“Apparently
by design
in Vista, only the user can set the hardware sampling rate”
Assuming
this thread is about programmatic control of Windows
Sound Control Panel settings:
Features
requested by this very community in the past; the need
for a transparent, predictable OS audio engine avoiding the OS audio
engine
mucking about with audio bits when not necessary lead to a Vista audio
system design
where the user is in control because:
1.
Devices
don’t know what content the user is playing, only
what that particular device/endpoint is best at rendering
2.
Applications
certainly should not muck around with settings that
affect other applications because an application does not know
what
other apps using that device is rendering.
Better
to leave it to the user or at the default setting.
Also,
in Vista the default device sample rate (if the device
supports it) is 44.1kHz because 95% of content is still mastered at
that rate
and it is the rate that offers the least amount of quality impact and
CPU
processing impact for the largest number of audio scenarios.
We
did a rough calculation of how many trees we would save by
not sample rate from 44.1kHz to for instance 48kHz (common sample rate
used by
devices) for let’s say 250 million PCs (about the number sold in a
year)
by users using the PC to play music (a common scenario for approx. 60%
of us)
and while I can’t find the numbers right now it amounted to A LOT of
trees.
So,
think green and don’t muck about with audio sample
rate settings programmatically J.
>Something related to this : It looks like
that 88.2 kHz
and 176.4 kHz is not enumerated when >SRB_GET_DATA_INTERSECTION is
sent. Is
that true?
>So now my question is : Is there any other
way to get
things done so that only current sample
>rate used by device is shown on Advance tab?
In
a word, no. Apparently by design in Vista, only the user can set the
hardware
sampling rate, not the hardware itself. About all you can do is set a
default
format in the INF file using the PKEY_AudioEndpoint_Association
and PKEY_AudioEngine_OEMFormat entries to make it something other than
44.1kHz 16-bit stereo, but that probably won't achieve what you want to
do.
