[wdmaudiodev] Re: Support for clock source selection for USB2 Audio?

  • From: Franz Detro <franz.detro@xxxxxxxxxxxxxxxxxxxxx>
  • To: wdmaudiodev@xxxxxxxxxxxxx
  • Date: Thu, 11 Jan 2018 09:14:05 +0100


KS wrote:

In USB2 Audio, it is possible for device to support multiple clock
source that can be selected through a clock selector.

I don't see that anywhere in the Audio Class specification.  Where is
that described?

Audio20 final.pdf, 3.13.11.2 Clock Selector, 3.16.3 Clock Model, 4.7.2.1 Clock 
Source Descriptor and 4.7.2.2 Clock Selector Descriptor

The Audio Class driver should extract clock information from the UAC 
descriptors and provide a GUI to select a clock (in case of multiple clocks) / 
configure the sample rate.

In case of externally driven clocks the driver should monitor an eventually 
existing interrupt notification endpoint for changes of current clock (clock 
selector) and sample rate.



In Mac OS, there is a droplist in audio MIDI app that allow user to
select the desired clock source.

What choices do you see?

-- 
Tim Roberts, timr@xxxxxxxxx
Providenza & Boekelheide, Inc.

******************

WDMAUDIODEV addresses:
Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx
Subscribe:    mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe
Unsubscribe:  mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe
Moderator:    mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx

URL to WDMAUDIODEV page:
http://www.wdmaudiodev.com/


******************

WDMAUDIODEV addresses:
Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx
Subscribe:    mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe
Unsubscribe:  mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe
Moderator:    mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx

URL to WDMAUDIODEV page:
http://www.wdmaudiodev.com/

Other related posts:

  1. Home
  2. wdmaudiodev
  3. Archive
  4. 01-2018