Re: [Discuss-gnuradio] Error in Interpolating FIR filter

[Brian Padalino]

On Fri, Apr 5, 2013 at 8:29 AM, Tom Rondeau <address@hidden> wrote:

On Fri, Apr 5, 2013 at 1:31 AM, Manu T S <address@hidden> wrote:
> Executing the attached flow graph I get the following error.
>
> #####################################################################################
>>>> gr_fir_ccc: using SSE
> Traceback (most recent call last):
>   File "/home/manu/coding/top_block.py", line 72, in <module>
>     tb.Run(True)
>   File
> "/usr/local/lib/python2.7/dist-packages/grc_gnuradio/wxgui/top_block_gui.py",
> line 76, in Run
>     self.start()
>   File "/usr/local/lib/python2.7/dist-packages/gnuradio/gr/top_block.py",
> line 97, in start
>     self._tb.start(max_noutput_items)
>   File
> "/usr/local/lib/python2.7/dist-packages/gnuradio/gr/gnuradio_core_runtime.py",
> line 3077, in start
>     return _gnuradio_core_runtime.gr_top_block_sptr_start(self,
> max_noutput_items)
> RuntimeError: gr_buffer_add_reader: nzero_preload must be >= 0
> #######################################################################################
>
> What could be the possible reason?
>
> I have installed using build-gnuradio script on day before yesterday.
>
>
>
> --
> Manu T S

Manu,

You have to give the interpolator taps. It can't run without a filter defined.

The error message could definitely be much better.

  "RuntimeError: gr_buffer_add_reader: nzero_preload must be >= 0"

Even to an experienced person, without seeing the flow graph, that error doesn't mean anything.  Debugging a large flow graph might be like looking for a needle in a haystack.

As a side note, what error gets thrown when this is in a straight C++ application?  Is it more informative or equally as ambiguous?

Is it possible to get the filter to throw the assertion/error versus the runtime?

Brian