Re: CPU Usage difference
Re: CPU Usage difference
- Subject: Re: CPU Usage difference
- From: Alex ROUGE <email@hidden>
- Date: Sat, 7 Mar 2009 00:21:54 +0100
When trying a sound with afplay The result are as follow :
line out / headphone : 2.2%
internal speaker : 9.6%
Regards
Alex
On 6 mars 09, at 19:59, William Stewart wrote:
Yes, this difference seems to high to me as well.
afplay (command line tool) should be a minimal set of code to play a
file, so you might want to measure that.
iTunes is also pretty good with the amount of CPU it uses.
I think that you'll see a similar magnitude of difference between
the line out and the speaker - you will also notice that there is
additional latency when going out the speaker (you can have a look
at this in HAL Lab)
Whether this is too high is an open question, but its worth filing a
bug to see :)
Bill
On Mar 6, 2009, at 2:25 AM, Alex ROUGE wrote:
Hi everybody.
Recently, while testing an home made application that requiere
CoreAudio I found something interesting.
I'm working with a Macbook (Alu) with 4GB memory, 2.4Ghz.....
What I found is that, all application who requiere audio output
doesn't have the same CPU usage depending if the audio output is
internal speaker or headphone/line out.
The difference is impressive.
For instance, if we use the Finder to play an audio file :
Line out : CPU charge = 3.5%
Internal speaker : CPU charge = 10.9%
I think Apple ® is doing a software filtering to compensate very
small sized speaker but this difference is really huge.
Can Apple ® provide more information about this behavior ?
Regards
Alex _______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
@apple.com
This email sent to email@hidden
_______________________________________________
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