Re: Re:long FIR filters
Re: Re:long FIR filters
- Subject: Re: Re:long FIR filters
- From: "Cor Jansen" <email@hidden>
- Date: Fri, 2 Feb 2007 21:53:23 +0100
Thanks Ian,
I found a vDSP library in the Accelerate framework that incluses a
convolution function!
But,
it uses 32 bit floats for signals and result.
I think that will be a problem with 10.000 taps.
Summing 10.000 float values will result in bad signal/noise figures.
I do not know if I can find a work around for this.
Regards, Cor
----- Original Message -----
From: "Ian Kemmish" <email@hidden>
To: <email@hidden>
Cc: "Cor Jansen" <email@hidden>
Sent: Friday, February 02, 2007 7:25 PM
Subject: Re:long FIR filters
On 2 Feb 2007, at 5:58 pm, "Cor Jansen" <email@hidden> wrote:
I would like to implement a very long FIR filter for a room correction
application (about 10.000 taps).
I know the PowerPC chips has the Altivec module to do this kind of tasks
efficiently.
The "Developer" section of Apple's website has some documents about
porting from well-designed instruction set architectures to brain- dead
ones.
For "straightforward" usage, such as filters (straightforward in the
sense that a lot of people do it), the key recommendation is that instead
of using the vec_* built-in functions, you first of all rewrite your code
to use the higher level functions in the Accelerate framework. Once
you've done that, your vector code should automagically become portable.
Of course, if you're not doing filters, life can be more interesting. I
cache short segments of audio in the vector register file and have
sequences of tens of thousands of vector instructions at a stretch which
have no equivalent on Intel at all. I'm not- entirely-flippantly
wondering how hard Apple's lawyers would jump on me if I wrote an AU host
for the version of Embedded Linux that runs on Playstation 3....
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
Ian Kemmish 18 Durham Close, Biggleswade, Beds SG18
8HZ
email@hidden Tel: +44 1767 601361 Mob: +44 7952
854387
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
_______________________________________________
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