Knowledge I've gained for Audio over DisplayPort

[sumsaykra-z]

I've had a successful macOS Sierra unit for quite some time now. Like everyone else, after the rig is 99% working you go about tweaking some things to make it perfect. One thing I've been battling with is audio output over DisplayPort. Don't misunderstand, it works and does so beautifully thanks to @toleda post here. It's my understanding there's a newer method now though. I have a 27" Apple Cinema Display. The trouble has always been getting the audio to DEFAULT to "Display Audio". Typically upon reboot or waking from sleep it will default back to "Digital Out". I couldn't figure out why it wouldn't just stay set the way I had it last.

I recently had some issues with my rig trying to update to High Sierra and in doing so I made a simple change in my config.plist. I always had Audio Inject set to 11. I followed a guide here that had it set to that. I believe 1 and 10 were the other options. I just went with 11. Well, I changed it to 1 and ever since then it consistently defaults to Display Audio.

I'm not sure WHY that's the case. Maybe toleda can speak to it or anyone with more knowledge than I have. Anyway, I thought I'd share this little bit of knowledge with the community. I don't have much to offer in the way some of these guys here have to offer. Happy hacking

 

[toleda]

changed it to 1 and ever since then it consistently defaults to Display Audio

AppleALC.kext does not support DP audio. For onboard audio, AppleALC aggregates the work of many developers and users. The Audio Inject/layout-id distinguishes the author. For Realtek desktop codecs, layouts 1, 2 and 3 represent my work.

 

[sumsaykra-z]

AppleALC.kext does not support DP audio. For onboard audio, AppleALC aggregates the work of many developers and users. The Audio Inject/layout-id distinguishes the author. For Realtek desktop codecs, layouts 1, 2 and 3 represent my work.

Ah. I understand you to an extent. You're saying the Inject Audio that must be used depends upon what the creator did. Like I said, Audio Inject 11 worked but I had to manually select that output all the time. Now I'm using 1 and it defaults to that all the time. What would be the benefit/disadvantage to using a certain inject over another? For example, if I used 2 instead of 1? I went ahead and googled what is clover audio inject trying to educate myself and wouldn't ya know it, the first link is a github address that you were answering someone's question to. https://github.com/toleda/audio_CloverALC/issues/49 . It seems to also be codec specific.

 

[toleda]

Missed my point. Audio ID 1, 2, 3 are all toleda solutions; each offers different functionality for the same codec. The different functionality applies to all toleda supported codecs. The Audio ID tells macOS exactly what to configure (or program) in the codec.

Audio ID: 11 is not my work, see Supported codecs · vit9696/AppleALC Wiki (click on codec link) to determine the author. Other Audio IDs by other authors work differently because their codec files are different. Audio ID: 11 does not support a feature you require, Audio ID: 1 does. Audio ID: 5 and 7, by a different author, don't support front panel switching.

Another point, the same AppleALC.kext files are installed by MultiBeast and cloverALC, see AppleHDA Realtek Audio/Post #1