• 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
Re: Help with monitoring system-wide audio
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Help with monitoring system-wide audio


  • Subject: Re: Help with monitoring system-wide audio
  • From: Jeff Moore <email@hidden>
  • Date: Mon, 26 Nov 2007 14:38:49 -0800

This would let you monitor the levels of incoming audio. But the question was about monitoring the levels of audio coming out of other application. The QT Sequence Grabber isn't going to help you with that.

On Nov 26, 2007, at 2:34 PM, Jaime Magiera wrote:

On Nov 26, 2007, at 5:22 PM, Bob Smith wrote:

Any suggestions, pointers to relevant docs, etc., greatly appreciated!


Hello,

Basically, you have a SequenceGrabber for the audio device. You set that SG into PreviewMode. Then you query the the properties kQTSGAudioPropertyID_ChannelMap, then kQTSGAudioPropertyID_AveragePowerLevels, then kQTSGAudioPropertyID_PeakHoldLevels. There's a little math in there, but it's easy.

There was sample code called "Silly Meters" or "Silly Levels", something to that effect. Also, there is a good example of how to do metering in "WhackTV".

If you can't figure it out from those examples, let us know.



--

Jeff Moore
Core Audio
Apple


_______________________________________________ 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: Help with monitoring system-wide audio
      • From: Jaime Magiera <email@hidden>
References: 
 >Help with monitoring system-wide audio (From: Bob Smith <email@hidden>)
 >Re: Help with monitoring system-wide audio (From: Jaime Magiera <email@hidden>)

  • Prev by Date: Re: Buffer Size in Audio Units
  • Next by Date: Re: Help with monitoring system-wide audio
  • Previous by thread: Re: Help with monitoring system-wide audio
  • Next by thread: Re: Help with monitoring system-wide audio
  • Index(es):
    • Date
    • Thread