Question for those who are experienced with sound card drivers. Is there
anything like sound card filter driver? Or perhaps some kind of user-mode
filter. I need to get all data played on soundcard. Target OS is Windows
2000/XP. Can any one give a hint as to where should I start my research?
–htfv
> Question for those who are experienced with sound card drivers. Is there
anything like sound card filter driver? Or perhaps some kind of user-mode
filter. I need to get all data played on soundcard. Target OS is Windows
2000/XP. Can any one give a hint as to where should I start my research?
If the card uses KS drivers I believe that you could write a KS filter
driver. I would say “pretty easily”, but in my experience that phrase has
absolutely nothing to do with KS drivers.
If the card uses old drivers, I don’t know if you could layer very
successfully at the kernel level. Generally there is a user driver that is
expecting to talk directly to the kernel driver and will open it by name,
and has undefined communications protocol.
Loren
Is it possible to say something like “if I write a KS filter driver I would
support XX% of soundcards”? Can legacy soundcard drivers really be such a
big problem to bother about it?
–htfv
“Loren Wilton” wrote in message news:xxxxx@ntdev…
> > Question for those who are experienced with sound card drivers. Is there
> > anything like sound card filter driver? Or perhaps some kind of
user-mode
> > filter. I need to get all data played on soundcard. Target OS is Windows
> > 2000/XP. Can any one give a hint as to where should I start my research?
>
> If the card uses KS drivers I believe that you could write a KS filter
> driver. I would say “pretty easily”, but in my experience that phrase has
> absolutely nothing to do with KS drivers.
>
> If the card uses old drivers, I don’t know if you could layer very
> successfully at the kernel level. Generally there is a user driver that
is
> expecting to talk directly to the kernel driver and will open it by name,
> and has undefined communications protocol.
>
> Loren
>
>
In my experience (have not done it myself, but we have one in house) “pretty easy” can be defined
as at least 1 month for a developer fluent in KS.
After that what you get is a somewhat running audio filter driver that works for one particular
low end audio card.
Wanna try doing something similar for a high end device? Add another month (at least).
We had a pretty darn good KS guy spending around 4 months to make it work in most of the cases.
Still once in a while we come accross some oddity with some card when the filter does not work
very well.
Obviously with the next version of DX everything can change so this approach is doomed from the
start. We gave up on this idea and keep the driver breathing only for the demo purposes.
If you are trying this for your own amusement, turn off audio optimization (lowest performance
level possible), get the debugger and be prepared to spend a while doing reverse engineering.
You’ll get it to work sooner or later.
Want to include it in a product for a mass market? Forget about it. Really.
– Max.
> Question for those who are experienced with sound card drivers. Is
> there anything like sound card filter driver? Or perhaps
some kind of
> user-mode filter. I need to get all data played on
soundcard. Target
> OS is Windows 2000/XP. Can any one give a hint as to where
should I start my research?If the card uses KS drivers I believe that you could write a
KS filter driver. I would say “pretty easily”, but in my
experience that phrase has absolutely nothing to do with KS drivers.If the card uses old drivers, I don’t know if you could layer
very successfully at the kernel level. Generally there is a
user driver that is expecting to talk directly to the kernel
driver and will open it by name, and has undefined
communications protocol.Loren