[wdmaudiodev] Re: Mixer API support on Vista?
- From: "Mike Dey" <mdey@xxxxxxxxx>
- To: <wdmaudiodev@xxxxxxxxxxxxx>
- Date: Fri, 11 Aug 2006 17:09:37 -0700
Hi Larry,
In my app, I tried changing the volume to 32767 on my USB audio device but
still got 65536 when I read it back. I am still not quite clear about the
"per-app" state of volume control concept? Does it really change the volume on
my hardware?
My company is doing USB VOIP hardware. Our customers like to directly adjust
the volume in the phone application while a call is connected.
Thanks!
Mike
----- Original Message -----
From: Larry Osterman
To: wdmaudiodev@xxxxxxxxxxxxx
Sent: Wednesday, August 09, 2006 1:49 PM
Subject: [wdmaudiodev] Re: Mixer API support on Vista?
In Vista, the old hardware mixer is gone (ok, it's not gone, it's just really
well hidden), and has been replaced with a "virtual" mixer that reflects the
per-app state of the volume controls. In your case, the reason you're always
seeing max volume is that nothing in your app has changed the volume from its
default.
For Vista, you have two options. The first is that you can apply one of the
legacy appcompat layers to your application (note: this doesn't work in current
Vista bits), which will tell Vista "my application is a control panel
replacement and should be allowed to see the actual hardware values". The
second option is to use the new IAudioEndpointVolume interface to control the
volume of the speakers.
If you chose to go the former route, it's important to understand that the
Vista mixer no longer lies about the topology of the audio solution on the
machine - if the audio solution doesn't have a hardware volume control, then
the mixer APIs won't return a hardware volume control. The
IAudioEndpointVolume interface will correctly handle audio solutions without
hardware volume controls though.
Larry Osterman
This posting is provided "AS IS" with no warranties, and confers no rights.
From: wdmaudiodev-bounce@xxxxxxxxxxxxx
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Mike Dey
Sent: Wednesday, August 09, 2006 1:29 PM
To: wdmaudiodev@xxxxxxxxxxxxx
Subject: [wdmaudiodev] Mixer API support on Vista?
Does Vista still support mixer APIs? I have a volume control application
using mixer APIs (such as mixerOpen, mixerGetDevCaps, mixerGetLineControls...).
It works well on 2K/XP. However, on Vista build 5472 the volume I got from
mixerGetControlDetails API is always 65535. Anyone know what's the problem?
Thanks!
Mike
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