[wdmaudiodev] Re: AVStream and WDF

  • From: Eliyas Yakub <eliyasy@xxxxxxxxxxxxx>
  • To: "wdmaudiodev@xxxxxxxxxxxxx" <wdmaudiodev@xxxxxxxxxxxxx>
  • Date: Sun, 25 Oct 2009 05:52:10 +0000

Yes the latest version of KMDF (1.9) is compatible with Windows 2000 and beyond.

All KMDF driver packages should include MS provided redistributalbe 
coinstaller. This coinstaller installs the KMDF runtime on the target machine 
as needed.

Please read this presentation to learn more about the coinstaller.

http://download.microsoft.com/download/5/E/6/5E66B27B-988B-4F50-AF3A-C2FF1E62180F/COR-T593_WH08.pptx



From: wdmaudiodev-bounce@xxxxxxxxxxxxx 
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of KS
Sent: Saturday, October 24, 2009 9:20 PM
To: wdmaudiodev@xxxxxxxxxxxxx
Subject: [wdmaudiodev] Re: AVStream and WDF

Hi Eliyas,

Just another question. Is KMDF driver supported by default in WinXP, Vista and 
Windows 7? Or do we need to install some service pack or components (eg. .NET 
framework needed for .NET) before KMDF driver can be used? What happen when the 
KMDF driver is installed in an OS that does not have all the necessary 
components required?

Thanks
KS
On Sun, Oct 25, 2009 at 8:22 AM, Eliyas Yakub 
<eliyasy@xxxxxxxxxxxxx<mailto:eliyasy@xxxxxxxxxxxxx>> wrote:
Yes if you want to use full capabilities of WDF then two driver model is best.

Does anybody know whether AVSTREAM support selective suspend?

From: wdmaudiodev-bounce@xxxxxxxxxxxxx<mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx> 
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx<mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx>]
 On Behalf Of Sam Tertzakian
Sent: Saturday, October 24, 2009 5:18 PM

To: wdmaudiodev@xxxxxxxxxxxxx<mailto:wdmaudiodev@xxxxxxxxxxxxx>
Subject: [wdmaudiodev] Re: AVStream and WDF

Hi, Eliyas,

Would you say it is true that if you want to use the full capabilities of  WDF 
using a two driver model is best?  I say this because your slide 30 shows that 
many important features of WDF cannot be used in a single driver model.

In the past I have written code such that a  single AVStream driver could be 
used with both an underlying PCI  bus or a USB bus. I used an  underlying WDF 
or WDM driver to deal with the buffer transfer between the bus/card and host 
memory...then, I exposed  a device interface that an AVStream driver used to 
expose the board as an AVStram device.

In this way, I get full use of WDF for all the hardware stuff, but I only have 
to write the code that exposes the card to AVStream one time. If I want to add 
another bus type, then I can just write another underlying WDF driver for that 
bus and reuse the same AVStream layer without modification.

From: wdmaudiodev-bounce@xxxxxxxxxxxxx<mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx> 
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx<mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx>]
 On Behalf Of Eliyas Yakub
Sent: Saturday, October 24, 2009 7:17 AM
To: wdmaudiodev@xxxxxxxxxxxxx<mailto:wdmaudiodev@xxxxxxxxxxxxx>
Subject: [wdmaudiodev] Re: AVStream and WDF

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> 
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx<mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx>]
 On Behalf Of KS
Sent: Saturday, October 24, 2009 4:37 AM
To: wdmaudiodev@xxxxxxxxxxxxx<mailto: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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