• Open Menu Close Menu
  • Apple
  • Shopping Bag
  • Apple
  • Mac
  • iPad
  • iPhone
  • Watch
  • TV
  • Music
  • Support
  • Search apple.com
  • Shopping Bag

Lists

Open Menu Close Menu
  • Terms and Conditions
  • Lists hosted on this site
  • Email the Postmaster
  • Tips for posting to public mailing lists
AppleUSBAudio reads GET_MAX volume, won't change range on status interrupt
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

AppleUSBAudio reads GET_MAX volume, won't change range on status interrupt


  • Subject: AppleUSBAudio reads GET_MAX volume, won't change range on status interrupt
  • From: Dominik Peklo <email@hidden>
  • Date: Mon, 31 Jan 2011 06:49:59 -0800 (PST)

Dear Alison,

My USB Audio 1.0 device has a feature unit with volume control. I've set up status interrupt endpoint notifying host of device originated volume changes. Observing traffic with USB bus analyzer, I can see that upon raising interrupt pointing to the feature unit, Mac OS X issues all the GET_CUR, GET_MIN, GET_MAX & GET_RES requests. However, even if I report modified GET_MAX value, the volume control range does not change and remains at the value initially reported during enumeration. You might ask why would I need to change the range on-the-fly - the device has two user selectable means of volume control, both with a different maximum gain. Is there anything I can do on the device side to make this work or should I just file a bug report?

Best Regards,
Dominik

 _______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list      (email@hidden)
Help/Unsubscribe/Update your Subscription:

This email sent to email@hidden

  • Follow-Ups:
    • Re: AppleUSBAudio reads GET_MAX volume, won't change range on status interrupt
      • From: Alison Hughes <email@hidden>
  • Prev by Date: Re: What sort of timer should I use for my sequencer?
  • Next by Date: Racing Game Audio System
  • Previous by thread: calling AudioSessionInitialize multiple times
  • Next by thread: Re: AppleUSBAudio reads GET_MAX volume, won't change range on status interrupt
  • Index(es):
    • Date
    • Thread