[wdmaudiodev] Re: GFX/LFX fullduplex support.

  • From: pete c <prchan_0779@xxxxxxxxx>
  • To: wdmaudiodev@xxxxxxxxxxxxx
  • Date: Thu, 4 Sep 2008 12:19:26 -0700 (PDT)

if i ditch the lfx/gfx approach and rely on the DMO approach, can you inplement 
your own AEC at that level and can it be applied as a global system wide effect 
or does the audio application that would utilize AEC now have to specifically 
call into this DMO layer to take advantage of this custom AEC functionality. 

--- On Thu, 9/4/08, Tim Roberts <timr@xxxxxxxxx> wrote:

From: Tim Roberts <timr@xxxxxxxxx>
Subject: [wdmaudiodev] Re: GFX/LFX fullduplex support.
To: wdmaudiodev@xxxxxxxxxxxxx
Date: Thursday, September 4, 2008, 2:03 PM

pete c wrote: 

In regards to the following statement below:
>> Of course, you are going to NEED such synchronization if you hope to do
>> echo cancellation.  That's another thing that makes this tricky.  You
>> will need some pretty brainy algorithm scientists to make this work.

I know that i need GFX/LFX synchronization for AEC to work, however im not 
convinced that it may even be possible,  since the GFX is independent (speaker 
driver) process from the LFX (microphone driver) process. Is it possible to 
synchronize these two independent processes with each other within Vista and if 
so what type of mechanism would be recommended? 

The "recommended" approach is not to do this at all, and instead rely on the 
DMO approach.  ;)

You know the output sample rate.  You know the input sample rate.  Yes, they 
drift, but you can detect that.  You will be getting blocks at regular (short) 
intervals, so you can detect changes in timing over time.  It's not easy, but I 
told you that already.
Tim Roberts, timr@xxxxxxxxx
Providenza & Boekelheide, Inc.


Other related posts: