USB display adapter

NTDEV
1

Hi, All,

As you known, that DisplayLink have their own chip/products for USB display adapter.
And also, windows driver for their device on Windows7,8 or even 8.1.

My question is:
Does windows 7,8 or 8.1 have native driver support for USB display adapter class device?
And if it does have, what spec or rules should the USB display adapter device comply with to load the native USB display adapter driver successfully?

For example, USB webcam, with UVC spec 1.1 or 1.5, or even 1.0.

There is one USB AV function spec, what does this spec aim for?

2

And does windows support USB AV class spec defined device by supply this class driver, like usbaudio.sys, usbvideo.sys and so on.

3

There is no class driver or in box support for USB indirect display

d

dent from my phone

From: workingmailing@163.commailto:workingmailing
Sent: ?2/?19/?2014 7:27 PM
To: Windows System Software Devs Interest Listmailto:xxxxx
Subject: RE:[ntdev] USB display adapter

And does windows support USB AV class spec defined device by supply this class driver, like usbaudio.sys, usbvideo.sys and so on.

—
NTDEV is sponsored by OSR

Visit the list at: http://www.osronline.com/showlists.cfm?list=ntdev

OSR is HIRING!! See http://www.osr.com/careers

For our schedule of WDF, WDM, debugging and other seminars visit:
http://www.osr.com/seminars

To unsubscribe, visit the List Server section of OSR Online at http://www.osronline.com/page.cfm?name=ListServer</mailto:xxxxx></mailto:workingmailing>

4

Thank you, Doran.

So the USBVideo.sys could not support OUTPUT, but just INPUT device, such as USB webcam?

5

Correct

d

dent from my phone

From: workingmailing@163.commailto:workingmailing
Sent: ?2/?19/?2014 11:08 PM
To: Windows System Software Devs Interest Listmailto:xxxxx
Subject: RE:[ntdev] USB display adapter

Thank you, Doran.

So the USBVideo.sys could not support OUTPUT, but just INPUT device, such as USB webcam?

—
NTDEV is sponsored by OSR

Visit the list at: http://www.osronline.com/showlists.cfm?list=ntdev

OSR is HIRING!! See http://www.osr.com/careers

For our schedule of WDF, WDM, debugging and other seminars visit:
http://www.osr.com/seminars

To unsubscribe, visit the List Server section of OSR Online at http://www.osronline.com/page.cfm?name=ListServer</mailto:xxxxx></mailto:workingmailing>

6

workingmailing@163.com wrote:

As you known, that DisplayLink have their own chip/products for USB display adapter.
And also, windows driver for their device on Windows7,8 or even 8.1.

My question is:
Does windows 7,8 or 8.1 have native driver support for USB display adapter class device?
And if it does have, what spec or rules should the USB display adapter device comply with to load the native USB display adapter driver successfully?

DisplayLink does a fair amount of rather ugly magic to do what they do.
Microsoft does not currently have ANY kind of mirror driver solution for
WDDM. That’s one of the biggest things that was lost in the transition
to WDDM, and I’m a little surprised that gap has been allowed to remain
for so long.

For example, USB webcam, with UVC spec 1.1 or 1.5, or even 1.0.

There is one USB AV function spec, what does this spec aim for?

And does windows support USB AV class spec defined device by supply this class driver, like usbaudio.sys, usbvideo.sys and so on.

The USB Video Class spec does cover video output, but the spec only
covers dumb monitors, where you’re transmitting whole frames, exactly
like a webcam in reverse. And, in the Windows world, such a device
would only be usable as a renderer in a DirectShow or Media Foundation
graph. For use as a system monitor, you need something with GDI
integration.

Honestly, I don’t know if usbvideo.sys handles “video out” devices.

–
Tim Roberts, xxxxx@probo.com
Providenza & Boekelheide, Inc.

7

Thank you all.

Another question:
Recently, USB.org release a new USB device class spec"

USB Audio/Video class device.

My qeustion is:
Does Win7 or any later version support USB AV function class devices?

8

workingmailing@163.com wrote:

Thank you all.

Another question:
Recently, USB.org release a new USB device class spec"

USB Audio/Video class device.

My qeustion is:
Does Win7 or any later version support USB AV function class devices?

Well, USB 3.0 appeared in late 2008, and wasn’t in the box with Windows
until 4 years later. Since The AV Class spec wasn’t released until late
2011, we are probably a couple of years ways away from in the box support.

I’m not sure I understand why they chose to redo much of what’s already
in the Audio Class spec.

–
Tim Roberts, xxxxx@probo.com
Providenza & Boekelheide, Inc.

9

Same with you Tim on USB org release a AV function device spec.

Why it is needed when USB audio and vidoe spec is operating now.

10

workingmailing@163.com wrote:

Same with you Tim on USB org release a AV function device spec.

Why it is needed when USB audio and vidoe spec is operating now.

Well, the video part of the new spec does address some things that the
USB Video Class spec did not. UVC does include video output devices,
although only as kind of a dumb “reverse web cam”. I don’t know that
any UVC output devices were ever built, and I’m dubious that
usbvideo.sys would handle them if they were. The new spec is intended
to handle things like the DisplayLink monitors, which UVC doesn’t fully
address. The AV spec, for example, allows for transmission of graphics
commands.

On the other hand, the philosophy is so similar that it seems like it
would have made more sense to modify the UVC spec to cover these new
devices, instead of creating an all new class.

–
Tim Roberts, xxxxx@probo.com
Providenza & Boekelheide, Inc.