• 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: kAudioOutputUnitProperty_IsRunning doesn't correspond to the audio device running
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: kAudioOutputUnitProperty_IsRunning doesn't correspond to the audio device running


  • Subject: Re: kAudioOutputUnitProperty_IsRunning doesn't correspond to the audio device running
  • From: Steve Checkoway <email@hidden>
  • Date: Mon, 13 Nov 2006 20:50:06 -0800

Jeff Moore wrote:

On Nov 11, 2006, at 7:25 AM, Steve Checkoway wrote:

(My apologies if this goes through twice, I had some mail server issues.)

No doubt. Your message ended up in both the body and the subject field.

I saw that. Sorry about that.


I'm not sure that kAudioOutputUnitProperty_IsRunning is what you want. To my knowledge, the value of this property merely reflects whether or not AudioOutputUnitStart()/AudioOutputUnitStop() have been called. If you want to monitor whether or not the actual device AUHAL is talking to is running or not, you have to use/monitor the HAL device property, kAudioDevicePropertyDeviceIsRunning.

I started printing out all of the properties that get changed for both the AUHAL and the device and I came to the same conclusion. It looks like the clock is reset whenever the device stops running everywhere.


--
Steve Checkoway
"Apple is the first company that doesn't feel like Dilbert." -- Apple Employee




_______________________________________________
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


References: 
 >kAudioOutputUnitProperty_IsRunning doesn't correspond to the audio device running When I change the default output's format (by changing from 44.1kHz to 48kHz, for example), my audio unit property listener fires with kAudioUnitProperty_StreamFormat. If I then call AudioDeviceGetCurrentTime on the corresponding audio device, I get the error kAudioHardwareNotRunningError but the kAudioOutputUnitProperty_IsRunning never fires (as a result of the device stopping). I really need to keep the time stamps returned by AudioDeviceGetCurrentTime() and those passed to my render function in sync but I'm unsure how to do that in the face of changing output formats. Actually, looking back at my logs, it looks like when the kAudioOutputUnitProperty_IsRunning fires for the first time I start the output unit, the device is still saying that it isn't running. Lastly, I'm setting kAudioOutputUnitProperty_StartTimestampsAtZero to zero but this constant doesn't appear in the 2.8 sdk s o I'm using the constant 2007, will this not work on 2.8? (I realize I asked this before in mid June, but no one answered.) If not, I need to deal with this as well. Any advice is very much appreciated. -- Steve Checkoway (From: Steve Checkoway <email@hidden>)
 >Re: kAudioOutputUnitProperty_IsRunning doesn't correspond to the audio device running (From: Jeff Moore <email@hidden>)

  • Prev by Date: Getting Default Output Device gives a strange answer
  • Next by Date: Re: Getting Default Output Device gives a strange answer
  • Previous by thread: Re: kAudioOutputUnitProperty_IsRunning doesn't correspond to the audio device running
  • Next by thread: Re: Reading midi events from device
  • Index(es):
    • Date
    • Thread