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 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. 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

on 2007-03-09 20:05

on 2007-03-12 20:16

Martin D. wrote: > 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 > > But I couldn't find it in my source or any of the older gnuradio > releases I have laying around. It doesn't appear to have ever existed, as far as I can tell. Everywhere fractional interpolation is used in the tree, the low-level gri_mmse_fir_interpolator implementation is used. The gr_ wrapper does look functional, but I just spotted a bug in its constructor, so it looks like a work-in-progress that never got finished. > Could anybody tell me how to get gr_fractional_interpolator to work > or where gr_fractional_interpolator.i is. I'll add getting this to work to my queue :-) -- Johnathan C. Corgan Enterprises LLC http://corganenterprises.com

on 2007-03-12 22:02

Johnathan C. wrote: > > > It doesn't appear to have ever existed, as far as I can tell. > Everywhere fractional interpolation is used in the tree, the low-level > gri_mmse_fir_interpolator implementation is used. > > The gr_ wrapper does look functional, but I just spotted a bug in its > constructor, so it looks like a work-in-progress that never got finished. Yes, I spotted it too now: d_mu (phase_shift), d_mu_inc (interp_ratio), d_interp() should be d_mu (phase_shift), d_mu_inc (interp_ratio), d_interp(new gri_mmse_fir_interpolator()) > > >>Could anybody tell me how to get gr_fractional_interpolator to work >>or where gr_fractional_interpolator.i is. > > > I'll add getting this to work to my queue :-) I don't mind getting it to work myself. I just don't like inventing the wheel twice. I will try to get it to work in my tree branches/developers/nldudok1/general-wip and let you know when its done. Greetings, Martin

on 2007-03-12 22:17

Martin D. wrote: > Yes, I spotted it too now: > d_mu (phase_shift), d_mu_inc (interp_ratio), d_interp() > should be > d_mu (phase_shift), d_mu_inc (interp_ratio), d_interp(new gri_mmse_fir_interpolator()) Yes. > I will try to get it to work in my tree > branches/developers/nldudok1/general-wip My plan was to rename the existing one and create a second one, so we'd have: gr_fractional_interpolator_ff (the current one) gr_fractional_interpolator_cc (the new one that does complex samples) That will require some changes to the gri_mmse* code. If you want to do this, have fun :-) -- Johnathan C. Corgan Enterprises LLC http://corganenterprises.com

on 2007-03-12 22:26

On Fri, Mar 09, 2007 at 07:04:06PM +0100, Martin D. 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