed? What do you see in System Preferences/Sound/Output?

 

[discreetlogic]

1- Check your manual for the SPDIF header location on the motherboard.

CHECK

2- Turn the audio codec switch on.

CHECK

3-Do you have the SPDIF audio cable installed?

CHECK

4- What do you see in System Preferences/Sound/Output?

2 Line outs, 1 digital, and headphones. (IIRC, @work now)

But I´ve got better other options in the future : Get audio out working on my brand new QUADRO 4000 if posible, or, better yet HDMI out the sandy bridge i7 graphics.

My applehda is currently a binary patched Lion one, could try a rollback judging by the developments in applehda you spoke of in a previous post.