User Mode Address for AVStream I/O Buffers

NTDEV
1

Is there any way, in which can get the user mode addresses for the
input/output buffers allocated by KS class?

2

Abhishek Joshi wrote:

Is there any way, in which can get the user mode addresses for the
input/output buffers allocated by KS class?

I don’t believe you can assume that there are ANY user mode addresses
for these buffers. The buffers might have been allocated by a kernel
allocator, not a user-mode allocator. It’s quite possible for KS
drivers to communicate with each other directly.

Why do you want to know? You can use a ksproxy plugin if you need to
participate in the user-mode part of the graph. That’s what they’re for.

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

3

But all the upstream/downstream filters are in user mode. So, I believe
there must be some user level address associated with the allocated
buffers.

Thanks & Regards
Abhishek Joshi
Quartics Inc.

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Tim Roberts
Sent: Wednesday, February 27, 2008 9:38 AM
To: Windows System Software Devs Interest List
Subject: Re: [ntdev] User Mode Address for AVStream I/O Buffers

Abhishek Joshi wrote:

Is there any way, in which can get the user mode addresses for the
input/output buffers allocated by KS class?

I don’t believe you can assume that there are ANY user mode addresses
for these buffers. The buffers might have been allocated by a kernel
allocator, not a user-mode allocator. It’s quite possible for KS
drivers to communicate with each other directly.

Why do you want to know? You can use a ksproxy plugin if you need to
participate in the user-mode part of the graph. That’s what they’re
for.

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

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4

Abhishek Joshi wrote:

But all the upstream/downstream filters are in user mode. So, I believe
there must be some user level address associated with the allocated
buffers.

Maybe. Maybe not. Again, why do you want to know? What would you do
with that information?

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