Re: How to avoid overhead of 30% CPU usage
Re: How to avoid overhead of 30% CPU usage
- Subject: Re: How to avoid overhead of 30% CPU usage
- From: Jens Alfke <email@hidden>
- Date: Mon, 6 Apr 2009 15:11:11 -0700
On Apr 6, 2009, at 2:49 PM, Jack Schmidt wrote:
I am writing a small program that needs to do some fairly trivially
tasks with data from the microphone and send some easily generated
data to the speakers. ...
I ran into the problem however that once I call AudioDeviceStart or
AudioOutputUnitStart, CPU usage goes to 30% on a 2.4GHz MacBook,
which is about 300 times higher than I would expect based on similar
programs on other architectures.
This came up last month. The explanation is that CoreAudio is by
default doing some fancy audio post-processing on the internal-
microphone input, to clean it up and lower the noise level. (30% CPU
still seems high, but I don't know the details of what it's doing.)
You should be able to get around this by using an external microphone
(or a non-laptop.) There might also be a way to tell CoreAudio to turn
off the processing; you could search the list archives for that thread.
—Jens
Attachment:
smime.p7s
Description: S/MIME cryptographic signature
_______________________________________________
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