crazii
HDMI audio output selection on Zotac Ion motherboard
With this motherboard, the SBEMU audio is only coming out of headphone jack and not the HDMI connection. Detection with /SCL says:
1: Intel HDA: NVidia MCP79 (10DE0AC0) -> Realtek (10EC0662) (max 96kHz/24bit/8ch)
I also tried setting the output to both 0 and 1. Any way to set it to the HDMI output?
I am seeing a similar problem on an Intel NUC, which has no means of audio output other than HDMI. Sbemu appears to be working, but I hear no sound. I also tried setting the output to both 0 and 1. Sound over HDMI works on the system when I'm running Windows, btw. Any suggestions would be greatly appreciated, please and thank you!
From my HD Audio low-level programming experience, making audio over HDMI work requires GPU-specific initialization, which is usually done in tandem with GPU drivers. Since legacy VGA BIOS on most GPUs usually treats HDMI outputs as simple video-only link (like DVI), it usually ignores any audio stuff, and thus audio over HDMI will not work with generic HDA support code.
Do Linux, FreeBSD or Illumos support HDMI/Displayport audio? There should be basically three implementations (Intel, AMD, Nvidia) - I doubt the audio part changes a lot between GPU models otherwise.
It seems HDMI/Displayport audio (AMD High Definition Audio Device) is based on HDA and is located at the PCIe bus and is not so different from regular HDA (Realtek(R) Audio):
Of course probably it uses different IDs, etc.?