Thanks for clarification, this information could save week of
development and debugging. Probably I missed something in MS docs,
though I read a lot.
On Thu, 12 Dec 2019 at 19:31, Matthew van Eerde
audiodg.exe is a “protected process lite” (PPL) process on Windows Vista
through Windows 8.1 inclusive. If your APO is not adequately signed, it will
not be loaded into audiodg.exe at all. (This recursively applies to any
dependencies your APO has.)
HDC will adequately sign your APO if you set the [SignatureAttributes]
PETrust=true attribute on it as documented here:
You can use signtool.exe to verify the adequacy of the signature:
As of Windows 10, audiodg.exe is no longer a PPL.
From: Tim Roberts
Sent: Wednesday, December 11, 2019 10:33 AM
Subject: [EXTERNAL] [wdmaudiodev] Re: LFX APO on Windows 7 x64
1. Do we need MS EV certificate for userspace drivers and APOs? Or
what kind of digital signature and its properties Windows 7 x64
expects for APO dlls?
This is a topic where I'd like some clarification, as well. Early on,
the documentation seemed to imply that, because an APO lives in the DRM
protected audio path, there would be a separate Microsoft-supplied
approval and signing process for APOs, but experience seems to
contradict that, at least on Windows 10.
Tim Roberts, timr@xxxxxxxxx
Providenza & Boekelheide, Inc.