[Dspforum] IIR audio output question

[Alan Ding]

1)      *Conversion between floating point and integer formats shall be done
using DSPlib functions, or optimized C routines*

I'm guessing we are suppose to use the DSPF functions....  How do you
optimize C routines to do casting between types?

~Alan

On Sun, Nov 8, 2009 at 4:43 PM, O'Connor, Sean R.
<Sean.OConnor at jhuapl.edu>wrote:

>
> Even with no audio input, I hear a faint eerie resonance on both channels.
>  The oscillations are of the correct frequency, namely ~697Hz on the left
> channel and ~770Hz on the right channel.  The design seems to work when I
> input test tones, but the resonance is always present (it is even quieter
> with only one biquad).  It seems like there is some instability in the
> filter, although the output does not 'run away' or saturate the output.  Any
> thoughts on this?
>
> Also, is the float to integer conversion supposed to be done with
> DSPF_fltoq15()?  Currently I am just casting the float filter output to an
> integer, this is the approach taken in the book.
>
> Thanks,
> Sean
> _______________________________________________
> Dspforum mailing list
> Dspforum at echelonembedded.com
> http://echelonembedded.com/mailman/listinfo/dspforum_echelonembedded.com
>



-- 
-------------------------------------------------------
Alan Ding
Master of Sci, Electrical Engineering
Johns Hopkins University

Email: alan33d at gmail.com
Contact #: 4844593290
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://echelonembedded.com/pipermail/dspforum_echelonembedded.com/attachments/20091109/08ef2b7d/attachment.html>