Lists

Open Menu Close Menu

Terms and Conditions
Lists hosted on this site
Email the Postmaster
Tips for posting to public mailing lists

Re: how to access HAL buffer timestamps when using AUHAL?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: how to access HAL buffer timestamps when using AUHAL?

Subject: Re: how to access HAL buffer timestamps when using AUHAL?
From: "Ross Bencina" <email@hidden>
Date: Mon, 27 Jul 2009 17:12:08 +1000

Jeff Moore wrote:

The output time would be (using your terminology, but counting in
samples, since that's what most of the relevant values are measured in):

scheduled IoProcTime + [kAudioDevicePropertySafetyOffset] +
[kAudioDevicePropertyBufferFrameSize] == inOutputTime->mSampleTime

scheduled IoProcTime + [kAudioDevicePropertySafetyOffset] +
[kAudioDevicePropertyBufferFrameSize]  + [kAudioDevicePropertyLatency]  ==
analog voltage output from DAC time


Thanks, I seem to be getting somewhere now...

and for the input case is it:

scheduled IoProcTime - [kAudioDevicePropertySafetyOffset] -
[kAudioDevicePropertyBufferFrameSize] == inInputTime->mSampleTime

scheduled IoProcTime - [kAudioDevicePropertySafetyOffset] -
[kAudioDevicePropertyBufferFrameSize]  - [kAudioDevicePropertyLatency]
== analog voltage input at ADC time

(?)

Now, with a full duplex HAL AU component I only get one timstamp, which I assume is the output timestamp. So I guess I can work backwards from the output time to get scheduled IoProcTime and from there the ADC time.

Another question: Can I rely on AudioTimeStamp::mSampleTime and AudioTimeStamp::mHostTime always being valid in a HAL and AU HAL ioProc?

Thanks!

Ross.


_______________________________________________
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: how to access HAL buffer timestamps when using AUHAL?
From: Jeff Moore <email@hidden>


References:  
  >how to access HAL buffer timestamps when using AUHAL? (From: "Ross Bencina" <email@hidden>)
  >Re: how to access HAL buffer timestamps when using AUHAL? (From: Jeff Moore <email@hidden>)
  >Re: how to access HAL buffer timestamps when using AUHAL? (From: "Ross Bencina" <email@hidden>)
  >Re: how to access HAL buffer timestamps when using AUHAL? (From: Jeff Moore <email@hidden>)
  >Re: how to access HAL buffer timestamps when using AUHAL? (From: "Ross Bencina" <email@hidden>)
  >Re: how to access HAL buffer timestamps when using AUHAL? (From: Jeff Moore <email@hidden>)




Prev by Date:
Encoding AAC in an M4A using ExtCoreAudioFile on iPhone OS

Next by Date:
Re: how to access HAL buffer timestamps when using AUHAL?

Previous by thread:
Re: how to access HAL buffer timestamps when using AUHAL?

Next by thread:
Re: how to access HAL buffer timestamps when using AUHAL?

Index(es):

Date
Thread