Re: Implementing FFT for an EQ filter on iPhone
Re: Implementing FFT for an EQ filter on iPhone
- Subject: Re: Implementing FFT for an EQ filter on iPhone
- From: William Stewart <email@hidden>
- Date: Tue, 8 Sep 2009 10:55:42 -0700
Apple also ships various filters as audio unit effects. In the
situation you describe, you could just connect the appropriate filter
for you needs and you should be fine. You can have a look at what is
available by running the AULab application and then have a look at the
insert effects on a track. All of these AUs are available for your use
as well.
Bill
On Sep 7, 2009, at 4:47 PM, Aran Mulholland wrote:
you dont want to use fft, too much processing, what you want is a
simple high pass filter (high pass allows all freq above a certain
hz value to pass thru) set at 1000hz, there are some good code
resources at:
www.musicdsp.org/archive.php?classid=3#116
On Tue, Sep 8, 2009 at 6:53 AM, Darren Baptiste <email@hidden
> wrote:
Hello all,
I am trying to figure out how to process audio data inside the
callback of the an mixer AU.
I'd like to be able to remove all bass frequencies, say below
1000Hz, by setting the gain levels for those packets to 0, before
passing the audio through to the next AU in the graph.
From my readings, I think that FFTs are useful for this sort of
analysis. However, I am unable to understand exactly how to
implement one in this scenario. I am attempting to reuse the fft
classes from the aurioTouch sample in the iPhone SDK.
I seem to be getting stuck in figuring out how to properly call the
SpectrumAnalysisProcess() method, and then what next? Once the data
is analyzed, how can I operate on just the parts I want?
Maybe I going about this all wrong? The addition of the graphics
processing makes the aurioTouch sample quite complicated for me to
follow. Any suggestions are most welcome.
Cheers,
Darren
_______________________________________________
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