Re: [Discuss-gnuradio] pfb_decimator_ccf(13): insufficient connected input ports (5 needed, 1 connected)

[Tom Rondeau]

On Sun, Feb 9, 2014 at 5:24 PM, Martin Braun <address@hidden> wrote:
> On 09.02.2014 07:39, JIANG Pin A wrote:
>>
>> Hi, all
>>
>>           I try to re-structure the osmo-tetra to work with GNU Radio
>> 3.7. The osmo-tetra is based on GNU Radio 3.6.
>
>
> OK, don't know about osmo-tetra but...
>
>
>
>> RuntimeError: pfb_decimator_ccf(13): insufficient connected input ports
>> (5 needed, 1 connected)
>>
>>           Does it indicate pfb_decimator_ccf take 5 inputs ? It puzzled
>> me.
>
>
> ...the pfb_decimator takes 1 input. Not sure what's going on there.
>
> MB


Actually, this is a bit of a tricky one, though it hasn't changed in a
while. Basically, because we insert samples into each filter of the
filterbank consecutively, we're performing the role of the
stream_to_streams block. Instead of duplicating that work, the
pfb_decimator and pfb_channelizer actually take M input streams (where
M is the number of channels or amount of decimation). Also, this
allows us to use the more efficient fir_filter blocks that expect a
data stream of continuous samples.

There are wrappers in Python for this in the filters.pfb module where
the stream_to_streams block is in there for you, so
filter.pfb.decimator_ccf takes only 1 input, but a
filter.pfb_decimator_ccf block would take M inputs.

Tom