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Old January 3rd 15, 03:15 AM posted to alt.comp.hardware.pc-homebuilt
Paul
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Posts: 13,364
Default I missed this transition

hp wrote:
Ok, when did video cards take over sound processing for PC's ?
This did not register on my forebrain until several updates
pounded in that 'Hay, my video drivers package has sound drivers
too'.

What the hockey puck?

OldGeek perplexed

Ok, is there a way to return sound processing to the mommyboard??


It's been around for a while.

On the Nvidia side, the first implementation used S'PDIF passthru.
The video card had a two pin connector on the upper edge. You could
take an adapter cable from a four pin motherboard header, and connect
it to the video card. In that case, the controls and driver in the
OS thought they were dealing with motherboard built-in audio. You
would specify digital out over S'PDIF in your RealTek driver, and sound
would come out of the HDMI monitor speakers.

AMD did a "real" sound solution on their card. There was no plug on
the top edge of the card. Basically the card appeared as some sort of
bus to the OS, and on the video connector side, it would stream out the
data bytes as digitsl audio (LPCM over HDMI). The weird part of
that solution, is AMD/ATI did not write the driver for the hardware
they added. Instead, it was a driver written by RealTek, which was
bundled with the card.

Later, both companies added the appropriate hardware, and the also
started writing their own audio driver. That driver should be bundled
with the video driver now. Probably to this day, not all possible
audio formats are supported. The only thing you can bs sure of,
is some number of channels of LPCM (uncompressed) audio over HDMI.
Everything else is optional or costs somebody money
for a license.

The end result, is if you do a new build today, you get to see
two audio devices in Device Manager. The motherboard HDAudio is
one device. The video card build-in digital audio is the second
device. And you have to be careful to switch to the one you want,
before it'll work.

It's even worse in Linux, as they chose not to use the same names/terminology
for things. I wasted a whole freakin day doing experiments trying
to figure out where the "What You hear" or "Stereo Mix" option went.
That's important if you want to record the audio which is being played
on the speakers. That happens to be called "Stereo Duplex Output" (as
opposed to just "Stereo Output"). The Duplex is meant to imply that the
signal being output, is also being digitized and sent back into
the sound chip for recording purposes. And as far as I know, the video
card audio subsystem is Output Only. I don't think it has any option
for recording the played sound to a file. And even if you use the
motherboard analog audio, the newer Windows OSes make it nearly
impossible to figure out how to get Stereo Mix working again.
They like the default to be, that it's turned off and hidden.

And as an industry observation, sound sucks just as much as it
did 20 years ago. It just sucks for different (DRM) reasons.

Paul