Re: [Discuss-gnuradio] gr_fractional_interpolator.i missing, does anybody have it

[Eric Blossom]

On Fri, Mar 09, 2007 at 07:04:06PM +0100, Martin Dvh wrote:
> I would like to use gr_fractional_interpolator
> But I get:
>     self.interp=gr.fractional_interpolator( options.phase_shift,interp_ratio)
> AttributeError: 'module' object has no attribute 'fractional_interpolator'
> 

> Apparantly the module doesn't exist anymore, although
> gr_fractional_interpolator.h and gr_fractional_interpolator.cc
> exist.
>

> I suspect there should also be a:
> gr_fractional_interpolator.i

This was apparently never finished or tested.
I understand that Johnathan has a patch that will fix this.
The underlying code is known to work.

> But I couldn't find it in my source or any of the older gnuradio
> releases I have laying around.

> I know there is a rational_resampler in gnuradio now, but there you
> have to give your interpolator taps.

Actually, if you use blks.rational_resampler_fff it'll design an
appropriate filter for you.  See 
gnuradio-examples/python/audio/test_resampler.py


> The good thing of gr_fractional_interpolator is that it uses
> mmse_fir_interpolator which has optimized performance for
> low-tap-numbers.

> Could anybody tell me how to get gr_fractional_interpolator to work
> or where gr_fractional_interpolator.i is.

> Greetings,
> Martin

Eric