Re: [orca-list] Video interceptor

[Christopher Chaltain <chaltain gmail com>]

I assume DCM refers to Driver Chain Management (DCM), which was the MS 
standard allowing multiple access technologies to coexist on the same 
system. It's discussed on the link I provided, as well as on this link 
http://www.gwmicro.com/Support/Knowledge_Base/?kbnumber=GWKB1016 
Unfortunately, the link to more information off of this page goes no 
where, but maybe Google will dig it up. DCM isn't an alternative to 
video interceptors, it's a device driver standard allowing for multiple 
video interceptors to exist on the same system.

It's been a while, but I know I've used JAWS with MS Powerpoint in slide 
show mode. I used to use this combination to give presentations years 
ago. I seem to recall though that JAWS waas a bit flaky afterwards, 
requiring a reboot, but I think this was more due to switching back and 
forth between my display and an external projector than the fact that I 
was using MS Powerpoint's slide show mode. Either way, I can't see how 
DCM would allow Window Eyes to work with MS Powerpoint in slide show 
mode while keeping JAWS from working. IMHO, although this solution of 
video interceptors was needed in it's day, and required a lot of hard 
work to implement, it did make things very complicated, and I could see 
that if someone didn't have the right versions of JAWS, Windows, video 
device drivers and so on that you could have problems with various 
applications. I also seem to recall that my results were also dependent 
on whether I was running JAWS as an application or a service. Hopefully, 
the days of needing video interception is behind us.

On 11/18/2013 03:58 PM, Alex Midence wrote:
> Interesting.  I thought they used some other technology called DCM which was
> supposed to be different from Video Intercept.  It's why Window Eyes can
> read Powerpoint slide shows but Jaws cannot.  Oh, well.  This is getting off
> topic.  You have my thanks as well for the link.
>
> Alex M
>
>
> -----Original Message-----
> From: orca-list [mailto:orca-list-bounces gnome org] On Behalf Of
> Christopher Chaltain
> Sent: Monday, November 18, 2013 12:11 PM
> To: orca-list gnome org
> Subject: Re: [orca-list] Video interceptor
>
> Window Eyes definitely uses, or at least use to use video interception.
> Here's a knowledge base article from GW Micro explaining it's use of video
> interception
> http://www.gwmicro.com/Support/Knowledge_Base/?kbnumber=GWKB1073
>
> Note that Freedom Scientific, GW Micro, Microsoft and others worked on a
> driver chaining protocol used when multiple access technologies all wanted
> to tap into the video chain and insert their device drivers into the device
> driver stack. This allowed users to have both JAWS, Window Eyes and other
> magnification programs using video interception to coexist on the same
> machine. As above, this is also easy enough to find with Google if you want
> more information.
>
> On 11/18/2013 09:08 AM, Alex Midence wrote:
> > As far as I know, Video Intercepter is only found in Jaws.  I don't
> > think Window Eyes and NVDA use it.  I also don't think it's used in
> > Linux since Linux has at-spi which is far more comprehensive than
> > MSAA.  MSAA is Microsoft Accessibility so, you will not find it in
> > Linux at all and, even in Windows it is being replaced by UIA because it
> is so out dated.
> > HTH,
> > Alex M
> >
> >
> > -----Original Message-----
> > From: orca-list [mailto:orca-list-bounces gnome org] On Behalf Of
> > MENGUAL Jean-Philippe
> > Sent: Saturday, November 16, 2013 4:30 PM
> > To: orca-list gnome org
> > Subject: [orca-list] Video interceptor
> >
> >
> >
> > Hi,
> >
> > I have to do a talk soon about the screen readers, and I'll talk about
> > ORCA, of course. I wonder if someone can help me about a technical
> > point: video interceptor.
> > I'd like to know what's this and how it works (in the guidelines), to
> > compare with commercial screen readers such as Jaws for Windows. If I
> > understand, it's an utility which enables a screen reader to
> > understand the widgets that are not connected to the MSAA. Am I right?
> > Could I be more precise or more exact technically  ? On Linux, could
> > an equivalent exist or is it excluded?
> >
> > Thanks for your help.
> >
> > Regards,
> --
> Christopher (CJ)
> chaltain at Gmail
>
> _______________________________________________
> orca-list mailing list
> orca-list gnome org
> https://mail.gnome.org/mailman/listinfo/orca-list
> Visit http://live.gnome.org/Orca for more information on Orca.
> The manual is at
> http://library.gnome.org/users/gnome-access-guide/nightly/ats-2.html
> The FAQ is at http://live.gnome.org/Orca/FrequentlyAskedQuestions
> Log bugs and feature requests at http://bugzilla.gnome.org Find out how to
> help at http://live.gnome.org/Orca/HowCanIHelp

--
Christopher (CJ)
chaltain at Gmail