+wdmaudiodev again
I’m glad you asked, because marking the voice chat data as protected will not
do anything helpful for you. It’s really for paid music services that want to
protect their content from being extracted digitally, e.g. anything that uses
PlayReady.
The solution to your problem, I think, is to break the feedback loop using
other means, such as acoustic echo cancelation.
From: ambrish dantrey<mailto:a4ambrish@xxxxxxxxx>
Sent: Thursday, September 29, 2016 10:33 AM
To: Matthew van Eerde<mailto:Matthew.van.Eerde@xxxxxxxxxxxxx>
Subject: Re: [wdmaudiodev] Re: AUDCLNT_STREAMFLAGS_LOOPBACK
Thanks. I have tried this approach and it works under limited testing but as
you mentioned, it seems rather elaborate way of achieving this.
What happens if I mark the voice chat data as protected? I know it would
prevent loopback mode from capturing it but would other applications still be
able to render on that endpoint?
On Thu, Sep 29, 2016 at 10:58 PM, Matthew van Eerde
<Matthew.van.Eerde@xxxxxxxxxxxxx<mailto:Matthew.van.Eerde@xxxxxxxxxxxxx>> wrote:
You can get what is coming out of the speaker, but you cannot get
everything-coming-out-the-speaker-except-for-one-app.
I have heard of people ginning up a solution based on virtual audio endpoints.
1. Suppose your physical output is Speakers.
2. Create a new virtual endpoint – call it Virtual – and make it the
default audio output.
3. All audio apps will play to Virtual.
4. Except your app. Your app will play directly to Speakers.
5. Create a virtual audio cable from Virtual to Speakers.
6. So everything ends up coming out of Speakers.
7. Have your app do loopback capture on Virtual
This is, of course, a tremendous hack.
From: ambrish dantrey<mailto:a4ambrish@xxxxxxxxx>
Sent: Thursday, September 29, 2016 10:12 AM
To: wdmaudiodev@xxxxxxxxxxxxx<mailto:wdmaudiodev@xxxxxxxxxxxxx>
Subject: [wdmaudiodev] Re: AUDCLNT_STREAMFLAGS_LOOPBACK
To elaborate further, my application is a chat application. It intends to
render is audio coming from client. There is another application that uses
loopback mode to capture audio data and send it back to client.
Right now, client's voice, that gets played out on default endpoint, gets
recorded using loopback mode and gets sent back to client, creating a bad echo
effect.
On Thu, Sep 29, 2016 at 10:28 PM, ambrish dantrey
<a4ambrish@xxxxxxxxx<mailto:a4ambrish@xxxxxxxxx>> wrote:
Hi Guys,
I know I can initialize an IAudioClient with AUDCLNT_STREAMFLAGS_LOOPBACK flag
and it would let me capture audio data from Windows audio mixer. I also know
that this doesn't work if an application has opened its audio stream in
exclusive mode.
Is there another way for application to indicate that it doesn't want its data
to be captured using loopback mode, but without using endpoint in exclusive
mode? I want to write a render application that plays audio data in shared mode
(rendering on default audio endpoint along with other applications) but I don't
want my data to be captured by an application which is using loopback capture.
Please note that intention behind this question is not security or content
protection. There is a peculiar usecase I am trying to enable.
Would appreciate any insights greatly.
Thanks
