[wdmaudiodev] Re: Windows usbaudio.sys architecture question
- From: Bartosik Lukasz-ALB045 <lukasz.bartosik@xxxxxxxxxxxxxxxxxxxxx>
- To: "wdmaudiodev@xxxxxxxxxxxxx" <wdmaudiodev@xxxxxxxxxxxxx>
- Date: Fri, 14 Sep 2012 21:22:57 +0000
Hello,
As I described in my previous post our device has one audio control interface
which defines 5 input terminals. The input terminals are connected to one usb
streaming output terminal through mixer unit. Then usb streaming output
terminal is mapped to one audio streaming interface which defines one
isochronous IN endpoint.
For such USB descriptors configuration Windows reports 5 recording devices.
What is a bit surprising to me is that each of the 5 recording devices has 5
channels and can be used to receive data from all 5 channels. What's more when
one of the
five devices is being used to receive audio data then an attempt to use other
device ends with an error message "device already in use".
And here goes my question whether this behavior fits into Windows audio
architecture or is it just lucky coincidence it works ?
Sorry for being so stubborn with this question, however if that's not
legitimate use case then we might run into issues when new Windows (and drivers
along with them) are released and this is something I would really like to
avoid.
Thanks,
Lukasz
From: wdmaudiodev-bounce@xxxxxxxxxxxxx
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Bartosik Lukasz-ALB045
Sent: Tuesday, September 11, 2012 11:19 AM
To: wdmaudiodev@xxxxxxxxxxxxx
Subject: [wdmaudiodev] Re: Windows usbaudio.sys architecture question
I have one audio control interface which defines 5 input terminals. The input
terminals are connected to one usb streaming output terminal through mixer unit.
Then usb streaming output terminal is mapped to one audio streaming interface
which defines one isochronous IN endpoint.
Thanks,
Lukasz
From: wdmaudiodev-bounce@xxxxxxxxxxxxx
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Tim Roberts
Sent: Monday, September 10, 2012 7:26 PM
To: wdmaudiodev@xxxxxxxxxxxxx
Subject: [wdmaudiodev] Re: Windows usbaudio.sys architecture question
Bartosik Lukasz-ALB045 wrote:
Hello,
We are developing USB audio device which will use generic usbaudio.sys driver
provided by Windows 7.
The device's USB descriptors define 5 input mono terminals (2 headsets, 1
microphone, 2 lines in) which use one isochronous IN USB endpoint to transport
audio data from the device to Windows OS.
Your description is a little bit vague. Do you mean you have one audio control
interface, one audio streaming interface, and one isochronous endpoint, but
your AC interface described 5 input terminals? Do you also have 5 output
terminals, or is there just one, mapping to the one AS interface?
--
Tim Roberts, timr@xxxxxxxxx<mailto:timr@xxxxxxxxx>
Providenza & Boekelheide, Inc.
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