[wdmaudiodev] Re: AVStream Audio Frustration
- From: Matthew van Eerde <Matthew.van.Eerde@xxxxxxxxxxxxx>
- To: "wdmaudiodev@xxxxxxxxxxxxx" <wdmaudiodev@xxxxxxxxxxxxx>
- Date: Sat, 3 Nov 2012 00:00:47 +0000
I see. Yes, KSEVENT_PINCAPS_FORMATCHANGE is what you want. That should
trigger a renegotiation of the default format.
I believe (hope) it is possible to raise that event even without any active
streams.
From: wdmaudiodev-bounce@xxxxxxxxxxxxx
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Tim Roberts
Sent: Friday, November 2, 2012 4:46 PM
To: wdmaudiodev@xxxxxxxxxxxxx
Subject: [wdmaudiodev] Re: AVStream Audio Frustration
Matthew van Eerde wrote:
Can you clarify why it is a problem for a format converter to be inserted above
you?
I may have thrown up too much information and distracted us from the main
point, or maybe it's just that I'm isolating the problem better as time goes
on. I don't really care about DirectShow; my use case is waveIn. It just so
happens that Graphedt shows the same behavior in that one case.
Someone, somewhere, is caching my "default audio format". I think we can all
agree that's true; it's displayed in the control panel Microphone Properties
"Advanced" tab. When I change that selection (as I've just learned), the Audio
Engine does go through my intersect handler. It will only allow a selection
that passes my intersection.
The issue is that, in the sysaudio/waveIn scenario, the system will only send
me the "default audio format", even if that format no longer passes my
intersection. If my format set has changed, I fail in the SetFormat handler
and unhappiness ensues.
Say that I select 22-M-16 in control panel. Now, let's say that I reboot, and
after the reboot I can only handle 44-S-8. In that case, the system will still
only connect at 22-M-16 (from the cache), even though that no longer passes my
intersect handler.
Matt Gonzalez wrote:
Have you tried KSEVENT_PINCAPS_FORMATCHANGE? It's only supported on Windows 7,
but that may be what you're looking for.
I'm not sure I know how to send that. That would be a pin event (wouldn't
it?), and I can't connect the pin if the format doesn't match. I suppose I
could accept the bad format then generate the event. Hmmm.
--
Tim Roberts, timr@xxxxxxxxx<mailto:timr@xxxxxxxxx>
Providenza & Boekelheide, Inc.
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