[wdmaudiodev] Re: AVStream and WDF
- From: Eliyas Yakub <eliyasy@xxxxxxxxxxxxx>
- To: "wdmaudiodev@xxxxxxxxxxxxx" <wdmaudiodev@xxxxxxxxxxxxx>
- Date: Sat, 24 Oct 2009 14:16:32 +0000
Yes it's possible to write AVStream driver with KMDF. You don't need to have a
filter driver. Please go through this presentation and let me know if you have
question. Using KMDF to interface with the USB stack is the best way of doing
it. Most NDIS miniport drivers for USB drivers are written using KMDF.
http://download.microsoft.com/download/D/1/D/D1DD7745-426B-4CC3-A269-ABBBE427C0EF/DDE-T685_DDC08.pptx
This model has been supported from version 1.0. Latest WDF version that was
release with Win7 is 1.9 and you should use that.
From: wdmaudiodev-bounce@xxxxxxxxxxxxx
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of KS
Sent: Saturday, October 24, 2009 4:37 AM
To: wdmaudiodev@xxxxxxxxxxxxx
Subject: [wdmaudiodev] Re: AVStream and WDF
Hi,
While this is possible and would work, I think it would be something that would
be considered as one of the last resort if there is no other way and the change
must be made. This is something like asking Microsoft to split their
usbaudio.sys driver, which is an AVStream driver, into 2 drivers so that it is
WDF compilant and fulfill WLP requirement.
I would hope that there should be some method that is less painful for those
who have an existing AVStream driver that communicate with a usb device. (Or
that the WLP requirement does not apply to usb drivers that are using AVStream
framework)
KS
On Sat, Oct 24, 2009 at 7:17 PM, Sam Tertzakian
<saekisam@xxxxxxxxx<mailto:saekisam@xxxxxxxxx>> wrote:
You would write two drivers...a lower wdf driver that talks directly to the
hardware as a generic wdf driver. Then you install an upper filter driver over
the wdf driver that exposes the device as an avstream driver. Avstream driver
then sends and receives data from the lower driver.
________________________________
From: KS <wakeup1504@xxxxxxxxx<mailto:wakeup1504@xxxxxxxxx>>
Date: Sat, 24 Oct 2009 18:50:00 +0800
To: <wdmaudiodev@xxxxxxxxxxxxx<mailto:wdmaudiodev@xxxxxxxxxxxxx>>
Subject: [wdmaudiodev] AVStream and WDF
Hi,
Is it possible to write an AVStream driver using WDF? I posted this questions a
few years back and the answer was no.
There were some code snippets on using AVStream with WDF in the Winhec 2008
presentation, and there is also some new WLP requirements for USB drivers to be
WDF compilant. So does this mean that it is now possible to use AVStream with
WDF (since many usb audio/video device would be using AVStream driver)? If this
is true, is there any info on what is the minimum KMDF version that can support
this, and any info on what can and what cannot be done with WDF for AVStream
would be appreciated.
Thanks
KS
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