From Dexterus xxxxx@yahoo.com
xxxxx@easynet.ro
I need to write a transform filter for audio processing. After many
unsuccesful atempts I found out about WDM streaming filters. I think this
is
the only way to write a program that DOESN’T
INTERRUPT when you open menus, or move window and also has LOW LATENCY.
I have both the Win98 DDK and the Win2000 DDK so if you bother
responding me don’t give any quotes from those, like I already found
online.
Also I want WDM Streaming specific information and I do not want to
try
other non kernel sollutions- I already tried those
and they don’t work.
Also, I do not want to use a minidriver-class_driver pair because my
transform filter must have COMMUNICATION
SOURCE pins.
So,can anyone please explain how do you create a FILE_OBJECT for a new
filter or pin in a streaming WDM and what do you do with it after that so
that the IRP-s for that filter or driver are routed to the rigth handler
functions.
Are those FILE_OBJECT-s the handles that you can obtain by
IoCreateFile
or ZwCreateFile? And, if so, how do you convert them in FO-s and what file
name do you use in IoCreateFile (or Zw…) ?
How the IO Manager knows what FILE_OBJECT you made for a specific pin
or filter so that it uses the specific dispatch table pointed by
.FsContext
to route the IRP-s to corect handlers for that type of pin? Also, if this
is
the case , can I get an instance number for the pin that the IRP is sent
for ? In such handler, for example, I need to know where the the pin is
connected so I can send streaming IRP-s.
Please explain this IRP routing process in detail or give me some
references to online documentation.
Also, explain me what is the stack recalculation thing. How do I find
the stack depth of the sink pin ?
Also, in Win98 DDK (or Win ME) help , in WDM filters … ,“General
Layout of a WDM Driver” subchapter there is a reference to a sample
called
“msfsio.c”. It says there:
"Create the file object using a routine such as FilterDispatchCreate
in
the sample filter (msfsio.c) that comes with the WDM DDK documentation. "
Now, this sample doesn’t exist in Win98 DDK ,also not in Win2000 DDK.
I’ve searched it at microsoft.com and it doesn’t show up. Can you tell me
where I can find it?
And what WDM DDK means ? Win98 DDK, or Win2000 DDK ? Or something
else?
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The WDMAUDIODEV mailing list at eGroups also
discusses WDM Streaming related topics. Perhaps
you will find an answer there…
Here are the addresses:
WDMAUDIODEV addresses:
Post message: mailto:xxxxx@egroups.com
Subscribe: mailto:xxxxx@egroups.com
Unsubscribe: mailto:xxxxx@egroups.com
List owner: mailto:xxxxx@egroups.com
URL to WDMAUDIODEV page: http://www.egroups.com/group/wdmaudiodev
Best Regards,
Carsten Schulz
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com]On Behalf Of xxxxx@yahoo.com
Sent: Dienstag, 23. Januar 2001 21:39
To: NT Developers Interest List
Subject: [ntdev] WDM Streaming
>From Dexterus xxxxx@yahoo.com
xxxxx@easynet.ro
I need to write a transform filter for audio processing. After many
unsuccesful atempts I found out about WDM streaming filters. I think this
is
the only way to write a program that DOESN’T
INTERRUPT when you open menus, or move window and also has LOW LATENCY.
I have both the Win98 DDK and the Win2000 DDK so if you bother
responding me don’t give any quotes from those, like I already found
online.
Also I want WDM Streaming specific information and I do not want to
try
other non kernel sollutions- I already tried those
and they don’t work.
Also, I do not want to use a minidriver-class_driver pair because my
transform filter must have COMMUNICATION
SOURCE pins.
So,can anyone please explain how do you create a FILE_OBJECT for a new
filter or pin in a streaming WDM and what do you do with it after that so
that the IRP-s for that filter or driver are routed to the rigth handler
functions.
Are those FILE_OBJECT-s the handles that you can obtain by
IoCreateFile
or ZwCreateFile? And, if so, how do you convert them in FO-s and what file
name do you use in IoCreateFile (or Zw…) ?
How the IO Manager knows what FILE_OBJECT you made for a specific pin
or filter so that it uses the specific dispatch table pointed by
.FsContext
to route the IRP-s to corect handlers for that type of pin? Also, if this
is
the case , can I get an instance number for the pin that the IRP is sent
for ? In such handler, for example, I need to know where the the pin is
connected so I can send streaming IRP-s.
Please explain this IRP routing process in detail or give me some
references to online documentation.
Also, explain me what is the stack recalculation thing. How do I find
the stack depth of the sink pin ?
Also, in Win98 DDK (or Win ME) help , in WDM filters … ,“General
Layout of a WDM Driver” subchapter there is a reference to a sample
called
“msfsio.c”. It says there:
"Create the file object using a routine such as FilterDispatchCreate
in
the sample filter (msfsio.c) that comes with the WDM DDK documentation. "
Now, this sample doesn’t exist in Win98 DDK ,also not in Win2000 DDK.
I’ve searched it at microsoft.com and it doesn’t show up. Can you tell me
where I can find it?
And what WDM DDK means ? Win98 DDK, or Win2000 DDK ? Or something
else?
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