Vista fails switching default device when HDMI is plug/unplug

[Edge30]

Hello
I've have a big number of systems (several brand/models/configurations) but
they all have this problem.
We use Vista 64bit.
When a HDMI monitor is connected, the sound should automatically select HDMI
as default device
When the HDMI monitos is disconnected, the sound should automatically select
the system's internal audio device
But this doesn't happen, sometimes it fails when selecting the HDMI monitor
audio as default, sometimes it works ok but fails to return to the system's
internal audio when the HDMI monitor is disconnected.
Sometimes it works ok once, but if we repeat the test several times, after 4
or 5 times it fails.

We have lots of customers complaining for this.

As I said, this happens in many different platforms: desktops, laptops, with
Nvidia Gfx, with ATI Gfx, with several HDMI monitor brands/models
Also we tested with:
Vista in-the-box audio drivers
Latest Gfx vendor's drivers: i.e. ATI, Nvidia
Previous Gfx vendor drivers (previous versions from ATI, Nvidia)
Realtek HD drivers (realtek makes drivers for ATI and offers them
separately)

They ALL fail. Basically I haven't found a system that doesn't show the
problem

Any idea what's going on? any solution known?

Thanks
e.

 

[Curious]

Vista does not make the decision on incorporating sound from your graphics
card over it's HDMI interface. Your graphic card drivers make this
decision based on how you have your graphics card and it's cable configured
with it's current drivers and on what EDID information it receives from the
destination HDMI interface. The EDID information from the destination HDMI
interface may state that it only accepts video over HDMI for example.
Since Vista itself does not know AFAIK what your graphics card is doing it
does not know when to shift audio from the graphics card output to internal
audio connections.

 

[Edge30]

I see, however I'm still confused.
Vista uses TMM to detect when a external device is connected.
TMM then calls the driver to set up the proper display profile... so how can
possibly Vista not know what the Gfx is doing? Vista detect the HDMI device
in first place.
From my tests, EDID is read ok each time and the monitor is properly
identified also.
Also, if the HDMI's EDID wouldn't indicate sound support then it would
always fail. How come it sometimes work ok? it is after testing 4 or 5 times
that the switching fails.
Also, I've tested over 12 different HDMI monitors, I doubt they all have the
same EDID problem and -of course- they all support audio.

Thanks
e.

 

[Curious]

I do not know what the actual cause is of all of your problems,
But is important to realize that your display cable is connected to a
connector on your graphics card which is why Vista has no real idea of what
is happening. It is your graphics card that accepts the video content from
Vista and processes it as necessary to send to your display based on the
settings you have set for your graphics card. with it's driver.